Polyphenolic composition and antioxidant, antiproliferative, and antimicrobial activities of mushroom Inonotus sanghuang

Inonotus sanghuang (IS) is a mushroom species with some bioactivity. In this study, we characterized in Inonotus sanghuang polyphenolic compounds and assessed antioxidant, antiproliferative, and antimicrobial activities. Inonotus sanghuang was first extracted using ethanol and then the resulting ethanol extract was sequentially partitioned into four fractions. Among these fractions, ethyl acetate fraction (EAF) appeared to contain constituents with the largest antioxidant capacity as demonstrated by DPPH, ABTS, FRAP, and lipid peroxidation inhibition assays (p ≤ 0.05). This fraction also displayed the strongest antiproliferative effect against tumor cell PC3 (IC50, 70.8 μg/mL) determined using a CCK-8 assay. Further, the EAF showed antimicrobial activities against 3 gram-positive bacteria evaluated using an agar well diffusion method. Using LC-MS, six polyphenolics, e.g., rutin, chlorogenic acid, quercitrin, isorhamnetin, quercetin and icarisid II, were identified in the EAF. Total phenol content of Inonotus sanghuang was correlated significantly with FRAP value (r = 0.988, p ≤ 0.001). Thus, the EAF of wild Inonotus sanghuang contains constituents with potent antioxidant, antiproliferative and antimicrobial activities.