Inhibitory effect of naringin on the micronuclei induced by ifosfamide in mouse, and evaluation of its modulatory effect on the Cyp3a subfamily

Chromosomal aberrations, DNA damage and biochemical disturbances induced by silver nanoparticles in mice: Role of particle size and natural compounds treatment

CONTEXT

Nanotechnology is widely used nowadays in several fields of industry, engineering, and medicine, the biological action mechanisms of AgNPs, which mainly involve the release of silver ions (Ag⁺), generation of reactive oxygen species (ROS).

OBJECTIVE

The potential toxicity AgNPs of damages to hepatic cells, hesperidin, and naringin role for their protective effect against the increase of ROS due to AgNPs toxicity. They can be restored, most cellular biochemical parameters, genotoxicity, mutagenicity, and histopathological analysis.

MATERIALS AND METHODS

Toxicity was induced by an oral dose of Ag NPs of (20-100 nm) for one month, after that treated with hesperidin, naringin (100 mg/kg) for three weeks, malondialdehyde (MDA) levels, nitric oxide (NO), glutathione (GSH) and catalase were estimated. Also, aminotransferases (AST and ALT), alkaline phosphatase (ALP), γ-glutamyltransferase (GGT), albumin, and total bilirubin were determined, following Chromosomal aberrations, DNA breaks and histological analyses.

RESULTS

hesperidin, and naringin treatment, recorded amelioration in most biochemical, genetic and spermatogenesis disturbances Also, histological Investigations were improved.

CONCLUSION

Their biological safety problems such as potential toxicity on cells, tissue, and organs should be paid enough attention, hesperidin and naringin amelioration fundamental alterations, as hepatic architectural and DNA damage, related to its role as antioxidant and anti-inflammatory agent.

Induced Cell Death as a Possible Pathway of Antimutagenic Action

The existing concepts of antimutagenesis are briefly reviewed. Published reports on antimutagenic and proapoptotic properties of some polyphenols and compounds of other chemical groups obtained in representative in vitro and in vivo experiments on eukaryotic test systems are discussed. The relationships between the antimutagenic and proapoptotic properties of the analyzed compounds (naringin, apigenin, resveratrol, curcumin, N-acetylcysteine, etc.) are considered in favor of the hypothesis on induced cell death as an antimutagenic tool.

Pharmacokinetic parameters of ifosfamide in mouse pre-administered with grapefruit juice or naringin

Grapefruit juice (GFJ) and naringin when consumed previously or together with medications may alter their bioavailavility and consequently the clinical effect. Ifosfamide (IF) is an antitumoral agent prescribed against various types of cancer. Nevertheless, there is no information regarding its interaction with the ingestion of GFJ or naringin. The aims of the present report were validating a method for the quantitation of IF in the plasma of mouse, and determine if mice pretreated with GFJ or naringin may modify the IF pharmacokinetics. Our HPLC results to quantify IF showed adequate intra and inter-day precision (RSD < 15%) and accuracy (RE < 15%) indicating reliability. Also, the administration of GFJ or naringin increased C_max of IF 22.9% and 17.8%, respectively, and decreased T_max of IF 19.2 and 53.8%, respectively. The concentration of IF was higher when GFJ (71.35 ± 3.5 µg/mL) was administered with respect to that obtained in the combination naringin with IF (64.12 ± µg/mL); however, the time required to reach such concentration was significantly lower when naringin was administered (p < 0.5). We concluded that pre-administering GFJ and naringin to mice increased the T_max and decreased the C_max of IF.

