Evaluation of Antioxidant and Xanthine Oxidase Inhibitory Potential of Methanolic Leaf Extract of Stevia rebaudiana

Background: Stevia rebaudiana is a shrub-like plant that belongs to the sunflower family and is commonly referred as stevia.It is 1000 times sweeter than sugar even at a very low concentration. Xanthine oxidase is an enzyme that generates oxygen species and catalyzes the production of uric acid from purine metabolism.Overproduction of uric acid results in a clinical condition called gout. The aim of this study is to explore the phytochemicals, antioxidant and xanthine oxidase inhibitory potential of methanolic leaf extract of stevia rebaudiana.

Methods: Methanolic leaf extract of Stevia rebaudiana was prepared by the Hot Percolation method. Phytochemical screening was done to analyse the presence of various phytochemicals. The leaf extract was tested for its antioxidant and xanthine oxidase inhibitory potentials. The data were analyzed statistically by a one-way analysis of variance (ANOVA) followed by Duncan’s multiple range test was used to see the statistical significance among the groups. The results with the p<0.05 level were considered to be statistically significant.

Results: It was observed that the methanolic leaf extract of Stevia rebaudiana has significant antioxidant potential (Ic50 of = 310 μg/ml) as well as xanthine oxidase inhibitory potentials(Ic50 of = 270 μg/ml) and the activity increased in a dose dependent manner as compared to that of standard (Vitamin C and Allopurinol respectively).

Conclusion: The study proves the antioxidant and xanthine oxidase inhibitory efficacy of Stevia rebaudiana and throws light on the prospects of drug formation against oxidant activity and gout formation.