Preliminary Study of Antioxidant Potential and Gas Chromatography-mass Spectroscopy (GC-MS) Analysis of Brassica oleracea Florets

Abstract

Introduction: Brassica oleracea var. Italica ordinarily known as “broccoli†is a cruciferous green leafy vegetable and has been reported to have antioxidant, anti-inflammatory, antibacterial, anticancer, antiatherosclerotic, antimucolytic, antinitrosaminic, anti-nyctalopic, antiproliferant, and hypocholesterolemic potential. To determine the presence of bioactives, preliminary phytochemical screening of methanol extract was done and its antioxidant potential was evaluated by in vitro radical scavenging assays. Phytoconstituents present in the extract were identified by gas chromatography-mass spectroscopy (GC-MS) analysis. Materials and Methods: In the preliminary phytochemical screening, various chemical tests were performed. Evaluation of the in vitro antioxidant efficacy of the extract was done by 1,1-Diphenyl-2-picrylhydrazyl (DPPH) scavenging assay and ferrous ion-chelating ability assay. Various phytoconstituents were identified on the basis of retention indices and mass spectra fragmentation pattern obtained through GC-MS studies. Results: Phytochemical screening of the floret extract revealed the presence of terpenoids, alkaloids, tannins, steroids, and saponins. Plant has significant scavenging effect on DPPH (half maximal inhibitory concentration [IC50] = 0.070 ± 0.67 mg/ml) which is comparable to that of ascorbic acid (IC50 = 0.045 ± 0.61 mg/ml) and butylated hydroxytoluene (BHT) (IC50 = 0.118 ± 0.53 mg/ml). The highest chelating activity of methanol extract and ethylenediaminetetraacetic acid is found to be 83.69% and 98.91%, respectively. GC-MS analysis report confirmed the presence of ascorbic acid 2,6-dihexadecanoate, phytosterols, linoleic acid, palmitic acid, and oleic acid as the major constituents. Terpenoids, namely squalene and geraneol, were found in traces. Discussion and Conclusion: From the study, it has been concluded that the B. oleracea is a potential source of plant-based therapeutics and a natural source of antioxidants. It has been found that the extract contains a significant amount of phytochemicals with antioxidants which could act as scavengers of free radicals. From this study, we got a sound base for further investigation of B. oleracea for its pharmaceutical application.