The grapefruit flavanone naringin protects against the radiation-induced genomic instability in the...

Mutation Research 519 (2002) 37–48

The grapefruit flavanone naringin protects against theradiation-induced genomic instability in the mice

bone marrow: a micronucleus study

Ganesh Chandra Jagetia∗, Tiyyagura Koti ReddyDepartment of Radiobiology, Kasturba Medical College, Manipal 576119, India

Received 31 January 2002; received in revised form 3 May 2002; accepted 9 May 2002

Abstract

The effect of various doses, viz. 0, 0.5, 1, 2, 4, 6 and 8 mg/kg body weight of naringin (NIN) (a citrus flavanone) was studiedon the alteration in the radiation-induced micronucleated polychromatic (MPCE) and normochromatic (MNCE) erythrocytesin mouse bone marrow exposed to 2 Gy of60Co�-radiation. The treatment of mice with various doses of NIN before exposureto 2 Gy resulted in a significant decline in the frequency of MPCE when compared to the non-drug-treated irradiated control.However, the greatest reduction in MPCE was observed for 2 mg/kg body weight NIN, accompanied by a highest PCE/NCEratio when compared with the non-drug-treated irradiated control. Therefore, further studies were carried out using this doseof NIN, where the animals were administered with 2 mg/kg body weight of NIN before exposure to 0, 0.5, 1, 2, 3 and 4 Gy of�-radiation. The frequency of MPCE and MNCE increased in a dose-dependent manner in both the non-drug-treated irradiatedcontrol and NIN-pretreated irradiated groups up to a dose of 2 Gy, while a further increase in the irradiation dose resulted in asignificant decline in MPCE and MNCE frequencies in both groups. Pretreatment of mice with 2 mg/kg body weight of NINresulted in a significant decline in the frequencies of MPCE and MNCE. NIN treatment not only reduced the frequency ofMPCE with one micronucleus, but also of MPCE with multiple micronuclei (MN), indicating its ability to reduce complexchromosome aberrations. Conversely, the PCE/NCE ratio declined in a dose-dependent manner in both groups. The treatmentof mice with NIN before exposure to different doses of�-radiation resulted in the inhibition in this decline in the PCE/NCEratio. Our study demonstrates that NIN is able to protect mouse bone marrow cells against the radiation-induced DNA damageand decline in the cell proliferation as observed by a reduction in the micronucleus frequency and an increase in PCE/NCEratio, respectively, in the NIN-pretreated irradiated group.© 2002 Elsevier Science B.V. All rights reserved.

Keywords:Radiation; Radiation protection; Naringin; Bone marrow; Micronuclei; PCE/NCE ratio; Mice

1. Introduction

Ionizing radiation and numerous chemical muta-gens cause structural chromosomal aberrations, and

∗ Corresponding author. Tel.:+91-8252-571201-572001x22814,22122, 22815, 22816; fax:+91-8252-570062/571927.E-mail address:[email protected] (G.C. Jagetia).

a proportion of these aberrations (usually referred toas “asymmetrical events” or “unstable aberrations”)give rise to chromosome fragments without spindle at-tachment organelles (kinetochores, centromeres)[1,2].These are termed “acentric fragments” (AF). Whenthe cell divides, some of these fragments are excludedfrom the main daughter nuclei and form small extranuclei within the cytoplasm, either on their own, or in

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38 G.C. Jagetia, T.K. Reddy / Mutation Research 519 (2002) 37–48

conjunction with other fragments and are termed asmicronuclei (MN). Not only the acentric fragments,but also the whole chromosome that lag behind duringthe cell division due to defect in kinetochore or spin-dle fibers also give rise to MN. Such MN can appearin the cytoplasm of either, or both, daughter cells. MNare small round spherical chromatin bodies, found incytoplasm outside the main nucleus or in the erythro-cytes, which resembles the main nucleus of a cell inshape, size structure and staining properties[3,4]. Themicronucleus assay is used as an effective cytogeneticendpoint for assessing the chromosomal damage in-duced by ionizing radiation, mutagens and carcino-gens[5–8]. MN formation in erythrocytes of the bonemarrow can be studied with a high resolution power,where it is possible to study the measurement of in-duced MN at very low doses of radiation and chemi-cals[9–12].

