The hemostatic effects of orally administered Yunnan Bai Yao in rats and rabbits.

The effects of orally administered Yunnan Bai Yao were studied on the bleeding time in rats and the blood clotting time in rabbits. Significant decreases were seen in both the bleeding and clotting times, observed over a 4 h period following administration. These effects were seen as early as 1/2 h and were still present at 4 h. Graded doses of Yunnan Bai Yao produced dose-related decreases in blood clotting times in the rabbits. The findings suggest that some active principle, able to affect the hemostatic mechanism, is absorbed after oral administration of the herbal preparation.