Analgesic topical capsaicinoid therapy increases somatostatin-likeimmunoreactivity in the human plasmaKatalin Horvaacuteth a1 Melinda Boros b1 Tereacutez Bagoly b Viktor Saacutendor ce Ferenc Kilaacuter deAacutegnes Kemeacuteny be Zsuzsanna Helyes be Jaacutenos Szolcsaacutenyi b Erika Pinteacuter bea Zsigmondy Vilmos Harkaacuteny Medicinal Spa Hospital 1 Zsigmondy Street Harkaacuteny 7815 Hungaryb Department of Pharmacology and Pharmacotherapy University of Peacutecs 12 Szigeti Street Peacutecs 7624 Hungaryc MTA-PTE Molecular Interactions in Separation Science Research Group 12 Szigeti Street Peacutecs 7624 Hungaryd Department of Bioanalysis University of Peacutecs 12 Szigeti Street Peacutecs 7624 Hungarye Szentaacutegothai Research Center University of Peacutecs 20 Ifjuacutesaacuteg Street Peacutecs 7624 Hungary

A R T I C L E I N F O

Article historyReceived 28 May 2014Accepted 7 October 2014Available online 16 October 2014

KeywordsChronic low back painCapsaicinoidNonivamideSomatostatinTRPV1 receptorMechanism of actionAnalgesic effect

A B S T R A C T

The aim of the present study was to evaluate the therapeutic potential of local capsaicinoid (EMSPOMAreg

cream) treatment on chronic low back pain in patients with degenerative spine diseases and to inves-tigate the possible mechanism of action of the therapy

The qualitative and quantitative analyses of capsaicinoids in EMSPOMAreg cream were performed byliquid chromatographyndashtandem mass spectrometry (LCndashMSMS) In the clinical study 20 patients withdegenerative spine diseases were involved in a self-controlled examination During the 21 day therapythey received 30 min daily treatment with capsaicinoid (EMSPOMAreg) cream to the lumbar region of theback The pain (VASs Oswestry Disability Index) and the mobility of the lumbar region of the spine(Schoberrsquos Domjaacutenrsquos L and R test) were detected at baseline and at the end of the 1st 2nd and 3rd weeksThe plasma level of somatostatin-like immunoreactivity (SST-LI) was measured by radioimmunoassay(RIA) before and after the treatment on the first and the last day of the therapy

Nonivamide (001) was identified as the only capsaicinoid molecule in the cream In the clinical studythe 21 day local nonivamide treatment reduced the pain sensation Oswestry Disability Index de-creased from 39 plusmn 39 to 325 plusmn 44 VASs showed 3729ndash5951 improvement In the plasma level ofSST-LI threefold elevation was observed after the first nonivamide treatment

We conclude that nonivamide treatment exerts analgesic action in chronic low back pain and causesthe release of the antinociceptive and anti-inflammatory neuropeptide somatostatin which may play pivotalrole in the pain-relieving effect

copy 2014 Elsevier Ltd All rights reserved

1 Introduction

The local capsaicinoid treatment is an old fashioned but still ef-fective therapy in wide range of pain conditions includingrheumatoid arthritis (Deal et al 1991) osteoarthritis (Cameron et al2009) neuropathic pain (de Leon-Casasola 2011) and soft tissuepain (Chrubasik et al 2010) The chronic musculoskeletal disor-ders back pain and arthritis influence negatively the quality oflife (Sprangers et al 2000) and cause high economic costs mainlybecause of the persistent inability to return to work due to thechronic pain (Gatchel et al 1995 Yelin 1998)

Non-steroidal anti-inflammatory drugs (NSAIDs) and COX-2 in-hibitors with several adverse effects (Hawkey and Langman 2003Laine 2003) are most commonly applied to relieve pain howeversufficient evidence for NSAIDs efficacy on chronic low back pain isstill lacking (Frerick et al 2003)

Topical capsaicinoid treatments (creams lotions and patches) withdifferent concentrations of capsaicin (0015ndash1 8) have becomewidespread in inflammatory and arthritic conditions since the 1980s(Fernandes et al 2013) Low-concentration capsicum patches havebeen described as an effective analgesic clinically relevant treat-ment in low back pain without systemic side effects compared toplacebo controls (Frerick et al 2003 Keitel et al 2001) Capsaicincream (0015 0025 0075) has significantly reduced pain in kneeand hand osteoarthritis evaluated in multiple double-blind vehicle-controlled clinical trials (De Silva et al 2010)

Most of the clinical studies investigate capsaicin or capsicumextracts The effectiveness of nonivamide alone has not yet beenexamined in a clinical study (Weiser et al 2013)

Corresponding author Department of Pharmacology and PharmacotherapyUniversity of Peacutecs 12 Szigeti Street H-7624 Hungary

E-mail address erikapinteraokptehu (E Pinteacuter)1 Katalin Horvath and Melinda Boros equally contributed for the study

httpdxdoiorg101016jnpep2014100010143-4179copy 2014 Elsevier Ltd All rights reserved

Neuropeptides 48 (2014) 371ndash378

Contents lists available at ScienceDirect

Neuropeptides

journal homepage wwwelseviercom locate npep

Nonivamide (pelargonic acid vanillylamide N-nonanoylvanillylamide) a naturally occurring capsaicinoid in chili pepper(Kozukue et al 2005 Reilly et al 2001a) seemed to be less effec-tive in several in vivo studies than capsaicin (Kawamura et al 1993Skofitsch et al 1984) However it was proved equipotent agonistof transient receptor potential vanilloid 1 (TRPV1) receptor inves-tigated at the receptor level by voltage-clamp recordings usingtransfected cells (Weiser et al 2013) TRPV1 is expressed on no-ciceptive nerve endings of unmyelinated C and small myelinatedAδ fibers TRPV1 is non-selective cation channel which can be ac-tivated by exogenous and endogenous physical (heat) and chemical(low pH vanilloid structures capsaicin resiniferatoxin nonivamide)stimuli Stimulation of the capsaicin-sensitive afferents causes localneurogenic inflammation (vasodilatation and plasma protein ex-travasation leading to edema formation) via the release ofproinflammatory neuropeptides such as substance P (SP) neuro-kinin A and calcitonin gene-related peptide (CGRP) (Maggi 1995Pinter and Szolcsanyi 1995 Szolcsanyi et al 1998a) Besides theseproinflammatory neuropeptides anti-inflammatory and analgesicneuropeptides such as somatostatin (SST) are also released fromcapsaicin-sensitive nerve endings and exerts systemic effects via thecirculation (Szolcsaacutenyi 2004 Szolcsanyi et al 1998a 1998b) SSTacts on five (sst1ndash5) Gi-protein coupled receptors which are ex-pressed on variety of immune cells vascular endothelial and smoothmuscle cells as well as neurons (Csaba and Dournaud 2001 Pinteret al 2006) The antinociceptive and anti-inflammatory actions ofSST are mediated by sst1 and sst4 receptors (Helyes et al 2001 Pinteret al 2002 2006 Szolcsanyi et al 2004) but recently publisheddata suggest that sst2 receptor also plays role in the exertion of theseeffects of SST (Imhof et al 2011 Shi et al 2014) SST is able to elicitantinociceptive actions in acute (Szolcsanyi et al 2004) and chronic(Bar et al 2004 Helyes et al 2004 Imhof et al 2011) animalmodels SST inhibits the release of proinflammatory mediators ex-erting immuno-regulatory function (Chowers et al 2000 Elliott et al1999 Helyes et al 1996 2004 Szolcsanyi et al 1998a) and reducesnociception by stimulation of peripheral and central neurons (Carltonet al 2001 Helyes et al 2000 2004 Szolcsanyi et al 1998b) SSTand its receptors are expressed in the pain processing and regula-tory pathways in the central nervous system (dorsal horn of cervicaland lumbar spinal cord motor neurons in ventral horn of spinalcord spinal cord dorsal root ganglion hypothalamus thalamus tri-geminal sensory nucleus cortex hippocampus striatum) and inthe periphery (Kumar 2009) SST inhibits the nociceptive dorsal hornneurons and exerts peripheral control on nociceptive input (Pinteret al 2006)

The molecular mechanism of pain relieving effect of SST is notwell understood yet Activation of Gi-protein coupled SST recep-tors opens various K+ channels and inhibits voltage gated Ca2+

channels (Koch et al 1988) resulting inhibition of spike genera-tion and release of neurotransmitters (Weckbecker et al 2003)which processes play role in reduction of nociception

SP which is thought to be important signal for pain neurotrans-mission is reduced in the skin after local capsaicin administration(Bernstein et al 1981) Since 1980s these processes have been con-sidered as the mechanism of action of topical capsaicin treatmentbut reduction of SP content in the skin is rather a consequence ofdefunctionalization of capsaicin sensitive nerve terminals (Anandand Bley 2011) Capsaicin is unable to diffuse into the deeper layerof the skin or to the joint thus the defunctionalization cannot explainits analgesic effect in the case of musculoskeletal disorders (Anandand Bley 2011)

It is supposed that release of SST from the capsaicin-sensitivenerve endings may play key role in the analgesic effect of localcapsaicinoid treatment in joint diseases and can be consideredas a possible mechanism of action of the therapy On the basisof our quantitative and qualitative analysis of the commercially

available capsaicinoid cream EMSPOMAreg by liquid chromatographyndashtandem mass spectrometry (LCndashMSMS) it has been found thatnonivamide (001) is the only capsaicinoid molecule in the creamTherefore we have investigated the effect of local nonivamide treat-ment in low back pain in patients with degenerative spine diseasesand we have detected the changes in SST plasma concentrationduring the therapy

2 Materials and methods

21 Determination of capsaicinoids in EMSPOMAreg cream

211 High pressure liquid chromatographyndashtandem massspectrometry (HPLCndashMSMS) system and method

The qualitative and quantitative analyses of capsaicinoids inEMSPOMAreg cream were performed by LCndashMSMS using an Agilent6530 Accurate Mass Q-TOF LCMS system The protonated mol-ecules produced from capsaicin (mz 306) dihydrocapsaicin(mz 308) and nonivamide (mz 294) were monitored The Q-TOFMS instrument was operated with an Agilent Jet Stream ES ion sourcein positive ionization mode with a mass accuracy lt1 ppm a massresolution of 10000ndash20000 (121ndash922 mz) a measuring frequen-cy of 10000 transientss and a detection frequency of 4 GHz TheJet Stream ion source was operated using the following condi-tions pressure of nebulizing gas (N2) was 25 psi the temperatureand flow rate of drying gas (N2) were 325 degC and 7 lmin the tem-perature and flow rate of sheath gas were 300 degC and 10 lmin Thecapillary voltage was 3000 V fragmentor and skimmer potential wasset to 125 V and 65 V respectively For the MSMS analysis collision-induced dissociation (CID) with a collision energy of 30 V was usedReference ions used for mass calibration purine 121050873 [M + H]+HP-921 = hexakis (1H1H3H-tetrafluoropropoxy)phosphazine922009798 [M + H]+ The measurements and post-run analyses werecontrolled by the software MassHunter Acquisition B0400 for theAgilent TOF and QTOF

