Metabolic Profiling GC‒MS, HPLC‒ESI‒MS/MS, In Vitro, and In Silico Assessment of the Cytotoxic and Antimicrobial Effects of Gmelina philippensis Cham. Bark Extract.

Abstract

Gmelina philippensis is an ornamental plant from the family Lamiaceae. From published data, not enough information concerning our targeted species' active constituents or even cytotoxic and antimicrobial effects. In accordance, this study aimed to investigate the phytoconstituents through GC‒MS and HPLC‒ESI‒MS/MS analysis, followed by assessing antimicrobial and cytotoxic activities and elucidating the mechanism via an in silico study. GC‒MS revealed 25 compounds, 1,2,5,6-tetrahydroxy-9,10-dimethyl anthracene and 5-phenyl undecane benzene, 1-butyl heptyl, of the highest concentrations. Thirty compounds, mainly flavonoids and phenolic acids, were identified through HPLC‒ESI‒MS/MS. Cytotoxicity was evaluated against five cancer cell lines, including A-549, WI-38, HepG-2, HCT-116, and MCF-7, and using cisplatin as a reference drug. The highest activity was on HCT-116 cells, with an IC₅₀ of 1.56 µg/mL. Evaluation of the antimicrobial activity with ciprofloxacin as a positive control showed potent antimicrobial activity. In silico study indicated that compounds, including 1,2,5,6-tetrahydroxy-9,10-dimethylanthracene from GC‒MS analysis and isorhamnetin-3-O-rutinoside from LC‒ESI‒MS/MS analysis, demonstrated potential binding affinities with docking scores of -6.912 and -9.306 kcal/mol, respectively. Such highly negative docking scores reflect strong binding interactions with the EGFR protein, suggesting their potential to inhibit its kinase activity and thereby contribute to the observed anticancer effects. Finding implies anticancer effects observed in the extract could be associated with their potential to inhibit the EGFR protein, a key target involved in cancer cell proliferation and survival. In conclusion, G. philippensis can be a successful natural substitute with fewer side effects than synthetic agents.