Chemical composition and biological potential characterization of leaf extracts of Ocimum gratissimum L with different solvent systems

Abstract

newline xi newlineABSTRACT newlineThe Ocimum gratissimum (family Lamiaceae) is one of the most important medicinal plants, rich newlinein various biological activities. The present study deals with to study the chemical composition newlineand biological potential characterization of leaf extracts of Ocimum gratissimum L. with newlinedifferent solvent systems. In addition to these morphological and anatomical characteristics of newlinethe leaves were also studied. Morphologically plants were observed to be branched, sub shrub newlinewith taproot system. The leaves of the plant were ovate, oppositely arranged and have slender newlinepetiole. Inflorescences were verticillaster type with whitish colour, hermaphrodite flowers. The newlineanatomical study of the leaf of O. gratissimum (T.S.) showed various layers of cells like newlineepidermis, mesodermis, vascular bundle, trichomes, etc. newlineThe phytochemical study showed the presence of alkaloids, saponins, tannins, phenols, newlineflavonoids, carbohydrates and proteins in different leaf extracts (methanol, chloroform, ethyl newlineacetate and hexane) of O. gratissimum. Quantitative analysis revealed maximum carbohydrate newline(304.29±0.35 mg/g GLU), proteins (222.73±0.68 and#956;g/g BSA), flavonoids (125.56±0.52 mg/g newlineRUT), phenols (416±0.50 mg/g GAE), alkaloids (46.36±0.97 %), saponins (61.33±0.16 %) and newlinechlorophyll (0.35±0.04 mg/g) content in the methanolic leaf extract whereas the ethyl acetate newlineextract was observed to be rich in tannin content (448.36±0.55 mg/g GAE). newlineThe DPPH and FRAP assays were used to observe the antioxidant potential of each extract. In newlinethe DPPH assay the highest antioxidant activity showed by the methanolic leaf extract of O. newlinegratissimum (IC50-0.049 and#956;g/ml) followed by ethyl acetate extract (IC50-0.111 and#956;g/ml), chloroform newlineleaf extract (IC50-0.373 and#956;g/ml) and hexane leaf extract (IC50-1.007 and#956;g/ml). Similarly, FRAP newlineassay of O. gratissimum also showed highest antioxidant potential of methanolic leaf extract newline(IC50-9.61 and#956;g/ml) as compared to other extracts. Statistical analysis showed significant and nonsignificant newlinevariations in different leaf extracts of O. gratissimum. The antibacterial activity also newlineshowed the higher antibacterial potential of leaf methanolic extract than the remaining extracts. newlineThe study revealed that the methanolic leaf extract showed best antibacterial results against E. newlinecoli (MIC-0.625 mg/ml), K. pneumoniae (MIC-0.625 mg/ml), B. subtilis (MIC-1.25 mg/ml) and newlineS. aureus (MIC-1.25 mg/ml). newlinexii newlineGC-MS technique is used to know the chemical profile of the methanolic leaf extract of O. newlinegratissimum. Total 8 major bioactive compounds were reported from the methanolic leaf extract newlineof O. gratissimum which were Phenol,2-Methoxy-4-(1-Propenyl), Eugenol, Neophytadiene, newline3,7,11,15-Tetramethyl-2-Hexadecen-1-ol, N-Hexadecanoic Acid, 1H-Cycloprop(E)azulene, newlinePhytol Acetate, DL-Alpha-Tocopherol, Squalene. The present study revealed that from all the newlinetested solvents, methanol had maximum extraction potential for maximum number of newlinephytoconstituents from the leaf extracts of O. gratissimum therefore it can be explored by the newlinepharma companies. newlineKeyword: Ocimum gratissimum, Anatomy, Phytoconstituents, Antioxidant activity, newlineAntibacterial activity, GC-MS.