Hypotensive effects of a methanol extract from Bidens pilosa Linn on hypertensive rats

Bidens pilosa Linn is highly regarded in some parts of Cameroon in traditional folk medical pratices. The hypotensive effects of the leaf methanol extract from Bidens pilosa Linn (Asteraceae) were evaluated in spontaneously hypertensive rats (SHR), salt-loading hypertensive rats (SLHR) and normotensive Wistar rats (NTR) using the indirect (tail-cuff) method. Acute changes in urine volume and urinary excretion of Na+ and K+ were also studied. The hypotensive effect of the extract was more remarkable in hypertensive than in normotensive rats. Bidens pilosa did not provoke significant changes in the heart rare and urine volume. Urinary excretion of Na+ was decreased by 36 % in spontaneously hypertensive rats and che excretion of K+ increased by 35 % in normotensive rats but the effects were not: statistically significant. These results suggest that the extract: is a useful antihypertensive drug which has no effect on the heart frequency. The hypotensive effects of the extract may be induced by vasodilation. ((C) Academie des sciences / Elsevier, Paris.)