Genotoxic and mutagenic studies of teratogens in developing rat and mouse

In this review, genotoxic and mutagenic effects of teratogenic chemical agents in both rat and mouse have been reviewed. Of these chemicals, 97 are drugs and 33 are pesticides or belong to other groups. Large literature searches were conducted to determine the effects of chemicals on chromosome abnormalities, sister chromatid exchanges, and micronucleus formation in experimental animals such as rats and mice. In addition, studies that include unscheduled DNA synthesis, DNA adduct formations, and gene mutations, which help to determine the genotoxicity or mutagenicity of chemicals, have been reviewed. It has been estimated that 46.87% of teratogenic drugs and 48.48% of teratogenic pesticides are positive in all tests. So, all of the teratogens involved in this group have genotoxic and mutagenic effects. On the other hand, 36.45% of the drugs and 21.21% of the pesticides have been found to give negative results in at least one test, with the majority of the tests giving positive results. However, only 4.16% of the drugs and 18.18% of the pesticides were determined to give negative results in the majority of the tests. Among tests with major negative results, 12.50% of the teratogenic drugs and 12.12% of the teratogenic pesticides were negative in all conducted tests.

Heated naringin mitigate the genotoxicity effect of Mitomycin C in BALB/c mice through enhancing the antioxidant status

A major problem with cancer chemotherapy is its severe toxic effects on non-target tissues. Assessment of natural products for their protective effect against anticancer drugs induced toxicity is gaining importance in cancer biology. The aim of the present study was to evaluate the effect of native and thermal treated naringin on the protective effect against mitomycin C (MMC) induced genotoxicity. The genotoxicity in liver kidney and brain cells isolated from Balb/C mice were evaluated by performing the comet assay. Antioxidant and lipid peroxidation assays were carried out to understand the protective effects of these compounds. The comet assay showed that heated and native naringin were not genotoxic at the tested dose (40 mg/kg b.w) on liver, kidney and brain cells. A significant decrease in DNA damages was observed, at the tested doses (20 mg/kg b.w and 40 mg/kg b.w) suggesting a protective role of these molecules against the genotoxicity induced by mitomycin C on liver, kidney and brain cells. Moreover, administration of MMC (6 mg/kg b.w.) altered the activities of glutathione peroxidase and superoxide dismutase accompanied by a significant increase of lipid peroxidation. Pretreatment of mouse with heated and native naringin before MMC administration significantly raised the glutathione peroxidase and superoxide dismutase activities followed by a reduced MMC-induced lipid peroxidation. Our study demonstrated that heat treatment of naringin preserve activities of native naringin. The genoprotective properties of heated and native naringin against MMC could be attributed to its antioxidant activities and its inhibitory effect on lipid peroxidation.

Evidence of Some Natural Products with Antigenotoxic Effects. Part 1: Fruits and Polysaccharides

Cancer is one of the leading causes of deaths worldwide. The agents capable of causing damage to genetic material are known  as genotoxins and, according to their mode of action, are classified into mutagens, carcinogens or teratogens. Genotoxins are  involved in the pathogenesis of several chronic degenerative diseases including hepatic, neurodegenerative and cardiovascular  disorders, diabetes, arthritis, cancer, chronic inflammation and ageing. In recent decades, researchers have found novel bioactive  phytocompounds able to counteract the effects of physical and chemical mutagens. Several  studies  have  shown potential antigenotoxicity in a variety of fruits. In this review (Part 1), we present an overview of research conducted on some fruits (grapefruit, cranberries, pomegranate, guava, pineapple, and mango) which are frequentl consumed by humans, as well as  the  analysis of some phytochemicals extracted from fruits and yeasts which have demonstrated antigenotoxic capacity in various  tests, including the Ames assay, sister chromatid exchange, chromosomal aberrations, micronucleus and comet assay.

Chemopreventive Agents and Inhibitors of Cancer Hallmarks: May Citrus Offer New Perspectives?

Fruits and vegetables have long been recognized as potentially important in the prevention of cancer risk. Thus, scientific interest in nutrition and cancer has grown over time, as shown by increasing number of experimental studies about the relationship between diet and cancer development. This review attempts to provide an insight into the anti-cancer effects of Citrus fruits, with a focus on their bioactive compounds, elucidating the main cellular and molecular mechanisms through which they may protect against cancer. Scientific literature was selected for this review with the aim of collecting the relevant experimental evidence for the anti-cancer effects of Citrus fruits and their flavonoids. The findings discussed in this review strongly support their potential as anti-cancer agents, and may represent a scientific basis to develop nutraceuticals, food supplements, or complementary and alternative drugs in a context of a multi-target pharmacological strategy in the oncology.

