Thymol mitigates cadmium-induced behavioral and cognitive deficits by up-regulating hippocampal BDNF levels in rats

Cadmium is a potent neurotoxin and induces adverse impact on brain function. Protective effects of monoterpenes on the CNS have been reported previously. The present study was designed to investigate the beneficial effect of thymol on cadmium-induced neurotoxicity. Rats were initially divided into 2 groups, vehicle control and thymol. Thymol (40mg/kg) was given orally for 14 days. Each group was subdivided into two groups (Vehicle control and Cadmium, Thymol and Thymol+Cadmium). Cadmium Chloride (5mg/kg) was given for last 3 days only to the groups assigned as Cadmium and Thymol+Cadmium. Behavioral parameters were assessed after 24h of last dose of cadmium. Brain sample were collected and BDNF was measured in hippocampus. The present study suggests that pre-administration of thymol provides a protective therapy against cadmium-induced intoxication by enhancing the brain BDNF levels and plasticity. Results further suggest that thymol not only ameliorates cadmium-induced learning and memory impairment but also reduced anxiety, motor incoordination and depression assessed by various behavioral tests. The study may provide a better apprehension of the neuroprotective role of thymol and highlighting its significance in the diet for human health particularly in cadmium intoxication.