Antioxidant potentials of extracts from different parts of Clinacanthus nutans (Burm. f.) Lindau.

The research aimed to explore the antioxidant potential of extracts from different parts of Clinacanthus nutans growing in Vietnam, a member of the Acanthaceae family. The plant's roots, stem and leaves were extracted using 96% ethanol. The antioxidant actions of these extracts were evaluated by DPPH (2,2-diphenyl-1-picryl-hydrazyl-hydrate) assay on thin-layer plates and 96 well plates. The extract with the most potent activity was applied for distribution extraction with solvents with different polarities, including dichloromethane, ethyl acetate and water. Dry column vacuum chromatography was utilized to obtain the most antioxidant-potent extract fractions. The stem extract had the lowest IC₅₀ value of 6.85µg/mL, showing the most potent antioxidant activity. The ethyl acetate fraction from the stem extract expressed the lowest IC₅₀ value of 9.67µg/mL. Meanwhile, fraction 5, separated from the ethyl acetate fraction of the stem extract, had the lowest IC50 value of 9.89µg/mL. In conclusion, the extracts from different parts of Clinacanthus nutans all expressed antioxidant action at different levels, in which the stem extract, the ethyl acetate fraction and fraction 5 from the ethyl acetate fraction displayed the most effective actions. These findings highlight the promising potential of Clinacanthus nutans in treating oxidative stress-associated diseases, inspiring further research and exploration in this area.