In vitro effects of the citrus flavonoids diosmin, naringenin and naringin on the hepatic drug-metabolizing CYP3A enzyme in human, pig, mouse and fish

Flavonoids are known to have effects on cytochrome P450 enzymatic activity. However, little effort has been made to examine species differences and the relevance of studies on mammalian and fish microsomes so that extrapolations can be made to humans. Therefore, the effects of several naturally occurring flavonoids on the activity of CYP3A-dependent 7-benzyloxy-4-trifluoromethylcoumarin O-debenzylase (BFCOD) were evaluated in human, pig, mouse, and juvenile rainbow trout sources of hepatic microsomes. Each was exposed to three concentrations (1, 10, and 100μM) of diosmin, naringin, and naringenin. Naringenin competitively inhibited BFCOD activity (Ki values were 24.6μM in human, 15.6μM in pig, and 19.6μM in mouse microsomes). In fish, BFCOD activity was inhibited in a noncompetitive manner (Ki=7μM). Neither diosmin nor naringenin affected BFCOD activity in hepatic microsomes from the studied model organisms. These results suggest that dietary flavonoids potentially inhibit the metabolism of clinical drugs.

Up-regulation of PPARγ, heat shock protein-27 and -72 by naringin attenuates insulin resistance, β-cell dysfunction, hepatic steatosis and kidney damage in a rat model of type 2 diabetes

Naringin, a bioflavonoid isolated from grapefruit, is well known to possess lipid-lowering and insulin-like properties. Therefore, we assessed whether naringin treatment ameliorates insulin resistance (IR), β-cell dysfunction, hepatic steatosis and kidney damage in high-fat diet (HFD)–streptozotocin (STZ)-induced type 2 diabetic rats. Wistar albino male rats were fed a HFD (55 % energy from fat and 2 % cholesterol) to develop IR and on the 10th day injected with a low dose of streptozotocin (40 mg/kg, intraperitoneal (ip)) to induce type 2 diabetes. After confirmation of hyperglycaemia (>13·89 mmol/l) on the 14th day, different doses of naringin (25, 50 and 100 mg/kg per d) and rosiglitazone (5 mg/kg per d) were administered orally for the next 28 d while being maintained on the HFD. Naringin significantly decreased IR, hyperinsulinaemia, hyperglycaemia, dyslipidaemia, TNF-α, IL-6, C-reactive protein and concomitantly increased adiponectin and β-cell function in a dose-dependent manner. Increased thiobarbituric acid-reactive substances and decreased antioxidant enzyme activities in the serum and tissues of diabetic rats were also normalised. Moreover, naringin robustly increased PPARγ expression in liver and kidney; phosphorylated tyrosine insulin receptor substrate 1 in liver; and stress proteins heat shock protein (HSP)-27 and HSP-72 in pancreas, liver and kidney. In contrast, NF-κB expression in these tissues along with sterol regulatory element binding protein-1c and liver X receptor- expressions in liver were significantly diminished. In addition, microscopic observations validated that naringin effectively rescues β-cells, hepatocytes and kidney from HFD-STZ-mediated oxidative damage and pathological alterations. Thus, this seminal study provides cogent evidence that naringin ameliorates IR, dyslipidaemia, β-cell dysfunction, hepatic steatosis and kidney damage in type 2 diabetic rats by partly regulating oxidative stress, inflammation and dysregulated adipocytokines production through up-regulation of PPARγ, HSP-27 and HSP-72.

