Extraction and Determination of Antioxidants, Polyphenols, Flavonoids and Antioxidant Activity in some PlantsAuthor(s): Abdelrahim A. Ali and Mohydeen N. Gimaabi
The methanolic extracts of the leaves and stem of some plants (Calotropis procera, Juniperus procera, Lantana camara and Olea europaea) were screened for polyphenols, flavoides and their free radical scavenging properties using ascorbic acid as standard antioxidant. Free radical scavenging activity was evaluated using 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radical. Generally leaves of Calotropis procera and Lantana Camara, which are the highest records of polyphenol, 943.90 and 917.60 mg/100 mL of polyphenols, respectively while leaves of Calotropis procera and Juniperus procera are highest in flavonoids, which contain 55.60 and 53.43 mg/100 g, respectively. The leaves of Juniperus procera and Olea europaea showed the highest antioxidant activity, 12.66 and 11 μg/mL, respectively, where as methanolic extract from the stem of Lantana Camara and Calotropis procera showed weak antioxidant activity, with values of 6.0 and 4.33 μg/mL. The study reveals that the use of the leaves of these plants would exert several beneficial effects by virtue of their antioxidant activity.