Lead-induced DNA damage in Vicia faba root cells: potential involvement of oxidative stress

Genotoxic effects of lead (0-20μM) were investigated in whole-plant roots of Vicia faba L., grown hydroponically under controlled conditions. Lead-induced DNA damage in V. faba roots was evaluated by use of the comet assay, which allowed the detection of DNA strand-breakage and with the V. faba micronucleus test, which revealed chromosome aberrations. The results clearly indicate that lead induced DNA fragmentation in a dose-dependant manner with a maximum effect at 10μM. In addition, at this concentration, DNA damage time-dependently increased until 12h. Then, a decrease in DNA damages was recorded. The significant induction of micronucleus formation also reinforced the genotoxic character of this metal. Direct interaction of lead with DNA was also evaluated with the a-cellular comet assay. The data showed that DNA breakages were not associated with a direct effect of lead on DNA. In order to investigate the relationship between lead genotoxicity and oxidative stress, V. faba were exposed to lead in the presence or absence of the antioxidant Vitamin E, or the NADPH-oxidase inhibitor dephenylene iodonium (DPI). The total inhibition of the genotoxic effects of lead (DNA breakage and micronucleus formation) by these compounds reveals the major role of reactive oxygen species (ROS) in the genotoxicity of lead. These results highlight, for the first time in vivo and in whole-plant roots, the relationship between ROS, DNA strand-breaks and chromosome aberrations induced by lead.     

Antioxidant vitamins C, E and beta-carotene reduce DNA damage before as well as after gamma-ray irradiation of human lymphocytes in vitro

The protective effect of Vitamins C, E and beta-carotene against gamma-ray-induced DNA damage in human lymphocytes in vitro was investigated. Cultured lymphocytes were exposed to increasing concentration of these vitamins either before or after irradiation with 2Gy of gamma-rays and DNA damage was estimated using micronucleus assay. A radioprotective effect was observed when antioxidant vitamins were added to cultured cells before as well after irradiation; the strongest effect was observed when they were added no later than 1h after irradiation. The radioprotective effect of vitamins also depended on their concentration; Vitamins C added at low concentration (1 microg/ml) before exposure of the cells to radiation prevented induction of micronuclei. Vitamin E at the concentration above 2 microg/ml decreased the level of radiation-induced micronuclei when compared to the cells irradiated without vitamin treatment. beta-Carotene was effective at all tested concentrations from 1 to 5 microg/ml and reduced the number of micronuclei in irradiated cells. The vitamins had no effect on radiation-induced cytotoxicity as measured by nuclear division index. The radioprotective action of antioxidant Vitamins C, E and beta-carotene was dependent upon their concentration as well as time and sequence of application.     

DNA Damage Profiling in Motor Neurons: A Single-Cell Analysis by Comet Assay

We developed a method to measure DNA damage in single motor neurons (MN). A cell fraction enriched in viable -motor neurons was isolated from adult rat spinal cord. This cell preparation was used to measure the vulnerability of the MN genome to different reactive oxygen species (ROS). MN were exposed in vitro to hydrogen peroxide, nitric oxide and peroxynitrite. Specific types of DNA lesions (e.g., abasic sites, single-strand breaks, and double-strand breaks) were measured using single-cell gel electrophoresis (comet assay). The MN genome was very susceptible to attack by ROS. Different ROS induced different DNA damage profiles in MN. MN were also isolated from adult rats with sciatic nerve avulsions to show that DNA damage emerges early during their degeneration in vivo. This study demonstrates that the comet assay is a feasible method for profiling DNA lesions in the genome of single MN. Viable mature MN can be isolated and used for in vitro models of MN genotoxicity and can be isolated from in vivo models of MN degeneration for profiling DNA damage on a single-cell basis.     

