Total flavonoids content and reducing power assay of twelve common Bangladeshi leafy vegetables

Around hundred different types of vegetable are available in Bangladesh for human consumption that are the important nutritional source of dietary fibers and antioxidants. Amaranthus gangeticus, Amaranthus viridis, Basella alba, Brassica campestris, Chenopodium album, Centella asiatica, Coriandrum sativum, Enhydra fluctuans, Ipomoea aquatica, Lagenaria siceraria, Pisum sativum and Spinacia oleracea are the twelve common leafy vegetables of Bangladesh. In this study, their ethanol extracts were studied to determine total flavonoids (TF) content and reducing power (RP) to evaluate the antioxidant activity of the extracts. This study reveals the high antioxidant contents in the leaves of the vegetables. I. aquatica was found to highest in TF and RP followed by P. sativum and L. siceraria. The lowest TF was found in S. oleracea which also showed the lowest RP. A significant correlation between flavonoids content and reducing power (r² = 0.87) was found. The high antioxidant contents in the vegetables may the reason behind high life expectancy of people in this region although they are highly exposed to high oxidative stress, risky food habit and worst level of pollution.