Total Flavonoid Content and Antioxidant Activity of Three Fractions Vernonia amygdalina Del. from Bali

Abstract

African leaves (Vernonia amygdalina Del.) are known to contain flavonoids and have antioxidant activity. This study aims to determine differences in total flavonoid levels and antioxidant activity in the three fractions (n-hexane; ethyl acetate; aqueous) of african leaves extract from Tabanan (Bali). Extraction was carried out by maceration method using 96% ethanol, the extract was tested for flavonoid phytochemical screening using the Shinoda method. A total of 10 g of extract was fractionated using n-hexane, ethyl acetate, and water, then identified flavonoids by TLC. The total flavonoid content of each fraction was tested using the colorimetric method (AlCl₃ reagent), while the antioxidant activity used the DPPH radical reduction method. The results of this study obtained that the extract weight was 28.905 g, with fractional weights, i.e. 3.0046 g (n-hexane), 0.6399 g (ethyl acetate), and 0.9158 g (aqueous) which were positive for flavonoids. The total flavonoid levels in the ethyl acetate, n-hexane, and aqueous fractions, respectively, were 12.668%w/w; 1.469%w/w; 0.031% w/w, then the IC₅₀ value is 82.596 mg/L; 121.077 mg/; 70.101 mg/L. Therefore, it can be concluded that the aqueous fraction of african leaves extract provides better antioxidant activity with the lowest total flavonoid content than the ethyl acetate and n-hexane fractions.