Effects of Bai-Hu decoction on fever induced by lipopolysaccharide.

This study was designed to investigate the antifebrile effect and mechanisms of Bai-Hu decoction (BHD), a traditional Chinese medical (TCM) prescription. The rabbits used in this study received an intravenous injection of lipopolysaccharide (LPS) after being orally administered with BHD, ibuprofen, or saline, and their rectal temperatures were monitored by a copper-constantan thermocouple. Concentrations of interleukin-1 beta (IL-1β) and tumor necrosis factor alpha (TNF-α) in serum and hypothalamus were assayed using the commercially available rabbit IL-1β and TNF-α enzyme-linked immunosorbent assay kits following the manufacturer's instructions. The BHD treatment group exhibited a significant fall in body temperature in both peaks compared with the LPS group (p<0.05). BHD reduced the concentrations of IL-1β and TNF-α in serum, and of TNF-α in hypothalamus to control the febrile responses at 1 hour. Besides the levels of IL-1β in hypothalamus and serum, the concentration of TNF-α in hypothalamus was decreased remarkably in the BHD group than in the LPS group at 3 hours. The main findings, the partial mechanisms of BHD in reducing biphasic fever elicited by LPS, were that treatments with the crude extract of BHD could remarkably reduce the increased concentrations of IL-1β and TNF-α, not only in serum but also in hypothalamus. The results indicated that BHD would be a valuable candidate for further investigation as a traditional antifebrile and anti-inflammatory natural drug.