Comprehensive UPLC-QTOF-MS based metabolic profiling and insights into the bioactive potential of Vanda tessellata: a medicinal orchid

Vanda tessellata (Roxb.) Hook. Ex Don. is a medicinal epiphytic orchid traditionally used to treat inflammation, rheumatism, bronchitis, and other neurological disorders. The present study aimed to investigate the phytochemical composition and evaluate the antioxidant, antityrosinase, antibacterial, and antiproliferative activities of the methanolic extract of Vanda tessellata (VTE). Ultra-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UHPLC-QTOF-MS) was employed to identify the phytoconstituents of VTE tentatively. The phenolic and flavonoid contents were assessed as gallic acid equivalents (GAE) and quercetin equivalents (QE), respectively. The evaluation of antioxidant activity determined using DPPH and ABTS radical scavenging assays. Antityrosinase activity was determined using the mushroom tyrosinase inhibition assay, while antibacterial activity was measured using both well diffusion and broth microdilution methods. Additionally, antiproliferative activity was investigated against Panc-1, HepG2, PC3, and HEK-293 cell lines using the MTT assay. The extract exhibited significant total phenolic and flavonoid content, measuring 95.72 µg GAE/mg of extract and 113.49 µg QE/mg o f extract, respectively. Comprehensive UHPLC-QTOF-MS analysis tentatively identified 33 metabolites, predominantly flavonoids, phenolic acids, carboxylic acids, terpenoids, and alkaloids. VTE showed significant antioxidant activity, with IC₅₀ values of 59.38 ± 0.27 µg/mL and 27.63 ± 0.14 µg/mL in DPPH and ABTS assays, respectively. The extract also exhibited moderate tyrosinase inhibitory activity (IC₅₀ = 235.36 µg/mL), indicating its potential relevance to regulating melanin biosynthesis. Antibacterial evaluation revealed moderate activity against Bacillus cereus and Enterococcus faecalis , with MIC values of 62.5 µg/mL. Furthermore, VTE demonstrated selective antiproliferative activity against Panc-1, HepG2, and PC3 cancer cell lines with IC₅₀ values of 31.16, 54.09, and 62.24 µg/mL, respectively, while exhibiting substantially lower cytotoxicity toward normal HEK-293 cells (IC₅₀ = 221.47 µg/mL). Overall, the findings provide scientific evidence supporting the pharmacological potential of V. tessellata and highlight its promise as a natural source of antioxidant, tyrosinase inhibitory, anticancer, and antibacterial agents.