Human beings are exposed to ionizing radiation dur-ing medical diagnosis or treatment and/or air travel.A sizeable number of people also get exposed to ra-diation while working in nuclear plants or handlingradionuclides or other radiation sources in hospitalsand/or during space travel. The deleterious effects ofionizing radiation are fairly well established in liv-ing systems. Therefore, it is essential to protect hu-man subjects against the damaging effects of radiationor reduce the radiation-induced damage to genome toavoid later complications. Patt et al.[13] for the firsttime attempted to protect mice and rats against theradiation-induced sickness and mortality using cys-teine. Since, then several chemical compounds havebeen screened for their radioprotective action, how-ever, none has reached to the stage of clinical applica-tion including WR-2721, because of high toxicity atthe optimum protective dose[14]. Therefore, there isa need to screen new agents, which can provide pro-tection at low non-toxic levels.

Flavonoids occur ubiquitously in the plant king-dom and are common components of the humandiet [15]. Flavonoids have been shown to havestructurally-dependent, highly specific effects on avariety of enzymes and are able to interfere with nu-merous cellular processes, including growth and dif-ferentiation[16]. The diverse effects of flavonoid mayrelate to their structural similarity to ATP, and hence,to their ability to compete with ATP for binding tovarious enzymatic sites[17]. Naringin (NIN) (glyco-

side) is the predominant flavanone found in grapefruit(Citrus paradisi, Citrus sinensis, Citrus unshiu, Citrusnobilis, andCitrus tachibana, Citrus junos, Artemisiaselengensis, Artemisia stolonifera[18], roots of Cu-drania cochinchinensisvar. geronatogea[19], aerialparts of Thymusherba barona[20], fruits of Poncirus species[21], Mabea fistulifera[22], Swartizapolyphylla [23], and related citrus species. Like mostflavonoids, NIN has metal chelating, antioxidant, andfree radical scavenging properties[24–26] and hasbeen reported to offer some protection against muta-genesis[27] and lipid peroxidation[28]. The presenceof free radical scavenging and antimutagenic proper-ties in NIN stimulated us to evaluate the radioprotec-tive potential of NIN in mice bone marrow. Therefore,the present study was undertaken to obtain an insightinto the effect of NIN pretreatment on the alterationin MN frequency in the bone marrow of mice exposedto different doses of whole body60Co �-radiation.

2. Materials and methods

The animal care and handling was done accordingto the guidelines issued by the World Health Organi-zation, Geneva, Switzerland and the Indian NationalScience Academy (INSA), New Delhi, India. The8–10-week-old male Swiss albino mice weighing30–36 g were selected from an inbred colony main-tained under the controlled conditions of temperature(23 ± 2 ◦C), humidity (50± 5%) and light (10 and14 h of light and dark, respectively). The animalswere provided with the sterile food and water ad li-bitum. Four animals were housed in a polypropylenecage containing sterile paddy husk (procured locally)as bedding throughout the experiment.

2.1. Preparation of drug

The drug NIN was procured from Acros OrganicsLimited, Belgium and it was dissolved in sterile doubledistilled water (DDW).

2.2. Mode of administration

An amount of 0.01 ml/g body weight of distilled wa-ter or drug solution was administered intraperitoneally,45 min before irradiation.

G.C. Jagetia, T.K. Reddy / Mutation Research 519 (2002) 37–48 39

2.3. Experiment 1: selection of optimum dose of NIN

2.3.1. NIN+ sham-irradiation groupThe animals of this group were injected with 0, 0.5,

1, 2, 4, 6 and 8 mg/kg body weight of NIN.

2.3.2. NIN+ irradiation groupThe animals of this group were injected with 0, 0.5,

1, 2, 4, 6 and 8 mg/kg body weight of NIN beforeexposure to 2 Gy�-irradiation.

2.4. Experiment 2: radioprotective effect of NIN

2.4.1. DDW+ irradiation groupThe animals of this group received 0.01 ml/g body

weight of sterile double distilled water (DDW) beforeirradiation.

