Extraction and Characterization of the Essential Oil from the Leaves of Ocimum basilicum and Evaluation of its Antioxidant Properties

Abstract

The essential oil was extracted from the leaves of Ocimum basilicum using a modified steam distillation method. The chemical composition and free radical inhibition property of the plant essential oil were investigated. Results from gas chromatography-mass spectrometry revealed the presence of 39 different compounds in the essential oil of Ocimum basilicum. The major components, Terpinen-4-ol (21.31%), Eucalyptol (18.97%), α-Terpineol (14.41%), γ-Terpinene (12.61%), Caryophyllene (11.90%), α-Pinene (6.11%), and β-Myrcene (5.54%), were found in high percentages. The antioxidant activity of the essential oil was evaluated using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide free radical scavenging assays, with Ascorbic acid as a standard drug. The results showed that the essential oil extracted from Ocimum basilicum leaves exhibited positive effects at different concentrations when tested using both methods. At a concentration of 2.5 μL/mL, the Ocimum basilicum essential oil significantly scavenged 60.89% of hydrogen peroxide radicals, while the standard Ascorbic acid scavenged 79.13%. Similarly, at a concentration of 10 μL/mL, the plant’s volatile oil inhibits 87.12% of DPPH radicals, while the standard Ascorbic acid inhibits 90.40%. This study highlights the potential of the essential oil derived from Ocimum basilicum leaves as a valuable source of compounds with free radical scavenging properties, consistent with its traditional medicinal applications. Graphical Abstract showing the entire experimental process: