Biological Activity of Cordyceps (Fr.) Link Species (Ascomycetes) Derived from a Natural Source and from Fermented Mycelia on Diabetes in STZ-Induced Rats
The Chinese traditional herb medicine Cordyceps (natural source) and the mycelial preparations of different species of genus Cordyceps (Fr.) Link (fermented mycelia) produced by fermentation, as well as a commercial product, have been compared in terms of biological activity of in a diabetic animal model using STZ-induced rats. The respective changes of several indices in serum substrate levels and blood analysis, and relative organ weights, were characterized to judge the ability of these preparations of meliorating diabetes by the consecutive intake intragastrically for 14 days. There were significant differences statistically both in the daily average water intake and the daily average urine volume of the STZ-treated group with naturally produced of Cordyceps compared to those of the fermentated mycelial preparations. Although there were no differences in plasma glucose levels among between the Cordyceps-treated group and that of the Cordyceps-untreated STZ rats, all the values of glucose, albumin, cholesterol, HDLcholesterol, triglycerides, BUN in serum, and WBC, RBC, Ht, and MCH in the blood for of the Cordyceps-treated diabetic rats are were between those of the Cordyceps-untreated diabetic rats and the control group. The effects of all the Cordyceps preparations were not reflected in changes of relative organ weight of the rats. This combination of events suggested that a mild and inconspicuous improvement of severe diabetes in STZ-treated rats with the Cordyceps preparations under the experimental conditions. In general, there were no differences between the naturally produced and fermented mycelia of Cordyceps in alleviating diabetes in the present experiments.