Identification of anticancer compounds from Tapinanthus globiferus: integrating in vitro and in silico approaches

Medicinal plants remain a valuable source of structurally diverse natural products with therapeutic potential. Tapinanthus globiferus (Loranthaceae) is widely used for the treatment of cancer-related conditions, yet its chemical and pharmacological basis remains poorly defined. In this study, phytochemical profiling, cytotoxicity testing, and computational analyses were employed to characterize the bioactive potential of T. globiferus leaves. The leaves were subjected to extraction using 70% methanol and subsequently fractionated using butanol. The butanol fraction demonstrated notable cytotoxic activity against HT29 colon cancer cells, consistent with morphological evidence of apoptosis. High-performance liquid chromatography with diode array detection (HPLC-DAD) revealed the presence of abundant phenolic and flavonoid constituents, including kaempferol and quercetin derivatives, rutin, isoquercetin, catechin, and protocatechuic acid, which were identified as candidate marker compounds. To explore mechanisms, major identified compounds were docked in silico to VEGF-A and the anti-apoptotic protein BCL-2. Rutin, trifolin (a kaempferol glycoside), and epigallocatechin exhibited the strongest binding (e.g. rutin: - 8.85 kcal/mol to VEGF-A), surpassing the reference inhibitor Pazopanib (- 3.56 kcal/mol) with multiple stabilizing interactions with these proteins, suggesting potential to interfere with tumor angiogenesis and cell survival pathways. Collectively, these findings provide a scientific basis for the traditional use of T. globiferus and support its fraction as promising sources of multi-targeted anticancer agents. The identification of bioactive compounds further establishes a foundation for bioassay-guided isolation, mechanistic validation, and future drug development.