Influence of naringin on cadmium-induced genomic damage in human lymphocytes in vitro

Cadmium is an important toxic environmental heavy metal. Generally, occupational and environmental exposures to cadmium result from heavy metal mining, metallurgy and industrial use and the manufacturing of nickel-cadmium batteries, pigments and plastic stabilizers. Cadmium induces oxidative stress and alters the antioxidant system, resulting in oxidative DNA damage and lipid peroxidation. The effect of naringin, a grapefruit flavonone, on cadmium-induced genomic damage was studied by using an in vitro system to test for chromosomal aberrations and sister chromatid exchanges. Cadmium significantly increased the total chromosomal aberrations in human lymphocytes at concentrations of 20 and 40 μM, and although naringin alone did not induce any chromosomal aberrations, it decreased those induced by cadmium. The mitotic index was not affected by either cadmium or naringin. Cadmium also induced a significant number of sister chromatid exchanges, but naringin alone did not induce sister chromatid exchanges and was unable to decrease the frequency of sister chromatid exchanges induced by cadmium. Replicative index analysis revealed that naringin and cadmium did not significantly alter replicative index frequencies. In this study, we show that plant-based flavonoids, such as naringin, may reduce the genomic damage induced by cadmium and may protect the cellular environments from free radical damage by its possible antioxidative potential.

Inhibitory effect of grapefruit juice on the genotoxic damage induced by ifosfamide in mouse

The consumption of grapefruit juice (GJ) has been associated with various activities potentially beneficial for human health, including protection against the DNA damage produced by various compounds. In the present report, we evaluated the capability of this juice to inhibit the rate of micronucleated polychromatic erythrocytes (MNPE) and sister chromatid exchanges (SCE) induced by the antineoplastic alkylating agent ifosfamide (IF). We tested the effect of administering 100, 500, and 1000 mg/kg of GJ in mouse and obtained the following results: a) with the high dose, a reduction of 72% in the rate of SCE induced by IF; b) a mean reduction of 65.3% in the rate of MNPE compared with the damage induced by IF at 48 h post-administration; c) no modification induced by GJ either on the cellular proliferation kinetics or in the mitotic index; and d) neither induction of bone marrow cytotoxicity by GJ nor a protective effect of the juice against the cytotoxicity induced by IF. These data showed a significant inhibitory effect of GJ against the chromosome damage induced by the tested agent; they also suggest the relevance of carrying out studies to clarify the involved mechanism of action as well as to determine the cancer chemopreventive capacity of the juice.

Antigenotoxic, antioxidant and lymphocyte induction effects produced by pteropodine

Pteropodine is a heterohimbine-type oxindole alkaloid specifically isolated from 'Cat's claw' (Uncaria tomentosa), a plant that has shown cytostatic, anti-inflammatory and antimutagenic properties and is used in traditional medicine to cure a number of diseases. In this report, we studied the ability of pteropodine to decrease the rate of sister-chromatid exchanges and micronucleated polychromatic erythrocytes in mice administered doxorubicin. We also determined its capacity to induce lymphocyte production in mice as well as its free radical scavenging potential by applying the DPPH assay. We found pteropodine (100-600 mg/kg) to significantly decrease the frequency of sister-chromatid exchanges and micronucleated polychromatic erythrocytes in mice administered with 10 mg/kg of doxorubicin. Furthermore, we determined that pteropodine partially corrected bone marrow cytotoxicity induced by doxorubicin, as it showed an improvement in the rate of polychromatic erythrocytes. Besides, 600 mg/kg of pteropodine increased 25.8% of the production of lymphocytes over the control value along a 96-hr assay, and it exhibited a strong capacity to trap the DPPH-free radical (98.26% with 250 microg/ml). Our results establish that pteropodine is an effective antimutagen in the model used, and suggest that pteropodine deserves further research in the area of cell protective potential and its mechanism of action.

