Polysaccharide-Protein Complex Isolated from Fruiting Bodies and Cultured Mycelia of Lingzhi or Reishi Medicinal Mushroom, Ganoderma lucidum (Agaricomycetes), Attenuates Doxorubicin-Induced Oxidative Stress and Myocardial Injury in Rats

This study aimed to evaluate the effect of the polysaccharide-protein complex isolated from the fruiting bodies (GLFPPC) and cultured mycelia (GLMPPC) of a highly valued medicinal mushroom, Ganoderma lucidum, to alleviate doxorubicin (DOX)-induced cardiotoxicity. GLFPPC and GLMPPC were isolated from aqueous-alcoholic extracts of fruiting bodies and cultured mycelia of G. lucidum by repeated ethanol precipitation, dialysis, treatment with Sevag reagent, and freeze drying. The polysaccharide component was confirmed by assays with anthrone and phenol-sulphuric acid regents and protein moiety with Bradford reagent. The amino acid profile of protein moiety was determined by high-performance liquid chromatography analysis. DOX-induced cardiotoxicity was determined using Swiss albino mice. DOX administration caused a marked increase of creatine kinase and lactate dehydrogenase enzyme activities, indicating injury to the myocardium. The polysaccharide-protein complex downregulated cardiac injury marker enzymes, enhanced activities of endogenous antioxidants (namely, superoxide dismutase, catalase, glutathione peroxidase, and reduced glutathione levels), and significantly attenuated lipid peroxidation. The results indicated that GLFPPC and GLMPPC imparted protection against DOX-induced oxidative stress. Biochemical assays coupled with histopathological observations supported this conclusion. These experimental findings suggest that the polysaccharide-protein complex isolated from G. lucidum might be a useful therapeutic agent to ameliorate DOX-induced cardiomyopathy.