Antioxidant potential and cytotoxicity of Cordyceps militaris in vitro culture extracts

Abstract

Cordyceps militaris is an entomopathogenic fungus with therapeutic potential in humans. The focus is on its hydroalcoholic extracts, which were obtained from biomass cultured in vitro in molasses. The media were subjected to a colourimetric chemical screening, an in vitro antioxidant potential evaluation by DPPH, ABTS and FRAP, and a cytotoxicity test by MTT assay. The results evidenced the presence of reducing sugars, alkaloids, coumarins, cardiac glycosides, and sesquiterpene lactones in both extracts. Additionally, tannins and quinones were identified exclusively in EHM. EHG exhibited a higher concentration of phenolic compounds (6.6 µg GAE/mg), while EHM demonstrated a higher concentration of phytates (40 µg PAE/mg), and both exhibited similar amounts of saponins (2.55±0.18 µg DGE/mg).

The antioxidant potential of the extracts was assessed using the DPPH, ABTS and FRAP assays. The results demonstrated that EHG exhibited a greater effect in both assays, with 60.98 % and 80.70 % inhibition, respectively. In contrast, no significant difference was observed in the DPPH assay, with an average inhibition of 77.83 %. Both extracts exhibited no cytotoxicity at the concentrations tested, demonstrating 100 % viability (LC₅₀ > 300 µg/mL). It was concluded that the use of different carbon sources in both enriched media for the in vitro culture of C. militaris resulted in a modified chemical profile of the obtained biomass, which exhibited greater phytochemical complexity when cultured with molasses. In contrast, the biomass cultured with glucose showed a notable antioxidant potential in vitro, and no extract exhibited cytotoxicity in the tested cell lines.