[The pharmacologic action of extracts of Polygonum punctatum Elliot (= P. acre HBK)]

In vivo pharmacological studies were carried out with the aqueous and hydroalcoholic extracts of P. punctatum Elliot. Previously we have made a phytochemical screening and a essay of acute toxicity. The extracts exhibited an inhibition of the carrageenan-induced rat paw oedema, at doses of 300 and 600 mg.kg-1 p.o. and the hydroalcoholic extract at a dose range of 100-600 mg.kg-1 p.o. reduced significantly the increase of the vascular permeability induced by histamine. The extracts showed antipyretic activity only by i.p. administration. The gastrointestinal propulsion of a charcoal suspension was affected by both extracts, but significantly only by the aqueous extract. They elicited bradycardia and lowered the arterial blood pressure, but they do not demonstrate analgesic and diuretic activities. The pharmacological effects assayed are discussed in relation to the chemical composition of this plant and also to its popular use.