2.4.2. NIN+ irradiation groupThe animals of this group were injected with

2 mg/kg body weight of NIN before irradiation.

2.5. Irradiation

Forty-five minutes after DDW or drug administra-tion, the prostrate and immobilized animals (achievedby inserting cotton plugs in the restrainer) of experi-ment 1 were whole body exposed to 0 or 2 Gy, whilethat of experiment 2 were exposed to 0, 0.5, 1, 2, 3and 4 Gy of�-irradiation from a60Co Tele therapysource (Theratron, Atomic Energy Agency, Canada)in a specially designed well ventilated acrylic box. Abatch of eight animals (four each from DDW and drugtreated groups) was irradiated each time at a dose rateof 1.66 Gy/min at a source to animal distance (midpoint) of 87 cm.

The animals were killed by cervical dislocation at24 h after exposure to�-radiation. The MN were pre-pared according to the method of Schmid[29] withcertain modifications described by Jagetia et al.[30].Briefly, the femurs of each animal were dissected outand the bone marrow was flushed out into Dulbecco’smodified Eagle’s medium (DMEM) separately. Thesuspension was centrifuged. A few drops of fetal calfserum (FCS) was added and the pellet was mixedthoroughly. Smears were drawn on to precleanedcoded slides using a drop of the resultant suspensionin FCS. The slides were air dried and fixed in absolute

methanol. The results were confirmed by repetitionof the experiment.

The slides were stained with 0.125% acridine or-ange (BDH, England, Gurr Cat. no. 34001 9704640E)in Sorensen’s buffer (pH 6.8). The slides were washedtwice in Sorensen’s buffer. The slides mounted inSorensen’s buffer were observed under a fluorescencemicroscope (Carl Zeiss Photomicroscope III, Ger-many) using a 40× Neofluar objective. A minimumof 1000 each polychromatic erythrocytes (PCE) andnormochromatic erythrocytes (NCE) were counted forthe presence of MN for each animal. A total of 4000each PCE or NCE were scored for each radiation dosefor each group. Data regarding the polychromaticand normochromatic erythrocyte ratio (PCE/NCEratio) were also collected, where a minimum of4000 erythrocytes per animal were scored. Four an-imals were used for each irradiation dose for eachgroup.

The statistical significance between the treatmentswas determined using Mann–WhitneyU-test and oneway analysis of variance (ANOVA). Bonferroni’spost-hoc test was applied for multiple comparisons,where necessary. The data were fitted on to linear (Y =α + βD) and linear quadratic (Y = C + αD + βD2)equation to describe the dose–response, if any, whereC is control MN frequency,D is radiation dose andαandβ are the constants.

3. Results

3.1. Selection of optimum dose of naringin

The results are expressed as micronucleated PCE(MPCE) or micronucleated NCE (MNCE) per 1000±S.E.M. and PCE/NCE ratio± S.E.M. (Tables 1 and 2andFigs. 1–4).

Administration of 0–4 mg/kg NIN did not alter thecontrol frequency of MPCE. A further increase in thedrug dose caused a significant elevation in the MPCEfrequency for 6 and 8 mg/kg NIN (Fig. 1). However,NIN alone did not change PCE/NCE ratio signifi-cantly (Table 1). Treatment of mice with 0, 0.5, 1, 2,4, 6 and 8 mg/kg body weight of NIN before expo-sure to 2 Gy caused a significant reduction in the fre-quency of MPCE and a nadir (Fig. 1) was observed for2 mg/kg followed by 4 mg/kg NIN (Table 1). When the

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Fig. 1. Effect of various doses of naringin on the radiation-induced micronuclei formation and PCE/NCE ratio: (a) MPCE, (b) MNCE and(c) PCE/NCE ratio. (�) NIN + sham-irradiation; (�) NIN + irradiation.

comparisons were made among different doses a sig-nificant (p < 0.01) reduction in MPCE was observedfor 2 and 4 mg when compared with 0.5 mg/kg NIN.The decline in MNCE frequency after NIN treatmentwas significant only for 2 and 4 mg/kg body weightand remained unaltered for rest of the NIN doses(Table 1). In contrast, the PCE/NCE ratio showed anelevation in NIN+ irradiation group for all NIN dosesexcept 0.5 and 8 mg/kg NIN. PCE/NCE ratio reacheda peak level at 2 mg/kg followed by 4 mg/kg bodyweight (Fig. 1). Since the highest reduction in MPCE

was observed for 2 mg/kg further studies were carriedout using 2 mg/kg NIN.

