Reduction of Mouse Body Fats by Water Extract of Pleurotus ostreatus

Body fat-reducing ability of oyster mushroom (Pleurotus ostreatus) water extract (OMWE) was investigated for mice by supplying it drinking water. OMWE (2.95% solid content) was prepared by extracting a low grade of the mushroom at 120℃ for 10 min. The solid material of OMWE was composed of 65.2% reducing sugar, 0.23% crude fat, 0.5% total protein, 1.2% ash and 32.9% others. OMWE was appropriately diluted with drinking water. Seventy two male ICR mice (25±1 g, 7~8 weeks of age, 6 mice/cage, 18 mice/treatment) housed in polycarbonate cages containing β-chips were adopted in a temperature- and humidity-controlled facility with free access to water and diet. One week later, the mice were subjected to one of the treatments for 36 days: 0 (control), 10, 50 and 100% OMWE. Drinking water with or without OMWE was supplied twice (40 ml each, 80 ml in total) daily per cage. Body weight and feed intake were recorded every three days. At the end of the experiment, mice were sacrificed to determine the chemical composition (fat, protein, ash and water). Body weight of mice treated with OMWE (10, 50 and 100%) at day 36 was 35.9, 35.9 and 35.5 g per mouse, respectively, and not significantly reduced as compared to that (36.5 g/mouse) of control mice. Average body fat of 0, 10, 50 and 100% OMWE-treated mice was 14.3, 13.1, 10.7 and 12.0%, respectively. Body fat reduction by 50% OMWE treatment was 25.2% (p<0.05), relative to control. OMWE did not affect feed intake. The contents of body protein and ash were increased with respect to body fat decrease, while water content was not changed much. These results suggest that OMWE could reduce body fat of the mice without body weight change, giving the best effect by 50% OMWE.