Usefulness of combined in vivo skin comet assay and in vivo skin micronucleus test

We have already found that the in vivo skin comet assay is useful for the evaluation of primary DNA damage induced by genotoxic chemicals in epidermal skin cells. The aim of the present study was to evaluate the sensitivity and specificity of the combined in vivo skin comet assay and in vivo skin micronucleus (MN) test using the same animal to explore the usefulness of the new test method. The combined alkaline comet assay and MN test was carried out with three chemicals: 4-nitroquinoline-1-oxide (4NQO), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and benzo[a]pyrene (B[a]P). In the first experiment, we compared DNA- and chromosome-damaging effects of 3 [72, 24 and 3 hours (h) before sacrifice] and 4 applications (72, 48, 24 and 3h before sacrifice) of 4NQO, which induces dermal irritancy. The animals were euthanized and their skin was sampled for the combination test. As a result, the 4-application method was able to detect both DNA- and chromosome-damaging potential with a lower concentration; therefore, in the second experiment, MNNG and B[a]P were topically applied four times, respectively. The animals were euthanized, and then their skins were sampled for combination tests. In the alkaline comet assay, significant differences in the percent of DNA (%DNA) in the tail were observed in epidermal skin cells treated with MNNG and B[a]P. In the MN test, an increased frequency of MN cells (%MN) cells was observed by treatment with MNNG; however, there were no significant increases. In contrast, significant differences in %MN were observed by treatment with B[a]P. From these results, we conclude that the combined in vivo skin comet assay and in vivo MN test was useful because it can detect different genotoxicity with the same sampling time and reduce the number of animals used.     

Inhibition of Sudan I genotoxicity in human liver-derived HepG2 cells by the antioxidant hydroxytyrosol

The chemoprotective effect of hydroxytyrosol (HT) against Sudan I-induced genotoxicity was investigated in a human hepatoma cell line, HepG2. The comet assay and micronucleus (MN) assay were used to monitor genotoxicity. Intracellular reactive oxygen species (ROS) formation was measured using a fluorescent probe, 2,7-dichlorofluorescein diacetate (DCFH-DA). The levels of oxidative DNA damage and lipid peroxidation were estimated by immunocytochemistry analysis of 8-hydroxydeoxyguanosine (8-OHdG) and by measuring levels of thiobarbituric acid-reactive substances (TBARS), respectively. Intracellular glutathione (GSH) level was estimated by fluorometric methods. The results showed that HT significantly reduced the genotoxicity caused by Sudan I. Furthermore, HT ameliorated lipid pexidation as demonstrated by a reduction in TBARS formation and attenuated GSH depletion in a concentration-dependent manner. It was also found that HT reduced intracellular ROS formation and 8-OHdG level caused by Sudan I. These results strongly suggest that HT has significant protective ability against Sudan I-induced genotoxicity.     

Vitamin complex (ascorbic acid,alpha-tocopherol and beta-carotene) induces micronucleus formation in PBMNC unrelated to ROS production

Abstract

Objectives

To evaluate the correlation between reactive oxygen species (ROS) production and micronucleus formation induced by a vitamin complex in peripheral blood mononuclear cells from healthy people aged between 40 and 85 years old.

Methods

Peripheral blood mononuclear cells (PBMNCs) were purified utilizing ficoll-hypaque gradient. ROS production by PBMNCs was quantified by luminol-dependent chemiluminescence in the presence or in the absence of the vitamin complex. DNA damage in PBMNC by the vitamin complex was detected by the micronucleus technique. Statistical analyses were made with the Student's ‘t’ test and the Pearson correlation. P < 0.05 was considered significant.

Results

The vitamin complex induced MN formation in PBMNC but did not augment ROS production. There was no correlation between ROS production and MN formation either in the presence or in the absence of the vitamin complex.

Discussion

There was no increase in the ROS production in the presence of the vitamin complex. The vitamin complex induced an augmentation in the MN formation. There was no correlation between ROS production and the induction of MN formation. Since no association could be detected between ROS production and MN formation, additional studies are required in order to investigate the possible mechanism of vitamin-induced MN formation.     

Ganoderma lucidum total triterpenes prevent radiation-induced DNA damage and apoptosis in splenic lymphocytes in vitro

The development of radioprotective agents has been the subject of intense research, especially in the field of radiotherapy. In this study, we examined the radioprotective activity of the total triterpenes isolated from Ganoderma lucidum (Fr.) P. Karst in mouse splenic lymphocytes in vitro. Using the MTT assay, Ganoderma triterpenes were found to have no effect on cell viability, indicating that they are non-toxic to splenic lymphocytes. The effect of the total triterpenes on DNA damage and apoptosis induced by radiation was analyzed using the comet assay, DNA ladder assay and flow cytometric analysis. Total triterpenes were found to be highly effective in preventing DNA laddering, even at low concentrations (25μg/ml). The comet assay demonstrated that the G. triterpenes effectively prevented DNA damage, and flow cytometry revealed a reduction in apoptotic cells. The effect of the total triterpenes on intracellular reactive oxygen species (ROS) level and endogenous antioxidant enzyme activity in splenic lymphocytes were determined to elucidate possible radioprotective mechanisms. Total triterpenes successfully reduced the formation of intracellular ROS and enhanced endogenous antioxidant enzyme activity in splenic lymphocytes following irradiation. Thus, these findings indicate that the total triterpenes isolated from G. lucidum have a remarkable ability to protect normal cells from radiation-induced damage, which suggests therapeutic potential.     