3.2. Radioprotective effect of naringin

The frequency of MPCE increased with the in-crease in irradiation dose up to 2 Gy, while thefurther increase in exposure dose resulted in a sig-nificant decline in the frequency of MPCE in boththe DDW+ irradiation and NIN+ irradiation groups.Similarly, irradiation also increased the frequency of


Fig. 2. Effect of naringin on the frequency of micronuclei in the bone marrow of mice exposed to different doses of�-radiation. (�)DDW + irradiation; ( ) NIN + irradiation. (a) Total MPCE, (b) MPCE with one MN and (c) MPCE with more than one MN.

PCE bearing two and three MN in a dose related man-ner. The frequency of PCE bearing two MN increasedup to 2 Gy and declined thereafter for 3 and 4 Gyirradiation (Fig. 2). The dose–response relationshipwas linear up to 2 Gy irradiation. The total reduc-

tion in MPCE was 4.5-, 6-, 2.6-, 2.9- and 2.8-fold inNIN + irradiation group after exposure to 0.5, 1, 2, 3and 4 Gy of�-radiation, respectively when comparedwith the concurrent DDW+ irradiation group. Sim-ilarly, NIN treatment reduced the frequency of PCE


Fig. 3. Effect of naringin on the frequency of micronuclei in the bone marrow of mice exposed to different doses of�-radiation. (�)DDW + irradiation; ( ) NIN + irradiation. (a) Total MNCE, (b) MNCE with one MN and (c) MNCE with more than one MN.

bearing two MN drastically in the NIN+ irradiationgroup compared to the DDW+ irradiation group. Thepattern of increase in the frequency of MNCE wassimilar to that of MPCE, where the frequency ofMNCE increased with increase in the irradiation

dose up to 2 Gy and declined thereafter (Fig. 3). Thedose–response was linear up to 2 Gy irradiation. Thetreatment of mice with 2 mg/kg body weight NIN be-fore irradiation reduced the frequency of MN signifi-cantly (Table 2). The dose–response relationship was


Fig. 4. Effect of naringin on the radiation-induced alteration in thePCE/NCE ratio in the bone marrow of mice exposed to differentdoses of�-radiation (�: DDW+irradiation;�: NIN+irradiation).

linear up to 2 Gy exposure. In contrast, the PCE/NCEratio declined in a dose-dependent manner in boththe DDW+ irradiation and NIN+ irradiation groups(Fig. 4). The treatment of mice with NIN arrested theradiation-induced decline in the PCE/NCE ratio andthis increase in the PCE/NCE ratio in NIN+irradiationgroup was significantly higher than that of concurrentDDW + irradiation group. The dose–response forboth DDW+ irradiation and NIN+ irradiated groupswas linear quadratic.

4. Discussion

Ionizing radiation induces deleterious effects onthe cellular genome resulting in the instability of thegenome. It is necessary to protect the genome againstthe adverse effect of ionizing radiation, as the insta-bility caused in the genome is an important causeof mutagenesis and carcinogenesis. Several syntheticcompounds have been screened for their radiopro-tective action against ionizing radiation. However,metabolic components have received little attention inthis regard. Since dietary ingredients form an impor-

tant part of human intake, it is essential to evaluatetheir potential as the agents that can modulate theresponse of ionizing radiation towards the benefit ofman. NIN, a grapefruit flavanone has been evaluatedfor its potential to protect against radiation-inducedgenomic instability.

