The Chinese medicinal herbs of spleen-meridian property regulate body temperature in yeast-induced fever rats

Background: According to traditional Chinese medicine (TCM) theory, the herbal property is the most important guiding principle of ancient medication in China. The classification of warm- and cold-stimulating TCM is defined mainly based on the effects of herbs in regulating body temperature; however, the underlying mechanism of such distinction has not been fully identified. Methods: Here, four commonly used spleen-meridian herbs, Ginseng Radix and Astragali Radix as typical warmstimulating herbs, and Nelumbinis Semen and Coicis Semen as typical cold-stimulating herbs, were selected to test their effects in regulating body temperature, as well as its triggered thermo-regulatory factors and energy related metabolites, in yeast-induced fever rats. Results: The intake of Astragali Radix increased body temperature in yeast-induced fever rats; while Coicis Semen showed cooling effects in such rats. In parallel, the levels of cAMP, PGE2 and thermo-related metabolites, including choline, creatine, alanine, lactate and leucine, in the blood of yeast-induced rats were increased significantly by the intake of Astragali Radix. Oppositely, the cold-stimulating herbs, Nelumbinis Semen and Coicis Semen, showed cooling effects by increasing certain metabolites, e.g. histidine, tyrosine, lipid, myo-inositol, as well as AVP level. Conclusion: Here, we compared different effects of warm and cooling spleen-meridian herbs in the regulation of body temperature. By providing an intuitive comparison of thermo-regulatory factors and related metabolites after intake of selected herbs, the mechanism behind the warm and cooling effects of specific herbs were revealed.