Comparative evaluation of 12 immature citrus fruit extracts for the inhibition of cytochrome P450 isoform activities

In a previous study we found that 50% ethanol extracts of immature fruits of Citrus unshiu (satsuma mandarin) have anti-allergic effects against the Type I, II and IV allergic reactions. However, many adverse interactions between citrus fruit, especially grapefruit juice, and drugs have been reported due to the inhibition of cytochrome P450 (CYP) activities. The purpose of this study was to examine the competitive inhibitory effects of extracts from immature citrus fruit on CYP activity. Extracts were prepared from 12 citrus species or cultivars, and were tested against three kinds of major CYPs, CYP2C9, CYP2D6 and CYP3A4, in human liver microsomes. We also estimated the amounts of flavonoids (narirutin, hesperidin, naringin and neohesperidin) and furanocoumarins (bergapten, 6',7'-dihydroxybergamottin and bergamottin) in each extract using HPLC. Citrus paradisi (grapefruit) showed the greatest inhibition of CYP activities, while Citrus unshiu which has an antiallergic effect, showed relatively weak inhibitory effects. Extracts having relatively strong inhibitory effects for CYP3A4 tended to contain higher amounts of naringin, bergamottin and 6',7'-dihydroxybergamottin. These results, providing comparative information on the inhibitory effects of citrus extracts on CYP isoforms, suggest that citrus extracts containing high levels of narirutin and hesperidin and lower levels of furanocoumarins such as C. unshiu are favorable as antiallergic functional ingredients.

Genotoxic and cytotoxic studies of beta-sitosterol and pteropodine in mouse

Beta-sitosterol (BS) and pteropodine (PT) are constituents of various plants with pharmacological activities potentially useful to man. The chemicals themselves possess biomedical properties related to the modulation of the immune and the nervous systems, as well as to the inflammatory process. Therefore, safety evaluation of the compounds is necessary in regard to their probable beneficial use in human health. The present study evaluates their genotoxic and cytotoxic potential by determining the capacity of the compounds to induce sister chromatid exchanges (SCE), or to alter cellular proliferation kinetics (CPK) and the mitotic index (MI) in mouse bone marrow cells. Besides, it also determines their capacity to increase the rate of micronucleated polychromatic erythrocytes (MNPE) in peripheral mouse blood, and the relationship polychromatic erythrocytes/normochromatic erythrocytes (PE/NE) as an index of cytotoxicity. For the first assay, four doses of each compound were tested: 200, 400, 600, and 1000 mg/kg in case of BS, and 100, 200, 300, and 600 mg/kg for PT. The results in regard to both agents showed no SCE increase induced by any of the tested doses, as well as no alteration in the CPK, or in the MI. With respect to the second assay, the results obtained with the two agents were also negative for both the MNPE and the PE/NE index along the daily evaluation made for four days. In the present study, the highest tested dose corresponded to 80% of the LD₅₀ obtained for BS and to 78% in the case of PT. The results obtained establish that the studied agents have neither genotoxic nor cytotoxic effect on the model used, and therefore they encourage studies on their pharmacological properties.

Naringin, a grapefruit flavanone, protects V79 cells against the bleomycin-induced genotoxicity and decline in survival