A preliminary study was carried out to select theoptimum protective dose. Administration of micewith different doses of NIN up to 4 mg/kg did notalter the control frequency of MPCE and these dosesare considered non-mutagenic. However, a further in-crease in drug dose caused a marginal, but significantelevation in the MPCE suggesting that high dosesof NIN may have mutagenic potential. Treatment ofmice with 0.5–8 mg/kg body weight of NIN beforeexposure to 2 Gy radiation reduced the frequency ofMPCE almost 2-fold. This reduction was statisticallysignificant when compared with the non-drug-treated2 Gy irradiation group. However, greatest reduction(2.5-fold) in the radiation-induced MPCE was ob-served for 2 mg/kg followed by 4 mg/kg. A similareffect was observed earlier for DMAP and the herbalpreparation abana in mouse bone marrow[30,31].The radioprotective agents are reported to give pro-tection at a particular dose, and may even be toxicthereafter[32–34]. Our findings support the hypothe-sis that radioprotectors do have an optimum dose fortheir action.

The frequency of MN (MPCE and MNCE) in-creased with the increase in exposure dose up to 2 Gyand declined thereafter for 3 and 4 Gy in the vehiclecontrol+ irradiation group. This is in contrast to ourearlier reports, where a dose-dependent elevation inMN was observed up to 4 Gy irradiation (the highestdose that was studied) in mouse erythrocytes[35–37].The reason for this decline at 3 and 4 Gy may be dueto the use of higher dose rate of 1.66 Gy/min for irra-diation when compared with our earlier studies, wherethe dose rate was≤1 Gy/min. The use of higher doserate for irradiation may have deposited more ionizingevents per cell per Gray inducing greater damage tothe cellular genome, when compared with the earlierdose rate, resulting in a significant decline in the mi-cronucleus frequency. The change in the micronucleusfrequency with alteration in dose rate has been re-ported after X-irradiation in mice[6]. The sudden andsignificant (p < 0.01) fall in the MN at 3 Gy whencompared with 2 Gy, may be attributed to greater


killing of the erythroblasts, which may have failedto differentiate into polychromatic erythrocytes andwere not available for scoring, leading to the observedreduction in the micronucleus frequency at 3 and 4 Gyexposure. This is supported by a greater decline inthe PCE/NCE ratio, observed at 3 and 4 Gy, since thePCE/NCE ratio gives a direct index of cell division.Ionizing radiation exerts its lethal effects by interact-ing directly with the macromolecules, by initiatingfree radical production, which cause damage to cellu-lar genome and also the cell membrane leading to lipidperoxidation. Malondialdehyde, the product of lipidperoxidation also interacts with DNA causing DNAstrand breaks that in turn develop into chromosomalbreaks. These chromosome breaks may appear as MNin the daughter cell after the first cell division. PCE/NCE ratio declined in a dose-dependent manner andthe dose–response was linear quadratic. A similar ef-fect on the PCE/NCE ratio in mouse bone marrow haspreviously been observed after irradiation[34–37].

Flavonoids are a group of naturally occurring lowmolecular weight polyphenols of plant origin andhave been reported to exert multiple biological effectslike antiinflammatory, antiallergic, antiviral, anti-cancer and radioprotective effects in vitro and in vivo[38–40]. The citrus fruit contains several flavonoidsof which NIN, a flavanone, is predominant in thegrapefruit. The treatment of mice with NIN beforeexposure to different doses of�-radiation resulted ina significant decline in the frequency of MPCE andMNCE. As far as the authors are aware this is proba-bly the first report regarding the potential of NIN asa radioprotective agent. However, NIN has also beenreported to reduce isofamide-induced MN in mousebone marrow[41]. The other citrus flavonoids likerutin, quercetin, etc. and tea flavonoids have been re-ported to reduce the radiation-induced micronucleusfrequency in mice[39,40]. Similarly, other dietarycompounds like caffeine, curcumin, ascorbic acid,tocopherol, ellagic acid and soybean have also beenreported to reduce the radiation-induced genomicinstability and MN in vivo [42–46]. NIN protectedagainst the radiation-induced decline in the cell pro-liferation as evidenced by increased PCE/NCE ratio.A similar effect has been reported earlier, for DMAP,and abana[30,31].