Caffeic acid protects human peripheral blood lymphocytes against gamma radiation-induced cellular damage

In the present study, we investigated in vitro radioprotective potential of caffeic acid (CA), a naturally occurring catecholic acid against gamma radiation-induced cellular changes. Different concentrations of CA (5.5, 11, 22, 44, 66, and 88 microM) were incubated with lymphocytes for 30 min prior to gamma-irradiation, and micronuclei (MN) scoring and comet assay were performed to fix the effective concentration of CA against gamma-irradiation. Among all concentrations, 66 microM of CA showed the optimum protection by effectively decreasing the MN frequencies and comet attributes. From the above-mentioned results, 66 microM of CA was selected as the effective concentration and was further used to investigate its radioprotective efficacy. For that purpose, a separate experiment was carried out on the lymphocytes in which lymphocytes were preincubated with CA (66 microM) and were exposed to different doses of radiation (1, 2, 3, and 4 Gy). Genetic damage (MN, dicentric aberration, and comet attributes) and biochemical changes were measured. Gamma-irradiated lymphocytes showed a dose-dependent increase in the genetic damage and thiobarbituric acid reactive substances, accompanied by the significant decrease in the antioxidant status, whereas CA pretreatment positively modulated all the radiation-induced changes through its antioxidant potential. The current study demonstrates that CA is effective in protecting lymphocytes against radiation-induced toxicity and encourages further in vivo study to evaluate radioprotective efficacy of CA.     

Protective effects of acerola juice on genotoxicity induced by iron in vivo

Metal ions such as iron can induce DNA damage by inducing reactive oxygen species (ROS) and oxidative stress. Vitamin C is one of the most widely consumed antioxidants worldwide, present in many fruits and vegetables, especially inMalpighia glabra L., popularly known as acerola, native to Brazil. Acerola is considered a functional fruit due to its high antioxidant properties and phenolic contents, and therefore is consumed to prevent diseases or as adjuvant in treatment strategies. Here, the influence of ripe and unripe acerola juices on iron genotoxicity was analyzed in vivo using the comet assay and micronucleus test. The comet assay results showed that acerola juice exerted no genotoxic or antigenotoxic activity. Neither ripe nor unripe acerola juices were mutagenic to animals treated with juices, in micronucleus test. However, when compared to iron group, the pre-treatment with acerola juices exerted antimutagenic activity, decreasing significantly micronucleus mean values in bone marrow. Stage of ripeness did not influence the interaction of acerola compounds with DNA, and both ripe and unripe acerola juices exerted protective effect over DNA damage generated by iron.     

杀虫剂啶虫脒和毒死蜱对捕食蜘蛛血细胞DNA的损伤作用

应用蜘蛛血细胞微核试验和单细胞凝胶电泳试验研究了两种杀虫剂啶虫脒和毒死蜱对蜘蛛头胸部和腹部血细胞DNA的损伤作用。结果表明：在啶虫脒和毒死蜱各供试浓度作用下,对蜘蛛血细胞微核率有明显的影响,与对照组相比有显著性差异(p<0.05,p<0.01);且随着两种农药浓度升高,血细胞微核率显著增加,存在明显的剂量-效应关系(啶虫脒浓度与星豹蛛头胸部血细胞微核率相关系数r=0.9284,腹部为r=0.9071;毒死蜱与星豹蛛头胸部血细胞微核率相关系数r=0.9841,腹部为r=0.9793);啶虫脒和毒死蜱对星豹蛛血细胞DNA损伤有明显的剂量-效应关系(啶虫脒浓度与星豹蛛头胸部血细胞DNA损伤相关系数r=0.9838,腹部为r=0.9834;毒死蜱与星豹蛛头胸部血细胞DNA损伤相关系数r=0.9807,腹部为r=0.9659);且两种农药在同种农药同一浓度作用下,对星豹蛛腹部血细胞微核率和DNA损伤程度要明显大于头胸部。     

