Chemical Profile, Antibacterial Activity and Antioxidant Activity of Bark Volatile Oil of Terminalia arjuna

Terminalia arjuna is an evergreen medicinal plant that belongs to the Combretaceae family of flowering plants. The bark of the plant exhibits antiviral, anticancer, hypocholesterolemic, antioxidant and antimicrobial properties. In this study, composition antibacterial activity, antioxidant activity and cytotoxicity of bark oil of Terminalia arjuna(Roxb.) were reported. Oils were extracted by microwave assisted hydrodistillation where an oil yield of 0.18 % was obtained followed by the identification of 35 compounds by gas chromatography mass spectrometry. The most abundant volatiles were furfural (11.11 %), isoeugenol (9.99 %), p-ethylguaiacol (9.97 %), α-cadinol (9.57 %), and estragole (9.47 %). The oil was further evaluated against ten different drug resistant strains where oil showed significant activity against all pathogens and the highest activity was found against Acinetobacter baumannii(22 mm), Klebsiella pneumoniae (22 mm) and Staphylococcus aureus(22 mm) in a concentration-dependent manner. Antioxidant activity evaluation demonstrated 68 % radical scavenging activity by the volatile oil as compared to 81 % of the standard, ascorbic acid at a concentration of 1000 μg. Cytotoxicity studies were conducted to see the effect of sample on the expression level of a housekeeping gene, Glyceraldehyde 3-phosphate dehydrogenase where it did not affect the normal transcription of the gene.