Extracts and Steroids from the Edible Mushroom Hypholoma lateritium Exhibit Anti-Inflammatory Properties by Inhibition of COX-2 and Activation of Nrf2

Hypholoma lateritium is an edible macrofungus with a common distribution in Europe, North America, and the Far East. The aim of this study was to investigate the potential anti-inflammatory effects of H. lateritium extracts and its isolated steroids: fasciculic acid B, fasciculol E, fasciculol C, lanosta-7,9(11)-diene-12β,21α-epoxy-2α,3β,24β,25-tetraol, fasciculol F, and demethylincisterol A2. Organic (hexane, chloroform and 50 % methanol) and water extracts of H. lateritium were subjected to in vitro assays to determine pro-inflammatory protein levels, such as cyclooxygenase-2 (COX-2), cytosolic prostaglandin E2 synthase (cPGES), and antioxidant nuclear factor (erythroid-derived 2)-like 2 (Nrf2). Fungal extracts demonstrated significant activities on pro-inflammatory protein levels with minor differences among the activities of the fractions of different polarities. All the compounds proved to exert notable inhibitory properties on COX-2 and were capable to stimulate the Nrf2 pathway. Fungal extracts and the compounds exerted no cytotoxic activities on RAW 264.7 cells.