Objective:To study the antipyretic activity and related mechanisms of total coumarins(TCs) from Artemisia annua.Methods:Total coumarins were extracted from Artemisia annua using Spth method

rectal temperature(Tr) responses were observed in both normothermia and fever rabbits induced by endogenous pyrogens after intraperitoneal treatment of TCs

the concentration of cAMP and PGE2 in either serum or cerebrospinal fluid of fever rabbits was measured by RIA

and Na+

K+-ATPase activity in liver and gastrocnemius was assayed.Results:Administration of TCs reduced Tr in both normothermia and fever rabbits

inhibited the rise of PGE2 in either serum or cerebrospinal fluid from fever rabbits

decreased the Na+

K+-ATPase activity in both liver and gastrocnemius.Conclusion: Coumarins are antipyretic fraction in Artemisia annua

and the inhibition of Na+

K+-ATPase activity and reduction in central PGE2 level may contribute to this activity.