TO STUDY IMMUNOMODULATORY AND ANTIOXIDANT ACTIVITY OF OCIMUM SPP OF WESTERN HIMALAYAN REGION

Abstract

newline ABSTRACT newlineHimalayan medicinal plants are being used since antiquity to treat variety of ailments. The prime objective of Ayurveda, one of the ancient Indian system of medicines, is the prevention of disease process. Tulsi plants (family Lamiaceae) are widely used in the Ayurvedic system of medicine for bronchitis, bronchial asthma, skin diseases, arthritis, inflammation, fever etc. Ocimum spp. have been shown contain several bioactive compounds which act as safe guards against several diseases. Using Liquid-liquid extraction method methanolic extracts of O. sanctum, O. basilicum, O. gratissimum leaves were fractionated into chloroform fraction, ethyl acetate fraction, butanol and aqueous fractions. The phytochemical screening showed presence of various compounds like tanins, flavonoids, alkaloids, carbohydrates, terpenoids in these extracts/fractions. ABTS assay was performed to analyze the antioxidant/ free radical scavenging properties of Ocimum spp. extracts/fractions. Among the selected species, O. gratissimum (aqueous fraction IC50 0.99±0.116) showed highest free radical scavenging activity as compared to O. sanctum (butanol fraction IC50 1.15±0.069), O. basilicum (butanol fraction IC50 1.33±0.058) and the results were comparable with that of the standard antioxidant compound ascorbic acid (IC50 1.58±0.03). The human peripheral blood mononuclear cells (PBMC) were used as model system to evaluate the comparative immunomodulatory effects of methanolic extracts and fractions of Ocimum spp. The cytostimulation assay demonstrated that ethyl acetate fraction of O. basilicum triggered maximum immunoenhancing effect on the PBMC (EC50 0.88±0.03). The butanol fraction of O. sanctum showed second best immunostimulating activity (EC50 1.15±0.91). The ethyl acetate fraction of O. gratissimum also exhibited stimulating effect on human PBMC (EC50 1.75±0.11) whereas it is observed that the chloroform fractions of O. gratissimum and O. sanctum have cytotoxic effect on human immune cells. As ethyl acetate fractio