We used the validated chromatographic method developedby Kaale et al (2002) to separate and quantitate capsaicinoidsextracted from a topical cream The chromatographic separa-tions were performed at 30 degC on a Zorbax Extend C18 column(50 mm times 21 mm 18 μm Agilent USA) Two mobile phases solventA which consisted of 01 vv formic acid in water and solvent B01 vv formic acid in methanol were used The gradient profilewas set as follows 000 min 50 B eluent 55 min 100 B eluentThe flow rate was 02 mlmin the injection volume was 1 μl

212 Preparation of sampleSample preparation was performed according to the extraction

method developed by Kaale et al (2002) for the extraction ofcapsaicinoids from a topical cream In their experiments recoveries ofmore than 95 were achieved with RSD values between 06 and 13Into a 100 ml conical flask 05051 g of the EMSPOMAreg cream wasweighed and 200 ml of methanolndash water (8020) and 200 ml of hexanewere added The mixture was thoroughly mixed for 10 min to make auniform emulsion The emulsion was centrifuged at 3580 g for 20 minand 150 ml of the lower aqueous layer was pipetted into a 500 ml vol-umetric flask The extraction procedure was repeated twice by addingeach time 150 ml of methanolndashwater (8020) and withdrawing the samevolume This makes a total volume of 45 ml which was replenishedto 500 ml using the same diluent We made a 50 dilution of thissolution and injected to the column

213 Preparation of quality control solutionStandard stock solution capsaicin (05 mg) dihydrocapsaicin

(05 mg) and nonivamide (05 mg) were solved in 10 ml methanolndashwater (8020) This stock solution was used to prepare the qualitycontrol solution (05 μgml)

372 K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

214 Quantification methodStandard addition method was used for the quantification

of nonivamide in EMSPOMAreg cream The calibration curve ofnonivamide was constructed by spiking 5 ml extract solution induplicate with a series of 12 μgml nonivamide standard solution(05 1 2 3 ml) and was replenished to 10 ml The calibration curvefor nonivamide showed good linearity with regression coeffi-cients gt09991 in the range of 06ndash36 mgl concentration

22 Clinical study

221 Inclusion criteriaTwenty patients (10 women 10 men 47ndash75 years) with chronic

low back pain of more than 12 weeksrsquo duration were included inthe study (seven persons with discopathia lumbalis seven with spon-dylosis lumbalis and six with post-laminectomy syndrome) Patientswere enrolled by the rheumatologist of the Zsigmondy VilmosHarkaacuteny Medicinal Spa Hospital from the inpatients who met theinclusion and exclusion criteria The patients were examined by thesame rheumatologist

All subjects were informed about the purpose conditions andcourse of the study prior to inclusion Patients have read and un-derstood the Patient Information Sheet and have signed the InformedConsent Form The study was approved by the Regional ResearchEthics Committee (Approval No 3787316ndash5960KK42010)

222 Exclusion criteriaPatients with the following diseases or conditions were ex-

cluded from the study acute low back pain acute organicneurological deficit accompanying low back pain confirmed os-teoporosis neoplastic or inflammatory lesion as the underlying causeof low back pain prior operation of the spine oral or parenteralnon-steroidal anti-inflammatory drug therapy non-cooperative pa-tients and patients with inadequate mental or psychic conditionPatients who had received any kind of physical therapy within 3months prior to the beginning of the study were also excluded

224 TreatmentPatients received treatment with EMSPOMAreg cream contain-

ing 001 nonivamide (Jutta Czech Republic) We applied the creamon a 25 times 40 cm area of the lumbar region of the spine (1 μgnonivamidecm2) as a pack for 30 minday during the 21 day therapy

225 Functional testsTo assess the effect of pain on everyday life Oswestry Disability

Index (ODI) was done on the first and the last day of the therapyData were expressed in percentage of the total score

A 100 mm visual analog scale (VAS) was used on the 1st 7th14th 21st days to record the low back pain as follows (Kulisch et al2009)

bull VAS I the severity of low back pain at rest as rated by the patientbull VAS II the severity of low back pain upon exertion as rated by

the patientbull VAS III the perceived status as rated by the patientbull VAS IV patientrsquos progress as rated by the investigator

Data were expressed in millimetersTo characterize the forward and lateral flexion of the lumbar

region Schoberrsquos and Domjaacutenrsquos L and R tests (Domjan et al 1990)were performed on the 1st 7th 14th 21st days Data wereexpressed in millimeters

226 Determination of SST-like immunoreactivity (SST-LI) ofthe plasma

The plasma level of SST-like immunoreactivity was measured byradioimmunoassay (RIA) (Nemeth et al 1996) on the first and thelast day of the therapy before and after the nonivamide treat-ment We have detected the whole amount of SST in the plasmaC-terminal sensitive somatostatin-14 antiserum was used whichproved to be able to bind both of the biologically active 14 and 28amino acid-containing molecular forms of SST Antibody binds toSST-14 in 100 to SST-28 in 867 Patients fasted for 12 h beforeblood sampling to avoid the gastrointestinal release of SST The cooledtubes contained protease inhibitor EDTA and 200 μl peptidase in-hibitor aprotinin (Trasylol Bayer Germany) was immediately addedto each sample Blood samples (10 ml) were centrifuged at 1000 rpmfor 5 min and 4000 rpm for 10 min at 4degC to separate the plasmaPlasma was stored at minus20 degC until further processing The peptidewas extracted from the plasma by addition of three volumes of ab-solute alcohol After precipitation and centrifugation (2000 rpm10 min 4 degC) the samples were dried under nitrogen flow and wereredissolved in assay buffer before RIA determination

227 StatisticsData are expressed as mean plusmn SEM Statistical analysis was per-

formed by the GraphPad Prism 51 software Normality of distributionof data was tested with the DrsquoAgostinondashPearson-test Data showingnormal distribution were compared with Studentrsquos t-test for pairedsamples in case of two time points (ODI) or repeated measuresANOVA and Dunettrsquos or Bonferronirsquos post test in case of various timepoints (Schoberrsquos and Domjaacutenrsquos test) Non-parametric statistical testswere employed for the analysis of data sets which were not nor-mally distributed Friedman test followed by Dunnrsquos multiplecomparison test was applied for comparing VAS results whileKruskalndashWallis test followed by Dunnrsquos multiple comparison testwas used for analyzing plasma SST-LI levels Probability valuesp lt 005 were accepted as significant

3 Results

31 Determination of capsaicinoids in EMSPOMAreg cream

The extracted ion chromatograms of nonivamide (mz 2942064)capsaicin (mz 3062064) and dihydrocapsaicin (mz 3082220) ob-tained from the analysis of a 05 μgml quality control standardsolution and the total ion chromatogram of the EMSPOMAreg creamextract are shown in Fig 1A As shown in the figure the standardanalytes were separated either chromatographically or by mzNonivamide may have been misidentified as nordihydrocapsaicindue to the same mass However according to a previous liquid chro-matographic method developed for the separation of capsaicinoidsnonivamide and capsaicin have similar retention factor andnordihydrocapsaicin eluates earlier (Choi et al 2006 Reilly et al2001b) The total ion chromatogram of the cream extract shows apeak at the same retention time observed for nonivamide and cap-saicin in standard solution There is no corresponding peak at theretention time of dihydrocapsaicin The capsaicinoid presented inthe cream extract was identified by comparing retention times massspectrum (Fig 1B) and fragment spectrum (Fig 1C) of the stan-dard components The mz 2942064 corresponds to the protonatednonivamide molecule ([M + H]+) the mz 3161884 and 3321623 cor-respond to the sodium ([M + Na]+) and the potassium ([M + K]+)adduct of nonivamide respectively The product ions presented onthe fragment spectrum (Fig 1C) correspond to characteristic frag-ment ions of capsaicinoids The vanillyl moiety (mz 1370589) asthe base peak resulting from cleavage of the C7ndashN8 bond and

373K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

subsequent rearrangement of the double bonds of the aromatic ringstructure the fragment at mz 1220353 was produced by a rapiddissociation of the methylene moiety from the pseudomolecular ionat mz 1370589 (Schweiggert et al 2006) The fragment at mz1581538 is the ion of the acyl residue of the molecule arising fromcleavage of the benzylic carbon bond Nonivamide was found asthe only identified capsaicinoid molecule in the cream extractwhile capsaicin and dihydrocapsaicin were not detectable The totalamount of nonivamide within the extract of EMSPOMAreg cream isobtained 959 ppm plusmn 165 RSD (000959)

32 Clinical study

All of the 20 patients completed the therapy Except for the knownlocal redness and warmth other adverse effects of the treatment werenot seen

We have found that ODI was significantly decreased at 21st dayfrom 39 plusmn 39 to 325 plusmn 44 (Fig 2A)

All kinds of parameters which were characterized by VAS im-proved remarkably during the 3 week therapy like pain at rest (VASI 1st day 299 plusmn 368 mm 21st day 1875 plusmn 482 mm minus3729) andupon exertion (VAS II 1st day 59 plusmn 42 mm 21st day 239 plusmn 554 mmminus5949) There was a remarkable improvement in the perceivedstatus of the patients (VAS III 1st day 6125 plusmn 468 mm 21st day248 plusmn 549 mm minus5951) and in patientrsquos progress (VAS IV 1st day5325 plusmn 308 mm 21st day 216 plusmn 462 mm minus5944) already duringthe first week of the therapy (VAS III minus2971 VAS IV minus1671)(Fig 2B)

We could not find any significant changes in the flexion of thelumbar region as Schoberrsquos and Domjaacutenrsquos tests showed (Fig 2C D)

The plasma level of SST-LI showed threefold increase on the 1stday of the therapy after 30 min nonivamide treatment comparedto baseline value (from 168 plusmn 312 fmolml to 569 plusmn 77 fmolml)On the last day of the study this significant difference could not bedetected however the SST-LI before nonivamide treatment

(195 plusmn 217 fmolml) was higher compared to healthy volunteers(1007 plusmn 061 fmolml) (Fig 3)

4 Discussion

Effective pain management without adverse effects is still an un-resolved issue in chronic conditions Topical capsaicinoid treatmenthas been used as analgesic in inflammatory and degenerative dis-eases since the nineteenth century however the molecular modeof action has not been elucidated yet

