Anticonvulsant, analgesic and antipyretic activities of Taxus wallichiana Zucc.

Taxus wallichiana Zucc. (Himalayan Yew) is often used in northern areas of Pakistan for the treatment of pyrexia, acute pains and epilepsy. We have investigated certain pharmacological activities of the methanol leaf extract against convulsion, nociception and pyrexia induced in rodents. The aim was to justify and explore its folk uses in these pathological conditions, on scientific basis. The studies were carried out using acetic acid-induced nociception and pentylenetetrazole-induced convulsions in mice, while formalin test and yeast-induced pyrexia in rats. Significant analgesic (67.77 and 74.29%) effect was found in acetic acid-induced model at doses of 100 and 200 mg/kg, i.p. respectively. Crude extract exhibited significant (P < 0.05) inhibition of the formalin noxious stimulation on both early and late phases of pain by the extracts (100 and 200 mg/kg doses). In case of yeast-induced pyrexia model, 200 mg/kg dose showed very significant (P < 0.01) inhibition while 50 and 100 mg/kg dose caused a significant (P < 0.05) inhibition. Plant extract has controlled the pentylenetetrazole-induced convulsions in mice. 100 and 200 mg/kg i.p doses of the extract significantly (P < 0.05) inhibited the mioclonus and clonus while inhibition of tonus and hind limb tonic extension (HLTE) was highly significant (P < 0.01). The anticonvulsant activity of this plant has been reported for the first time throughout the whole genus. The observed pharmacological activities provide the scientific basis for the folkloric use of the plant in treating epilepsy, pyrexia and acute pain. (C) 2008 Elsevier Ireland Ltd. All rights reserved.