GC-MS based essential oil profiling and antimicrobial activity evaluation of indigenous medicinal plants from the Himalayan Region

Abstract

Essential oils represent concentrated sources of bioactive secondary metabolites with demonstrated therapeutic potential. This research characterized the chemical composition and antimicrobial properties of essential oils from five indigenous Himalayan medicinal plants using gas chromatography-mass spectrometry analysis. Hydrodistillation of aerial parts yielded essential oils ranging from 0.8% to 2.3% (v/w). GC-MS identified 47-68 compounds per species accounting for 94.2-98.7% of total oil composition. Thymus serpyllum oil contained predominantly thymol (42.3%) and carvacrol (18.7%), while Mentha arvensis showed high menthol content (67.8%). Origanum vulgare demonstrated carvacrol dominance (54.2%). Antimicrobial screening against eight pathogenic bacteria and four fungi revealed broad-spectrum activity with minimum inhibitory concentrations ranging from 0.125 to 2.0 mg/mL. Thymus and Origanum oils exhibited strongest antibacterial effects particularly against Staphylococcus aureus and Escherichia coli. Correlation analysis identified phenolic monoterpenes as primary contributors to antimicrobial potency. These findings support traditional medicinal applications while identifying specific compounds warranting further pharmaceutical development.