Phytochemical and Antioxidant Activity of Water and Methanol Extracts of Oldenlandia corymbosa

Abstract

Background: Oldenlandia corymbose is a small perennial herb used traditionally to clear toxins, activate blood circulation, and relieve urinary obstruction. Objectives: This study investigated the phytochemical and antioxidant activity of water and methanol extracts of Oldenlandia corymbosa. Materials and Methods: Total phenolic, flavonoids, and tannin contents of Oldenlandia corymbosa were determined using Folin-Ciocalteau reagent, Colorimetric AlCl3 method, and spectrophometry method respectively. The antioxidant activities were analyzed using 2,2-diphenyl- 1-picrylhydrazyl (DPPH) radical scavenging activity, ferric reducing antioxidant power (FRAP), metal chelating activity (MCA), 2,2’-azino-bis-(3-ethyl) benzothiazoline-6-sulfonic acid (ABTS) radical scavenging, and phosphomolybdenum assay (PMA). Results: The total phenolic, flavonoid and tannin of the methanolic extracts were found to be higher than that of the water extracts. The DPPH, FRAP, MCA, ABTS and PMA for the water extracts were found to be 56.05 ± 0.1 %, 0.018 ± 0.002 mg Fe(II) equivalent/g, 0.346 ± 0.04 mg EDTA equivalent/g, 63.67 ± 0.6 mg trolox equivalent/g, 0.82 ± 0.03 ascorbic acid equivalents/g and greater than that of the methanol extract 47.26 ± 0.09 %, 0.009 ± 0.0001 mg Fe(II) equivalent/g, 0.198 ± 0.002 mg EDTA equivalent/g, 62.68 ± 0.7 mg trolox equivalent/g and 0.365 ± 0.008 ascorbic acid equivalents/g respectively. These results show that, though the methanol extracts contain more polyphenolic compounds, the water extract exhibits more antioxidant activity. Conclusion: The water extract of Oldenlandia corymbosa shows superior antioxidant activity due to the synergistic effects of its phytoconstituents than that of methanol extracts and can serve as a natural remedy for managing oxidative stress.