Objective: To study the antipyretic effect and the mechanism of gentianine by comparing with variances of the antipyretic effect among from water extract of Gentianae Radix Et Rhizoma

gentianine and gentiopcroside. Method: The rat febrile models induced by injecting fresh yeast subcutaneously and treated with gentianine

gentiopcroside intraperitoneally and fed with water extract of Gentianae Radix Et Rhizoma

then the rectal temperature was monitored to show the differences of effect from those groups. The contents of tumor necrosis factor(TNF-α)

interleukin-1(IL-1)

interleukin-6(IL-6) in blood serum and cyclic adenosine monophosphate (cAMP)

prostaglandin E2 (PGE2) in the hypothalamus were measured by radioimmunoassav (RIA)

respectively. Result: Three drug administration groups(including gentianine

gentiopcroside and water extract of Gentianae Radix Et Rhizoma)showed marked antipyretic effect on the yeast-induced fever(P<0.05) and the effects were stronger on the getianine group than other treated groups.Each treatment group showed remarkable decreased the contents of IL-6 in blood serum and PGE2 in the hypothalamus of febrile rats. Conclusion: Gentianine

gentiopcroside and water extract of Gentianae Radix Et Rhizoma all have obvious antipyretic effect

but the effect of gentianine is strongest of them and probably plays a more direct role in the antipyretic effect from Gentianae Radix Et Rhizoma

which might be related with decreasing the levels of IL-6 in serum and the interferencing the content of PGE2 in the hypothalamus.