Histopathologic Evidence Associated with Impaired Folliculogenesis Induced by Butachlor in Rat Ovaries

Background: Butachlor is one of the top members of the chlo-roacetanilide herbicide, extensively used for control of annual grasses and some broad-leaved weeds, particularly in rice crops. The studies of the possible toxic effects of butachlor have indicated that it is a suspected carcinogen and posing a potential threat to the agro-ecosystem and human health. The aim of this study was to evaluate the impact of butachlor on morphological and pathological changes of rat ovaries.Materials and Methods: Twenty-eight female Wistar rats were housed under standard housing conditions (controlled 12:12 hour light/dark cycles and an ambient temperature of 22-24 °C). The rats were acclimatized for two weeks before the ex-periment. Vaginal smears were examined daily in order to select normal estrous cycles in female rats. Female rats with regular estrous cycles were randomly divided into a control group or an experimental group to receive oral butachlor 72 mg/kg /day. Seven rats from each group were sacrificed after six weeks for blood collection from the dorsal aorta and removing the ovaries to pathological examination and measurement of ovarian fol-licles apoptosis. The same procedures were performed in the remaining rats form each group six weeks later. Ovaries tissue sections were prepared and stained with hematoxylin-eosin for morphometry by light microscopy. Serum levels of progester-one and estradiol were measured by ELISA.Results: Serum levels of progesterone and estradiol showed no significant difference between the experimental and the control group (P> 0.05). The number of primary and mature follicles statistically increased in the experimental group after 12 weeks of exposure. In addition, the primary follicles, as well as atretic follicles, had the highest mean number after 6 weeks of expo-sure in the experimental group compared to the control group (P<0.05).Conclusion: This study demonstrated that butachlor negatively impact ovarian folliculogenesis and maybe ovulation. Under the influence of butachlor, the appearance of the ovary has changed to the cystic ovary. Butachlor likely influences metabolic sys-tems that can exacerbate anovulation and the PCOS phenotype. Protective strategies and strong recommendations should be considered to decrease human exposure to this pesticide.

کلیدواژه ها:

Butachlor ، Ovary ، Rat