Phytochemical analysis and screening of antioxidant, antibacterial and anti-inflammatory activity of essential oil of Premna mucronata Roxb. leaves

Premna mucronata Roxb., commonly known as Agyon, is a plant of family Lamiaceae. This study dealt with the phytochemical analysis of the essential oil from the leaves of Premna mucronata Roxb. (PMLO) using GC/MS technique and screening of its antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH), metal chelating and reducing power assays along with the corresponding antiinflammatory activity using in-vitro albumin denaturation assay and antibacterial activity using well diffusion method against pathogenic bacterial strains, e.g. Escherichia coli and Staphylococcus aureus. The phytochemical analysis of PMLO revealed the presence of over 71 compounds. Accordingly, 3-octanone was found to be the major constituent component accounting for 23.6% of the total oil composition. The other major constituents identified were ethyl hexanol (13.9%), 1-octen-3-ol (9.6%), linalool (5.5%), methyl salicylate (2.9%) and (E)- caryophyllene (2.9%). Moreover, it was found that PMLO possessed satisfied antioxidant activity using DPPH (IC50 = 11.18 ± 0.03 μg/mL), metal chelating (IC50 = 18.82 ± 0.46 μg/mL), and reducing power activities (IC50 = 21.69 ± 0.02 μg/mL) assays. The assessment of in-vitro anti-inflammatory activity of PMLO also gave rise to an IC50 value of 30.27 ± 0.005 μg/mL. Antibacterial activity of PMLO showed zone of inhibitions of 14.33 ± 0.58 mm against E. coli and 14.66 ± 0.58 mm against S. aureus at higher concentrations (1000 ppm). This study revealed that PMLO contained high quantities of 3-octanone, 1-octen- 3-ol, ethyl hexanol, linalool, and exhibited antioxidant, anti-inflammation and antibacterial activities.