Total saponin from Korean red ginseng inhibits thromboxane A₂ production associated microsomal enzyme activity in platelets

Ginseng, the root of Panax ginseng Meyer, has been used frequently in traditional oriental medicine and is popular globally. Ginsenosides, which are the saponins in ginseng, are the major components having pharmacological and biological activities, including anti-diabetic and anti-tumor activities. In this study, we investigated the effects of total saponin from Korean red ginseng (TSKRG) on thrombin-produced thromboxane A₂ (TXA₂), an aggregating thrombogenic molecule, and its associated microsomal enzymes cyclooxygenase (COX)-1 and TXA₂ synthase (TXAS). Thrombin (0.5 U/mL) increased TXA₂ production up to 169 ng/10⁸ platelets as compared with control (0.2 ng/10²8 platelets). However, TSKRG inhibited potently TXA₂ production to the control level in a dose-dependent manner, which was associated with the strong inhibition of COX-1 and TXAS activities in platelet microsomes having cytochrome c reductase activity. The results demonstrate TSKRG is a beneficial traditional oriental medicine in platelet-mediated thrombotic diseases via suppression of COX-1 and TXAS to inhibit production of TXA₂.