Investigation of Proteomic Responses and Anticancer Activities of an Isolated Strain of Cordyceps sinensis Under Different Nutritional Fermentation Conditions

Cordyceps sinensis is a fungal parasite on the larvae of Lepidoptera and has been used as a tonic herb in the traditional Chinese medicines. The fruit bodies of C. sinensis are limited because of the difficulty in cultivation. The mycelia produced by the fermentation have already become the best substitute for C. sinensis. The fungus strain called G308-1 strain used in this study was isolated from the fruit bodies of C. sinensis in Yunan Province of People Republic of China. From the comparisons of rDNA sequences against Gene Bank, the G308-1 strain was identified as Paecilomyces farinosus. In this study, the proteomic profiles of the G308-1 strain grown in the different liquid media containing glucose, sucrose, maltose or lactose as the sole carbon source were established using two-dimensional gel electrophoreses. The proteomes of the mycelia in the glucose media were compared respectively to those in the other three media. The comparative results showed that two, five and seventeen protein spots were repressed respectively in the mycelia in the sucrose, maltose and lactose media while six, three and eight protein spots were induced respectively. In order to explore the correlation between the proteomes and the anticancer activities of the mycelia, the water or ethanol extracts of the G308- 1 strain cultivated in various media were examined for their abilities to suppress the HepG2, Du145, Hela and MCF-7 cells. The anticancer results demonstrated that the water extracts showed the selectivity to Hela and Du 145 cells and the high concentrations of the water extracts made from the mycelia in the lactose media had better suppressive effects on the HepG2 cells. Essentially the ethanol extracts prepared from the mycelia in the lactose media showed much better inhibitory activities to each cell line than those from the other three media. The above results suggested the anticancer results might vary with the proteome profile changes which probably resulted in the production of a different array of bio-products in the mycelia under the different nutritional conditions.