Reducing cellular inflammation and oxidation by supercritical CO₂ extracts from edible-medicinal mushrooms

Extracts from Hericium erinaceus, Ganoderma lucidum and Tremella fuciformis obtained with supercritical CO₂ showed high cellular antioxidant activity (CAA) when tested on Caco-2 cell cultures. Extract obtained in separator 2 (5 MPa) after 3 h extraction at 30 MPa and 40 °C from G. lucidum showed a remarkable higher CAA than noticed for the other species. In addition, extracts to THP-1 macrophages reduced secretion of TNF-α and particularly IL-6 (80-90 % applied at 15 μg/mL). The G. lucidum extract was also more effective than those from the other two species except for IL-1β. The use of ethanol 5 % (v/v) as co-solvent for extractions increased the yield but reduced both activities. Extracts from studied species contained linoleic, oleic, α-linolenic and palmitic acids as the main fatty acids, and ergosterol and ergosterol peroxide (EP) as fungal sterols. Those obtained from G. lucidum included ganoderic acids A and D, ganoderol B and lucidenic acid A. When identified compounds were tested, ganoderol B, ganoderic acid A, linoleic acid, α-linolenic acid and EP showed remarkable CAA. The anti-inflammatory activities of α-linolenic and linoleic acids were higher than those noticed for ergosterol and EP, and the latter compounds were more effective than the other tested triterpenoids. These results suggest that the anti-inflammatory effect noticed (particularly for G. lucidum extract) might be due to a synergistic activity of the indicated compounds.