Cytogenotoxic potential of a hazardous material, polystyrene microparticles on Allium cepa L.

Plastic pollution represents a global concern for the biodiversity conservation, ecosystem and public health. The polystyrene is one of the dominant pollutants in both terrestrial and aquatic ecosystem. This work measured the hazardous nature of 100 nm micropolystyrene (MPS) using 25, 50, 100, 200, and 400 mg/L concentrations in terms of oxidative stress, morphotoxicity and cytogenotoxicity in Allium cepa. The results were compared with the positive control (PC) (400 mg/L chlorpyrifos). MPS significantly (p < 0.05) reduced the root length while induced the production of hydroxyl, superoxide radicals with a concomitant increase in DPPH scavenging activity and lipid peroxidation as compared to the negative control. The significant decrease in mitotic index with respect to the negative control (MI: 23.855 ±â€¯5.336 %; lowest MI: 3.88 ±â€¯1.042 %) showed the cytotoxic nature of MPS. Genotoxicity was assessed by various chromosomal and nuclear aberrations. The highest 3.029 ±â€¯0.403 % (PC: 3.09 ±â€¯0.535 %) chromosomal abnormality index and 2.31 ±â€¯0.338 % (PC: 1.178 ±â€¯0.095 %) nuclear abnormality index were observed. MPS down-regulated the expression of plant CDKA encoding gene: cdc2, an important cell cycle regulator. The overall results indicated that MPS could induce cytogenotoxicity through the exacerbation of ROS production and inhibition of cdc2.

Oxidative Stress and Genomic Damage Induced In Vitro in Human Peripheral Blood by Two Preventive Treatments of Iron Deficiency Anemia.

Iron deficiency is the most prevalent nutritional deficiency and the main cause of anemia worldwide. Since children aged 6-24 months are among the most vulnerable groups at risk, daily supplementation with ferrous sulfate is recommended by the Argentine Society of Pediatrics as preventive treatment of anemia. However, a single weekly dose would have fewer adverse side effects and has been therefore proposed as an alternative treatment. Ferrous sulfate is known by its pro-oxidative properties, which may lead to increased oxidative stress as well as lipid, protein, and DNA damage. We analyzed the effect of daily and weekly preventive treatment of iron deficiency anemia (IDA) on cell viability, oxidative stress, chromosome, and cytomolecular damage in peripheral blood cultured in vitro. The study protocol included the following: untreated negative control; bleomycin, hydrogen peroxide, or ethanol-treated positive control; daily 0.14 mg ferrous sulfate-supplemented group; and weekly 0.55 mg ferrous sulfate-supplemented group. We assessed cell viability (methyl-thiazolyl-tetrazolium and neutral red assays), lipid peroxidation (thiobarbituric acid reactive substances assay), antioxidant response (superoxide dismutase and catalase enzyme analysis), chromosome damage (cytokinesis-blocked micronucleus cytome assay), and cytomolecular damage (comet assay). Lipid peroxidation, antioxidant response, and chromosome and cytomolecular damage decreased after weekly ferrous sulfate supplementation (p < 0.05), suggesting less oxygen free radical production and decreased oxidative stress and genomic damage. Such a decrease in oxidative stress and genomic damage in vitro positions weekly supplementation as a better alternative for IDA treatment. Further studies in vivo would be necessary to corroborate whether weekly supplementation could improve IDA preventive treatment compliance in children.

Geraniol and linalool anticandidal activity, genotoxic potential and embryotoxic effect on zebrafish.

AIM: Geraniol and linalool are major constituents of the essential oils of medicinal plants. MATERIALS & METHODS: Antifungal activity of geraniol and linalool were evaluated against five Candida species. The genotoxicity of these compounds was evaluated by the cytokinesis-block micronucleus test, and the embryotoxic assays use zebrafish model. RESULTS: Geraniol and linalool inhibited Candida growth, but geraniol was more effective. The geraniol at concentration of 800 µg/ml and the linalool at concentration of 125 µg/ml significantly increased chromosome damage. Geraniol was more toxic to zebrafish embryo than linalool: LC50 values were 31.3 and 193.3 µg/ml, respectively. CONCLUSION: Geraniol and linalool have anticandidal activity, but they also exert genotoxic and embryotoxic effects at the highest tested concentrations.

A high-throughput assay to identify modifiers of premature chromosome condensation.