The effect of naringin, a grapefruit flavonone was studied on bleomycin-induced genomic damage and alteration in the survival of cultured V79 cells. Exposure of V79 cells to bleomycin induced a concentration dependent elevation in the frequency of binucleate cells bearing micronuclei (MNBNC) and a maximum number of MNBNCs were observed in the cells treated with 50 microg ml(-1) bleomycin, the highest concentration evaluated. This genotoxic effect of bleomycin was reflected in the cell survival, where a concentration dependent decline was observed in the cells treated with different concentrations of bleomycin. Treatment of cells with 1 mm naringin before exposure to different concentrations of bleomycin arrested the bleomycin-induced decline in the cell survival accompanied by a significant reduction in the frequency of micronuclei when compared with bleomycin treatment alone. The cell survival and micronuclei induction were found to be inversely correlated. The repair kinetics of DNA damage induced by bleomycin was evaluated by exposing the cells to 10 microg ml(-1) bleomycin using single cell gel electrophoresis. Treatment of V79 cells with bleomycin resulted in a continuous increase in DNA damage up to 6 h post-bleomycin treatment as evident by migration of more DNA into the tails (% tail DNA) of the comets and a subsequent increase in olive tail moment (OTM), an index of DNA damage. Treatment of V79 cells with 1 mm naringin reduced bleomycin-induced DNA damage and accelerated DNA repair as indicated by a reduction in % tail DNA and OTM with increasing assessment time. A maximum reduction in the DNA damage was observed at 6 h post-bleomycin treatment, where it was 5 times lower than bleomycin alone. Our study, which was conducted on the basis of antioxidant, free radical scavenging and metal chelating properties of naringin demonstrates that naringin reduced the genotoxic effects of bleomycin and consequently increased the cell survival and therefore may act as a chemoprotective agent in clinical situations.

Antigenotoxic and antioxidant effect of grapefruit juice in mice treated with daunorubicin

Grapefruit juice (GJ) is widely consumed in many countries. Several of its constituents possess nutritive value, as well as antigenotoxic and antioxidant effects. Therefore, the aim of this investigation was to evaluate the capacity of GJ to inhibit the micronucleated polychromatic erythrocytes (MNPE) produced by daunorubicin (Dau) in an acute assay in mice, as well as to determine its antioxidant potential in mouse hepatic microsomes, and its capacity to trap free radicals in vitro. In regard to the first point, GJ produced no toxic or genotoxic damage; on the contrary, it generated a significant reduction of the MNPE formed by Dau. The effect was found throughout the examined schedule (from 24 to 96 h). The two high doses produced inhibition of about 60% at 48 h, 86% at 72 h and 100% at 96 h after the treatment. With respect to the GJ antioxidant potential, a 50% decrease in liver microsomal lipid peroxidation produced by Dau was found by quantifying malondialdehyde formation. Finally, a strong GJ scavenging activity evaluated with the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) was observed, giving rise to a concentration-dependent curve with a correlation coefficient of 0.98. Overall, our results established an efficient anticlastogenic potential of GJ, probably related to its antioxidant capacity, or to alterations of Dau metabolism, suggesting the pertinence of extending research on the matter using other mutagens and biological models.

Chromosomal aberrations in arsenic-exposed human populations: a review with special reference to a comprehensive study in West Bengal, India

For centuries arsenic has played an important role in science, technology, and medicine. Arsenic for its environmental pervasiveness has gained unexpected entrance to the human body through food, water and air, thereby posing a great threat to public health due to its toxic effect and carcinogenicity. Thus, in modern scenario arsenic is synonymous with "toxic" and is documented as a paradoxical human carcinogen, although its mechanism of induction of neoplasia remains elusive. To assess the risk from environmental and occupational exposure of arsenic, in vivo cytogenetic assays have been conducted in arseniasis-endemic areas of the world using chromosomal aberrations (CA) and sister chromatid exchanges (SCE) as biomarkers in peripheral blood lymphocytes. The primary aim of this report is to critically review and update the existing in vivo cytogenetic studies performed on arsenic-exposed populations around the world and compare the results on CA and SCE from our own study, conducted in arsenic-endemic villages of North 24 Parganas (district) of West Bengal, India from 1999 to 2003. Based on a structured questionnaire, 165 symptomatic (having arsenic induced skin lesions) subjects were selected as the exposed cases consuming water having a mean arsenic content of 214.96 microg/l. For comparison 155 age-sex matched control subjects from an unaffected district (Midnapur) of West Bengal were recruited. Similar to other arsenic exposed populations our population also showed a significant difference (P < 0.01) in the frequencies of CA and SCE between the cases and control group. Presence of substantial chromosome damage in lymphocytes in the exposed population predicts an increased future carcinogenic risk by this metalloid.

