Therapeutic Potential of Baicalein in Endometrial Cancer: Suppression of mTOR Signaling and Synergy with Metformin

Baicalein, a natural flavonoid derived from traditional medicinal herbs, has demonstrated anticancer activity in various malignancies, but its role in endometrial cancer remains largely unexplored. In this study, we investigated the therapeutic potential of baicalein, alone and in combination with metformin, in human endometrial cancer cells. Given that the mTOR signaling pathway is frequently dysregulated in endometrial cancer due to PTEN loss, we examined how baicalein affects this pathway. Our results demonstrated that baicalein significantly inhibited cell proliferation in a dose-dependent manner, which was associated with increased DDIT4 expression, activation of AMPK, and decreased phosphorylation of mTOR downstream targets S6K1 and S6. In vivo, baicalein treatment led to a reduction in tumor volume in HEC-1A xenograft female nude mice without affecting body weight. While metformin also reduced cell viability, baicalein achieved comparable effects at lower concentrations. The combination of baicalein and metformin produced a synergistic anti-tumor effect and more effectively inhibited the AMPK/PI3K/mTOR signaling pathway than either agent alone. These findings suggest that baicalein may represent a promising, non-toxic therapeutic option for endometrial cancer, particularly when used in combination with metformin. Further investigation is warranted to assess the clinical relevance of this strategy.