161. Schisandrin B enhances hepatic/myocardial glutathione regeneration capacity and protects against oxidant injury in rat livers and hearts.

Leong PK, Chen N, Ko KM

Division of Life Science, Hong Kong University of Science and Technology, Clear water bay, Hong Kong.

The effects of schisandrin B (Sch B), curcumin, epigallocatechin gallate (EGCG) and resveratrol on the glutathione regeneration capacity (GRC) of liver and heart tissues ex vivo were examined in relation to their protective effects against CCl4 hepatotoxicity in vivo and myocardial ischemia/reperfusion (I/R) injury ex vivo in rats. Results indicated that Sch B, but not curcumin, EGCG or resveratrol, caused hepatic and myocardial GRC enhancement, which was paralleled by its protection against CCl4 hepatotoxicity and myocardial I/R injury. Although resveratrol and curcumin failed to increase the GRC of liver/heart tissues, they did protect against CCl4 hepatotoxicity and myocardial I/R injury. In conclusion, the Sch B-induced enhancement of GRC ex vivo correlated well with its ability to protect tissues against oxidant injury in vivo/ex vivo, suggesting that the GRC assay can be used as a monitor of tissue protection for compounds stimulating glutathione redox cycling. However, phytochemicals can also protect against oxidant injury through various other mechanisms.