In our study we have established that 21 day topical nonivamidetreatment has analgesic effect in chronic low back pain Capsaicinoidcreams are applied in musculoskeletal pain conditions by therheumatologists without knowing the active components Therefore weexecuted the qualitative and quantitative analysis of the commercial-ly available EMSPOMAreg cream which is effective in treatment ofrheumatologic pains The only detectable capsaicinoid molecule wasthe nonivamide Analgesic effect of nonivamide has been proved inanimal models It reduced chemonociception in rats measured by eye-wiping test (wiping reductions after ocular instillation Skofitsch et al1984) and exerted inhibitory effect in vascular nociceptive response inguinea pigs detected by the vocalization response to noxious stimuli(Kawamura et al 1993) Nonivamide decreased pain sensation in micetail flick test (Walpole et al 1993)

The present clinical study provided the first evidence that topicalnonivamide therapy diminished the chronic low back painNonivamide proved to be effective in the functional tests as in ODI(effect of pain on everyday life) and VASs (pain at rest and uponexertion the perceived status as rated by the patient patientrsquos pro-gress as rated by the investigator) However there were not anysignificant changes in the forward and lateral flexion of the lumbarregion during the therapy

It has been established in animal experiments that anti-inflammatoryand antinociceptive peptide SST is released from capsaicin-sensitivenerve endings and exerts systemic analgesic effect which was

Fig 1 The qualitative and quantitative analyses of capsaicinoids in EMSPOMAreg cream by liquid chromatographyndashtandem mass spectrometry (LCndashMSMS) (A) Ion chro-matograms of the cream (a) Representative extracted ion chromatograms (EICs) of capsaicinoids from quality control standard solution (05 μgml each) The identities ofthe peaks are nonivamide (mz 2942064) capsaicin (mz 3062064) and dihydrocapsaicin (mz 3082220) (b) Total ion chromatogram (TIC) of the cream extract (B) Massspectrum of the component at the retention interval 3253ndash3519 min The mass of the protonated positively charged molecular ion of nonivamide [M + H] + is 2942064The sodium [M + Na] + and potassium [M + K] + adducts of nonivamide are also present on the spectrum (C) Identity confirmation of the detected capsaicinoid with LCndashMSMS Product ions produced from collision-induced dissociation of nonivamide

374 K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

inhibited by SST antiserum (Szolcsanyi et al 1998a 1998b 2004) An-algesic action of the exogenous SST and its analogs was reported in acuteand chronic pain models (Helyes et al 2000 Pinter et al 2002) Themain novelty of our study is that topical nonivamide treatment in-creases SST-LI in the human plasma Threefold elevation of SST-LI wasdetected in response to nonivamide on the 1st day There was no dif-ference between the SST-LI levels before and after the topical nonivamidetreatment at the end of the 21 day study because repeated stimula-tion of the capsaicin-sensitive nerve endings causes depletion of the

neural SST stores In spite of these findings functional measurementsas ODI and VASs showed significant reduction of pain on the 21st dayWe suppose that daily treatment with nonivamide throughout 21 daysinduced repetitive release of endogenous SST which exerted long-term centrally and peripherally mediated analgesic effect acting on SSTreceptors on the nerve endings and inflammatory cells

Up to now it has been believed in the clinical practice that high con-centration of the TRPV1 agonist capsaicin (8 Qutenzareg patch) orrepeated administration of lower concentration of capsaicin (00150025 0075) leads to desensitization or recently rather calleddefunctionalization (Bley 2010 Kaale et al 2002) of the capsaicin-sensitive nerve endings Thus the nociceptor function of the nerve fibresand SP release ndash which was thought to be important signal for pain neu-rotransmission ndash also become impaired for extended period (Bley 2010Kaale et al 2002) These processes have been considered as a poten-tial mechanism of analgesic action of topical capsaicin treatment butseveral clinical studies proved that SP receptor antagonists have failedto be analgesics (Hill 2000) Anand and Bley (2011) suggested that cap-saicin shows limited potential for transdermal delivery across humanskin thus it causes defunctionalization only of the cutaneous nociceptorswhich produces local pain relief Nonivamide is an equipotent capsa-icin agonist on TRPV1 receptors according to the in vitro studies (Weiseret al 2013) It is more hydrophilic capsaicinoid (Tsai et al 1994) as-sociated with poorer partitioning ability into the skin (Fang et al 1996)Antinociceptive effect developed in the deeper musculoskeletal and jointareas could not be explained by the desensitization of the cutaneousafferents (Anand and Bley 2011) Although the systemic antinociceptiveeffect of SST has been reported in previously published animal studies(Szolcsanyi et al 2004) our present findings provided the first hu-man data that systemic analgesic effect of the topical capsaicinoid

Fig 2 The effect of local treatment with EMSPOMAreg cream containing 001 nonivamide on low back pain Patients with degenerative spine disease received 30 min dailytreatment with EMSPOMAreg cream (001 nonivamide) to the lumbar region of the back during the 21 day therapy (A) To assess the effect of pain on everyday life OswestryDisability Index (ODI) was done on the first and the last day of the therapy (p lt 0001 day 21 vs day 1 Studentrsquos t-test) (B) A 100 mm visual analog scale (VAS) was usedon the 1st 7th 14th 21st days to record the low back pain (VAS I the severity of low back pain at rest as rated by the patient VAS II the severity of low back pain uponexertion as rated by the patient VAS III the perceived status as rated by the patient VAS IV patientrsquos progress as rated by the investigator p lt 005 p lt 001 p lt 0001vs VAS on the 1 day Friedman test Dunnrsquos multiple comparison test) (C) Schoberrsquos and (D) Domjaacutenrsquos L and R tests were executed on the 1st 7th 14th 21st days to detectthe mobility of the lumbar region of the spine

Fig 3 The changes in plasma SST-LI during the 21 day local nonivamide treat-ment We have detected the SST concentration of the plasma by RIA in healthyvolunteers and in the patients with low back pain before and after local nonivamidetreatment on the first and the last day of the 3 week therapy (p lt 001 after vs beforetreatment on the day 1 p lt 0001 after treatment on day 1 vs healthy volun-teers KruskalndashWallis test followed by Dunnrsquos multiple comparison test)

375K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

treatment could be related to the remarkable increase of SST-LI levelin the plasma It has been proved that SST receptors are expressed onthe nociceptive sensory nerve fibers in the joint (Helyes et al 2003)Their activation participates in the peripheral antinociceptive mecha-nisms (Carlton et al 2001 Heppelmann and Pawlak 1997) EndogenousSST released by nonivamide from the cutaneous afferents could reachthese receptors via the systemic circulation exerting analgesic effect byinhibition of their nociceptor excitability Furthermore SST inhibits therelease of nociceptive mediators such as proinflammatory neuropep-tides (SP CGRP) cytokines prostaglandin and reactive oxygen speciesfrom inflammatory cells (Pinter et al 2006)

Besides the peripheral action SST exerts central analgesic effect(Spampinato et al 1988) SST immunoreactive structures were

detected in lamina II of the lumbar spinal cord of the rat which wereproposed as the anatomical basis for SST-induced analgesia (Rosenthaland Ho 1989) SST was released in the spinal horn in response to noxiousstimuli (Kuraishi et al 1985) Activation of sst receptors in dorsal hornof the rat spinal cord inhibited nociceptive processes (Chapman andDickenson 1992 Miletic and Randic 1981 Murase et al 1982)Thus both peripheral and central processes may play role in theantinociceptive effect in the nonivamide treated skin While systemicanalgesic effect of SST in the deeper tissues (joint) is enforced byperipheral sst receptors (Fig 4)

According to recently published data a somatostatin-relatedpeptide cortistatin is able to release from peptidergic neurons andexerts central and peripheral antinociceptive effect via binding to

Fig 4 Hypothesis of analgesic mechanisms of SST released from the capsaicin-sensitive sensory nerve endings by topical nonivamide treatment (1) Nonivamide activatesTRPV1 receptor expressed on sensory nerve ending on the skin and causes SST release from the peripheral and central nerve terminals SST inhibits own release and de-liberation of proinflammatory neuropeptides (SP CGRP) from the peripheral nerve endings and also acts on the local inflammatory cells (2) Centrally released peptide actingin the dorsal horn inhibits the nociceptive pathway (3) SST reaches the systemic circulation and exerts inhibitory effect on nerve endings and inflammatory cells in thejoint via somatostatin receptors

376 K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

somatostatin and ghrelin receptors (Markovics et al 2013 Morellet al 2013 2014) On the basis of measurements in our laborato-ry SST antibody used in RIA cross reacted only in 75 with humancortistatin-17 and in 52 with human cortistatin-29 We cannotexclude the potential analgesic effect of cortistatin in the presentstudy but we have found threefold elevation of SST in the plasmaafter nonivamide treatment Therefore we suppose that SST itselfplays role in the analgesic action

5 Conclusions

Our study has provided the first human data that topicalnonivamide treatment exerts substantial analgesic activity in pa-tients suffering from low back pain and elevates the plasma levelof SST The analgesic effect of the therapy in deeper tissues is likelydue to the endogenous pain killer activity of SST released from thecapsaicin-sensitive nerve endings rather than the desensitizationof the cutaneous nociceptors We have clearly demonstrated a pos-sible molecular mechanism of an ldquoold fashionedrdquo well acceptedtherapeutic procedure in the rheumatology

Acknowledgement

The authors thank Mrs Maacuteria Zsoldos for excellent technical as-sistance and the nurses of the Zsigmondy Vilmos Harkaacuteny MedicinalSpa Hospital for medical attendance and administration

Funding

The research was supported by SROP-422A-111KONV-2012-0024 E Pinteacuter was supported by the European Union and the Stateof Hungary co-financed by the European Social Fund in the frame-work of TAacuteMOP 424 A1-11-1-2012-0001 lsquoNational ExcellenceProgramrsquo Grant number A2-SZJOuml-TOK-13-0149

References

Anand P Bley K 2011 Topical capsaicin for pain management therapeutic potentialand mechanisms of action of the new high-concentration capsaicin 8 patchBr J Anaesth 107 490ndash502

Bar KJ Schurigt U Scholze A Segond Von Banchet G Stopfel N Braumluer R et al2004 The expression and localization of somatostatin receptors in dorsalroot ganglion neurons of normal and monoarthritic rats Neuroscience 127197ndash206

Bernstein JE Swift RM Soltani K Lorincz AL 1981 Inhibition of axon reflexvasodilatation by topically applied capsaicin J Invest Dermatol 76 394ndash395

