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.