The exact mechanism of action of NIN is notknown. However, it has been reported that flavonoid

activities depend heavily on their antioxidant andchelating properties[47–49]. Being polyphenols, theflavonoids are excellent scavengers of free radicals dueto the high reactivity of their hydroxyl substituents.Both free-radical scavenging and chelating propertiesare apparently responsible for the inhibitory effectof flavonoids on lipid peroxidation. Since NIN is aflavonoid, similar action of free-radical scavengingat the critical sites of DNA damage cannot be ruledout in the present study. NIN has been reported toscavenge superoxide free radicals and lipid peroxides[26,50]. We have also observed scavenging of OH•and SO2

• free radicals in vitro by NIN (data notshown). NIN has also been reported to protect againstDNA cleavage[51]. The free-radical scavenging ac-tivity and protection against DNA damage by NINmay be responsible for the reduction in the micronu-cleus frequency and increase in PCE/NCE ratio in theNIN + irradiation group.

Acknowledgements

We thank Prof. M. S. Vidyasagar, and Dr. J. Velu-murugan, Department of Radiotherapy and Oncology,Kasturba Medical College, Manipal, India for provi-ding the necessary irradiation facilities and help inradiation dosimetry, respectively. The financial assis-tance by RVRR Biotech. Ltd., Hyderabad is thankfullyacknowledged.

References

[1] K.E. Buckton, Chromosome aberrations in patients treatedwith X-ray irradiation for ankylosing spondylitis, in: T.Ishihara, M. Sasaki (Eds.), Radiation-induced ChromosomeDamage in Man, Liss, New York, 1983, pp. 491–511.

[2] J.R.K. Savage, Annotation: classification and relationships ofinduced chromosomal structural changes, J. Med. Genet. 13(1976) 103–122.

[3] J. A Heddle, A rapid in vivo test for chromosomal damage,Mutat. Res. 61 (1973) 187–190.

[4] J.A. Heddle, A.V. Carrano, The DNA content of micronucleiinduced in mouse bone marrow by�-irradiation: evidencethat micronuclei arises from acentric chromosomal fragments,Mutat. Res. 44 (1977) 63–69.

[5] K.I. Yamamoto, Y. Kikuchi, A comparison of diameters ofmicronuclei induced by clastogens and poisons, Mutat. Res.71 (1980) 127–131.


[6] D. Jenssen, C. Ramel, Dose–response at low doses of X-irra-diation and MMS on the induction of micronuclei in mouseerythroblasts, Mutat. Res. 41 (1976) 311–320.

[7] J.A. Heddle, A.S. Raj, A.B. Krepinsky, The micronucleusassay. Part II. In vitro, in: H.F. Stich, K.H.C. San (Eds.), Short-term Tests for Chemical Carcinogens, Springer, New York,1981, pp. 250–254.

[8] J.A. Heddle, M. Hite, K. Kirkhart, K. Mavournin, J.T.MacGeorge, G.W. Newell, M.F. Salmone, The induction ofmicronuclei as a measure of genotoxicity, a report of the USEnvironmental Protection Agency Gene-Tox Program, Mutat.Res. 123 (1983) 61–118.

[9] K. Boller, W. Schmid, Chemische mutagenese beim Sauger.Das Knochenmark des Chinesischen Hamster als in vivo-Testsystem, Hamatologische Befunde nach Behandlung mitTrenimon, Humangenetik 11 (1970) 34–54.

[10] B. Matter, W. Schmid, Trenimon-induced chromosomaldamage in bone marrow cells of six mammalian species,evaluated by the micronucleus test, Mutat. Res. 12 (1971)417–425.

[11] B.E. Matter, J. Grauwiler, micronuclei in mice bone marrowcells: a simple in vivo model for the evaluation of druginduced chromosomal aberrations, Mutat. Res. 23 (1974)239-249.

[12] G.C Jagetia, N.G. Ganapathi, Radiation-induced micronucleusformation in mouse bone marrow after low dose exposures,Mutat. Res., 1993.

[13] H.M. Patt, E.B. Tyree, R.L. Straube, D.E. Smith, Cysteineprotection against X-irradiation, Science 110 (1949) 213–214.

[14] T.R. Sweeney, A survey of compounds from the antiradiationdrug development program of the US Army Medical Researchand Development command, Government Printing Office,Washington, DC, 1979, pp. 308–318.

