Free radical scavenging potential and total phenolic and flavonoid content of Ziziphus mauritiana and Ziziphus nummularia fruit extracts

Abstract

Background: Nowadays antioxidants have gained a lot of importance because of their potential as prophylactic and therapeutic agents in the diseases caused by free radicals. Presently, the active constituents from the natural sources are tested for their free radical scavenging potential. Plants are of enormous importance in the free radical and antioxidant field. Aim: The present study was carried out to evaluate the free radical potential, total phenolic and flavonoid content of edible and non-commercial fruits of Ziziphus mauritiana and Ziziphus nummularia belonging to the family Rhamnaceae. Materials and Methods: Free radical scavenging potential of methanolic extracts of the Ziziphus mauritiana and Ziziphus nummularia fruits (MEZM and MEZN) was evaluated by 1, 1-diphenyl-2-picryl-hydrazyl (DPPH) and hydrogen peroxide (H2O2) method. The total phenolic content of the methanolic extracts of fruits was determined using gallic acid as a standard. The total flavonoid content was determined using the Aluminium chloride reagent and quercetin as standard. Statistical analysis: The results were statistically analysed with the Student’s t-test. Results and Conclusions: The extracts showed significant free radical scavenging activity in a dose dependent manner when compared with ascorbic acid. The highest DPPH radical scavenging activity of MEZM and MEZN was found to be 79.5% and 77.5% respectively at concentration of 250 μg mL-1. The H2O2 scavenging effect of MEZM and MEZN was 73.4% and 71% respectively at a concentration of 250 μg mL-1. IC50 <1 mg/ ml shows that the fruits possess significant antioxidant activity. The phenolic as well as flavonoid content was found to be higher in MEZM. The fruits can be used as a natural source of antioxidants in combating diseases caused by free radicals. Key words: Antioxidants, free radicals, Rhamnaceae, Ziziphus mauritiana, Ziziphus nummularia