Premature chromosome condensation (PCC) is a consequence of early mitotic entry, where mitosis begins before completion of DNA replication. Previously we have identified mutations in MCPH1, a DNA damage response and potential tumor suppressor gene, as a cause of primary microcephaly and PCC. Here we describe a high-throughput assay to identify modifiers of PCC. Reverse transfection of control siRNA followed by a forward transfection of MCPH1 small interfering RNA (siRNA) was performed to induce PCC. Condensin II subunits CAPG2 and CAPH2 were validated as PCC modifiers and therefore positive controls. Cell nuclei were detected by DAPI staining using an Operetta imaging system. PCC and nuclei number were determined using Columbus analysis software. Two batches of nine plates were used to determine assay efficacy. Each plate contained four negative (nontargeting) and eight positive control siRNAs. Mean % PCC was 12.35% (n = 72) for negative controls and 4.25% (n = 144) for positive controls. Overall false-positive and false-negative rates were 0% (n = 72) and 2.1% (n = 144), respectively. This assay is currently being used to screen a human druggable genome siRNA library to identify novel therapeutic targets for cancer treatment. The assay can also be used to identify novel compounds and genes that induce PCC.

DNA topoisomerase II-dependent control of the cell cycle progression in root meristems of Allium cepa.

The catalytic ability of DNA topoisomerases (Topo) to generate short-term DNA breaks allow these enzymes to play crucial functions in managing DNA topology during S-phase replication, transcription, and chromatin-remodelling processes required to achieve commitment for the onset and transition through mitosis. Our experiments on root meristem cells of onion (Allium cepa) were designed to gain insight into the contribution of Topo II to plant-specific progression throughout interphase and mitosis. Irrespective of the position of the cell in interphase, the immunofluorescence of Topo II revealed similar nuclear labelling pattern with well defined signals dispersed in the nucleoplasm and the cortical zone of the nucleolus. Only weak labelling was detected in metaphase and anaphase chromosomes. Experiments with two potent anti-Topo II agents, doxorubicin (DOX, an anthracycline) and a bisdioxopiperazine derivative, ICRF-193, suggest that the inhibition-mediated increase in Topo II immunofluorescence may represent a compensatory mechanism, by which an up-regulated expression of the enzyme tends to counteract the drug-induced loss of indispensable catalytic and relaxation functions. γ-H2AX immunolabelling seems to indicate that both DOX- and ICRF-193-induced alterations in cell cycle progression reflect primarily the activity of the G2/M DNA damage checkpoint. Our findings provide evidence for the plant-specific cell cycle control mechanism induced by Topo II inhibitors under DNA stress conditions.

Characterization of Abcc4 gene amplification in stepwise-selected mouse J774 macrophages resistant to the topoisomerase II inhibitor ciprofloxacin.

Exposure of J774 mouse macrophages to stepwise increasing concentrations of ciprofloxacin, an antibiotic inhibiting bacterial topoisomerases, selects for resistant cells that overexpress the efflux transporter Abcc4 (Marquez et al. [2009] Antimicrob. Agents Chemother. 53: 2410-2416), encoded by the Abcc4 gene located on Chromosome 14qE4. In this study, we report the genomic alterations occurring along the selection process. Abcc4 expression progressively increased upon selection rounds, with exponential changes observed between cells exposed to 150 and 200 µM of ciprofloxacin, accompanied by a commensurate decrease in ciprofloxacin accumulation. Molecular cytogenetics experiments showed that this overexpression is linked to Abcc4 gene overrepresentation, grading from a partial trisomy of Chr 14 at the first step of selection (cells exposed to 100 µM ciprofloxacin), to low-level amplifications (around three copies) of Abcc4 locus on 1 or 2 Chr 14 (cells exposed to 150 µM ciprofloxacin), followed by high-level amplification of Abcc4 as homogeneous staining region (hsr), inserted on 3 different derivative Chromosomes (cells exposed to 200 µM ciprofloxacin). In revertant cells obtained after more than 60 passages of culture without drug, the Abcc4 hsr amplification was lost in approx. 70% of the population. These data suggest that exposing cells to sufficient concentrations of an antibiotic with low affinity for eukaryotic topoisomerases can cause major genomic alterations that may lead to the overexpression of the transporter responsible for its efflux. Gene amplification appears therefore as a mechanism of resistance that can be triggered by non-anticancer agents but contribute to cross-resistance, and is partially and slowly reversible.

[Genoprotective activities of the oils from leaves and fruits of Fagus orientalis Lipsky].

