Anti-inflammatory, antipyretic and anti-malarial activities of a West African medicinal plant--Picralima nitida.

A preliminary pharmacological screening of the methanolic extract of Picralima nitida fruit was carried out. The extract showed potent and dose-dependent anti-inflammatory, antipyretic and anti-malarial activities. Given intraperitoneally, it inhibited carrageenan-induced rat paw oedema with IC50 of 102mg/kg, and with the highest dose tested (300mg/kg) producing 72.2% inhibition. On the LPS-induced pyrexia in rabbits, 50mg/kg of the extract produced a mean percentage antipyrexia of (38.7%) compared with (29.0%) by 200mg/kg of aspirin. In a 4-day in vivo schizontocidal test in mice infected with P. berghei berghei, up to 300mg/kg daily for 4 days was ineffective in preventing the development of parasitaemia or the consequent mortality. However, marked inhibitory activity was obtained on multi-drug resistant human P. falciparium parasites cultured in in vitro. The dose causing 50% inhibition of parasite growth was 1.75 micrograms/ml compared with (0.14 microgram/ml for chloroquine. The results confirm the medicinal value of this plant and thus justify its use by natives of W. Africa.