Bley KR 2010 TRPV1 agonist approaches for pain management In Gomtsyan AFaltynek CR (Eds) Vanilloid Receptor TRPV1 in Drug Discovery Targeting Painand Other Pathological Disorders Wiley New York pp 325ndash347

Cameron M Gagnier JJ Little CV Parsons TJ Bluumlmle A Chrubasik S 2009Evidence of effectiveness of herbal medicinal products in the treatment ofarthritis Part I osteoarthritis Phytother Res 23 1497ndash1515

Carlton SM Du J Davidson E Zhou S Coggeshall RE 2001 Somatostatinreceptors on peripheral primary afferent terminals inhibition of sensitizednociceptors Pain 90 233ndash244

Chapman V Dickenson AH 1992 The effects of sandostatin and somatostatin onnociceptive transmission in the dorsal horn of the rat spinal cord Neuropeptides23 147ndash152

Choi SH Suh BS Kozukue E Kozukue N Levin CE Friedman M 2006 Analysisof the contents of pungent compounds in fresh Korean red peppers and inpepper-containing foods J Agric Food Chem 54 9024ndash9031

Chowers Y Cahalon L Lahav M Schor H Tal R Bar-Meir S et al 2000Somatostatin through its specific receptor inhibits spontaneous and TNF-α andbacteria-induced IL-8 and IL-1β secretion from intestinal epithelial cellsJ Immunol 165 2955ndash2961

Chrubasik S Weiser T Beime B 2010 Effectiveness and safety of topical capsaicincream in the treatment of chronic soft tissue pain Phytother Res 24 1877ndash1885

Csaba Z Dournaud P 2001 Cellular biology of somatostatin receptorsNeuropeptides 35 (1) 1ndash23

de Leon-Casasola O 2011 New developments in the treatment algorithm forperipheral neuropathic pain Pain Med 12 (Suppl 3) S100ndashS108

De Silva V El-Metwally A Ernst E Lewith G Macfarlane GJ 2010 Evidencefor the efficacy of complementary and alternative medicines in the managementof osteoarthritis a systematic review Rheumatology (Oxford) 5 10ndash15

Deal CL Schnitzer TJ Lipstein E Seibold JR Stevens RM Levy MD et al 1991Treatment of arthritis with topical capsaicin a double-blind trial Clin Ther 13383ndash395

Domjan L Nemes T Balint GP Toth Z Gomor B 1990 A simple method formeasuring lateral flexion of the dorsolumbar spine J Rheumatol 17 663ndash665

Elliott DE Li J Blum AM Metwali A Patel YC Weinstock JV 1999 SSTR2Ais the dominant somatostatin receptor subtype expressed by inflammatory cellsis widely expressed and directly regulates T cell IFN-γ release Eur J Immunol29 2454ndash2463

Fang JY Wu PC Huang YB Tsai YH 1996 In vivo percutaneous absorption ofcapsaicin nonivamide and sodium nonivamide acetate from ointment bases skinerythema test and noninvasive surface recovery technique in humans IntJ Pharm 131 143ndash151

Fernandes ES Awal S Karadaghi R Brain SD 2013 TRP receptors in arthritisgaining knowledge for translation from experimental models Open Pain J 6(Suppl1M7) 50ndash61

Frerick H Keitel W Kuhn U Schmidt S Bredehorst A Kuhlmann M 2003 Topicaltreatment of chronic low back pain with a capsicum plaster Pain 106 59ndash64

Gatchel RJ Polatin PB Mayer TG 1995 The dominant role of psychosocial riskfactors in the development of chronic low back pain disability Spine 202702ndash2709

Hawkey CJ Langman MJ 2003 Non-steroidal anti-inflammatory drugs overallrisks and management Complementary roles for COX-2 inhibitors and protonpump inhibitors Gut 52 600ndash608

Helyes ZS Pinter E Szolcsanyi J Horvath J 1996 Anti-inflammatory andantinociceptive effect of different somatostatin-analogs Neurobiology (Bp) 4115ndash117

Helyes ZS Than M Oroszi G Pinter E Nemeth J Keri G et al 2000 Anti-nociceptive effect induced by somatostatin released from sensory nerve terminalsand by synthetic somatostatin analogues in the rat Neurosci Lett 278 185ndash188

Helyes ZS Pinter E Nemeth J Keri G Than M Oroszi G et al 2001 Anti-inflammatory effect of synthetic somatostatin analogues in the rat BrJ Pharmacol 134 1572ndash1579

Helyes ZS Pinter E Nemeth J Szolcsanyi J 2003 Pharmacological targets forthe inhibition of neurogenic inflammation Curr Med Chem 2 191ndash218AIAAA

Helyes ZS Szabo A Nemeth J Jakab B Pinter E Banvolgyi A et al 2004Antiinflammatory and analgesic effects of somatostatin released from capsaicin-sensitive sensory nerve terminals in a Freundrsquos adjuvantndashinduced chronic arthritismodel in the rat Arthritis Rheum 50 1677ndash1685

Heppelmann B Pawlak M 1997 Inhibitory effect of somatostatin on themechanosensitivity of articular afferents in normal and inflamed knee joints ofthe rat Pain 73 377ndash382

Hill R 2000 NK1 (substance P) receptor antagonists ndash why are they not analgesicin humans Trends Pharmacol Sci 21 244ndash246

Imhof AK Gluumlck L Gajda M Lupp A Braumluer R Schaible HG et al 2011Differential antiinflammatory and antinociceptive effects of the somatostatinanalogs octreotide and pasireotide in a mouse model of immune-mediatedarthritis Arthritis Rheum 63 2352ndash2362

Kaale E Van Schepdael A Roets E Hoogmartens J 2002 Determination ofcapsaicinoids in topical cream by liquid-liquid extraction and liquidchromatography J Pharm Biomed Anal 30 (4) 1331ndash1337

Kawamura S Kume H Yonezawa A Ando R Sakurada T 1993 Desensitizingmechanism of capsaicin and nonanoyl vanillylamide on the vascular nociceptiveresponse in the guinea pig Regul Pept 46 415ndash417

Keitel W Frerick H Kuhn U Schmidt U Kuhlmann M Bredehorst A 2001Capsicum pain plaster in chronic non-specific low back pain Arzneimi-ttelforschung 51 896ndash903

Koch BD Blalock JB Schonbrunn A 1988 Characterization of the cyclic AMP-independent actions of somatostatin in GH cells I An increase in potassiumconductance is responsible for both the hyperpolarization and the decrease inintracellular free calcium produced by somatostatin J Biol Chem 263 216ndash225

Kozukue N Han JS Kozukue E Lee SJ Kim JA Lee KR et al 2005 Analysisof eight capsaicinoids in peppers and pepper-containing foods by highperformance liquid chromatography and liquid chromatography massspectrometry J Agric Food Chem 53 9172ndash9181

Kulisch A Bender T Nemeth A Szekeres L 2009 Effect of thermal water andadjunctive electrotherapy on chronic low back pain a double-blind randomizedfollow-up study J Rehabil Med 41 (1) 73ndash79

Kumar U 2009 Role of somatostatin and somatostatin receptors in pain In CairnsBE (Ed) Peripheral Receptor Targets for Analgesia Novel Approaches to PainManagement Wiley New Jersey pp 397ndash417

Kuraishi Y Hirota N Sato Y Kaneko S Satoh M Takagi H 1985 Noradrenergicinhibition of the release of substance P from the primary afferents in the rabbitspinal dorsal horn Brain Res 359 177ndash182

Laine L 2003 Gastrointestinal effects of NSAIDs and coxibs J Pain Symptom Manage25 (2 Suppl) S32ndashS40

Maggi CA 1995 Tachykinins and calcitonin gene-related peptide (CGRP) asco-transmitters released from peripheral endings of sensory nerves ProgNeurobiol 45 1ndash98

Markovics A Szoke E Sandor K Borzsei R Bagoly T Kemeny A et al 2013Comparison of the anti-inflammatory and anti-nociceptive effects of cortistatin-14and somatostatin-14 in distinct in vitro and in vivo model systems J MolNeurosci 46 40ndash50

Miletic V Randic M 1981 Neonatal rat spinal cord slice preparation postsynapticeffects of neuropeptides on dorsal horn neurons Brain Res 254 432ndash438

377K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

inhibited by SST antiserum (Szolcsanyi et al 1998a 1998b 2004) An-algesic action of the exogenous SST and its analogs was reported in acuteand chronic pain models (Helyes et al 2000 Pinter et al 2002) Themain novelty of our study is that topical nonivamide treatment in-creases SST-LI in the human plasma Threefold elevation of SST-LI wasdetected in response to nonivamide on the 1st day There was no dif-ference between the SST-LI levels before and after the topical nonivamidetreatment at the end of the 21 day study because repeated stimula-tion of the capsaicin-sensitive nerve endings causes depletion of the

neural SST stores In spite of these findings functional measurementsas ODI and VASs showed significant reduction of pain on the 21st dayWe suppose that daily treatment with nonivamide throughout 21 daysinduced repetitive release of endogenous SST which exerted long-term centrally and peripherally mediated analgesic effect acting on SSTreceptors on the nerve endings and inflammatory cells

Up to now it has been believed in the clinical practice that high con-centration of the TRPV1 agonist capsaicin (8 Qutenzareg patch) orrepeated administration of lower concentration of capsaicin (00150025 0075) leads to desensitization or recently rather calleddefunctionalization (Bley 2010 Kaale et al 2002) of the capsaicin-sensitive nerve endings Thus the nociceptor function of the nerve fibresand SP release ndash which was thought to be important signal for pain neu-rotransmission ndash also become impaired for extended period (Bley 2010Kaale et al 2002) These processes have been considered as a poten-tial mechanism of analgesic action of topical capsaicin treatment butseveral clinical studies proved that SP receptor antagonists have failedto be analgesics (Hill 2000) Anand and Bley (2011) suggested that cap-saicin shows limited potential for transdermal delivery across humanskin thus it causes defunctionalization only of the cutaneous nociceptorswhich produces local pain relief Nonivamide is an equipotent capsa-icin agonist on TRPV1 receptors according to the in vitro studies (Weiseret al 2013) It is more hydrophilic capsaicinoid (Tsai et al 1994) as-sociated with poorer partitioning ability into the skin (Fang et al 1996)Antinociceptive effect developed in the deeper musculoskeletal and jointareas could not be explained by the desensitization of the cutaneousafferents (Anand and Bley 2011) Although the systemic antinociceptiveeffect of SST has been reported in previously published animal studies(Szolcsanyi et al 2004) our present findings provided the first hu-man data that systemic analgesic effect of the topical capsaicinoid