The antimutagenic activities of the oils obtained from leaves and fruits of Fagus orientalis have been shown in experiments with spontaneous and mutagen- and ageing-induced variability. The aberrations of chromosomes in the meristematic cells of the Allium cepa L., Vicia faba L., Triticum aestivum L., and marrow cells of Vistar rats as well as Arabidopsis thaliana gene mutations have been mobilized as experimental tests.

Whole body radioprotective activity of an acetone-water extract from the seedpod of Nelumbo nucifera Gaertn. seedpod.

Procyanidins extracted with acetone-water from lotus (Nelumbo nucifera Gaertn.) seedpod (LSPCs) were evaluated for in vivo radioprotective activity against whole body gamma irradiation in Swiss albino mice. Pretreated with LSPCs 200 mg/kg by intragastric (i.g.) for 15 days was found to be the most effective dose in preventing radiation sickness, reducing radiation-induced mortality, increasing mean survival time and elevating radiation median lethal dose (LD(50)) from 8.9 to 10.5 Gy, indicating a dose modifying factor (DMF) of 1.18. Further, administered LSPCs at a dose of 200 mg/kg could effectively maintain spleen index close to normal, stimulate endogenous spleen colony forming units, promote the levels of red blood cells (RBC), white blood cells (WBC), platelets and hemoglobin in peripheral blood, and prevent spleen and skin damage in irradiated mice, reduce the level of radiation-induced micronucleated polychromatic erythrocytes in bone marrow, maintain the polychromatic erythrocytes (PCE) and normochromatic erythrocytes (NCE) ratio (P/N ratio) and significantly decrease bone marrow chromosomal damage. Alternatively, pretreated with LSPCs (200 mg/kg) significantly decreased the lipid peroxidation (LPO) level, and elevated the activities of endogenous antioxidant enzymes in liver after irradiation. Thus LSPCs possess a strong whole body radioprotective activity, and it may be used as a radioprotector.

Aldosterone causes DNA strand breaks and chromosomal damage in renal cells, which are prevented by mineralocorticoid receptor antagonists.

Epidemiological studies exploring the connection between hypertension and cancer incidence find a higher cancer mortality in hypertensive patients, particularly elevated in hypertension associated with a stimulation of the renin-angiotensin-aldosterone system. Primary aldosteronism, with plasma aldosterone levels between 0.5 and 1 nM (18-36 ng/dL) and local aldosterone levels up to 500 nM (18,000 ng/dL), is now recognised as a more common cause for hypertension. We recently found angiotensin II to be genotoxic due to its induction of oxidative stress. Since aldosterone in higher concentrations also has oxidative effects, its potential genotoxic action in pig LLC-PK1 cells with properties of proximal tubules was analysed. DNA damage was evaluated by two test systems: the comet assay, and the micronucleus frequency test. The results showed that aldosterone concentrations starting from 10 nM (360 ng/dL) caused a significant increase of DNA damage monitored with the comet assay in LLC-PK1, while there was no change in cell vitality and proliferation. The micronucleus frequency test revealed that 10 nM aldosterone also leads to the formation of micronuclei. Furthermore, the formation of superoxide radicals in the cells by this aldosterone concentration could be detected with the superoxide-specific stain dihydroethidium. Further evidence for oxidative stress-induced DNA damage was its reversibility by the antioxidants tempol and catalase. Addition of the steroidal mineralocorticoid receptor antagonist spironolactone or the novel selective nonsteroidal antagonist (R)-BR-4628 reduced the DNA damage and the amount of superoxide radicals indicating a receptor-dependent process.

Mutagenic and genotoxic effects of Baccharis dracunculifolia (D.C.).

Baccharis dracunculifolia (D.C.) (Asteraceae), a native plant to Brazil known as "vassourinha" or "alecrim-do-campo", is the most important botanical source of a Brazilian propolis called green propolis. The leaf extracts of this plant have been used to treat liver and digestive disorders. It has been recognized that green propolis can induce mutagenic effects at high doses, but no study reporting possible mutagenic effects by Baccharis dracunculifolia extracts in the maximum tolerated dose has been conducted. The aim of the present study was to investigate the genotoxic and mutagenic effects of this plant in vivo. Adult CF-1 mice were treated with 0.5g/kg, 1.0g/kg or 2.0g/kg of an aqueous extract of Baccharis dracunculifolia by gavage for 3 consecutive days. Blood and liver samples were collected to detect DNA damage using the comet assay, while bone marrow samples were used to assess chromosome mutations by the micronucleus test. The extract increased the DNA damage in blood and liver tissues and the frequency of micronucleus in bone marrow. These findings suggest genotoxic and mutagenic effects of Baccharis dracunculifolia comparable to green propolis in mice.

