Inhibitory Action of Shosaikoto and Daisaikoto (Traditional Chinese Medicine) on Collagen-Induced Platelet Aggregation and Prostaglandin Biosynthesis

Abstract

Inhibitory effects of Shosaikoto and Daisaikoto (Kampohozai: traditional Chinese medicine) on the collagen-induced platelet aggregation in vivo and prostaglandin biosynthesis in vitro and in vivo were investigated. Shosaikoto, 1.1 g/kg p. o., and Daisaikoto, 1.1 g/kg p. o., showed the inhibition of platelet aggregation 1 h (inhibitory rate: 53% and 45%) and 5 h (inhibitory rate : 65% and 50%) after their treatments. On the other hand, Shosaikoto and Daisaikoto inhibited prostaglandin H₂ (PGH₂) biosynthesis in vitro using the microsome fraction of bovine vesicular gland. Furthermore, Shosaikoto, 1.1 g/kg p. o., and Daisaikoto. 1.1 g/kg p. o., administered for 30 days decreased the plasma prostaglandin E₂ (PGE₂) level as determined by radioimmunoassay. These results indicate that the anti-aggregant action of Shosaikoto and Daisaikoto should be partially due to their inhibition of cyclooxygenase activity.