Bioactivity-guided isolation followed by network pharmacology and molecular docking reveals a novel polyphenolic xanthone, β-mangostin from Garcinia cowa leaves as a potent compound against non-small cell lung cancer

Abstract

Objective: Garcinia spp. is a very popular genus in China used by the Chinese ethnic people for hundreds of years for its several ethnomedicinal uses. The plant is popularly known in China as 藤黄 Ténghuáng (yellow gum resin) as they are characterized by a brownish-yellow gum resin. Previously, we reported that leaf methanol extract of Garcinia cowa induces robust anti-proliferative activity against A549 cells. However, bioactivity-guided isolation of the lead molecules and the possible mechanism of apoptosis were unclear. Hence, the present study aims to identify the lead molecules against non-small cell lung cancer (NSCLC). Also, to assess the molecule's apoptotic potentials and explore the potential anti-NSCLC targets and pathways. Methods: The lead fraction was isolated and identified through the bioactivity-guided isolation process from the leaf methanol extract using several chromatographic methods against the A549 cell line. Molecules were identified through LCMS analysis. The apoptotic effect of the lead molecule was assessed through Annexin V/PI, AO-EtBr, DAPI staining, cell cycle analysis, and measurement of caspase activity. Intracellular redox balance and mitochondrial depolarization were assessed using fluorescent probes like H2DCFDA and JC1. Then, network pharmacology screened key targets and related pathways against NSCLC through protein-protein interaction. The key targets were selected and docked via molecular docking. Results: β-Mangostin was found to be the most abundant lead molecule. β-Mangostin showed an appreciable anti-proliferative and apoptotic effect on A549 cells in contrast to minimal effect on normal BEAS-2B cells and normal PBMC. β-Mangostin induced apoptosis was associated with the generation of intracellular ROS, mitochondrial membrane depolarization, and caspase 3 and 9 activations. The PPI network and network pharmacology results showed that EGFR, MAPK1, MAPK8, and MAPK14 were the possible key targets of the lead molecules. In-silico molecular docking revealed that β-mangostin shows higher binding affinities than the standard anticancer drug nintedanib. Among the four targets, β-mangostin showed the strongest affinity towards MAPK14. Conclusion: Through network pharmacology, molecular docking, and in vitro experiments, β-mangostin an active phytoconstituent of the Chinese medicinal plant Garcinia cowa showed significant anti-NSCLC activity targeting the MAPK pathway.

Keywords

• Garcinia cowa
• NSCLC, β-Mangostin
• Apoptosis
• Network pharmacology
• Molecular docking