Background/Objectives: Breast cancer is the most commonly diagnosed cancer among women worldwide, with triple-negative breast cancer (TNBC) being a highly aggressive subtype characterized by early recurrence, limited targeted therapies, and poor clinical outcomes. Despite advances in chemotherapy, therapeutic resistance remains a major challenge, underscoring the need for alternative therapeutic approaches. Natural products continue to serve as important sources of bioactive compounds for cancer drug discovery. Tiliacora triandra, a Thai medicinal plant traditionally used to manage inflammatory and metabolic disorders, has not been extensively investigated for its potential against TNBC. In this study, we evaluated the anti-cancer effects of T. triandra extracts and its major flavonoid constituent, pectolinarigenin, in triple-negative breast cancer, MDA-MB-231 cells. Methods: An 80% ethanolic root extract was sequentially partitioned into hexane, dichloromethane, and ethyl acetate fractions. High-performance liquid chromatography identified pectolinarigenin as a predominant component of the dichloromethane fraction (TT-DCM), with a quantified content of 14.24 ± 2.32 mg/g extract. The anti-cancer effect of TT-DCM and pectolinarigenin on MDA-MB-231 cells were investigated using colony formation, cell cycle analysis, PI/Annexin V staining, and Western blot analysis. Results: Both TT-DCM and pectolinarigenin significantly reduced MDA-MB-231 cell viability and clonogenic growth. Treatment resulted in G0/G1 phase accumulation, accompanied by decreased expression of cyclin D1, CDK2, and CDK4. Apoptotic induction was observed, as evidenced by lower expression levels of Bcl-xL, Bcl-2, and surviving proteins, together with increased caspase-9 and caspase-3 activities. Additionally, TT-DCM and pectolinarigenin were associated with reduced phosphorylation of ERK1/2, JNK1/2, and p38 MAPKs. Conclusions: Collectively, these findings demonstrate that pectolinarigenin derived from T. triandra exerts potent anti-cancer activity in MDA-MB-231 TNBC cells through coordinated modulation of cell cycle progression, apoptotic signaling, and MAPK pathway activity. Further studies are warranted to validate these effects in additional TNBC models.
Arjsri et al. (Fri,) studied this question.