Cytogenetic investigation of chromosomal aberrations in cells treated with plantamajoside from Plantago asiatica.

Plantago asiatica is a member of the Plantaginaceae family, and is widely distributed in East Asia. In our previous work, a single active compound, plantamajoside was isolated and confirmed to have glycation inhibitory activity, and did not possess toxicity during a 90 day repeated oral toxicity test in rats. In the present study, a chromosomal aberration test was performed to investigate the genotoxicity of plantamajoside. From the results of the cytotoxicity test, plantamajoside proved to be less toxic when it was treated combined with S9 cell fractions. However, there was a significant increase in structural aberrations during the short-term treatment of plantamajoside at its highest dose (5000 microg/mL) even when combined with S9. This seems to have been a natural phenomenon due to the very high dose of plantamajoside that was used. However, to confirm the safety of plantamajoside for its potential use as a phytochemical agent in health products, additional mutagenicity tests are necessary.

Verminoside- and verbascoside-induced genotoxicity on human lymphocytes: involvement of PARP-1 and p53 proteins.

Verminoside and verbascoside are natural compounds present in plants used in traditional medicine. They exhibit several biological activities including anti-inflammatory, anti-bacterial and anti-tumor properties. The potential applications of these compounds as ingredients in pharmaceutical formulations and cosmetics prompted us to investigate on cytotoxic and genotoxic activity of verminoside and verbascoside on human lymphocytes using genetic toxicity assays recommended in preclinical studies by the US Food and Drug Administration (FDA). We analyzed chromosome aberrations (CAs) and sister chromatid exchanges (SCEs) as well as the mitotic index (MI) and cell viability after the treatments with verminoside and verbascoside. This report is the first to clearly demonstrate a significant increase of structural CAs and SCEs on normal human lymphocytes associated with a reduction of the MI in both verminoside- and verbascoside-treated cells. Moreover, we observed enhanced protein expression levels of PARP-1 and p53 that are key regulatory proteins involved in cell proliferation and DNA repair. Interestingly, mass spectrometric analysis of the compounds in the culture supernatants also showed that verminoside remained unchanged during the culture period while verbascoside was hydrolyzed to its derivative, caffeic acid and the last one seems to be responsible for the observed biological activity.

Radioprotective effect of sulfasalazine on mouse bone marrow chromosomes.

Sulfasalazine (SAZ), a prescribed drug for inflammatory bowel disease, is a potent scavenger of reactive oxygen species. The present study was undertaken to ascertain its ability to protect against gamma radiation-induced damage. Acute toxicity of the drug was studied taking 24-h, 72-h and 30-day mortality after a single intraperitoneal injection of 400-1200 mg/kg body weight (b.wt.) of the drug. The drug LD(50) for 24- and 72-h/30-day survival were found to be 933 and 676 mg/kg b.wt., respectively. The optimum time of drug administration and drug dose-dependent effect on in vivo radiation protection of bone marrow chromosomes was studied in mice. Injection of 30-180 mg/kg SAZ 30 min before gamma irradiation (RT) with 4 Gy produced a significant dose-dependent reduction in the RT-induced percent aberrant metaphases and in the frequency of micronucleated erythrocytes at 24 h after exposure, with a corresponding decrease in the different types of aberrations. The optimum dose for protection without drug toxicity was 120 mg/kg b.wt. At this dose, SAZ produced >60% reduction in the RT-induced percent aberrant metaphases and micronucleated erythrocytes. SAZ also produced a significant increase in the ratio of polychromatic erythrocytes to normochromatic erythrocytes from that of irradiated control. Injection of 120 mg/kg of the drug 60 or 30 min before or within 15 min after 4 Gy whole-body RT resulted in a significant decrease in the percent of aberrant metaphases and in the frequency of micronucleated erythrocytes at 24 h post-irradiation; the maximum effect was seen when the drug was administered 30 min before irradiation. These results show that SAZ protect mice against RT-induced chromosomal damage and cell cycle progression delay. SAZ also protected plasmid DNA (pGEM-7Zf) against Fenton's reactant-induced breaks, suggesting free radical scavenging as one of the possible mechanism for radiation protection.

