Total Phenolic Content and Antioxidant Activity of Mycelial Extracts from the Medicinal Fungus Paecilomyces hepiali (Ascomycetes)

Paecilomyces hepialid, a fungus originating in the Tibetan Plateau, has been used as a substitute for Ophiocordyceps sinensis because the primary chemical compounds and pharmacological effects of P. hepialid are similar to those of O. sinensis. P. hepialid has been developed into a dietary supplement and pharmaceutical products. The antioxidant activity of extracts using 2 solvents (water and ethanol) from mycelia obtained from 2 cultivation modes (solid-state and submerged cultivation) were evaluated in this study. Four strains of P. hepialid obtained from Qinghai, Sichuan, and Yunnan Provinces were included; the total phenolic content and in vitro antioxidant activity of mycelial extracts were compared. The total phenolic content and antioxidant activity of strains were found to be affected by the cultivation mode and extraction solvent. The ethanol extracts of solid-state cultivation of strain 2138, obtained from Sichuan Province, exhibited the highest antioxidant activity. The results showed that different strains might require different cultivation modes and extraction solvents for better antioxidant activity. However, solid-state cultivation and ethanol extraction are generally recommended based on the analyses conducted. Strain 2138 may be a good candidate for the purpose of producing functional foods. The results suggest that strain selection is important when P. hepialid is used to manufacture pharmaceutical products.