Abstract
Cypermethrin (CYP) is a commonly used type II Pyrethroid pesticide, that normally accumulates in the various body tissues, causing organ dysfunction. In order to reduce its toxicity, we primarily investigated the potential of Bacopa monnieri (BM) extract in the amelioration of CYP-induced hypothyroidism in female Swiss mice. Animals were divided into 4 groups of 6 each. Group I, without receiving any treatment served as control, Group II was orally administered with CYP at 15 mg/kg, while Group III animals were administered only with BM extract at 200 mg/kg, and Group IV received equivalent dose of CYP along with BM extract (CYP + BM). The treatment was continued for 28 days. At the end, serum levels of triiodothyronine (T(3)), thyroxin (T(4)), and thyroid-stimulating hormone (TSH) were measured. Also, thyroidal histopathology and tissue peroxidation were evaluated. Results revealed that CYP administration induced hypothyroidism in the animals, as indicated by reduced serum thyroid hormones and enhanced TSH levels. Thyroid follicles were of reduced diameter and with flattened epithelium and vacuolated cytoplasm. Also, a significant increase in the body weight and thyroid weight was seen. Further, a decreased expression of TSHr and THR β-1 receptors was also found in this group. Interestingly, the co-administration of BM extract and CYP could ameliorate hypothyroidism in mice. A reversal in the pesticide-induced increase in oxidative stress was also seen in the CYP + BM group, suggesting a reduction in CYP-induced thyroid toxicity. BM was also found to be antiperoxidative. These results suggest the potential of BM extract in the mitigation of cypermethrin-induced Hypothyroidism and its adverse effects. This work further demonstrates the expression of TSHr and THR β-1 and suppression of the oxidative stress in the test extract administered to hypothyroid female mice.