The extract prepared from hawthorn (Crataegus fruit) was examined for its relaxant effect in rat isolated mesenteric arteries. Hawthorn extract induced concentrationdependent relaxation of the U46619-precontracted artery with an IC50 of 0.22

The present study examined the hypolipidemic activity of hawthorn fruit. New Zealand white rabbits were fed one of three diets, a reference diet with no cholesterol added (NC), a high cholesterol diet (1g/100g, HC) and a HC diet supplemented with 2g/100g hawthorn fruit powder (HC-H). After 12 wk, serum total cholesterol (TC) and triacylglycerols (TG) were 23.4 and 22.2% lower, respectively, in the hawthorn fruit group compared with the HC rabbits (P﹤0.05). Hawthorn supplementation led to 50.6% less cholesterol accumulation in aorta (P﹤0.05) and 23-95% greater excretion of neutral and acidic sterols (P﹤0.05). Supplementation of hawthorn fruit did not affect the activities of hepatic 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMG-CoA-R) or cholesterol 7 -hydroxylase (CH) but it suppressed the activity of intestinal acyl CoA:cholesterol acyltransferase (ACAT, P ﹤0.05). The results suggest that the mechanism by which hawthorn fruit decreases serum cholesterol involves, at least in part, the inhibition of cholesterol absorption mediated by down-regulation of intestinal ACAT activity. J. Nutr. 132: 5-10, 2002.