Fig 2 The effect of local treatment with EMSPOMAreg cream containing 001 nonivamide on low back pain Patients with degenerative spine disease received 30 min dailytreatment with EMSPOMAreg cream (001 nonivamide) to the lumbar region of the back during the 21 day therapy (A) To assess the effect of pain on everyday life OswestryDisability Index (ODI) was done on the first and the last day of the therapy (p lt 0001 day 21 vs day 1 Studentrsquos t-test) (B) A 100 mm visual analog scale (VAS) was usedon the 1st 7th 14th 21st days to record the low back pain (VAS I the severity of low back pain at rest as rated by the patient VAS II the severity of low back pain uponexertion as rated by the patient VAS III the perceived status as rated by the patient VAS IV patientrsquos progress as rated by the investigator p lt 005 p lt 001 p lt 0001vs VAS on the 1 day Friedman test Dunnrsquos multiple comparison test) (C) Schoberrsquos and (D) Domjaacutenrsquos L and R tests were executed on the 1st 7th 14th 21st days to detectthe mobility of the lumbar region of the spine

Fig 3 The changes in plasma SST-LI during the 21 day local nonivamide treat-ment We have detected the SST concentration of the plasma by RIA in healthyvolunteers and in the patients with low back pain before and after local nonivamidetreatment on the first and the last day of the 3 week therapy (p lt 001 after vs beforetreatment on the day 1 p lt 0001 after treatment on day 1 vs healthy volun-teers KruskalndashWallis test followed by Dunnrsquos multiple comparison test)

375K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

treatment could be related to the remarkable increase of SST-LI levelin the plasma It has been proved that SST receptors are expressed onthe nociceptive sensory nerve fibers in the joint (Helyes et al 2003)Their activation participates in the peripheral antinociceptive mecha-nisms (Carlton et al 2001 Heppelmann and Pawlak 1997) EndogenousSST released by nonivamide from the cutaneous afferents could reachthese receptors via the systemic circulation exerting analgesic effect byinhibition of their nociceptor excitability Furthermore SST inhibits therelease of nociceptive mediators such as proinflammatory neuropep-tides (SP CGRP) cytokines prostaglandin and reactive oxygen speciesfrom inflammatory cells (Pinter et al 2006)

Besides the peripheral action SST exerts central analgesic effect(Spampinato et al 1988) SST immunoreactive structures were

detected in lamina II of the lumbar spinal cord of the rat which wereproposed as the anatomical basis for SST-induced analgesia (Rosenthaland Ho 1989) SST was released in the spinal horn in response to noxiousstimuli (Kuraishi et al 1985) Activation of sst receptors in dorsal hornof the rat spinal cord inhibited nociceptive processes (Chapman andDickenson 1992 Miletic and Randic 1981 Murase et al 1982)Thus both peripheral and central processes may play role in theantinociceptive effect in the nonivamide treated skin While systemicanalgesic effect of SST in the deeper tissues (joint) is enforced byperipheral sst receptors (Fig 4)

According to recently published data a somatostatin-relatedpeptide cortistatin is able to release from peptidergic neurons andexerts central and peripheral antinociceptive effect via binding to

Fig 4 Hypothesis of analgesic mechanisms of SST released from the capsaicin-sensitive sensory nerve endings by topical nonivamide treatment (1) Nonivamide activatesTRPV1 receptor expressed on sensory nerve ending on the skin and causes SST release from the peripheral and central nerve terminals SST inhibits own release and de-liberation of proinflammatory neuropeptides (SP CGRP) from the peripheral nerve endings and also acts on the local inflammatory cells (2) Centrally released peptide actingin the dorsal horn inhibits the nociceptive pathway (3) SST reaches the systemic circulation and exerts inhibitory effect on nerve endings and inflammatory cells in thejoint via somatostatin receptors

376 K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

somatostatin and ghrelin receptors (Markovics et al 2013 Morellet al 2013 2014) On the basis of measurements in our laborato-ry SST antibody used in RIA cross reacted only in 75 with humancortistatin-17 and in 52 with human cortistatin-29 We cannotexclude the potential analgesic effect of cortistatin in the presentstudy but we have found threefold elevation of SST in the plasmaafter nonivamide treatment Therefore we suppose that SST itselfplays role in the analgesic action

5 Conclusions

Our study has provided the first human data that topicalnonivamide treatment exerts substantial analgesic activity in pa-tients suffering from low back pain and elevates the plasma levelof SST The analgesic effect of the therapy in deeper tissues is likelydue to the endogenous pain killer activity of SST released from thecapsaicin-sensitive nerve endings rather than the desensitizationof the cutaneous nociceptors We have clearly demonstrated a pos-sible molecular mechanism of an ldquoold fashionedrdquo well acceptedtherapeutic procedure in the rheumatology

Acknowledgement

The authors thank Mrs Maacuteria Zsoldos for excellent technical as-sistance and the nurses of the Zsigmondy Vilmos Harkaacuteny MedicinalSpa Hospital for medical attendance and administration

Funding

The research was supported by SROP-422A-111KONV-2012-0024 E Pinteacuter was supported by the European Union and the Stateof Hungary co-financed by the European Social Fund in the frame-work of TAacuteMOP 424 A1-11-1-2012-0001 lsquoNational ExcellenceProgramrsquo Grant number A2-SZJOuml-TOK-13-0149

References

Anand P Bley K 2011 Topical capsaicin for pain management therapeutic potentialand mechanisms of action of the new high-concentration capsaicin 8 patchBr J Anaesth 107 490ndash502

Bar KJ Schurigt U Scholze A Segond Von Banchet G Stopfel N Braumluer R et al2004 The expression and localization of somatostatin receptors in dorsalroot ganglion neurons of normal and monoarthritic rats Neuroscience 127197ndash206

Bernstein JE Swift RM Soltani K Lorincz AL 1981 Inhibition of axon reflexvasodilatation by topically applied capsaicin J Invest Dermatol 76 394ndash395

Bley KR 2010 TRPV1 agonist approaches for pain management In Gomtsyan AFaltynek CR (Eds) Vanilloid Receptor TRPV1 in Drug Discovery Targeting Painand Other Pathological Disorders Wiley New York pp 325ndash347

Cameron M Gagnier JJ Little CV Parsons TJ Bluumlmle A Chrubasik S 2009Evidence of effectiveness of herbal medicinal products in the treatment ofarthritis Part I osteoarthritis Phytother Res 23 1497ndash1515

Carlton SM Du J Davidson E Zhou S Coggeshall RE 2001 Somatostatinreceptors on peripheral primary afferent terminals inhibition of sensitizednociceptors Pain 90 233ndash244

Chapman V Dickenson AH 1992 The effects of sandostatin and somatostatin onnociceptive transmission in the dorsal horn of the rat spinal cord Neuropeptides23 147ndash152

Choi SH Suh BS Kozukue E Kozukue N Levin CE Friedman M 2006 Analysisof the contents of pungent compounds in fresh Korean red peppers and inpepper-containing foods J Agric Food Chem 54 9024ndash9031

Chowers Y Cahalon L Lahav M Schor H Tal R Bar-Meir S et al 2000Somatostatin through its specific receptor inhibits spontaneous and TNF-α andbacteria-induced IL-8 and IL-1β secretion from intestinal epithelial cellsJ Immunol 165 2955ndash2961

Chrubasik S Weiser T Beime B 2010 Effectiveness and safety of topical capsaicincream in the treatment of chronic soft tissue pain Phytother Res 24 1877ndash1885

Csaba Z Dournaud P 2001 Cellular biology of somatostatin receptorsNeuropeptides 35 (1) 1ndash23

de Leon-Casasola O 2011 New developments in the treatment algorithm forperipheral neuropathic pain Pain Med 12 (Suppl 3) S100ndashS108

De Silva V El-Metwally A Ernst E Lewith G Macfarlane GJ 2010 Evidencefor the efficacy of complementary and alternative medicines in the managementof osteoarthritis a systematic review Rheumatology (Oxford) 5 10ndash15

Deal CL Schnitzer TJ Lipstein E Seibold JR Stevens RM Levy MD et al 1991Treatment of arthritis with topical capsaicin a double-blind trial Clin Ther 13383ndash395

Domjan L Nemes T Balint GP Toth Z Gomor B 1990 A simple method formeasuring lateral flexion of the dorsolumbar spine J Rheumatol 17 663ndash665

Elliott DE Li J Blum AM Metwali A Patel YC Weinstock JV 1999 SSTR2Ais the dominant somatostatin receptor subtype expressed by inflammatory cellsis widely expressed and directly regulates T cell IFN-γ release Eur J Immunol29 2454ndash2463

Fang JY Wu PC Huang YB Tsai YH 1996 In vivo percutaneous absorption ofcapsaicin nonivamide and sodium nonivamide acetate from ointment bases skinerythema test and noninvasive surface recovery technique in humans IntJ Pharm 131 143ndash151

Fernandes ES Awal S Karadaghi R Brain SD 2013 TRP receptors in arthritisgaining knowledge for translation from experimental models Open Pain J 6(Suppl1M7) 50ndash61

Frerick H Keitel W Kuhn U Schmidt S Bredehorst A Kuhlmann M 2003 Topicaltreatment of chronic low back pain with a capsicum plaster Pain 106 59ndash64

Gatchel RJ Polatin PB Mayer TG 1995 The dominant role of psychosocial riskfactors in the development of chronic low back pain disability Spine 202702ndash2709

Hawkey CJ Langman MJ 2003 Non-steroidal anti-inflammatory drugs overallrisks and management Complementary roles for COX-2 inhibitors and protonpump inhibitors Gut 52 600ndash608

Helyes ZS Pinter E Szolcsanyi J Horvath J 1996 Anti-inflammatory andantinociceptive effect of different somatostatin-analogs Neurobiology (Bp) 4115ndash117

Helyes ZS Than M Oroszi G Pinter E Nemeth J Keri G et al 2000 Anti-nociceptive effect induced by somatostatin released from sensory nerve terminalsand by synthetic somatostatin analogues in the rat Neurosci Lett 278 185ndash188

Helyes ZS Pinter E Nemeth J Keri G Than M Oroszi G et al 2001 Anti-inflammatory effect of synthetic somatostatin analogues in the rat BrJ Pharmacol 134 1572ndash1579

Helyes ZS Pinter E Nemeth J Szolcsanyi J 2003 Pharmacological targets forthe inhibition of neurogenic inflammation Curr Med Chem 2 191ndash218AIAAA

Helyes ZS Szabo A Nemeth J Jakab B Pinter E Banvolgyi A et al 2004Antiinflammatory and analgesic effects of somatostatin released from capsaicin-sensitive sensory nerve terminals in a Freundrsquos adjuvantndashinduced chronic arthritismodel in the rat Arthritis Rheum 50 1677ndash1685