[15] M.G. Hertog, P.C. Hollman, M.B. Katan, D. Kromhout,Intake of potentially anticarcinogenic flavonoids and theirdeterminants in adults in The Netherlands, Nutr. Cancer 20(1993) 21–29.

[16] M.L. Brandi, Flavonoids: biochemical effects and therapeuticapplications, Bone Miner. 19 (1) (1992) S3–S14.

[17] Y. Graziani, E. Erikson, R.L. Erikson, The effect of quercetinon the phosphorylation activity of the Rous sarcoma virustransforming gene product in vitro and in vivo, Eur. J.Biochem. 135 (1983) 583–589.

[18] K.E. Swiader, E. Zarawska, Flavonoids of rare artemisiaspecies and their antifungal properties, Fitoterapia 67 (1996)77–78.

[19] C.-C. Lin, H.-Y. Lee, C.-H. Chang, T. Namba, M. Hattori,Evaluation of the liver protective principles from the root ofCudrania cochinchinensisvar. geronatogean, Phytother. Res.10 (1996) 13–17.

[20] M.C. Chiato, et al., Free flavonoid from thymusherba baronaand its monoterpenoid chemotypes, Phytochemistry 40 (1995)115–120.

[21] D.H. Kim, et al., Metabolism of poncirin and naringin byhuman intestinal bacteria, Yakhak Horji. 38 (1994) 286–292.

[22] W.S. Graciz, A bioactive naringenin coumaroyl glucosidefrom Mabea fistuliferasubsp., Robusta, Planta Medica 63(1997) 386.

[23] J.L. Dubeois, A.T. Seneden, Dihydrolicoisoflavanone fromSwartiza polyphyllaof natural products, Vol. 58, 1995,pp. 629–632.

[24] G. Jung, G. Hennings, M. Pfeifer, W.G. Bessler, Interactionof metal complexing compounds with lymphocytes and lym-phoid cell lines, Mol. Pharmacol. 23 (1983) 698–702.

[25] G. Kroyer, The antioxidant activity of citrus fruit peels, Z.Ernahrungswiss. 25 (1986) 63–69.

[26] Y.T. Chen, R.L. Zheng, Z.J. Jia, Y. Ju, Flavonoids as super-oxide scavengers and antioxidants, Free Rad. Biol. Med. 9(1990) 19–21.

[27] A.R. Francis, T.K. Shetty, R.K. Bhattacharya, Modulatingeffect of plant flavonoids on the mutagenicity ofN-methyl-N′-nitro-N-nitrosoguanidine, Carcinogenesis 10 (1989)1953–1955.

[28] I. Maridonneau-Parini, P. Braquet, R.P. Garay, Heterogeneouseffect of flavonoids on K+ loss and lipid peroxidation inducedby oxygen-free radicals in human red cells, Pharmacol. Res.Commun. 18 (1986) 61–72.

[29] W. Schmid, The micronucleus test, Mutat. Res. 31 (1975)9–12.

[30] G.C. Jagetia, P.S. Jacob, M.N.A. Rao, (E) 4-[4-N,N′-dimethyl-aminophenyl]-but-3-en-2-one (DMAP) treatment inhibits theradiation-induced micronucles formation in bone marrow ofBALB/c mice. Mutat. Res. 306 (1994) 71–80.

[31] G.C. Jagetia, R. Aruna, The herbal preparation abana protectsagainst the radiation-induced micronuclei in mouse bonemarrow, Mutat. Res. 391 (1997) 157–163.

[32] J.F. Thomson, Radiation Protection in Mammals, Reinhold,New York, USA, 1962.

[33] G.C. Jagetia, M.S. Baliga, K.J. Malagi, M.S. Kamath, Theevaluation of the radioprotective effect of Triphala (an Ayur-vedic rejuvenating drug) in the mice exposed to�-radiation,Phytomedicine 9 (2) (2002) 99–108.

[34] G.C. Jagetia, M.S. Baliga, Treatment of mice with a herbalpreparation mentat protects against the radiation-inducedmortality, Phyother. Res., 2002 (in press).

