Phytochemical analysis of Ocimum gratissimum by LC-ESI-MS/MS and its antioxidant and anxiolytic effects

Abstract

Herbal extracts have been reported as alternate therapies for the treatment of psychiatric disorders and its associated oxidative stress. In the present study we investigated the phytochemical constituents of Ocimum gratissimum leaf 70% ethanolic fraction (OGE) by LC-ESI-MS/MS which showed a variety of compounds that include polyphenols, flavonoids and fatty acids. OGE showed 124.3±5.8mg/g gallic acid equivalents of polyphenols and 25.33±1.8mg/g catechin equivalents of flavonoids. The antioxidant activity of O. gratissimum was analyzed by in vitro antioxidant assays such as DPPH, iron chelating, ABTS, nitric oxide and hydroxyl radical scavenging which showed a potent free radical scavenging activity with IC50 values of 470±28.6, 330±17.4, 133±7.2, 83±4.4, 260±12.7μg/mL. OGE was checked for its macromolecules such as DNA, protein and lipidperoxidation damage protective activities. The extract showed 44.8% DNA damage protection against H2O2 induced SH-SY5Y human neuronal cell damage, 80% protection against AAPH induced BSA oxidation and also showed lipid peroxidation inhibition with an IC50 value of 735±38.3μg/mL. O. gratissimum also exhibited a significant anxiolytic effect at a dose of 400mg/kg/b/wt as analyzed by the open field and elevated plus maze tests in mice. Overall our study demonstrates that O. gratissimum exhibits antioxidant, macromolecule damage protective and anxiolytic effects. © 2014 South African Association of Botanists.