Radical Scavenging Activities, Total Reducing Power, Total Phenolic and Flavonoids Contents of Four Common Vegetables

Abstract

Aim: This study aimed at evaluating the antioxidant activities of extracts from four vegetables namely: Beta vulgaris, Raphanus sativus, and two varieties (red and green) of Brassica oleracea.
 Method: The antioxidant properties of these extracts were assessed using five different methods including 2,2-diphényl 1-picrylhydrazyl (DPPH), Nitrogen Oxyde (NO), total reducing power, total phenolic and flavonoids content. 
 Results: All the four vegetable extracts showed free radical-scavenging activity against DPPH· with RSa50 (Radical scavenging activity 50) ranging between 129.77 and 323.64 µg/ml, and inhibitory activity against NO radical (RSa50 ranging from 1454,52 to 4479,97 µg/ml). The four vegetable extracts also showed total reducing powers ranging between 2.41 and 9.37 AAE (mg ascorbic acid equivalents per gram of dried extract). These antioxidant activities can be justified by the presence of different antioxidant compounds like total phenol contents which were present in all studied vegetable extracts with quantities varying between 4.37 and 11.83 GAE (mg of garlic acid equivalents per gram of dried extract) of dry extract, or flavonoids which were also present in all the plants with total contents ranging between 0.1 and 0.25 RE (rutin equivalents per gram of dried extract). 
 Conclusion: The different antioxidant activities demonstrated in this study provide scientific evidence that some vegetables commonly consumed in Cameroon including B. oleracea, R. sativus and B. vulgaris can serve as a dietary supplement or in preventive medicine in the management of oxidative stress and associated pathologies.