Chemical composition of the mushroom Meripilus giganteus Karst. and bioactive properties of its methanolic extract

- M. giganteus showed to be rich in carbohydrates and proteins, with low fat content.
- Tocopherols, five organic acids and three phenolic acids were identified.
- M. giganteus extract exhibited antioxidant and antimicrobial activity.
- M. giganteus extract reduced cancer cells viability and induced apoptosis.
- M. giganteus extract inhibited migration of cancer cells in vitro.

Wild Meripilus giganteus Karst belongs to the order Polyporales, in which some members are known to possess a wide range of pharmacological properties. M. giganteus showed to be rich in carbohydrates (74.49 g/100 g) and proteins (15.94 g/100 g), presenting low fat content (1.51 g/100 g). Chemical composition was determined by using chromatographic techniques. Also, various bioactive compounds were detected including all four tocopherol isoforms with δ- and γ-tocopherols being predominant (123.35 and 77.80 μg/100 g, respectively); five organic acids (oxalic, malic, quinic, citric and fumaric acids) with predominant malic acid (3.17 g/100 g); and three phenolic acids and related compounds (p-hydroxybenzoic, p-coumaric and cinnamic acids; 1010, 2420 and 340 μg/100 g, respectively). M. giganteus methanolic extract exhibited antioxidant activity tested by five different assays with the strongest potential in TBARS assay (EC50 0.31 mg/mL); and antimicrobial activities (MIC/MBC 0.0125-5 mg/mL; MIC/MFC 0.025-0.4 mg/mL). Furthermore, treatment of cervical carcinoma cell line (HeLa) led to reduction in cell's viability in MTT assay (IC50 0.41 mg/mL after 48 h), induced process of apoptosis and inhibited cell's migration in vitro. The analysed extract was not toxic for zebrafish embryos (at 0.5 mg/mL), indicating its biosafety and potential application as a dietary supplement in chemoprevention.