Protective effects of Hibiscus tiliaceus L. methanolic extract to V79 cells against cytotoxicity and genotoxicity induced by hydrogen peroxide and tert-butyl-hydroperoxide.

Plants of the genus Hibiscus thrives produce a diversity of molecules with bioactive properties. In a previous study of Hibiscus tiliaceus L. methanolic extract (HME) using bacteria and yeast, as test media, it has been shown that HME strongly inhibited the mutagenic action of H(2)O(2) or tert-butyl-hydroperoxide (t-BHP). Here, our interest is to evaluate the genotoxicity and the antigenotoxic/antimutagenic properties of HME using oxidative challenge with H(2)O(2) and t-BHP in V79 cells. We determined cytotoxicity using clonal survival assay; evaluated DNA damage using the comet assay and the micronucleus test in binucleated cells besides of the lipid peroxidation degree and the reduced glutathione content. We examined the ability of HME in quenching hydroxyl radical by means of a HPLC-based method utilizing the hypoxanthine/xanthine oxidase assay. At concentrations ranging from 0.001 to 0.1mg/mL, HME was not cytotoxic, genotoxic or mutagenic. Treatment with non-cytotoxic concentrations of HME increased cell survival after H(2)O(2) and t-BHP exposure and prevented DNA damage. The pre-treatment with HME also was able to decrease the mutagenic effect of these genotoxins, evaluated using the micronucleus test. HME prevented the increase in lipid peroxidation and decrease in GSH content in response to the oxidative challenge. Therefore, the ability in preventing against H(2)O(2)- and t-BHP-induced GSH depletion and lipid peroxidation was probably a major contribution to the cytoprotective effects. Moreover, HME acts as a hydroxyl radical scavenger. In summary, HME did not have a harmful or inhibitory effect on the growth of V79 cells and presented antioxidant activity, consequently, both antigenotoxic and antimutagenic effects against oxidative DNA damage.

Low folate status increases chromosomal damage by X-ray irradiation.

PURPOSE: To examine how folate status influences chromosomal damage following X-ray irradiation. MATERIAL AND METHODS: In an animal study, mice were fed either a low, basal, or high folic acid diet (0, 2, or 40 mg/kg diet, respectively) for 4 weeks, and then given total body irradiation (TBI) at 0.5 Gy. In a human study, subjects were supplemented with folic acid (800 microg/day) for 2 weeks and their peripheral blood was irradiated at 0.5 Gy in vitro. Chromosomal damage was determined by micronucleus assay. RESULTS: In an animal study, TBI-induced chromosomal damage was higher and folate concentration was lower in the bone marrow of the low folic acid group compared to the other two diet groups. The chromosomal damage and folate concentration were comparable between the basal and high folic acid groups. TBI administered to mice decreased folate in the plasma, erythrocyte and bone marrow. In a human study, supplementation with folic acid increased plasma folate, but did not influence either plasma homocysteine or X-ray-induced chromosomal damage in lymphocytes. CONCLUSION: Low folate status increases susceptibility to X-ray-induced chromosomal damage, but excessive folic acid supplementation under normal conditions yields no further protection due to folate saturation in the target tissue.

Evaluation of clastogenic potential of the antimalarial plant Solanum nudum.

Compounds isolated from Solanum nudum have shown in vitro antimalarial activity against the FCB-2 strain of Plasmodium falciparum. Diosgenone (C27H40O3) the main component isolated from the hexane extract and an aqueous extract were evaluated to measure their clastogenic potential using the micronucleus test. Three concentrations (16, 32 and 64 g/kg of weight) of the aqueous extract were administered intraperitoneally into mice, (the highest concentration corresponded to 80% LD50) and diosgenone solubilized in olive oil was inoculated at the highest concentration possible (11.187 g/kg of weight). After administration of the compounds, no induction of micronucleus was observed either in polychromatic or normochromatic erythrocytes. Interestingly, a reduction of 51% in the young/mature erythrocytes ratio was seen in cells treated with aqueous extract. We conclude that neither diosgenone nor the aqueous extract have clastogenic activity, and that the aqueous extract showed some toxicity at the above mentioned concentrations. These results are significant since diosgenone could be a new therapeutic alternative for the treatment of malaria.

Radioprotective effects of citrus extract against gamma-irradiation in mouse bone marrow cells.

