Evaluation of protective effects of sulforaphane on DNA damage caused by exposure to low levels of pesticide mixture using comet assay

The objective of the study was to evaluate the potential risk of DNA damage due to exposure to a mixture of the most widely used pesticides, namely endosulfan, chlorpyriphos and thiram at an environmentally relevant concentration (5 microM each) and the DNA protective capacity of sulforaphane (SFN) (10-30 microg/mL). DNA damage in human lymphocytes was ascertained with Single Cell Gel Electrophoresis (SCGE), also called Comet Assay. For positive control, H(2)O(2) at 100 mM was used. The pesticide mixture produced DNA damage at the concentration used in the lymphocytes. SFN was able to offer a statistically significant (P < 0.01), concentration-dependant protection to DNA damage between 10-20 microg/mL in both the pre-incubation and co-incubation strategies. The results indicate that exposure to low levels of these pesticide mixtures can induce DNA damage, and the presence of SFN in diet may reduce the incidence of genetic damage, especially in farm workers. However, it is not clear whether SFN is involved in quenching of the free radicals generated by the pesticide mixture or it is involved in DNA repair mechanism.

L-ascorbic acid ameliorates postnatal endosulfan induced testicular damage in rats

The aim of the present study is to investigate the effect of L-ascorbic acid on postnatal exposure of endosulfan induced testis damage in the rat. Four groups of seven day old male Wistar rats were treated with 3, 6, 9 and 12 mg/kg endosulfan orally (10 pups/group), from postnatal day 7 to 60 at intervals of 24 h. For 2 more groups (n = 10/group), endosulfan (9 mg/kg and 12 mg/kg) was administered along with L-ascorbic acid (20 mg/kg). The sperm morphology, sperm count and sperm motility was analyzed in all the groups on postnatal day 70. Endosulfan significantly affected the testicular function enhancing the incidence of abnormal spermatozoa, decreasing the sperm count and sperm motility in a dose dependent manner. Abnormalities were of both head and tail and increase in their frequency was more than two-fold of the control value. Sperm count abruptly decreased in 12 mg/kg group and sperm motility decreased up to 50% of the control value. L-ascorbic acid has nullified the toxic effects of the pesticide significantly, but not to the control level. Endosulfan induces the testicular damage following postnatal exposure and L-ascorbic acid prevents the adverse effects considerably in the rat.

Antimutagenic efficacy of higher doses of vitamin C

Vitamin C, when administered concurrently with a pesticide (endosulfan, phosphamidon or mancozeb), could significantly decrease the frequency of pesticide-induced clastogenic and mitosis-disruptive changes in the bone marrow cells of young Swiss albino mice. Of the three doses (10, 20 or 40 mg/kg b.wt./day) of the vitamin, the one which is double the human therapeutic dose (20 mg/kg b.wt./day) was most effective as an antimutagen to be followed by 40 mg and 10 mg. None of these doses of vitamin C showed any genotoxicity of their own for the parameters studied here.

Neonatal endosulfan neurotoxicity: behavioral and biochemical changes in rat pups

Repeated administration of 0.5 mg/kg endosulfan (for 5 days a week) for 3 and 5 weeks of age, produced no significant alteration either in the binding of 3H-5HT to frontal cortical membranes or in foot-shock induced fighting behavior. However, administration of 1 mg/kg endosulfan for 5 weeks caused a significant increase in 3H-5HT binding as well as in foot shock induced aggressive behavior. The endosulfan-induced increase in aggressive behavior and increased binding of 3H-5HT were detectable even 8 days after the cessation of endosulfan treatment. Scatchard analysis revealed that exposure to endosulfan altered the affinity (KD) of the receptors without causing any significant change in maximum number of high affinity binding sites (Bmax). The endosulfan-induced fighting behavior was blocked by the pretreatment of animals with methysergide, a 5-HT blocker. These results suggest an involvement of serotonergic systems in the neonatal neurotoxicity of endosulfan.