[ ABSTRACT] AIM:To investigate the antipyretic effect of patchouli oil on lipopolysaccharide ( LPS)-induced fe-ver in rabbits.METHODS:Male rabbits (n=42) were randomly divided into 7 groups according to their body weight and basal body temperature, including control group, model group, western medical positive group, traditional Chinese medical positive group, and high, middle and low doses (2%, 1%and 0.5%) of patchouli oil groups.Subsequently, except the controls, the rabbits were injected with LPS at a dose of 1 mL/kg (2 mg/L) through marginal ear vein to establish rabbit fever model and the rabbits in control group received the same volume of NS.The rabbits in control group and model group were injected with 0.5%Tween-80 0.5 h late, and the rabbits in the other groups were treated with correspoonding drugs. The effect of patchouli oil on the body temperature was observed, and the levels of interleukin-1β( IL-1β) and tumor nec-rosis factor-α(TNF-α) in the serum, and prostaglandin E2(PGE2) and cyclic adenosine monophosphate (cAMP) in the hypothalamus were measured by radioimmunoassay.RESULTS: The body temperature and the levels of IL-1β, TNF-α, cAMP and PGE2 in model group were significant higher than those in control group.Patchouli oil notably inhibited the body temperature in the febrile rabbits.From 1.5 h to 5.5 h after administration, the body temperatures were increased by (1.06 ±1.55), (1.62 ±1.36), (1.38 ±1.22), (0.98 ±0.98) and (0.48 ±0.95) ℃in high patchouli oil group, re-spectively.From 3.5 to 5.5 h after administration, the body temperatures were elevated by ( 1.47 ±0.73 ) , ( 1.15 ± 0.68) and (0.63 ±0.54) ℃ in middle patchouli oil group, respectively.A tendency of downregulation of the elevated body temperatures was observed at every time point after administration in low patchouli oil group.Patchouli oil significantly decreased the levels of TNF-αin the serum and cAMP content in the hypothalamus, and attenuated the elevated tendency of the IL-1βlevel in the serum and PGE2 level in the hypothalamus.CONCLUSION:Patchouli oil evidently has antipyretic effect on LPS-induced fever in the rabbits.The antipyretic mechanism might be related to the inhibition of TNF-αlevel in serum and cAMP content in the hypothalamus.