ABSTRACT
Since lipid oxidation is involved in the deterioration of hypercholesterolemia-related atherosclerosis, ingestion of drinks and foods with antioxidant actions is useful for preventing lipid oxidation. Goishi-tea is a post-fermented-tea manufactured by a unique method in Japan, and may be useful for preventing various disorders. However, there is no scientific evidence. In this study, we compared the radical scavenging activity of goishi-tea with that of other teas, and administered this tea to a rabbit model of hypercholesteremia to evaluate its usefulness in the inhibition of hypercholesteremia and atherosclerosis. The radical scavenging activity of goishi-tea was similar to that of green-tea, and was higher than that of other types of fermented-teas. On the other hand, some difference of components was found between goishi-tea and green-tea. In cholesterol-fed rabbits, low-density lipoprotein (LDL)-cholesterol level in the goishi-tea-group was lower than that in the green-tea-group. Plasma lipidperoxide value was also lower in the goishi-tea-group than in the green-tea and tap-water-groups. On aortic endothelial staining, fat area in the goishi-tea-group was lower than that in the tap-water-group. Furthermore, fat accumulation in the aortic intima in the goishi-tea-group was very low. Goishi-tea has higher antioxidant activities than the other fermented-teas tested, which were generally low, and decreased serum lipid levels, suggesting that goishitea is a very peculiar fermented-tea with usefulness in the prevention of hypercholesterolemia and atherosclerosis.