Anticonvulsant and antioxidative activity of hydroalcoholic extract of tuber of Orchis mascula in pentylenetetrazole and maximal electroshock induced seizures in rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Orchis mascula tuber is used in many polyherbal formulations as a nerve tonic in India.

AIM OF THE STUDY: In the present study, effect of hydroalcholic extract of O. mascula (HEOM) tuber was evaluated against seizures, seizure-induced oxidative stress and cognitive deficit in pentylenetetrazole and maximal electroshock-induced seizures in rats.

MATERIALS AND METHODS: HEOM was administered orally 30 min before induction of seizures by pentylenetetrazole (PTZ; 60 mg/kg, i.p) or maximal electroshock (MES; 70 mA). Elevated plus maze and passive avoidance tests were used to assess the learning and memory. Oxidative stress was studied by estimation of reduced glutathione and lipid peroxidation. Whole brain total cholinesterase activity was also evaluated.

RESULTS: HEOM produced 33.3%, 50% and 66.7% protection in PTZ model and 16.7%, 16.7% and 33.3% at 250, 500 and 1000 mg/kg, respectively, in MES-induced seizures. Pre-treatment with HEOM significantly decreased the retention transfer latency in elevated plus maze test, and an increase in the retention latency in passive avoidance test was observed. Oxidative stress induced by seizures was also attenuated as indicated by significant increase in GSH and decrease in MDA levels in HEOM treated groups. PTZ and MES caused a significant decrease in AChE and BChE activities, which was prevented by HEOM.

CONCLUSIONS: HEOM thus showed protection against seizures, prevented the associated memory impairment probably by modulating cholinergic status and reducing oxidative stress.