Abstract: AIM: To investigate the free radical scavenging activity of Ganoderma lucidum polysaccharides peptide (GLPP) on peritoneal macrophages in mice.METHODS: Alloxan and tert-butylhydroperoxide (tBOOH) were used as an oxidant to injury peritoneal macrophages in vivo in mice or in vitro, respectively. 2', 7'-dichlorodihydrofluorescein diacetate (DCHF-DA) was used as fluorescent probe.The fluorescence from cells was observed under the laser confocal microscope. Time series scan of conforcal microscope was used to observe the changes of fluorescence by GLPP in mice peritoneal macrophages over time.RESULTS: The results of confocal microscopy showed that GLPP (100 mg·kg^-1, ig for 5 d) lowed fluorescence in the mice macrophages injured by alloxan (75 mg·kg^-1 iv).GLPP (10 mg·L^-1)also lowed fluorescence in the mice macrophages injuredby tBOOH (7.76 ×10^-5mol·L^-1) in vitro as well. Time series scan showed that GLPP (10 mg·L^-1) lowed fluorescence in the mice macrophages at rest state or during the respiratory burst induced by PMA (50 nmol·L^-1).CONCLUSION: GLPP shows antioxidant effects and might have free radical scavenging effects on peritoneal macrophages in mice.

Key words: Ganoderma lucidum polysaccharides peptide, free radicals, peritoneal macrophages, DCHFDA, tBOOH