Anti-inflammatory and anticancer effects of the styrylpyrone-class polyphenol hypholomine B from Tropicoporus linteus (syn. Phellinus linteus) HN00K9.

Hypholomine B, a styrylpyrone-class polyphenol, was isolated from the fruiting body of Tropicoporus linteus (syn. Phellinus linteus) HN00K9 and identified using mass spectrometry and NMR spectroscopy. We evaluated the anti-inflammatory effects of hypholomine B using lipopolysaccharide (LPS)-stimulated mouse macrophage RAW 264.7 cells. The hypholomine B showed proliferative activity in LPS-activated cells at a high concentration of 250 µg/mL, without cytotoxicity. In contrast, hispidin was cytotoxic, inhibiting cell viability at concentrations above 30 µg/mL. Treatment with hypholomine B caused a concentration-dependent decrease in nitric oxide (NO) release from LPS-activated cells. In addition, hypholomine B suppressed the LPS-induced secretion of the proinflammatory cytokines IL-6 and TNF-α in RAW 264.7 cells. Furthermore, it was revealed that hypholomine B has an anticancer effect against HCT116 human colon cancer cells through apoptosis induction.