Resveratrol, a red wine constituent polyphenol, protects from ischemia-reperfusion damage of the ovaries

OBJECTIVE

The aim of this study is to investigate the effects of resveratrol on histopathological changes, antioxidant status and lipid peroxidation, in torsion-detorsion injury in rat ovaries.

METHOD

To determine whether ischemia followed by reperfusion can induce ovarian oxidative damage, we created a model of adnexal ischemia-reperfusion by using rats. Ischemia was induced by unilateral occlusion of the tubo-ovarian vessels for 3 h. Reperfusion was achieved by releasing the occlusion and restoring the circulation for 3 h. Thirty-two adult female albino rats were divided equally into 4 groups: sham operation, torsion, saline/detorsion and resveratrol/detorsion. Rats in the torsion group were killed after 360 degrees clockwise adnexal torsion for 3 h. Resveratrol was injected intraperitoneally 30 min before detorsion in the resveratrol/detorsion group, and saline was administered in the saline/detorsion group. After 3 h of adnexal detorsion in both of these groups, the rats were killed and adnexa were removed. The tissue levels of malondialdehyde, reduced glutathione and xanthine oxidase activity were measured.

RESULTS

Malondialdehyde and xanthine oxidase levels in the saline/detorsion group were increased significantly when compared to the torsion and sham operation groups (p < 0.001). Malondialdehyde levels in the resveratrol group were lower than in the saline/detorsion group, and differences between the two groups were statistically significant (p < 0.001). Xanthine oxidase levels in the resveratrol group were lower than in the saline/detorsion and torsion groups, and differences between these groups were statistically significant (p < 0.001). Reduced glutathione levels in the saline/detorsion group were decreased significantly when compared to the torsion and sham operation groups. Reduced glutathione levels in the resveratrol group were significantly higher than in the saline/detorsion group (p < 0.006). Histological examination showed a significant improvement in ovarian morphology in the resveratrol-treated rats compared with the ischemia and ischemia-reperfusion groups.

CONCLUSION

Our results demonstrated that intraperitoneal resveratrol administration reduced the lipid peroxidation products of ischemic rats and ovarian damage was reduced as indicated by histological examination.

The grapefruit flavanone naringin protects against the radiation-induced genomic instability in the mice bone marrow: a micronucleus study

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 studied on the alteration in the radiation-induced micronucleated polychromatic (MPCE) and normochromatic (MNCE) erythrocytes in mouse bone marrow exposed to 2 Gy of 60Co gamma-radiation. The treatment of mice with various doses of NIN before exposure to 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 2mg/kg body weight NIN, accompanied by a highest PCE/NCE ratio when compared with the non-drug-treated irradiated control. Therefore, further studies were carried out using this dose of NIN, where the animals were administered with 2mg/kg body weight of NIN before exposure to 0, 0.5, 1, 2, 3 and 4 Gy of gamma-radiation. The frequency of MPCE and MNCE increased in a dose-dependent manner in both the non-drug-treated irradiated control and NIN-pretreated irradiated groups up to a dose of 2 Gy, while a further increase in the irradiation dose resulted in a significant decline in MPCE and MNCE frequencies in both groups. Pretreatment of mice with 2mg/kg body weight of NIN resulted in a significant decline in the frequencies of MPCE and MNCE. NIN treatment not only reduced the frequency of MPCE with one micronucleus, but also of MPCE with multiple micronuclei (MN), indicating its ability to reduce complex chromosome aberrations. Conversely, the PCE/NCE ratio declined in a dose-dependent manner in both groups. The treatment of mice with NIN before exposure to different doses of gamma-radiation resulted in the inhibition in this decline in the PCE/NCE ratio. Our study demonstrates that NIN is able to protect mouse bone marrow cells against the radiation-induced DNA damage and decline in the cell proliferation as observed by a reduction in the micronucleus frequency and an increase in PCE/NCE ratio, respectively, in the NIN-pretreated irradiated group.