Evaluation of antioxidant potential in selected green leafy vegetables

Green leafy vegetables represent a class of underexploited plants that are stipulated to be rich sources of natural antioxidants. A fundamental study of free radical-scavenging activity in four plant species, namely Trigonella foenum-graecum, Centella asiatica, Sauropus androgynus and Pisonia alba, was carried out by measuring the ability of methanol extracts of these plants to scavenge radicals generated by in vitro systems and by their ability to inhibit lipid peroxidation. The levels of non-enzymatic antioxidants were also determined by standard spectrophotometric methods. Correlation and regression analysis established a positive correlation between some of these antioxidants and the in vitro free radical-scavenging activity of the plant extracts. The conclusions drawn from the study indicate that in vivo studies, isolation and analysis of individual bioactive components will reveal the crucial role that these plants may play in several therapeutic formulations.