ABSTRACT
1. Changes in the cardiovascular parameters of Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR) were examined following a 4-week diet of either Brazilian propolis or Eucommia uloides OLIVER (tochu). 2. A 4-week diet of propolis or tochu resulted in significant reductions in systolic blood pressure in SHR but had no effect on WKY. Experiments using aorta isolated from animals fed a diet of propolis or tochu revealed increased acetylcholine-induced relaxation in SHR and no change in acetylcholine-induced relaxation in WKY. Sodium nitroprusside-induced relaxation was unaffected by propolis or tochu in both animal groups. 3. These results suggest that propolis and tochu produce an antihypertensive effect that may be mediated by potentiation of acetylcholine-induced vasodilatation.