Evaluation of Antiarthritic Effect of Culinary-Medicinal Oyster Mushroom Pleurotus ostreatus cv. Florida (Agaricomycetes) on Complete Freund's Adjuvant Induced Arthritis in Rats.

The present study evaluates the antiarthritic effect of hydroethanolic extract of Pleurotus ostreatus cv. Florida, which was tested against adjuvant induced arthritis in rat models. Arthritis was induced by administration of complete Freund's adjuvant into the subplantar surface of left paw of rats. The extract was given orally at doses 200 mg/ kg and 400 mg/kg and piroxicam was administered intraperitonially (4 mg/kg). In vitro testing on parameters including antiproteinestrase, albumin denaturation and heat induce hemolysis was also carried out. There was significant decrease (p < 0.001) in proteinase activity and membrane stabilization in vivo studies on cv. Florida extract treated rats showed a significant (p < 0.001) decrease in paw volume, joint diameter, and spontaneous change in body weight recorded for 21 days. The treatment also resulted in an increase in rats' gripping activity compared with arthritic control rats. X-ray examinations showed a decrease in joint swelling. Histopathological examination of the extract treated group showed a significant decrease in joint space. There was also an increase in antibody levels. The antioxidant parameters showed a significant (p < 0.001) increase in superoxide dismutase and catalase enzymatic activities. Thus P. ostreatus cv. Florida extract demonstrates a potent antioxidant activity in a rat model. It is concluded that the P. ostreatus cv. Florida extract contains medicinally important constituents that show antiarthritic activity in rats.