Chemical composition, antioxidative and antimicrobial activity of essential oil of Ocimum sanctum L.

Abstract

Ocimum sanctum L. (Lamiaceae) sin. Ocimum tenuiflorum L. or Tulsi basil is a plant originating from the tropical and subtropical areas of India. It is used in both the traditional and official medicine in India. Tulsi is a type of basil that is insufficiently explored and studied in Europe. The goal of this paper is to determine the chemical composition, antioxidative, and antimicrobial activity of the essential oil Ocimum sanctum L. grown in Serbia. The quantity of essential oil in 100 g of herb (v/w) is 0.68%, with 41 components identified in the tested essential oil. The most represented chemical group were sesquiturpene hydrocarbonates with 80.47%. Other groups were much less represented. Sesquiturpene hydrocarbonate β-cariophyllene is a predominant component in the essential oil with 63.80%. The quantity of tested essential oil needed to achieve 50% of inhibition of DPPH radicals is 0.35 µg/ml, and it has high potential to neutralize free radicals. The essential oil exhibited antibacterial activity to all tested strains of bacteria, both Gram-positive and Gram-negative. It affected all strains in an inhibitory way in the interval 0.34-41.50 µl/ml, and in a bactericide way within the range 22.50-124.5 µl/ml. The most sensitive strains of bacteria were Salmonella typhimurium and Escherichia coli, while Listeria monocytogenes and Enterococus faecalis showed greatest resistance. The essential oil exhibited antifungal activity on all tested fungi. It affected all tested fungi in an inhibitory way in the interval 4.42-8.83 µl/ml, and in a microbicide way within the range 10.00-50.00 µl/ml. The most sensitive fungi are: Aspergillus ochraceus, Penicillium ochrochloron and Penicilium funiculosum, while the most resistant one is Aspergillus niger. The tested basil essential oil Ocimum sanctum demonstrated significant antioxidative and antimicrobial effect and may be used as a raw material in food, pharmaceutical and chemical industries.

U radu su prikazani rezultati ispitivanja hemijskog sastava, antioksidativne i antimikrobne aktivnosti etarskog ulja Ocimum sanctum L. gajenog u Srbiji. Količina etarskog ulja u suvoj herbi prosečno iznosi 0,68%. U njemu je identifikovana 41 komponenta. Najzastupljenija hemijska grupa su seskviterpenski ugljovodonici sa 80,47%. Seskviterpenski ugljovodonik β-kariofilen je sa 63,80% dominantna komponenta u etarskom ulju. Količina etarskog ulja koja je potrebna da se ostvari 50% inhibicije DPPH radikala iznosi 0,35 |µg/ml te ono poseduje visoku sposobnost neutralizacije slobodnih radikala. Etarsko ulje je ispoljilo antibakterijsku aktivnost na sve testirane Gram-pozitivne i Gram-negativne bakterijske sojeve. Ono je delovalo na sve sojeve inhibitorno u intervalu 0,34-41,50 |µl/ml i baktericidno u opsegu 22,50-124,50 |µl/ml. Etarsko ulje je ispoljilo i antifungalnu aktivnost na sve testirane gljive i delovalo je inhibitorno u intervalu 4,42-8,83 |µl/ml i mikrobicidno u opsegu 10,00-50,00 |µl/ml.