Heppelmann B Pawlak M 1997 Inhibitory effect of somatostatin on themechanosensitivity of articular afferents in normal and inflamed knee joints ofthe rat Pain 73 377ndash382

Hill R 2000 NK1 (substance P) receptor antagonists ndash why are they not analgesicin humans Trends Pharmacol Sci 21 244ndash246

Imhof AK Gluumlck L Gajda M Lupp A Braumluer R Schaible HG et al 2011Differential antiinflammatory and antinociceptive effects of the somatostatinanalogs octreotide and pasireotide in a mouse model of immune-mediatedarthritis Arthritis Rheum 63 2352ndash2362

Kaale E Van Schepdael A Roets E Hoogmartens J 2002 Determination ofcapsaicinoids in topical cream by liquid-liquid extraction and liquidchromatography J Pharm Biomed Anal 30 (4) 1331ndash1337

Kawamura S Kume H Yonezawa A Ando R Sakurada T 1993 Desensitizingmechanism of capsaicin and nonanoyl vanillylamide on the vascular nociceptiveresponse in the guinea pig Regul Pept 46 415ndash417

Keitel W Frerick H Kuhn U Schmidt U Kuhlmann M Bredehorst A 2001Capsicum pain plaster in chronic non-specific low back pain Arzneimi-ttelforschung 51 896ndash903

Koch BD Blalock JB Schonbrunn A 1988 Characterization of the cyclic AMP-independent actions of somatostatin in GH cells I An increase in potassiumconductance is responsible for both the hyperpolarization and the decrease inintracellular free calcium produced by somatostatin J Biol Chem 263 216ndash225

Kozukue N Han JS Kozukue E Lee SJ Kim JA Lee KR et al 2005 Analysisof eight capsaicinoids in peppers and pepper-containing foods by highperformance liquid chromatography and liquid chromatography massspectrometry J Agric Food Chem 53 9172ndash9181

Kulisch A Bender T Nemeth A Szekeres L 2009 Effect of thermal water andadjunctive electrotherapy on chronic low back pain a double-blind randomizedfollow-up study J Rehabil Med 41 (1) 73ndash79

Kumar U 2009 Role of somatostatin and somatostatin receptors in pain In CairnsBE (Ed) Peripheral Receptor Targets for Analgesia Novel Approaches to PainManagement Wiley New Jersey pp 397ndash417

Kuraishi Y Hirota N Sato Y Kaneko S Satoh M Takagi H 1985 Noradrenergicinhibition of the release of substance P from the primary afferents in the rabbitspinal dorsal horn Brain Res 359 177ndash182

Laine L 2003 Gastrointestinal effects of NSAIDs and coxibs J Pain Symptom Manage25 (2 Suppl) S32ndashS40

Maggi CA 1995 Tachykinins and calcitonin gene-related peptide (CGRP) asco-transmitters released from peripheral endings of sensory nerves ProgNeurobiol 45 1ndash98

Markovics A Szoke E Sandor K Borzsei R Bagoly T Kemeny A et al 2013Comparison of the anti-inflammatory and anti-nociceptive effects of cortistatin-14and somatostatin-14 in distinct in vitro and in vivo model systems J MolNeurosci 46 40ndash50

Miletic V Randic M 1981 Neonatal rat spinal cord slice preparation postsynapticeffects of neuropeptides on dorsal horn neurons Brain Res 254 432ndash438

377K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

treatment could be related to the remarkable increase of SST-LI levelin the plasma It has been proved that SST receptors are expressed onthe nociceptive sensory nerve fibers in the joint (Helyes et al 2003)Their activation participates in the peripheral antinociceptive mecha-nisms (Carlton et al 2001 Heppelmann and Pawlak 1997) EndogenousSST released by nonivamide from the cutaneous afferents could reachthese receptors via the systemic circulation exerting analgesic effect byinhibition of their nociceptor excitability Furthermore SST inhibits therelease of nociceptive mediators such as proinflammatory neuropep-tides (SP CGRP) cytokines prostaglandin and reactive oxygen speciesfrom inflammatory cells (Pinter et al 2006)

Besides the peripheral action SST exerts central analgesic effect(Spampinato et al 1988) SST immunoreactive structures were

detected in lamina II of the lumbar spinal cord of the rat which wereproposed as the anatomical basis for SST-induced analgesia (Rosenthaland Ho 1989) SST was released in the spinal horn in response to noxiousstimuli (Kuraishi et al 1985) Activation of sst receptors in dorsal hornof the rat spinal cord inhibited nociceptive processes (Chapman andDickenson 1992 Miletic and Randic 1981 Murase et al 1982)Thus both peripheral and central processes may play role in theantinociceptive effect in the nonivamide treated skin While systemicanalgesic effect of SST in the deeper tissues (joint) is enforced byperipheral sst receptors (Fig 4)

According to recently published data a somatostatin-relatedpeptide cortistatin is able to release from peptidergic neurons andexerts central and peripheral antinociceptive effect via binding to

Fig 4 Hypothesis of analgesic mechanisms of SST released from the capsaicin-sensitive sensory nerve endings by topical nonivamide treatment (1) Nonivamide activatesTRPV1 receptor expressed on sensory nerve ending on the skin and causes SST release from the peripheral and central nerve terminals SST inhibits own release and de-liberation of proinflammatory neuropeptides (SP CGRP) from the peripheral nerve endings and also acts on the local inflammatory cells (2) Centrally released peptide actingin the dorsal horn inhibits the nociceptive pathway (3) SST reaches the systemic circulation and exerts inhibitory effect on nerve endings and inflammatory cells in thejoint via somatostatin receptors

376 K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

somatostatin and ghrelin receptors (Markovics et al 2013 Morellet al 2013 2014) On the basis of measurements in our laborato-ry SST antibody used in RIA cross reacted only in 75 with humancortistatin-17 and in 52 with human cortistatin-29 We cannotexclude the potential analgesic effect of cortistatin in the presentstudy but we have found threefold elevation of SST in the plasmaafter nonivamide treatment Therefore we suppose that SST itselfplays role in the analgesic action

5 Conclusions

Our study has provided the first human data that topicalnonivamide treatment exerts substantial analgesic activity in pa-tients suffering from low back pain and elevates the plasma levelof SST The analgesic effect of the therapy in deeper tissues is likelydue to the endogenous pain killer activity of SST released from thecapsaicin-sensitive nerve endings rather than the desensitizationof the cutaneous nociceptors We have clearly demonstrated a pos-sible molecular mechanism of an ldquoold fashionedrdquo well acceptedtherapeutic procedure in the rheumatology

Acknowledgement

The authors thank Mrs Maacuteria Zsoldos for excellent technical as-sistance and the nurses of the Zsigmondy Vilmos Harkaacuteny MedicinalSpa Hospital for medical attendance and administration

Funding

The research was supported by SROP-422A-111KONV-2012-0024 E Pinteacuter was supported by the European Union and the Stateof Hungary co-financed by the European Social Fund in the frame-work of TAacuteMOP 424 A1-11-1-2012-0001 lsquoNational ExcellenceProgramrsquo Grant number A2-SZJOuml-TOK-13-0149

References

Anand P Bley K 2011 Topical capsaicin for pain management therapeutic potentialand mechanisms of action of the new high-concentration capsaicin 8 patchBr J Anaesth 107 490ndash502

Bar KJ Schurigt U Scholze A Segond Von Banchet G Stopfel N Braumluer R et al2004 The expression and localization of somatostatin receptors in dorsalroot ganglion neurons of normal and monoarthritic rats Neuroscience 127197ndash206

Bernstein JE Swift RM Soltani K Lorincz AL 1981 Inhibition of axon reflexvasodilatation by topically applied capsaicin J Invest Dermatol 76 394ndash395

Bley KR 2010 TRPV1 agonist approaches for pain management In Gomtsyan AFaltynek CR (Eds) Vanilloid Receptor TRPV1 in Drug Discovery Targeting Painand Other Pathological Disorders Wiley New York pp 325ndash347

Cameron M Gagnier JJ Little CV Parsons TJ Bluumlmle A Chrubasik S 2009Evidence of effectiveness of herbal medicinal products in the treatment ofarthritis Part I osteoarthritis Phytother Res 23 1497ndash1515

Carlton SM Du J Davidson E Zhou S Coggeshall RE 2001 Somatostatinreceptors on peripheral primary afferent terminals inhibition of sensitizednociceptors Pain 90 233ndash244

Chapman V Dickenson AH 1992 The effects of sandostatin and somatostatin onnociceptive transmission in the dorsal horn of the rat spinal cord Neuropeptides23 147ndash152

Choi SH Suh BS Kozukue E Kozukue N Levin CE Friedman M 2006 Analysisof the contents of pungent compounds in fresh Korean red peppers and inpepper-containing foods J Agric Food Chem 54 9024ndash9031

Chowers Y Cahalon L Lahav M Schor H Tal R Bar-Meir S et al 2000Somatostatin through its specific receptor inhibits spontaneous and TNF-α andbacteria-induced IL-8 and IL-1β secretion from intestinal epithelial cellsJ Immunol 165 2955ndash2961

Chrubasik S Weiser T Beime B 2010 Effectiveness and safety of topical capsaicincream in the treatment of chronic soft tissue pain Phytother Res 24 1877ndash1885

Csaba Z Dournaud P 2001 Cellular biology of somatostatin receptorsNeuropeptides 35 (1) 1ndash23

de Leon-Casasola O 2011 New developments in the treatment algorithm forperipheral neuropathic pain Pain Med 12 (Suppl 3) S100ndashS108

De Silva V El-Metwally A Ernst E Lewith G Macfarlane GJ 2010 Evidencefor the efficacy of complementary and alternative medicines in the managementof osteoarthritis a systematic review Rheumatology (Oxford) 5 10ndash15

Deal CL Schnitzer TJ Lipstein E Seibold JR Stevens RM Levy MD et al 1991Treatment of arthritis with topical capsaicin a double-blind trial Clin Ther 13383ndash395

Domjan L Nemes T Balint GP Toth Z Gomor B 1990 A simple method formeasuring lateral flexion of the dorsolumbar spine J Rheumatol 17 663ndash665

Elliott DE Li J Blum AM Metwali A Patel YC Weinstock JV 1999 SSTR2Ais the dominant somatostatin receptor subtype expressed by inflammatory cellsis widely expressed and directly regulates T cell IFN-γ release Eur J Immunol29 2454ndash2463

