The pharmacological activities of the n -butanol alkaloids extracted from the stem bark of Hunteria zeylanica (Retz) Gardn. ex Thw. ( H. zeylanica ) and its major constituent, strictosidinic acid, on nociceptive response using writhing and hot plate tests, the antipyretic activity in yeast-induced fever, pentobarbital-induced sleep, and locomotor activity were examined in mice. Oral administration of H. zeylanica extract at 200 mg/kg significantly decreased the number of contortions and stretchings induced by acetic acid but not heat-induced pain. Strictosidinic acid (5-20 mg/kg, p.o.) also produced a similar effect but less pronounced than the extract. The antipyretic effect of strictosidinic acid (5-20 mg/kg, p.o.) was stronger than that of the extract (100-200 mg/kg, p.o.). The H. zeylanica extract dose-dependently (50-200 mg/kg, p.o.) prolonged the duration of pen-tobarbital-induced sleep but had no sign ificant effect on locomotor activity. No effect of strictosidinic acid was noted on both pentobarbital-induced sleep and locomotor activity. These results suggest that the H. zeylanica extract possesses peripheral analgesic and mild antipyretic effects and its major constituent, strictosidinic acid, exerts a similar analgesic effect with marked antipyretic activity.

The pharmacological activities of the n-butanol alkaloids extracted from the stem bark of Hunteria zeylanica (Retz) Gardn. ex Thw. (H. zeylanica) and its major constituent, strictosidinic acid, on nociceptive response using writhing and hot plate tests, the antipyretic activity in yeast-induced fever, pentobarbital-induced sleep, and locomotor activity were examined in mice. Oral administration of H. zeylanica extract at 200 mg/kg significantly decreased the number of contortions and stretchings induced by acetic acid but not heat-induced pain. Strictosidinic acid (5-20 mg/kg, p.o.) also produced a similar effect but less pronounced than the extract. The antipyretic effect of strictosidinic acid (5-20 mg/kg, p.o.) was stronger than that of the extract (100-200 mg/kg, p.o.). The H. zeylanica extract dose-dependently (50-200 mg/kg, p.o.) prolonged the duration of pentobarbital-induced sleep but had no significant effect on locomotor activity. No effect of strictosidinic acid was noted on both pentobarbital-induced sleep and locomotor activity. These results suggest that the H. zeylanica extract possesses peripheral analgesic and mild antipyretic effects and its major constituent, strictosidinic acid, exerts a similar analgesic effect with marked antipyretic activity.