Puerarin Acts Through Brain Serotonergic Mechanisms to Induce Thermal Effects

Abstract

Abstract. The present study was attempted to investigate the effect of puerarin, an isoflavone compound isolated from Pueraria lobata, on both the basal body temperature and pyrogenic fever in unanesthetized, restrained rats. Intraperitoneal administration of puerarin or crude extracts of Pueraria lobata elicited hypothermia. Direct administration of a small amount of puerarin into the lateral cerebral ventricle produced the same extent of hypothermia. Systemic or central administration of puerarin causes a decrease in both colonic temperature and hypothalamic 5-HT efflux in rats. The puerarin-induced hypothermia and decreased 5-HT efflux in the hypothalamus were attenuated by selective depletion of hypothalamic 5-HT produced by intracerebroventricular injection of 5,7-dihydroxytryptamine. Furthermore, the puerarin-induced hypothermia was almost completely abolished by treatment with a 5-HT 2A -receptor agonist (DOI or quipazine) or a 5-HT 1A -receptor antagonist [(-)-pindolol]. A 5-HT 2A -receptor antagonist (ketanserin) or a 5-HT 1A -receptor agonist (8-OH-DPAT) had additive effects with puerarin. Intracerebroventricular administration of interleukin-1 caused an increase in both colonic temperature and hypothalamic 5-HT efflux. The interleukin-1-induced hyperthermia and increased 5-HT efflux in the hypothalamus were attenuated by treatment with systemic administration of puerarin. The data indicate that puerarin exerts its hypothermic and antipyretic effects by activating 5-HT 1A receptor and / or antagonizing 5-HT 2A receptors in the hypothalamus.

Antipyretic effect of the aqueous extract obtained from leaves of Neurolaena lobata (Asteraceae) on a pyretic model induced by brewer's yeast

“…The experimental group, group C, received N. lobata leaves extract. This group had an antipyretic effect evident also 30 minutes after administration with a maximum antipyretic effect of 0.81 o C. As it has been described before [12], isoflavones have antipyretic effects. Kerr and collaborators [4] had isolated 12 different flavonoides from N. lobata and it is suggested that these could be some of the components responsible for N. lobatas´ antipyretic effect.…”

Puerarin decreases serum total cholesterol and enhances thoracic aorta endothelial nitric oxide synthase expression in diet-induced hypercholesterolemic rats

“…Ohwi (Chueh et al, 2004). This medicinal herb has been demonstrated to have effects on treatment of fever (Zhou et al, 1995;Chueh et al, 2004), liver diseases (Keung and Vallee, 1993;Overstreet et al, 1996) and cardiovascular diseases (Fang, 1980;Chai et al, 1985;Song et al, 1988;Fan et al, 1992;Wang et al, 1994). In China, P. lobata is also used as a health supplement for reducing risk factors of cardiovascular diseases.…”

Protective effect of daidzin against d‐galactosamine and lipopolysaccharide‐induced hepatic failure in mice

“…Puerariae radix contains several isoflavonoids, including puerarin, daidzin, daidzein, formononetine and their C-and O-glycosides (Prasain et al, 2003). These compounds have been associated with antioxidant, antidipsotropic, and other pharmacological activities (Chueh et al, 2004;Lee, 2004). It was reported recently that daidzin and daidzein offer protection against carbon tetrachloride-, D-GalN-and t-butyl hydroperoxide-induced hepatotoxicity in vitro (Park et al, 2007).…”