Secondary Metabolites from Hericium erinaceus and Their Anti-Inflammatory Activities

Hericium erinaceus, a culinary and medicinal mushroom, is widely consumed in Asian countries. Chemical investigation on the fruiting bodies of Hericium erinaceus led to the isolation of one new ergostane-type sterol fatty acid ester, erinarol K (1); and eleven known compounds: 5 alpha,8 alpha -epidioxyergosta-6,22-dien-3 beta-yl linoleate (2); ethyl linoleate (3); linoleic acid (4); hericene A (5); hericene D (6); hericene E (7); ergosta-4,6,8(14),22-tetraen-3-one (8); hericenone F (9); ergosterol (10); ergosterol peroxide (11); 3 beta,5 alpha,6 alpha,22E-ergosta-7,22-diene-3,5,6-triol 6-oleate (12). The chemical structures of the compounds were determined by 1D and 2D NMR (nuclear magnetic resonance) spectroscopy, mass spectra, etc. Anti-inflammatory effects of the isolated aromatic compounds (5-7, 9) were evaluated in terms of inhibition of pro-inflammatory mediator (TNF-alpha, IL-6 and NO) production in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophage cells. The results showed that compounds 5 and 9 exhibited moderate activity against TNF-alpha (IC50: 78.50 mu M and 62.46 mu M), IL-6 (IC50: 56.33 mu M and 48.50 mu M) and NO (IC50: 87.31 mu M and 76.16 mu M) secretion. These results supply new information about the secondary metabolites of Hericium erinaceus and their anti-inflammatory effects.