Anticancer Activity of Combined Extracts of Sappan Wood (Caesalpinia sappan L.) and Coffee Stem Parasite (Loranthus ferrugineus Roxb) Against MCF7 Breast Cancer Cells Through In Silico and In Vitro Approaches

Breast cancer remains the most prevalent malignancy among women worldwide. Adverse side effects associated with conventional cancer therapies have driven the search for alternative chemopreventive agents from natural sources. Caesalpinia sappan L. and Loranthus ferrugineus Roxb. have long been used in traditional medicine and possess anticancer properties. This study aimed to evaluate the anticancer activity of single and combined extracts of C. sappan L. and L. ferrugineus Roxb. against Michigan Cancer Foundation-7 (MCF-7) breast cancer cells and elucidate their molecular mechanisms via in silico docking simulations. In silico screening focused on brazilin and quercetin, the principal phytoconstituents of C. sappan L. and L. ferrugineus Roxb., respectively, compared with a standard drug targeting cytochrome P450 3A4 (CYP3A4, PDB ID: 1TQN) using PyRx AutoDock Vina. The resazurin reduction assay was used to determine in vitro cytotoxicity against MCF-7 cells using acetone extracts of L. ferrugineus Roxb., C. sappan L., and their combinations at ratios of 1:1, 2:1, and 1:2. In silico results indicated that brazilin and quercetin complied with Lipinski’s Rule of Five, with binding affinities of −8.2 kcal/mol and −8.9 kcal/mol, respectively, whereas their combination violated the rule. While both compounds individually exhibited promising anticancer potential, their combination showed a competitive antagonistic effect. In vitro findings showed that C. sappan L. extract exerted moderate cytotoxicity (IC50 = 56.21 µg/mL), whereas L. ferrugineus Roxb. extract had an IC50 of 112.9 µg/mL. All extract combinations were inactive, indicating antagonistic interactions between the secondary metabolites of both plants.