Histological investigation of the protective effect of curcumin on the toxicity of chlorpyrifos on the developing rat ovarium

Chlorpyrifos (CLP) is a broad spectrum organophosphorus pesticide widely used in agricultural and residential pest control worldwide. Exposure to CLP has been shown to cause oxidative stress on many organs. Curcumin (CUR) has been shown to have strong biological activities such as antioxidant, anti-inflammatory, antineoplastic and anti-mutagenic. The aim of this study was to reveal the possible effects of chlorpyrifos exposure in the prenatal period on the developing rat ovary and whether these effects can be reduced by curcumin. For this purpose, 21 female rats; They were divided into 5 groups as Chlorpyrifos (CLP), Curcumin (CUR), Chlorpyrifos+Curcumin (CLP+CUR), SHAM and Control (C) (n=3). Pregnant female rats were given 5mg/kg chlorpyrifos to the CLP group and 100mg/kg curcumin to all groups given CUR by gavage once a day throughout their pregnancy. Ovarian tissues taken from rats sacrificed at the end of the experiment were evaluated by histopathological, stereological and biochemical methods. It was determined that the gonadosomatic index (GSI) value of the CLP group was statistically significantly lower than all other groups (p<0.01). As a result of scoring with light microscopic evaluation, it was observed that the most degeneration in the ovaries was in the CLP group (p<0.01). As a result of the stereological analyzes, it was determined that the number of primordial, preantral and antral follicles decreased in the CLP group compared to all other groups (p<0.01). In addition, while the cortex volumes of the ovaries of this group decreased (p<0.01), there was no significant change in the medulla volume. In the biochemical analyzes of blood serum samples, it was determined that the catalase (CAT) and superoxide dismutase (SOD) enzyme activity values in the CLP group decreased compared to the other groups (p<0.01), similarly, the FSH value decreased, but the LH value did not change. In rats in the CLP+CUR group treated with curcumin, it was observed that the GSI value increased compared to the CLP group, the histopathological changes in the ovaries were alleviated, the number of follicles increased, and the SOD enzyme activity and FSH level increased in blood serum samples (p<0.01). As a result, we can say that curcumin reduces the oxidative stress caused by chlorpyrifos in the ovaries and accordingly alleviates the degeneration occurring in the ovaries.