Effect of leaf extract from Clerodendron colebrookianum on CNS function in mice

Effect of acute multiple (20, 40 and 80 mg/kg body wt, i.p.) doses of C. colebrookianum leaf extract on behaviour, convulsion, analgesia and sedative-hypnosis was studied in mice. A marginal reduction of awareness and motor activity was observed in low (20 mg) and moderate (40 mg) dose level of extract. However, 80 mg dose caused marked inhibition of awareness and motor activity. Grip strength and stereotypy was observed in all the dose levels. The extract alone did not show loss of righting reflex but it prolonged the effect of meprobamate, diazepam, chlorpromazine and pentobarbitone significantly in a dose dependent manner. The extract neither produced analgesia alone nor it altered analgesic effect of morphine and pethidine. Pretreatment of the extract caused significant protection of strychnine and leptazol induced convulsion and mortality. The results suggest a mild (or dose dependent) CNS depressant action of leaf extract of C. colebrookianum in mice.