Occupational genotoxicity risk evaluation through the comet assay and the micronucleus test

The micronucleus (MN) test and the alkaline single cell gel or comet assay were applied to exfoliated cells of the buccal mucous in order to evaluate the genotoxic risk associated with occupational exposure of 10 storage battery renovation workers, and 10 car painters, with age matched controls, in Pelotas, RS, in southern Brazil. In the MN test, 2000 exfoliated buccal cells were analyzed for each individual, while 100 cells were examined in the comet assay. In the comet test, both comet tail length and a damage index were calculated. Highly significant effects of occupational exposure were found with both the MN test and the comet assay (P<0.001). The comet assay was found to be rapid, of simple visualization, and it is a sensitive technique for measuring and analyzing DNA damage in human cells.     

Effects of estradiol and progesterone on the variability of the micronucleus assay

To investigate chromosomal radiosensitivity of lymphocytes the micronucleus (MN) assay has been used for many years. The results of these studies suggest the use of the MN assay as a biomarker for cancer predisposition. However, the MN assay has still some limitations associated with the reproducibility and sensitivity. Especially a high intra-individual variability has been observed. An explanation for this high intra-individual variability is not yet available. In literature it is suggested that the high variability among females is attributable to hormonal status. In this study we investigated if the high intra-individual variability in micronucleus formation in lymphocytes of females after in vitro exposure to ionising radiation is caused by variations in hormone levels of estradiol (E2) and progesterone (PROG). For this, the MN assay was performed on blood samples of 18 healthy women during 7 consecutive weeks while the estradiol and progesterone levels were determined at the same time. The MN assay was also examined in cultures of isolated blood lymphocytes with estradiol or progesterone levels added in vitro. The results demonstrated that estradiol and progesterone levels have no influence on the variations in radiation-induced MN yields observed in blood samples of healthy women. These conclusions were confirmed by the "in vitro" experiments as no correlation between the MN yields and the concentrations of hormones (estradiol or progesterone) added in vitro to isolated lymphocytes cultures was observed.     

Genotoxic effects of silver nanoparticles stimulated by oxidative stress in human normal bronchial epithelial (BEAS-2B) cells

Many classes of silver nanoparticles (Ag-NPs) have been synthesized and widely applied, but the genotoxicity of Ag-NPs and the factors leading to genotoxicity remain unknown. Therefore, the purpose of this study is to elucidate the genotoxic effects of Ag-NPs in lung and the role of oxidative stress on the genotoxic effects of Ag-NPs. For this, Ag-NPs were completely dispersed in medium by sonication and filtration. The Ag-NPs dispersed in medium were 43-260nm in size. We observed distinct uptake of Ag-NPs into BEAS-2B cells. The Ag-NPs aggregates were wrapped with an endocytic vesicle within the cytoplasm and nucleus of BEAS-2B cells. In the comet assay and micronucleus (MN) assay for BEAS-2B cells, Ag-NPs stimulated DNA breakage and MN formation in a dose-dependent manner. The genotoxic effect of Ag-NPs was partially blocked by scavengers. In particular, of the scavengers tested, superoxide dismutase most significantly blocked the genotoxic effects in both the cytokinesis-block MN assay and the comet assay. In the modified comet assay, Ag-NPs induced a significant increase in oxidative DNA damage. Furthermore, in the oxidative stress assay, Ag-NPs significantly increased the reactive oxygen radicals. These results suggest that Ag-NPs have genotoxic effects in BEAS-2B cells and that oxidative stress stimulated by Ag-NPs may be an important factor in their genotoxic effects.     

Comparative analysis of cytotoxic, genotoxic and antioxidant effects of 2,2,4,7-tetramethyl-1,2,3,4-tetrahydroquinoline and ethoxyquin on human lymphocytes

