Relaxant effects of the aqueous leaf extract of cassia occidentailis on rat aortic rings

The relaxant effects of an aqueous extract of the leaf of plant cassia occidentalis (C.O.) were investigated in rat aortic rings with or without intact endothelium. The extract inhibited contraction elicited by  noradrenaline (NA) and Potassium Chloride (KCI) dose dependently. It also relaxed aortic rings precontracted with 10-7 M NA and 50m M KCI. This relaxation did not require the presence of an intact vascular endothelium and was not affected by indomethacin (Prostacylin inhibitor) and methylene blue.