Comparison extraction methods for evaluating antioxidant and antibacterial properties of Vernonia amygdalina leaves extract

In this study, we were interested in comparing the influence of different extraction methods on antioxidant and antibacterial activities of V.amygdalina leaves extracts. The extracts were also analyzed for their total phenolic and flavonoid content.  The extraction methods used maceration, soxhlet, and fractionation, the evaluation of antioxidant activity using DPPH (1,1-diphenyl-2-picryl-hydrazyl) method and antibacterial activity by agar diffusion method. The total phenolic and flavonoids are determined by the spectrophotometric method.  Ethanol extract by fractionating on this method showed the highest antioxidant properties compared to other extracts with IC 50 170 μg/mL in category potent antioxidant with total phenolic content 28.83 ± 2.62 mg GAE/g, and the total flavonoid content 18.78 ± 0.15 mg QE/g. Evaluation of antibacterial properties the extracts of V. amyigdalina showed moderate antibacterial activity against all bacteria tests with inhibition zone  6.1 ± 0.1 to  9.4 ± 0.9 mm at variation concentration 62.5 – 1000 μg/mL. The fractionation method using ethanol solvent is the best for the extraction of antioxidant compounds from V. amygdalina .