Inhibitory effects of Oren-gedoku-to (Huanglian-Jie-Du-Tang) on free radical-induced lysis of human red blood cells

Oren-gedoku-to (Huanglian-Jie-Du-Tang, OGT) has been used for the treatment of cerebrovascular disease, hypertension, gastritis and liver disease in Japan. The present study was to test our hypothesis that ingestion of Oren-gedoku-to extract (TJ-15) would protect red blood cell (RBC) membrane from free radical-induced oxidation if antioxidants in OGT could be absorbed and circulated in blood. When incubated with RBC suspension, OGT and its four constituting herbs provided strong protection for RBC membrane to hemolysis induced by 2,2-azo-bis (2-amidinopropane) dihydrochloride (AAPH), an azo free radical initiator. The inhibitory effect was in a dose-dependent manner at concentrations of 5 μg/ml to 500 μg/ml. Furthermore, the ingestion of 7.5 g of OGT (daily dose) was associated with a significant decrease in susceptibility of RBC to hemolysis in humans. The direct protection of RBC membrane from free-radical attack as observed in the present study could provide an important pathophysiological basis for making use of the favorable hemorheological effect of OGT.