The radioprotective effects of citrus extract were investigated by using the micronucleus test for anticlastogenic and cell proliferation activity. A single intraperitoneal (i.p.) injection of citrus extract (Citrus aurantium var. amara) at 250, 500, 1000 mg/kg body weight 1 h prior to gamma-ray irradiation (1.5 Gy) reduced the frequencies of micronucleated polychromatic erythrocytes (MnPCE(S)) and normochromatic erythrocytes (MnNCE (S)). All three doses of citrus extract significantly reduced the frequencies of MnPCEs and MnNCEs in mice bone marrow compared to non-drug-treated irradiated control (p < 0.005-0.05). The optimum dose for protection in mouse was 250 mg/kg to protect mice bone marrow 2.2-fold against the side effects of gamma-irradiation with respect to the non-drug-treated irradiated control. The flavonoids were contained in citrus extract, probably to show protective activity, and reduced the clastogenic effect of radiation on mice bone marrow. Therefore fruits and vegetables contain flavonoids to be useful as protective effects under such stress conditions as irradiation.

Cytogenetic toxicity of neem.

The cytogenetic toxicity of the leaf extract of neem was evaluated in murine germ cells. The extract was found to induce structural and numerical changes in the spermatocyte chromosomes as well as synaptic disturbances in them at their first metaphase. A significant increase in the frequency of sperms with abnormal head morphology and the decrease in mean sperm count were also observed. This spermatotoxic effect of the neem extract corroborates its germ cell mutagenicity. The possible role of azadirachtin, the most active principle present in the neem extract, in producing the observed genotoxic effect is discussed.

Lack of in vivo clastogenic activity of grape seed and grape skin extracts in a mouse micronucleus assay.

Meganatural brand grape seed extract (GSE) and grape skin extract (GSKE), containing proanthocyanidin polyphenolic compounds, are intended for use in food as functional ingredients exhibiting antioxidant activity. Proanthocyanidins, as well as the minor constituent phenolic compounds in GSE and GSKE, are present naturally in many foods such as fruits, vegetables, chocolate, tea, etc., and on average people consume 460-1000 mg/day of these combined substances. While some polyphenolic compounds, tested individually, have demonstrated antitumorigenic or antipromotional activity, at least one minor component of GSE and GSKE, quercitin, has exhibited positive activity in Salmonella and other in vitro mutagenicity assays. As part of a program to investigate the safety of GSE and GSKE, these products were tested for in vivo clastogenic activity and/or disruption of the mitotic apparatus by detecting micronuclei in polychromatic erythrocyte (PCE) cells in Crl:CD-1(ICR) BR mouse bone marrow. The appropriate test article was dissolved in 0.5% carboxymethylcellulose and dosed by oral gavage to five males/test article/dose level/harvest time point. Animals were dosed at 500, 1000 and 2000 mg/kg. Five animals dosed with either test article at 500, 1000 and 2000 mg/kg dose levels and five animals dosed with the cyclophosphamide (80 mg/kg) positive control were euthanized approximately 24 h after dosing for extraction of bone marrow. Five animals dosed with either test article at the 2000 mg/kg dose level and five animals dosed with the vehicle control article were euthanized approximately 24 and 48 h after dosing for extraction of bone marrow. At least 2000 PCEs per animal were analyzed for frequency of micronuclei. Cytotoxicity was assessed by scoring the number of PCEs and normochromatic erythrocytes (NCEs) in at least the first 500 erythrocytes for each animal. For both GSE and GSKE, no statistically significant increase in micronucleated PCEs was observed at any dose level or harvest time point. GSE produced indication of cytotoxicity (decreased PCE:NCE ratio) at the 2000 mg/kg dose level for the 48-h harvest time point, confirming that the test article reached the target bone marrow in significant amount. Meganatural GSE and Meganatural GSKE were evaluated as negative in the mouse bone marrow micronucleus assay under the conditions of this assay.

The protective effect of calcium against genotoxicity of lead acetate administration on bone marrow and spermatocyte cells of mice in vivo.

The protective effect of calcium given orally by gavage with two doses (40 and 80mg/kg body weight) was evaluated against clastogenecity induced by lead acetate with two concentrations (200 and 400mg/kg diet) on bone marrow and spermatocyte cells of mice in vivo. The parameter screened was percentage of chromosomal aberrations with and without gaps and sperm abnormalities. Statistical analyses indicated the protection efficacy of calcium with the high dose rather than the other in both types of mouse cells. The observation from the laboratory tests, dealing that lead acetate can be considered as an environmental genotoxic material. We recommended that it must be administered of calcium (as calcium chloride) as a protective agent to reduce the genotoxic effect of lead in the somatic and germ cells.