Pharmacological evaluation of extracts of Hedychium spicatum (Ham-ex-Smith) rhizome.

Hedychium spicatum (Ham-ex-Smith), known as Shati in Ayurvedic classics, is documented for the treatment of cough, hiccough, fever and asthma. The present study includes the evaluation of aqueous and ethanolic extracts of the dried rhizome of H. spicatum for anti-histaminic and ulcer-protective activities in guinea pig (GP), anti-inflammatory and analgesic activities in rat and acute toxicity in mouse. The extracts were administered orally, daily as suspension, in 1% carboxymethyl cellulose either for 7 days in GP studies or 60 min before or just before experiment in rats and mice. An initial dose-dependent anti-histaminic action of both the extracts (100, 200 and 400 mg/kg) was performed against histamine-induced bronchospasm in GPs. The 200 mg/ kg dose of aqueous and ethanolic extracts was selected both in GP and rat for further studies. GPs treated with aqueous and ethanolic extracts showed gastric ulcer protection against histamine-induced gastric ulcer compared with the control group. Both the extracts also showed an anti-inflammatory effect against carrageenan-induced paw edema in rats from 1 h onwards, and this was maximum at 3 h. Analgesic effect was determined by using hot plate and tail flick tests in rats, and both the extracts at 200 mg/kg showed a significant increase in the latent period from 30 min onwards till 120 min of their study period. Both the extracts did not show any toxic effect like increased motor activity, salivation, clonic convulsion, coma and death in mice even at the 2000 mg/kg dose (nearly 10 times of the optimal effective dose), indicating the safety of the extracts. The result confirms the indigenous use of this plant in respiratory disorders.