Fang JY Wu PC Huang YB Tsai YH 1996 In vivo percutaneous absorption ofcapsaicin nonivamide and sodium nonivamide acetate from ointment bases skinerythema test and noninvasive surface recovery technique in humans IntJ Pharm 131 143ndash151

Fernandes ES Awal S Karadaghi R Brain SD 2013 TRP receptors in arthritisgaining knowledge for translation from experimental models Open Pain J 6(Suppl1M7) 50ndash61

Frerick H Keitel W Kuhn U Schmidt S Bredehorst A Kuhlmann M 2003 Topicaltreatment of chronic low back pain with a capsicum plaster Pain 106 59ndash64

Gatchel RJ Polatin PB Mayer TG 1995 The dominant role of psychosocial riskfactors in the development of chronic low back pain disability Spine 202702ndash2709

Hawkey CJ Langman MJ 2003 Non-steroidal anti-inflammatory drugs overallrisks and management Complementary roles for COX-2 inhibitors and protonpump inhibitors Gut 52 600ndash608

Helyes ZS Pinter E Szolcsanyi J Horvath J 1996 Anti-inflammatory andantinociceptive effect of different somatostatin-analogs Neurobiology (Bp) 4115ndash117

Helyes ZS Than M Oroszi G Pinter E Nemeth J Keri G et al 2000 Anti-nociceptive effect induced by somatostatin released from sensory nerve terminalsand by synthetic somatostatin analogues in the rat Neurosci Lett 278 185ndash188

Helyes ZS Pinter E Nemeth J Keri G Than M Oroszi G et al 2001 Anti-inflammatory effect of synthetic somatostatin analogues in the rat BrJ Pharmacol 134 1572ndash1579

Helyes ZS Pinter E Nemeth J Szolcsanyi J 2003 Pharmacological targets forthe inhibition of neurogenic inflammation Curr Med Chem 2 191ndash218AIAAA

Helyes ZS Szabo A Nemeth J Jakab B Pinter E Banvolgyi A et al 2004Antiinflammatory and analgesic effects of somatostatin released from capsaicin-sensitive sensory nerve terminals in a Freundrsquos adjuvantndashinduced chronic arthritismodel in the rat Arthritis Rheum 50 1677ndash1685

Heppelmann B Pawlak M 1997 Inhibitory effect of somatostatin on themechanosensitivity of articular afferents in normal and inflamed knee joints ofthe rat Pain 73 377ndash382

Hill R 2000 NK1 (substance P) receptor antagonists ndash why are they not analgesicin humans Trends Pharmacol Sci 21 244ndash246

Imhof AK Gluumlck L Gajda M Lupp A Braumluer R Schaible HG et al 2011Differential antiinflammatory and antinociceptive effects of the somatostatinanalogs octreotide and pasireotide in a mouse model of immune-mediatedarthritis Arthritis Rheum 63 2352ndash2362

Kaale E Van Schepdael A Roets E Hoogmartens J 2002 Determination ofcapsaicinoids in topical cream by liquid-liquid extraction and liquidchromatography J Pharm Biomed Anal 30 (4) 1331ndash1337

Kawamura S Kume H Yonezawa A Ando R Sakurada T 1993 Desensitizingmechanism of capsaicin and nonanoyl vanillylamide on the vascular nociceptiveresponse in the guinea pig Regul Pept 46 415ndash417

Keitel W Frerick H Kuhn U Schmidt U Kuhlmann M Bredehorst A 2001Capsicum pain plaster in chronic non-specific low back pain Arzneimi-ttelforschung 51 896ndash903

Koch BD Blalock JB Schonbrunn A 1988 Characterization of the cyclic AMP-independent actions of somatostatin in GH cells I An increase in potassiumconductance is responsible for both the hyperpolarization and the decrease inintracellular free calcium produced by somatostatin J Biol Chem 263 216ndash225

Kozukue N Han JS Kozukue E Lee SJ Kim JA Lee KR et al 2005 Analysisof eight capsaicinoids in peppers and pepper-containing foods by highperformance liquid chromatography and liquid chromatography massspectrometry J Agric Food Chem 53 9172ndash9181

Kulisch A Bender T Nemeth A Szekeres L 2009 Effect of thermal water andadjunctive electrotherapy on chronic low back pain a double-blind randomizedfollow-up study J Rehabil Med 41 (1) 73ndash79

Kumar U 2009 Role of somatostatin and somatostatin receptors in pain In CairnsBE (Ed) Peripheral Receptor Targets for Analgesia Novel Approaches to PainManagement Wiley New Jersey pp 397ndash417

Kuraishi Y Hirota N Sato Y Kaneko S Satoh M Takagi H 1985 Noradrenergicinhibition of the release of substance P from the primary afferents in the rabbitspinal dorsal horn Brain Res 359 177ndash182

Laine L 2003 Gastrointestinal effects of NSAIDs and coxibs J Pain Symptom Manage25 (2 Suppl) S32ndashS40

Maggi CA 1995 Tachykinins and calcitonin gene-related peptide (CGRP) asco-transmitters released from peripheral endings of sensory nerves ProgNeurobiol 45 1ndash98

Markovics A Szoke E Sandor K Borzsei R Bagoly T Kemeny A et al 2013Comparison of the anti-inflammatory and anti-nociceptive effects of cortistatin-14and somatostatin-14 in distinct in vitro and in vivo model systems J MolNeurosci 46 40ndash50

Miletic V Randic M 1981 Neonatal rat spinal cord slice preparation postsynapticeffects of neuropeptides on dorsal horn neurons Brain Res 254 432ndash438

377K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

somatostatin and ghrelin receptors (Markovics et al 2013 Morellet al 2013 2014) On the basis of measurements in our laborato-ry SST antibody used in RIA cross reacted only in 75 with humancortistatin-17 and in 52 with human cortistatin-29 We cannotexclude the potential analgesic effect of cortistatin in the presentstudy but we have found threefold elevation of SST in the plasmaafter nonivamide treatment Therefore we suppose that SST itselfplays role in the analgesic action

5 Conclusions

Our study has provided the first human data that topicalnonivamide treatment exerts substantial analgesic activity in pa-tients suffering from low back pain and elevates the plasma levelof SST The analgesic effect of the therapy in deeper tissues is likelydue to the endogenous pain killer activity of SST released from thecapsaicin-sensitive nerve endings rather than the desensitizationof the cutaneous nociceptors We have clearly demonstrated a pos-sible molecular mechanism of an ldquoold fashionedrdquo well acceptedtherapeutic procedure in the rheumatology

Acknowledgement

The authors thank Mrs Maacuteria Zsoldos for excellent technical as-sistance and the nurses of the Zsigmondy Vilmos Harkaacuteny MedicinalSpa Hospital for medical attendance and administration

Funding

The research was supported by SROP-422A-111KONV-2012-0024 E Pinteacuter was supported by the European Union and the Stateof Hungary co-financed by the European Social Fund in the frame-work of TAacuteMOP 424 A1-11-1-2012-0001 lsquoNational ExcellenceProgramrsquo Grant number A2-SZJOuml-TOK-13-0149

References

Anand P Bley K 2011 Topical capsaicin for pain management therapeutic potentialand mechanisms of action of the new high-concentration capsaicin 8 patchBr J Anaesth 107 490ndash502

Bar KJ Schurigt U Scholze A Segond Von Banchet G Stopfel N Braumluer R et al2004 The expression and localization of somatostatin receptors in dorsalroot ganglion neurons of normal and monoarthritic rats Neuroscience 127197ndash206

Bernstein JE Swift RM Soltani K Lorincz AL 1981 Inhibition of axon reflexvasodilatation by topically applied capsaicin J Invest Dermatol 76 394ndash395

Bley KR 2010 TRPV1 agonist approaches for pain management In Gomtsyan AFaltynek CR (Eds) Vanilloid Receptor TRPV1 in Drug Discovery Targeting Painand Other Pathological Disorders Wiley New York pp 325ndash347

Cameron M Gagnier JJ Little CV Parsons TJ Bluumlmle A Chrubasik S 2009Evidence of effectiveness of herbal medicinal products in the treatment ofarthritis Part I osteoarthritis Phytother Res 23 1497ndash1515

Carlton SM Du J Davidson E Zhou S Coggeshall RE 2001 Somatostatinreceptors on peripheral primary afferent terminals inhibition of sensitizednociceptors Pain 90 233ndash244

Chapman V Dickenson AH 1992 The effects of sandostatin and somatostatin onnociceptive transmission in the dorsal horn of the rat spinal cord Neuropeptides23 147ndash152

Choi SH Suh BS Kozukue E Kozukue N Levin CE Friedman M 2006 Analysisof the contents of pungent compounds in fresh Korean red peppers and inpepper-containing foods J Agric Food Chem 54 9024ndash9031

Chowers Y Cahalon L Lahav M Schor H Tal R Bar-Meir S et al 2000Somatostatin through its specific receptor inhibits spontaneous and TNF-α andbacteria-induced IL-8 and IL-1β secretion from intestinal epithelial cellsJ Immunol 165 2955ndash2961

Chrubasik S Weiser T Beime B 2010 Effectiveness and safety of topical capsaicincream in the treatment of chronic soft tissue pain Phytother Res 24 1877ndash1885

Csaba Z Dournaud P 2001 Cellular biology of somatostatin receptorsNeuropeptides 35 (1) 1ndash23

de Leon-Casasola O 2011 New developments in the treatment algorithm forperipheral neuropathic pain Pain Med 12 (Suppl 3) S100ndashS108

De Silva V El-Metwally A Ernst E Lewith G Macfarlane GJ 2010 Evidencefor the efficacy of complementary and alternative medicines in the managementof osteoarthritis a systematic review Rheumatology (Oxford) 5 10ndash15

Deal CL Schnitzer TJ Lipstein E Seibold JR Stevens RM Levy MD et al 1991Treatment of arthritis with topical capsaicin a double-blind trial Clin Ther 13383ndash395

Domjan L Nemes T Balint GP Toth Z Gomor B 1990 A simple method formeasuring lateral flexion of the dorsolumbar spine J Rheumatol 17 663ndash665

Elliott DE Li J Blum AM Metwali A Patel YC Weinstock JV 1999 SSTR2Ais the dominant somatostatin receptor subtype expressed by inflammatory cellsis widely expressed and directly regulates T cell IFN-γ release Eur J Immunol29 2454ndash2463

Fang JY Wu PC Huang YB Tsai YH 1996 In vivo percutaneous absorption ofcapsaicin nonivamide and sodium nonivamide acetate from ointment bases skinerythema test and noninvasive surface recovery technique in humans IntJ Pharm 131 143ndash151

