Lithospermic acid B as an antioxidant-based protector of cultured ventricular myocytes and aortic endothelial cells of rabbits.

Lithospermic acid B, an active principle found in a Chinese herbal medicine for treating various heart ailments, was recently isolated, purified and demonstrated by us to salvage the postischemic rabbit heart from reperfusion injury. In this work, we further report that lithospermate B is able to protect each of two types of rabbit cardiocytes, namely ventricular myocytes and aortic endothelial cells against necrosis inflicted by oxyradicals generated pharmacologically with xanthine oxidase and hypoxanthine. Biochemically, the lithospermate B also inhibits the reduction of cytochrome c by superoxide radical anion. Thus, our in vitro data here are in concord with our earlier in vivo finding that lithospermic acid B is most likely an effective antioxidant-based myocardial protector.