Herbal Medicine in Breast Cancer Therapy: Mechanisms, Evidence, and Future Perspectives

Breast cancer remains a leading global cause of cancer-related mortality among women, requiring the development of safer and more effective therapeutic strategies. Herbal medicines have gained increasing attention as complementary approaches due to their multi-targeted actions, more limited toxicities, and the potential ability to overcome resistance associated with conventional treatments. This review highlights the antitumor properties and underlying mechanisms of several well-studied herbal compounds, including curcumin, resveratrol, epigallocatechin gallate, withaferin A, thymoquinone, baicalin, berberine, Oldenlandia diffusa, and Salvia miltiorrhiza. These phytochemicals exert antitumor effects by inducing apoptosis, inhibiting cell proliferation and metastasis, modulating immune responses, and sensitizing tumor cells to chemotherapy and radiotherapy. Furthermore, many of these agents regulate key signaling pathways, such as nuclear factor kappa-light-chain-enhancer of activated B cells, phosphatidylinositol 3-kinase/AKT, p53, signal transducer and activator of transcription 3, and extracellular signal-regulated kinases 1/2, and the tumor microenvironment. Despite promising preclinical and early clinical evidence, challenges remain regarding the bioavailability, standardization, and large-scale clinical validation of these phytochemicals. This review underscores the therapeutic potential of herbal medicines in breast cancer treatment and advocates for further research to facilitate their integration into evidence-based oncology practice.