Fernandes ES Awal S Karadaghi R Brain SD 2013 TRP receptors in arthritisgaining knowledge for translation from experimental models Open Pain J 6(Suppl1M7) 50ndash61

Frerick H Keitel W Kuhn U Schmidt S Bredehorst A Kuhlmann M 2003 Topicaltreatment of chronic low back pain with a capsicum plaster Pain 106 59ndash64

Gatchel RJ Polatin PB Mayer TG 1995 The dominant role of psychosocial riskfactors in the development of chronic low back pain disability Spine 202702ndash2709

Hawkey CJ Langman MJ 2003 Non-steroidal anti-inflammatory drugs overallrisks and management Complementary roles for COX-2 inhibitors and protonpump inhibitors Gut 52 600ndash608

Helyes ZS Pinter E Szolcsanyi J Horvath J 1996 Anti-inflammatory andantinociceptive effect of different somatostatin-analogs Neurobiology (Bp) 4115ndash117

Helyes ZS Than M Oroszi G Pinter E Nemeth J Keri G et al 2000 Anti-nociceptive effect induced by somatostatin released from sensory nerve terminalsand by synthetic somatostatin analogues in the rat Neurosci Lett 278 185ndash188

Helyes ZS Pinter E Nemeth J Keri G Than M Oroszi G et al 2001 Anti-inflammatory effect of synthetic somatostatin analogues in the rat BrJ Pharmacol 134 1572ndash1579

Helyes ZS Pinter E Nemeth J Szolcsanyi J 2003 Pharmacological targets forthe inhibition of neurogenic inflammation Curr Med Chem 2 191ndash218AIAAA

Helyes ZS Szabo A Nemeth J Jakab B Pinter E Banvolgyi A et al 2004Antiinflammatory and analgesic effects of somatostatin released from capsaicin-sensitive sensory nerve terminals in a Freundrsquos adjuvantndashinduced chronic arthritismodel in the rat Arthritis Rheum 50 1677ndash1685

Heppelmann B Pawlak M 1997 Inhibitory effect of somatostatin on themechanosensitivity of articular afferents in normal and inflamed knee joints ofthe rat Pain 73 377ndash382

Hill R 2000 NK1 (substance P) receptor antagonists ndash why are they not analgesicin humans Trends Pharmacol Sci 21 244ndash246

Imhof AK Gluumlck L Gajda M Lupp A Braumluer R Schaible HG et al 2011Differential antiinflammatory and antinociceptive effects of the somatostatinanalogs octreotide and pasireotide in a mouse model of immune-mediatedarthritis Arthritis Rheum 63 2352ndash2362

Kaale E Van Schepdael A Roets E Hoogmartens J 2002 Determination ofcapsaicinoids in topical cream by liquid-liquid extraction and liquidchromatography J Pharm Biomed Anal 30 (4) 1331ndash1337

Kawamura S Kume H Yonezawa A Ando R Sakurada T 1993 Desensitizingmechanism of capsaicin and nonanoyl vanillylamide on the vascular nociceptiveresponse in the guinea pig Regul Pept 46 415ndash417

Keitel W Frerick H Kuhn U Schmidt U Kuhlmann M Bredehorst A 2001Capsicum pain plaster in chronic non-specific low back pain Arzneimi-ttelforschung 51 896ndash903

Koch BD Blalock JB Schonbrunn A 1988 Characterization of the cyclic AMP-independent actions of somatostatin in GH cells I An increase in potassiumconductance is responsible for both the hyperpolarization and the decrease inintracellular free calcium produced by somatostatin J Biol Chem 263 216ndash225

Kozukue N Han JS Kozukue E Lee SJ Kim JA Lee KR et al 2005 Analysisof eight capsaicinoids in peppers and pepper-containing foods by highperformance liquid chromatography and liquid chromatography massspectrometry J Agric Food Chem 53 9172ndash9181

Kulisch A Bender T Nemeth A Szekeres L 2009 Effect of thermal water andadjunctive electrotherapy on chronic low back pain a double-blind randomizedfollow-up study J Rehabil Med 41 (1) 73ndash79

Kumar U 2009 Role of somatostatin and somatostatin receptors in pain In CairnsBE (Ed) Peripheral Receptor Targets for Analgesia Novel Approaches to PainManagement Wiley New Jersey pp 397ndash417

Kuraishi Y Hirota N Sato Y Kaneko S Satoh M Takagi H 1985 Noradrenergicinhibition of the release of substance P from the primary afferents in the rabbitspinal dorsal horn Brain Res 359 177ndash182

Laine L 2003 Gastrointestinal effects of NSAIDs and coxibs J Pain Symptom Manage25 (2 Suppl) S32ndashS40

Maggi CA 1995 Tachykinins and calcitonin gene-related peptide (CGRP) asco-transmitters released from peripheral endings of sensory nerves ProgNeurobiol 45 1ndash98

Markovics A Szoke E Sandor K Borzsei R Bagoly T Kemeny A et al 2013Comparison of the anti-inflammatory and anti-nociceptive effects of cortistatin-14and somatostatin-14 in distinct in vitro and in vivo model systems J MolNeurosci 46 40ndash50

Miletic V Randic M 1981 Neonatal rat spinal cord slice preparation postsynapticeffects of neuropeptides on dorsal horn neurons Brain Res 254 432ndash438

377K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378

Morell M Souza-Moreira L Caro M OrsquoValle F Forte-Lago I de Lecea L et al2013 Analgesic effect of the neuropeptide cortistatin in murine models of arthriticinflammatory pain Arthritis Rheum 65 1390ndash1401

Morell M Camprubiacute-Robles M Culler MD de Lecea L Delgado M 2014Cortistatin attenuates inflammatory pain via spinal and peripheral actionsNeurobiol Dis 63 141ndash154

Murase K Nedeljkov V Randic M 1982 The actions of neuropeptides on dorsalhorn neurons in the rat spinal cord slice preparation an intracellular study BrainRes 234 170ndash176

Nemeth J Helyes ZS Gorcs T Gardi J Pinter E Szolcsanyi J 1996 Developmentof somatostatin radioimmunoassay for the measurement of plasma and tissuecontents of hormone Acta Physiol Hung 84 313ndash315

Pinter E Szolcsanyi J 1995 Plasma extravasation in the skin and pelvic organsevoked by antidromic stimulation of the lumbosacral dorsal roots of the ratNeuroscience 68 603ndash614

Pinter E Helyes ZS Nemeth J Porszasz R Petho G Than M et al 2002Pharmacological characterisation of the somatostatin analogue TT-232 effectson neurogenic and non-neurogenic inflammation and neuropathic hyperalgesiaNaunyn Schmiedebergs Arch Pharmacol 366 142ndash150

Pinter E Helyes ZS Szolcsanyi J 2006 Inhibitory effect of somatostatin oninflammation and nociception Pharmacol Ther 112 440ndash456

Reilly CA Crouch DJ Yost GS 2001a Quantitative analysis of capsaicinoids infresh peppers oleoresin capsicum and pepper spray products J Forensic Sci 46502ndash509

Reilly CA Crouc DJ Yost GS Fatah AA 2001b Determination of capsaicindihydrocapsaicin and nonivamide in self-defense weapons by liquidchromatography-mass spectrometry and liquid chromatography-tandem massspectrometry J Chromatogr 912 259ndash267

Rosenthal BM Ho RH 1989 An electron microscopic study of somatostatinimmunoreactive structures in lamina II of the rat spinal cord Brain Res Bull22 439ndash451

Schweiggert U Carle R Schieber A 2006 Characterization of major andminor capsaicinoids and related compounds in chili pods (Capsicumfrutescens L) by high-performance liquid chromatographyatmosphericpressure chemical ionization mass spectrometry Anal Chim Acta 557 1ndash2236ndash244

Shi TJS Xiang Q Zhang MD Barde S Kai-Larsen Y Fried K et al 2014Somatostatin and its 2A receptor in dorsal root ganglia and dorsal horn of

mouse and human expression trafficking and possible role in pain Mol Pain10 12

Skofitsch G Donnerer J Lembeck F 1984 Comparison of nonivamide and capsaicinwith regard to their pharmacokinetics and effects on sensory neuronsArzneimittelforschung 34 154ndash156

Spampinato S Romualdi P Candeletti S Cavicchini E Ferri S 1988Distinguishable effects of intrathecal dynorphins somatostatin neurotensin ands-calcitonin on nociception and motor function in the rat Pain 35 95ndash104

Sprangers MA de Regt EB Andries F van Agt HM Bijl RV de Boer JB et al2000 Which chronic conditions are associated with better or poorer quality oflife J Clin Epidemiol 53 895ndash907

Szolcsaacutenyi J 2004 Forty years in capsaicin research for sensory pharmacology andphysiology Neuropeptides 6 377ndash384

Szolcsanyi J Helyes ZS Oroszi G Nemeth J Pinter E 1998a Release ofsomatostatin and its role in the mediation of the anti-inflammatory effect inducedby antidromic stimulation of sensory fibres of rat sciatic nerve Br J Pharmacol23 936ndash942

Szolcsanyi J Pinter E Helyes ZS Oroszi G Nemeth J 1998b Systemic anti-inflammatory effect induced by counter-irritation through a local release ofsomatostatin from nociceptors Br J Pharmacol 125 916ndash922

Szolcsanyi J Pinter E Helyes ZS 2004 Sensocrine function of capsaicin-sensitivenociceptors mediated by somatostatin regulates against inflammation andhyperalgesia In Handwerker HO Brune K (Eds) Hyperalgesia MolecularMechanisms and Clinical Implications IASP Press Seattle pp 113ndash128

Tsai YH Huang YB Fang JY Wu PC 1994 Percutaneous absorption ofcapsaicin and its derivatives Drug Dev Ind Pharm 20 719ndash730

Walpole CS Wrigglesworth R Bevan S Campbell EA Dray A James IF et al1993 Analogues of capsaicin with agonist activity as novel analgesic agentsstructure-activity studies 3 The hydrophobic side-chain lsquoC-regionrsquo J Med Chem36 2381ndash2389

Weckbecker G Lewis I Albert R Schmid HA Hoyer D Bruns C 2003Opportunities in somatostatin research biological chemical and therapeuticaspects Nat Rev Drug Discov 2 999ndash1017

Weiser T Roufogalis B Chrubasik S 2013 Comparison of the effects of pelargonicacid vanillylamide and capsaicin on human vanilloid receptors Phytother Res27 1048ndash1053

Yelin E 1998 The economics of osteoarthritis In Brandt K Doherty M LohmanderLS (Eds) Osteoarthritis Oxford University Press New York p p23

378 K Horvaacuteth et alNeuropeptides 48 (2014) 371ndash378