Antioxidant Activity of Ethanolic Extract and Various Fractions from Green Tea (Camellia sinensis L.) Leaves

Background: Free radicals are one of the causes that can cause premature aging and degenerative disease. To overcome this problem, the body needs antioxidant intake. Green tea (Camellia sinensis L.) leaves are one of the plants known as antioxidant agent due to its flavonoids and phenolic compounds or better known as catechin compounds. Catechin is polar flavonoid compounds so it is necessary to separate it from non-polar compounds so their antioxidant activity becomes effective. Objective: This study aims to determine antioxidant activity of ethanolic extract of green tea leaves and its fractions namely ethyl acetate and water fraction, and measure the total flavonoid content, total phenolic content and catechin content. Materials and Methods: Green tea leaves extracted using maceration method with 96% ethanol. Fractionation was conducted using liquid-liquid extraction using a solvent of n-hexane, ethyl acetate and water. Screening of flavonoid and phenolic and antioxidant activity was performed against the ethanolic extract, ethyl acetate fraction and water fraction. Antioxidant activity was determined by 2,2-diphenyl-1-picrylhydrazyl method using ultravioletvisible spectrophotometry with ascorbic acid as standard. Results: The ethanolic extract, ethyl acetate fraction and water fraction contains flavonoids and phenolic compounds. The IC₅₀ value of ethanolic extract, ethyl acetate fraction and water fraction were 9.017; 3.926 and 7.408 μg/mL consecutively. The ethyl acetate fraction also showed better antioxidant activity than ascorbic acid (4.855 μg/mL). Conclusion: The ethanolic extract, ethyl acetate fraction and water fraction showed very powerful antioxidant activity but ethyl acetate fraction has the best antioxidant activity.