Flavonoids, the key active compounds in Epimedii Folium, have both protective and toxic effects on the liver. Their hepatoprotective effects are associated with reducing lipid accumulation and oxidative stress, which contribute to the management of various liver conditions. In contrast, the mechanisms driving Epimedii Folium-induced hepatotoxicity are less understood but likely involve oxidative stress and pyroptosis. Pharmacokinetic studies, especially on icaritin, indicate that it undergoes isopentenyl dehydrogenation, glycosylation, and glucuronidation in vivo, contributing to its pharmacological effects. However, intermediate metabolites of icaritin may interact with biomolecules, potentially leading to liver toxicity. This review offers a detailed examination of the dual effects of Epimedii Folium flavonoids on liver function, emphasizing recent discoveries in their hepatoprotective and hepatotoxic pathways. We also summarize and discuss the pharmacokinetics of these flavonoids, highlighting how their metabolism affects therapeutic efficacy and toxicity. Lastly, we propose strategies to mitigate liver injury, providing new perspectives on the safe use of Epimedii Folium.

Artemisinin and its derivatives (ARTs) were reported to display heme-dependent antitumor activity. On the other hand, histone deacetylase inhibitors (HDACi) were known to be able to promote heme synthesis in erythroid cells. Nevertheless, the effect of HDACi on heme homeostasis in non-erythrocytes remains unknown. We envisioned that the combination of HDACi and artesunate (ARS) might have synergistic antitumor activity through modulating heme synthesis. studies revealed that combination of ARS and HDACi exerted synergistic tumor inhibition by inducing cell death. Moreover, this combination exhibited more effective antitumor activity than either ARS or HDACi monotherapy in xenograft models without apparent toxicity. Importantly, mechanistic studies revealed that HDACi coordinated with ARS to increase 5-aminolevulinate synthase (ALAS1) expression, and subsequent heme production, leading to enhanced cytotoxicity of ARS. Notably, knocking down significantly blunted the synergistic effect of ARS and HDACi on tumor inhibition, indicating a critical role of ALAS1 upregulation in mediating ARS cytotoxicity. Collectively, our study revealed the mechanism of synergistic antitumor action of ARS and HDACi. This finding indicates that modulation of heme synthesis pathway by the combination based on ARTs and other heme synthesis modulators represents a promising therapeutic approach to solid tumors.