From Phytochemistry to Oncology: The Role of Bakuchiol in the Treatment of Breast Cancer.

Bakuchiol (BAK), a natural meroterpenoid with antioxidant, anti-inflammatory and anticancer properties, has recently gained attention as a potential adjunct in breast cancer therapy. This review contextualizes breast cancer as a major global health challenge and highlights BAK as a bioactive compound capable of modulating pathways relevant to tumor development and progression. A structured literature search identified studies examining its molecular activity, pharmacological profile, and effects on breast cancer cells and stem cells. Results show that BAK influences oxidative stress regulation, mitochondrial function, apoptosis and estrogen receptor signaling while also affecting PI3K/AKT, MAPK, NF-κB, and EMT-related pathways. In breast cancer models, BAK acts as a selective phytoestrogen, induces S-phase arrest, activates the ATM/ATR-Chk1/Chk2 axis, and triggers mitochondrial apoptosis, particularly in ERα-positive cells. It also suppresses breast cancer stem-cell renewal, promotes BNIP3- and DAPK2-mediated apoptosis, reduces metabolic and transcriptional drivers of metastasis, and shows enhanced anticancer activity in derivative forms. These findings suggest that BAK may provide therapeutic benefit across several mechanisms central to breast cancer biology. In this review, the inclusion criteria encompassed publications describing the action of bakuchiol, its chemical and pharmacological properties, as well as its role in the treatment of various conditions, including cancers. Exclusion criteria included works not related to BAK or its therapeutic use in breast cancer, as well as publications that did not meet basic scientific standards, such as lacking methodological rigor or presenting a low level of scientific evidence. However, current evidence is predominantly in vitro, and limitations such as poor bioavailability and lack of clinical validation underscore the need for further in vivo and translational studies before therapeutic application can be established.