Bioactivities of n-hexane fraction of Vateria copallifera and GC–MS analysis of its phytoconstituents

Abstract

Vateria copallifera (Retz.) is an important timber source belonging to the family of Dipterocarpaceae, which is acknowledged as a plant family rich in a variety of bioactive chemical constituents. This study was conducted to evaluate the chemical composition and the bioactivities of the non-polar n-hexane fraction obtained by dry column chromatography of the hexane extract of V. copallifera bark. n-Hexane fraction was analyzed by gas chromatography–mass spectrometry (GC–MS). Cytotoxicity was measured by the MTT assay against HeLa, MCF7, HepG2, HCT116 and SK-Mel 5 cell lines. The neuroprotective effect of the n-hexane fraction was assessed by oxygen glucose deprivation (OGD) assay using PC12 cells. Nitric oxide (NO) inhibitory activity was investigated on lipopolysaccharide (LPS)-stimulated microglial cells. The antioxidant activity was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging and oxygen radical absorbance capacity (ORAC) assays. Cholinesterase inhibitory activity was evaluated using acetylcholinesterase and butyrylcholinesterase inhibitory assays and protease inhibitory activity was evaluated by α-chymotrypsin and elastase enzyme inhibitory assays. Decane, dodecane, undecanes, naphthalene derivative, heptadecane, squalene, copaene and eicosane were identified as the major constituents (>2% peak area). The n-hexane fraction exhibited a concentration-dependent increase in the neuroprotective activity although it was not significant (p>0.05) at the tested concentrations. Contradictorily, the n-hexane fraction treated microglia cells released significantly (p<0.05) higher levels of NO into the medium (>100%) compared to the control counterpart. However, further studies are needed to assess the neuroprotective activity and to determine the cause of the increase of NO. The n-hexane fraction showed no cytotoxicity, antioxidant, ChE, protease and GST enzyme inhibitory activity at the tested concentrations. To our knowledge, this is the first report on the analysis of the chemical composition and the bioactive potential of the non-polar n-hexane fraction obtained by chromatography of the hexane extract of V. copallifera bark.