Abstract
Umezu (plum vinegar) is an exudate obtained from the pickled fruit of Prunus mume Sieb. et Zucc., Rosaceae. Umezu was passed through a Diaion HP20 adsorption column, which was washed with distilled water to remove salt and eluted with 90% ethanol solution. The eluate was concentrated in vacuo to obtain Umezu extract. In this study, the effects of dietary Umezu extract on blood pressure and lipid metabolism were examined in stroke-prone spontaneously hypertensive rats (SHRSP) fed a high-cholesterol diet. The high-cholesterol diet (control diet) was prepared by addition of 1% cholesterol and 0.25% sodium cholate to the purified diet according to the AIN-93G formula. Two groups of 6 male rats were used at the age of 6 weeks. One was fed the control diet and the other was fed the experimental diet (control diet containing 1% Umezu extract) for 6 weeks with free access to the diet and water. Elevation of systolic blood pressure was significantly suppressed with time in the experimental group (p<0.001 by two-way repeated ANOVA) after 4 weeks on the diet. Serum lipid hydroperoxide concentration was significantly decreased in the experimental group (p<0.05). Moreover, hepatic triglyceride content in the experimental group was significantly lower than that in the control group (p<0.05). These results indicate that Umezu extract suppresses the elevation of blood pressure, and the increases in serum lipid hydroperoxide concentration and hepatic triglyceride accumulation in SHRSP fed a high-cholesterol diet.
