RESEARCH ARTICLE
Chemical Composition, Free Radical Scavenging and Antimicrobial Activities of Essential Oil of Vahl

The study of medicinal plants in different parts of the world has led to major breakthroughs in drug chemistry. The increased interest in discovering drugs from natural source led to our investigation of the chemical composition, antioxidant and antimicrobial activities of the essential oil of Mariscus alternifolius Vahl, used in the treatment of wounds, bacterial and infectious diseases in ethno medicine.

The plant essential oil was collected over hexane by Hydro distillation technique and Gas Chromatography-Mass Spectrometry (GC- MS) was employed for analysis. Antioxidant activity of the essential oil was evaluated using the 2,2-diphenylpicrylhydrazyl (DPPH) method while the antimicrobial screening was determined by the agar well diffusion method.

GC-MS analysis revealed the presence of a total of 10 constituents representing 71.91% with tricosane (19.45%) as the most abundant constituent in the essential oil of the plant while others with relatively high percentages include z-14-nonacosene (13.37%) and octacosyltriflouroacetate (10.91%). The free radical scavenging activity of the essential oil gave percentage inhibition of 97.95% at 5 mg/ml which was comparable to that of the standard antioxidant ascorbic acid (97.88%) used for the assay. The essential oil inhibited the growth of Staphylococcus aureus, Escherichia coli, Bacillus substilis, Pseudomonas aeruginosa, Klebsiella pneumoniae, Salmonella typhi, Candida albicans and Aspergillus niger used in this study. The minimum inhibitory concentration (MIC) of 25 mg/ml was observed for Staphylococcus aureus and Escherichia coli.

In summary, the essential oil of M. alternifolius Vahl. possesses high antimicrobial and antioxidant activities.

This study therefore provide some scientific basis for its utilization in ethno medicine.