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 200mg/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 200mg/kg doses). In case of yeast-induced pyrexia model, 200mg/kg dose showed very significant (P<0.01) inhibition while 50 and 100mg/kg dose caused a significant (P<0.05) inhibition. Plant extract has controlled the pentylenetetrazole-induced convulsions in mice. 100 and 200mg/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.

Antinociceptive activity of natural honey in thermal-nociception models in mice.

Several honey samples of Pakistani origin have been analysed for their effect on nociception. Among the tested samples, Acacia honey showed most effective dose-dependent antinociceptive activity which was significantly different from the untreated group in tail-flick and paw-withdrawal tests (p < 0.01 and p < 0.003), respectively. The antinociceptive activity of honey reached a maximum at 60 min post-treatment and then gradually decreased, whereas the activity of indomethacin was persistent at 120 min post-treatment. The absence of antinociceptive activity in simulated honey (which contained fructose, glucose, maltose and sucrose representing the major constituents of honey) indicated that the active principle(s) might be present in minor constituents of honey.