Fractionation of an ethanolic extract of purple leaves (Graptophyllum pictum) with antioxidant and lipoxygenase activity inhibition assay.

Abstract

Graptophyllum pictum offers therapeutic potential that has received attention from researchers around the world. The purple leaf is native to New Guinea and has been widely distributed, including Indonesia. This study aims to determine the antioxidant activity and potential inhibition of the lipoxygenase (LOX) enzyme in the hexane fraction, ethyl acetate fraction, and water fraction of purple leaf. Samples were extracted by maceration using 96% ethanol, followed by multilevel fractionation using ethyl acetate, hexane, and water solvents. The fractions were determined for their antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl method, and their potential in LOX enzyme inhibition was analyzed using an ultraviolet-vis spectrophotometer. The ethyl acetate fraction showed the highest antioxidant activity with inhibition concentration (IC₅₀) of 17.23 µg/mL; LOX inhibition was also demonstrated by the highest ethyl acetate fraction with IC₅₀ 133.47 µg/mL, followed by the hexane fraction, and then the water fraction. These results suggest purple leaves with ethyl acetate fraction can be a new drug innovation with antioxidant and anti-inflammatory properties, and this study can be used as an evaluation material for further drug development.