Phytochemicals from Vanda bensonii and Their Bioactivities to Inhibit Growth and Metastasis of Non-Small Cell Lung Cancer Cells.

The most prevalent lung cancer is non-small cell lung cancer (NSCLC). This lung cancer type often develops other organ-specific metastases that are critical burdens in the treatment process. Orchid species in the genus Vanda have shown their potential in folkloric medication of diverse diseases but not all its species have been investigated, and little is known about their anticancer activities against NSCLC. Here, we firstly profiled the specialized metabolites of Vanda bensonii and examined their capability to inhibit growth and metastasis of NSCLC using NCI-H460 cells as a study model. Four phytochemicals, including phloretic acid methyl ester (1), cymbinodin-A (2), ephemeranthoquinone B (3), and protocatechuic acid (4), were isolated from the whole plant methanolic extract of V. bensonii. The most distinguished cytotoxic effect on NCI-H460 cells was observed in the treatments with crude methanolic extract and compound 2 with the half maximal inhibitory concentrations of 40.39 μg mL−1 and 50.82 μM, respectively. At non-cytotoxic doses (10 μg mL−1 or 10 μM), only compound 1 could significantly limit NCI-H460 cell proliferation when treated for 48 h, while others excluding compound 4 showed significant reduction in cell proliferation after treating for 72 h. Compound 1 also significantly decreased the migration rate of NCI-H460 cells examined through a wound-healing assay. Additionally, the crude extract and compound 1 strongly affected survival and growth of NCI-H460 cells under anchorage-independent conditions. Our findings proved that natural products from V. bensonii could be promising candidates for the future pharmacotherapy of NSCLC.