Effect of medicinal plant extracts on forced swimming capacity in mice.

The tonic effect of Cordyceps militaris (CM), Paecilomyces japonia (PJ), Phellinus linteus (PL), Ganoderma lucidum (GL), Grifola frondosa (GF), and Panax ginseng (PG) was examined based on the forced swimming capacity and the change of biochemical parameters in ICR mice. The treatment groups were orally administered medicinal plant extracts (500 mg/kg per day), while the control group received distilled water for 4 weeks. The swimming times to exhaustion were longer in the CM, PJ, and GF groups than in the control group (P < 0.05). Plasma TG levels were lower in the treatment groups than in the control group. Plasma glucose levels were not significantly different between the control group and each treatment group except the PG group. Plasma lactate and ammonia levels of the PJ and GF groups were lower than those of the control group (P < 0.05). There were no significant differences in the content of liver and gastrocnemius muscle glycogen between the control group and each treatment group. In conclusion, PJ and GF extracts enhanced the forced swimming capacity of mice by increasing fat utilization and by delaying the accumulation of plasma lactate and ammonia.