Anti-Inflammatory Activity of Chemical Constituents Isolated from the Willow Bracket Medicinal Mushroom Phellinus igniarius (Agaricomycetes)

Nuclear factor-κB (NF-κB) has an important role in immune response and inflammation. Phellinus igniarius (known as Sang huang in traditional Chinese medicine) has various pharmacologic effects. In this study, 19 chemical constituents (1-19) were isolated from the fruiting bodies of Ph. igniarius. Their structures were elucidated based on data from nuclear magnetic resonance spectroscopy and comparison with the literature. Overall, 3 compounds (2, 7, and 11) from this species were reported, to our knowledge for the first time. Two compounds (4 and 15) from the genus Phellinus and 9 compounds (1, 3, 5, 8-10, and 12-14) from the Hymenochaetaceae family were also reported for the first time. An NF-κB luciferase reporter assay of these compounds was carried out in tumor necrosis factor-α-induced HeLa cells-again, to our knowledge for the first time. Among them, compounds 5 and 7 showed moderate inhibition of NF-κB, with fold values of 0.48 ± 0.02 and 0.55 ± 0.09, respectively, in HeLa cells at 100 μmol/L. These results suggest that some of the ingredients from Ph. igniarius could be developed into antiinflammatory agents for use in clinical applications.