Evaluation of reprotoxic effects of orally administered endocrine disruptor Pyriproxyfen in adult female Sprague Dawley rats: A biochemical and histopathological study

Abstract

The phenomenon of endocrine disruption has been acknowledged for a long time and since the discovery of the first hormone in 1902. Endocrine disruptors can be pharmaceuticals, plasticizers, polychlorinated biphenyls, organochlorinated pesticides. With the growing population of the world there is a growing demand for food, thus, a growing demand for pesticides to increase crop production. Approximately 5.6 billion pounds of pesticides are being used annually in the world, and this usage is unexpectedly rising, of which 95% possess the ability to be widely dispersed in the environment and to affect non-target organisms. PYR is one of the most widely used pesticides in the world and is well known for its ability as an embryogenesis inhibitor in insects. It gets accumulated in the environment leading to detrimental effects in non-target organisms (plants, fish, amphibians, birds, and mammals etc.) through food web. The adverse effects due to continuous exposure of PYR include growth retardation, disruption of hormonal balance, impaired reproduction, and neurodevelopmental abnormalities. In order to check the reprotoxic effects of PYR in female Sprague Dawley rats, we designed an experiment consisting of four groups i.e., control, G1, G2, G3 and administered them with distilled water, 62, 124, and 186 mg/kg PYR, respectively. After 28 days the rats were dissected, different samples were collected, and analyzed for organ weights, BMI, blood glucose levels, total protein concentration, lipid profile, and ovarian histology. The results showed that PYR had non-significant (p>0.05) effects on body weight, and BMI but, caused a significant (p<0.05) reduction in the ovarian, uterine, kidney, heart, and liver weights. Also, it was found to be involved in significantly decreasing (p<0.01) the blood glucose levels and altering estrous cyclicity. In addition, non-significant decrease (p>0.05) was observed in total protein levels, while the lipid profiles were significantly (p<0.05) effected as a result of PYR administration. Moreover, PYR was found to have potential detrimental effects on the ovarian histoarchitecture. In conclusion, PYR was found to have reprotoxic effects and thus must be used with caution and only when necessary. Also, further research is needed to identify the possible mechanisms of PYR interaction with ovarian cells and other body organs.