Icariside II

The urgent need for new hepatocellular carcinoma (HCC) therapies has driven the exploration of natural product scaffolds. In this context, Icariside II (ICA-II) presents a valuable starting point for structural optimization. Applying bioisosterism and pharmacophore hybridization, we synthesized a series of 26 nitrogen heterocycle-modified ICA-II derivatives. Subsequent structure-activity relationship (SAR) profiling highlighted compound 3b as the most potent analog. This molecule exhibited robust anti-proliferative activity across multiple HCC cell lines (HepG2, Hep3B, and Huh7), surpassing both the parent ICA-II and the positive control Sorafenib. To uncover its primary target, we integrated network pharmacology with molecular docking and dynamics simulations. This computational prediction was further supported by cellular thermal shift assays and EGFR enzymatic inhibition studies, suggesting EGFR as a potential target of 3b. Compound 3b suppressed EGFR phosphorylation and inhibited the downstream PI3K/Akt signaling pathway. This blockade precipitates a profound intracellular accumulation of reactive oxygen species ultimately driving the cancer cells into caspase-dependent apoptosis. Animal studies using a Huh7 xenograft model further corroborated its therapeutic potential. Compound 3b administration markedly suppressed tumor growth without significant body weight loss or obvious histopathological abnormalities in major organs under the tested conditions, notably outperforming the clinically approved agent Icaritin. Preliminary pharmacokinetic studies further demonstrated that 3b achieved robust systemic exposure and a prolonged retention time following intravenous administration. Overall, our work provides a successful structural optimization rationale for ICA-II and advances 3b as a safe, EGFR-modulating lead compound for HCC intervention.