Polysaccharide peptide from Coriolus versicolor induces interleukin 6-related extension of endotoxin fever in rats

Purpose: Polysaccharide peptide (PSP) extracted from the Coriolus versicolor mushroom is frequently suggested as an adjunct to the chemo-or radiotherapy in cancer patients. In a previous study we showed that PSP induced a tumour necrosis factor-alpha (TNF-alpha)-dependent anapyrexia-like response in rats. Thus, PSP appears to be a factor which modifies a number of pathophysiological responses. Because of this, PSP is suggested as a potential adjuvant for cancer therapy during which cancer patients frequently contract microbial infections accompanied by fever. The aim of the present study was to investigate whether or not PSP can modulate the course of the fever in response to an antigen such as lipopolysaccharide (LPS). Materials and methods: Body temperature (Tb) of male Wistar rats was measured by biotelemetry. PSP was injected intraperitoneally (i.p.) at a dose of 100 mg kg(-1), 2 h before LPS administration (50 mu g kg(-1), i.p.). The levels of interleukin (IL)-6 and TNF-alpha in the plasma of rats were estimated 3 h and 14 h post-injection of PSP using a standard sandwich ELISA kit. Results: We report that i.p. pre-injection of PSP 2 h before LPS administration expanded the duration of endotoxin fever in rats. This phenomenon was accompanied by a significant elevation of the blood IL-6 level of rats both 3 h and 14 h post-injection of PSP. Pre-treatment i.p. of the rats with anti-IL-6 antibody (30 mu g/rat) prevented the PSP-induced prolongation of endotoxin fever. Conclusions: Based on these data, we conclude that PSP modifies the LPS-induced fever in IL-6-related fashion.