[35] G.C. Jagetia, N.G. Ganapathi, Radiation-induced micronucleiformation in mouse bone marrow after low dose exposures,Mutat. Res. 304 (1994) 235–242.

[36] G.C. Jagetia, R. Aruna, Teniposide (VM-26) treatment enhan-ces the radiation-induced micronuclei in the bone marrow ofmouse, Mutat. Res. 425 (1999) 87–98.

[37] G.C. Jagetia, V. Nayak, M.S. Vidyasagar, Evaluation of theantineoplastic activity of Guduchi (Tinospora cordifolia) incultured HeLa cells, Cancer Lett. 127 (1998) 71–82.

[38] B. Havsteen, Flavonoids, a class of natural products of highpharmacological potency, Biochem. Pharmacol. 32 (1983)1141–1148.

[39] K. Shimoi, S. Masuda, B. Shen, M. Furugori, S. Esaki, N.Kinae, Radioprotective effects of antioxidative flavonoids in�-ray-irradiated mice, Carcinogenesis 15 (1994) 2669–2672.

[40] K. Shimoi, B. Shen, R. Mochizuki, S. Toyokuni, N. Kinae,Protective effects of� G-Rutin on oxidative stress in mice,Food Fact. Cancer Prev. 15 (1997) 618–622.

[41] I. Alvarez-Gonzalez, E. Madrigal-Bujaidar, V. Dorado, J.J.Espinosa-Aguirre, Inhibitory effect of naringin on the micro-nuclei induced by ifosfamide in mouse, and evaluation of its


modulatory effect on the Cyp3a subfamily, Mutat. Res. 481(2001) 171–178.

[42] Z. Farooqi, P.C. Kesavan, Radioprotection by caffeine pre-and post-treatment in the bone marrow chromosomes of micegiven whole-body gamma-irradiation, Mutat. Res. 269 (1992)225–230.

[43] S.K. Abraham, L. Sarma, P.C. Kesavan, Protective effects ofchlorogenic acid, curcumin and beta-carotene against gamma-radiation-induced in vivo chromosomal damage, Mutat. Res.303 (1993) 109–112.

[44] L. Sarma, P.C. Kesavan, Protective effects of Vitamins C andE against�-radiation-induced in vivo chromosomal damagein mouse, Int. J. Radiat. Biol. 63 (1993) 759–764.

[45] K.C. Theresiamma, J. George, R. Kuttan, Protective effect ofcurcumin, ellagic acid and bixin on radiation-induced toxicity,Ind. J. Exp. Biol. 34 (1996) 845–847.

[46] R.S. Harapanhalli, V.R. Narra, V. Yaghmai, M.T. Azure, S.M.Goddu, R.W. Howell, D.V. Rao, Vitamins as radioprotectorsin vivo. Part II. Protection by Vitamin A and soybean oil

against radiation damage caused by internal radionuclides,Radiat. Res. 139 (1994) 115–122.

[47] L. Cavallini, A. Bindoli, N. Siliprandi, Comparative evaluationof antiperoxidative action of silymarin and other flavonoids,Pharmacol. Res. Commun. 10 (1978) 133–136.

[48] L.G. Korina, I.B. Afana’ev, Antioxidant and chelating proper-ties of flavonoids, Adv. Pharmacol. 38 (1997) 151–163.

[49] A. Affany, R. Salvayre, L. Douste-Blazy, Comparison of theprotective effect of various flavonoids against lipid peroxi-dation of erythrocyte membranes, Fundam. Clin. Pharmacol.1 (1987) 451–457.

[50] A.K. Ratty, N.P. Das, Effects of flavonoids on non-enzymaticlipid peroxidation: structure activity relation ship, Biochem.Med. Metab. Biol. 39 (1988) 69–79.

[51] A. Russo, R. Acquaviva, A. Campisi, V. Sorrenti, C. DiGiacomo, G. Virgata, M.L. Barcellona, A. Vanella, Bioflavo-noids as antiradicals, antioxidants and DNA cleavage protec-tors, Cell Biol. Toxicol. 16 (2) (2000) 91–98.

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