Bioactive Compounds, Antioxidant Potential, and Cytotoxic Activities of Submerged Cultivated Mycelia of Medicinal Higher Basidiomycetous Mushrooms

Natural antioxidants are essential for protecting the body against oxidative stress and exhibit a wide range of biological activities. In this context, forty extracts derived from ten submerged cultivated mushroom species were analyzed for their mycochemical composition, antioxidant capacity, and cytotoxic effects against MCF7 breast cancer cells. Qualitative and quantitative screening revealed that, among the detected classes of bioactive compounds, the extracts were predominantly enriched in flavonoids, terpenoids, and phenolic constituents. Considerable variation was observed in the levels of total phenolics, flavonoids, and ascorbic acid among different species and solvent extracts. The highest total phenolic contents were detected in ethanol and ethyl acetate extracts of G. frondosa (110.0 ± 6.4, 227.6 ± 14.2, and 160.5 ± 5.3 mg GAE/g), while the water extract of F. velutipes also exhibited elevated phenolic levels (119.2 ± 6.5 mg GAE/g). Flavonoid concentrations ranged from 102.5 ± 10.5 to 359.9 ± 2.5 mg QE/g in biomass and culture liquid extracts obtained with organic solvents. Ascorbic acid content was generally highest in ethyl acetate culture liquid extracts, suggesting solvent-dependent enrichment of antioxidant metabolites. Free radical scavenging activity increased in a concentration-dependent manner, reaching inhibition values more than 90% at 20 mg/mL in all tested mushrooms. Cytotoxicity assays demonstrated that extract type, solvent, and incubation time strongly influenced the inhibition of MCF7 cell viability. Ethyl acetate extracts from H. erinaceus, P. ostreatus, T. versicolor, and T. pubescens exhibited the strongest cytotoxic effects, reducing cell viability by up to 70% at higher concentrations. The results demonstrate that mushroom extracts, particularly ethyl acetate extracts, possess significant antioxidant and cytotoxic activities. These findings highlight their potential as promising natural sources of medicinal bioactive compounds for antioxidant and anticancer applications.