2,2,4,7-Tetramethyl-1,2,3,4-tetrahydroquinoline (THQ) is a new synthetic compound with potential antioxidant activity. In this study, cytotoxic, genotoxic and antioxidant activities of THQ were studied on human lymphocytes with the use of the trypan blue exclusion assay, the TUNEL method, the comet assay and the micronucleus test. The activities of THQ were compared with those of a structurally similar compound-ethoxyquin (1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline, EQ), which is used in animal feeds as a preservative. Cytotoxic effects of THQ were observed after 1-h treatment at the concentration of 500 microM and after 24-h treatments at the concentrations of 250-500 microM. Although the micronucleus test did not reveal a genotoxic effect of THQ, in the comet assay the statistically significant increase in DNA damage was observed as compared with the control. On the other hand, the protection of human lymphocytes against DNA damage induced by hydrogen peroxide suggests an antioxidant activity of THQ. The comparative analysis of THQ and EQ activities performed in these studies revealed that THQ was less cytotoxic and less genotoxic than EQ. Slightly lower antioxidant activity of THQ was also shown in the comet assay when it was used at the lower studied doses (1-5 microM), but for the highest one (10 microM) its efficiency was similar to that of EQ. In the micronucleus assay THQ was more effective than EQ in protecting the cultured lymphocytes from clastogenicity of H2O2. We believe that THQ is worthy of further detailed studies on its antioxidant properties to confirm its usefulness as a preservative.     

Intervention of astaxanthin against cyclophosphamide-induced oxidative stress and DNA damage: A study in mice

Astaxanthin, a natural and nutritional red carotenoid pigment, is used as a dietary supplement. The intention of the present study was to investigate the beneficial effects of dietary pigment astaxanthin, against cyclophosphamide-induced oxidative stress and DNA damage. The end points of evaluation of the study included: (a) malondialdehyde, glutathione and superoxide dismutase concentration in liver to detect oxidative stress; (b) normal and modified alkaline comet assays (the latter includes lesion-specific enzymes formamidopyrimidine-DNA glycosylase and endonuclease-III) to detect normal and oxidative stress-induced DNA damage by cyclophosphamide in the mouse bone marrow and the peripheral blood lymphocytes. In addition, micronucleus assay and chromosomal aberration test capable of detecting the DNA damage were also carried out in peripheral blood and bone marrow of mice. Cyclophosphamide (100 mg/kg intra-peritoneal) treatment led to significant increase in liver malondialdehyde and decreased the antioxidant enzymes glutathione and superoxide dismutase. Further, cyclophosphamide also significantly increased the DNA damage as observed from normal and modified comet assays as well as micronucleus and chromosomal aberration assay. Pre-treatment with astaxanthin (12.5, 25 and 50 mg/kg/day for 5 days per oral) resulted in the restoration of oxidative stress markers such as malondialdehyde, glutathione and superoxide dismutase in liver. The amelioration of oxidative stress with astaxanthin pre-treatment correlated well with the decreased DNA damage as evident from normal and modified alkaline comet assays of bone marrow cells and peripheral blood lymphocytes. Further astaxanthin pre-treatment also reduced the frequency of chromosomal breakage and micronucleus formation in the mouse bone marrow cells and peripheral blood reticulocytes. It is thus concluded that pre-treatment with astaxanthin attenuates cyclophosphamide-induced oxidative stress and subsequent DNA damage in mice and it can be used as a chemoprotective agent against the toxicity of anticancer drug cyclophosphamide.     

DNA damage and repair in lymphocytes of normal individuals and cancer patients: studies by the comet assay and micronucleus tests

A population study is reported in which the DNA damage induced by g-radiation (2 Gy) and the kinetics of the subsequent repair were estimated by the comet and micronucleus assays in isolated lymphocytes of 82 healthy donors and patients with head and neck cancer before radiotherapy. The parameters of background and radiation-induced DNA damage, rate of repair, and residual non-repaired damage were measured by comet assay, and the repair kinetics for every donor were computer-fitted to an exponential curve. The level of background DNA damage before irradiation measured by comet assay as well as the level of micronuclei were significantly higher in the head and neck cancer patient group than in the healthy donors, while the parameters of repair were widely scattered in both groups. Cancer patient group contained significantly more individuals, whose irradiated lymphocytes showed high DNA damage, low repair rate and high non-repaired DNA damage level. Lymphocytes of donors belonging to this subgroup showed significantly lower inhibition of cell cycle after irradiation.     

