Antioxidant and Antimicrobial Activities of β-Caryophyllene dominated Leaf Essential oil of Trichilia monadelpha (Thonn.) JJ De Wilde

Abstract

Trichilia monadelpha (Thonn) JJ De Wilde (Meliaceae) is an essential plant of diverse medicinal uses in folk medicine. It is deployed in the treatment of ulcers/epidermal infections, epilepsy, gonorrhea and inflammatory disorders such as arthritis etc. This study investigated the leaf essential oil constituents of T. monadelpha along with the corresponding antioxidant and antimicrobial activities. The essential oil of fresh leaves of T. monadelpha was isolated by hydrodistillation using all glass Clevenger distillation apparatus while the identification and characterization was done by Gas Chromatography-Mass Spectrometry (GC-MS). Antioxidant activity was carried out by scavenging effect on 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) at 517nm in a UV-Visible spectrophotometric assay with  Ascorbic acid,  Butylated hydroxylanisole (BHA) and α-Tocopherol as reference standards. Antimicrobial assay was examined by Agar diffusion method. A total of fifteen compounds were identified in the essential oil with β-Caryophyllene (35.41%) as the major constituent. The oil demonstrated moderate inhibition against seven of the ten microorganisms used for the assay, namely: Staphylococcus aureus, Esherichia coli, Bacillus subtilis, Pseudomonas aerugunosa, Candida albicans, Aspergillus niger, Rhizopus stolonifer. The antioxidant activity of the essential oil (IC₅₀ of 3.72 mg/ml) though lower than that of ascorbic acid (IC₅₀ of 1.47 mg/ml) and BHA (IC₅₀ of 1.88 mg/ml) was however better than that of α-Tocopherol (IC₅₀ of 4.83 mg/ml).The results obtained corroborated the uses of Trichilia monadelpha in folk medicine.

Keywords: Gas Chromatography-Mass Spectrometry, Essential oil, β-Caryophyllene, Antioxidant and Antimicrobial Activities.

DOI: 10.7176/JNSR/11-16-05

Publication date:August 31^st 2020