In Vitro Assessment of Antioxidant Effect of Aqueous Extract of Vernonia amygdalina (Bitter Leaf): A Quasi-experimental Study

Background: Medicinal plants are widely used in many countries for different ailments due to cost effectiveness and less side effects. Vernonia amygdalina (V.amygdalina) (Bitter leaf) is one of the important medicinal plant which has many pharmacological properties. Methods: This quasi-experimental study was carried out in the Department of Pharmacology and Therapeutics, Rajshahi Medical College, Rajshahi from January 2021 to December 2021. This study was conducted in two steps: Firstly, preparation of aqueous extract of leaves of V. amygdalina. Secondly, assessment of its antioxidant effect through DPPH free radical scavenging activity. Results: The results of the study showed that the antioxidant activity of aqueous extract of leaves of V. amygdalina at the concentration of 0.0625 mg/ml, 0.125 mg/ml, 0.25mg/ml, 0.5mg/ml and 1 mg/ml were 34.9±1.14, 63.3±0.62, 76±0.83, 77.9±1.37 and 84.9±1.86 respectively. The aqueous extract of Vernonia amygdalina gave the highest inhibition of 84.9±1.86% at 1mg/ml and lowest inhibition of 34.9±1.14% at 0.0625 mg/ml. The antioxidant activity of standard ascorbic acid at the concentration of 0.0625 mg/ml, 0.125 mg/ml, 0.25mg/ml, 0.5mg/ml and 1 mg/ml were also being evaluated which were 80.1±1.68, 86.5±2.47, 91.6±0.65, 93.2±0.44 and 94.5±0.62 respectively. Ascorbic acid gave the highest inhibition of 94.5±0.62% at 1 mg/ml and lowest inhibition of 80.1±1.68% at 0.0625 mg/ml. Comparing the antioxidant effect of Bitter leaf & Ascorbic acid difference was found statistically significant (p<0.05). Conclusions: These results revealed that antioxidant activity of different concentration of aqueous extract were found but it was less when compared to standard antioxidant effect of ascorbic acid. Hence it is concluded that aqueous leaves extract of V. amygdalina showed antioxidant effect.