Biotransformation and activity identification of icariin in human intestinal fungus <i>Pichia occidentalis</i>

Compared to icariin, icariside II demonstrates superior absorption and metabolic properties along with enhanced bioactivity. In this study, using DXM-Glc fluorescence assay, <i>Pichia occidentalis</i> was identified as an intestinal fungus expressing functional glucosidase, which could efficiently convert icariin to icariside II via glycosidic bond hydrolysis, revealing the fungus-mediated intestinal glycoside metabolism pathway and determining the optimal conditions for the conversion, including temperature, drug loading, pH and reaction time. Meanwhile, icariside II exhibited anti-glioma activity, and its mechanism of action involved the inhibition of the activation of NF-κB signaling pathway in glioma cells.