A direct protein kinase B-targeted anti-inflammatory activity of cordycepin from artificially cultured fruit body of Cordyceps militaris

BACKGROUND: Cordyceps militaris is one of well-known medicinal mushrooms with anti-inflammatory, anti-cancer, anti-diabetic, and anti-obesity activities. OBJECTIVE: The objective of the following study is to isolate chemical components from the ethanol extract (Cm-EE) from Cordyceps militaris and to evaluate their anti-inflammatory activities. MATERIALS AND METHODS: Column chromatographic separation was performed and anti-inflammatory roles of these compounds were also examined by using NO production and protein kinase B (AKT) activity assays. RESULTS: From Cm-EE, 13 constituents, including trehalose (1), cordycepin (2), 6-hydroxyethyladenosine (3), nicotinic amide (4), butyric acid (5), β-dimorphecolic acid (6), α-dimorphecolic acid (7), palmitic acid (8), linoleic acid (9), cordycepeptide A (10), 4-(2-hydroxy-3-((9E,12E)-octadeca-9,12-dienoyloxy)propoxy)-2-(trimethylammonio)butanoate (11), 4-(2-hydroxy-3-(palmitoyloxy)propoxy)-2-(trimethylammonio)butanoate (12), and linoleic acid methyl ester (13) were isolated. Of these components, compound 2 displayed a significant inhibitory effect on NO production in lipopolysaccharide (LPS)-activated RAW264.7 cells. Furthermore, this compound strongly and directly suppressed the kinase activity of AKT, an essential signalling enzyme in LPS-induced NO production, by interacting with its ATP binding site. CONCLUSION: C. militaris could have anti-inflammatory activity mediated by cordycepin-induced suppression of AKT.