Protection against X-ray radiation-induced cellular damage of human peripheral blood lymphocytes by an aminothiazole derivative of dendrodoine

The present study was aimed to evaluate the radioprotective efficacy of dendrodoine analog (DA), an aminothiazole derivative against X-ray radiation-induced cellular damage in cultured human peripheral blood lymphocytes. Different concentrations of DA (2, 4, 6, 8, 10 μg/ml or 6.15, 12.29, 18.44, 24.59, 30.73 μM) were pre-incubated with lymphocytes for 30 min prior to irradiation [4 Gy] and the micronuclei (MN) scoring and comet assay were performed to fix the effective concentration of DA against 4 Gy irradiation-induced cellular damage. The results indicated that among all the concentrations, 6 μg/ml concentration of DA showed optimum protection by effectively decreasing the MN frequencies and comet attributes. Based on the above results, 6 μg/ml concentration of DA was fixed as the effective dose to further investigate its radioprotective efficacy. This was carried out by pre-incubating the lymphocytes with 6 μg/ml concentration of DA followed by exposure of the lymphocytes to different doses (1, 2, 3 and 4 Gy) of radiation and investigating the radiation-induced genetic damage (MN, comet assay, DNA fragmentation assay) and biochemical changes (changes in the level of enzymic and non-enzymic antioxidants, lipid peroxidation). The results indicated a dose-dependent increase in both genetic damage and thiobarbituric acid reactive substances (TBARS), accompanied by a significant decrease in the antioxidant status in the irradiated groups compared to DA treated groups which modulated the toxic effects through its antioxidant potential. Thus the current study shows DA to be an effective radioprotector against X-ray radiation induced in vitro cellular damage in lymphocytes.     

Use of the alkaline comet assay for the detection of transplacental genotoxins in newborn mice

Several lines of evidence show that in utero exposure to different toxicants has greater consequences than their exposure during adult life. This may be due to involvement of critical developmental stages, physiological immaturity and the long later-life span over which disease may initiate, develop and progress. The in vivo alkaline comet (single-cell gel electrophoresis) assay has been favoured by the scientific community for the evaluation of genotoxins. The objective of this study was to demonstrate the suitability of alkaline comet assay in detecting transplacental genotoxins using newborn mice. Here, we report the successful use of the comet assay in detecting multi-organ genotoxicity of known transplacental genotoxins in newborn mice. Three well known transplacental genotoxic agents, cyclophosphamide (CP), mitomycin-C (MMC) and zidovudine (AZT) were tested in pregnant Swiss mice. These compounds were administered in the late gestational period (16-20th days of pregnancy) and the comet assay was performed with lymphocytes, bone marrow, liver and kidney cells of newborn mice. Significant DNA damage was observed in all the tissues with tested transplacental genotoxins. The results of the comet assay were confirmed by the micronucleus (MN) assay of the peripheral blood of newborn mice. The results of this study provide sufficient evidence that the comet assay can be applied successfully for the detection of transplacental genotoxins in newborn mice.     

Protective<Emphasis Type="Italic">in vivo</Emphasis> effect of curcumin on copper genotoxicity evaluated by comet and micronucleus assays

Curcumin is a phytochemical with antiinflammatory, antioxidant and anticarcinogenic activities. Apparently, curcumin is not genotoxic in vivo, but in vitro copper and curcumin interactions induce genetic damage. The aim of this study was to test if in vivo copper excess induces DNA damage measured by comet and micronucleus assays in the presence of curcumin. We tested 0.2% curcumin in Balb-C mice at normal (13 ppm) and high (65, 130 and 390 ppm) copper ion concentrations. The comet and micronucleus assays were performed 48 hr after chemical application. Comet tail length in animals treated with 0.2% curcumin was not significantly different from the control. Animals exposed to copper cations (up to 390 ppm) exhibited higher oxidative DNA damage. Curcumin reduced the DNA damage induced by 390 ppm copper. We observed statistically significant increase in damage in individuals exposed to 390 ppm copper versus the control or curcumin groups, which was lowered by the presence of curcumin. Qualitative data on comets evidenced that cells from individuals exposed to 390 ppm copper had longer tails (categories 3 and 4) than in 390 ppm copper + curcumin. A statistically significant increase in frequency of micronucleated erythrocytes (MNE/10000TE) was observed only in 390 ppm copper versus the control and curcumin alone. Also cytotoxicity measured as the frequency of polychromatic erythrocytes (PE/1000TE) was attributable to 390 ppm copper. The lowest cytotoxic effect observed was attributed to curcumin. In vivo exposure to 0.2% curcumin for 48 hr did not cause genomic damage, while 390 ppm copper was genotoxic, but DNA damage induced by 390 ppm copper was diminished by curcumin. Curcumin seems to exert a genoprotective effect against DNA damage induced by high concentrations of copper cations. The comet and micronucleus assays prove to be suitable tools to detect DNA damage by copper in the presence of curcumin.