Phytochemical analysis and antioxidant activity of Ipomoea aquatica from Ghodaghodi wet land area, Nepal

Abstract

Ipomoea aquatica is a green leafy vegetable; rich source of secondary metabolites, vitamins and amino acids with many health benefits. The present study was accomplished to analyze phytochemical constituents and antioxidant activity of hexane and methanol extracts of Ipomoea aquatica from Ghodaghodi wet land area, Nepal. For this purpose, first the powdered plant was extracted successively with hexane and then methanol. Thus obtained concentrated extracts were subjected to preliminary phytochemical screening following standard protocols. The antioxidant activities of extracts were evaluated by 2, 2-diphenyl -1-picrylhydrazyl (DPPH) radical scavenging assay. Ascorbic acid was used as standard antioxidant. Phytochemical screening of methanol extract of Ipomoea aquatica showed presence of wide array of natural bioactive chemical constituents such as alkaloids, carbohydrates, glycosides, flavonoids, phenolics, saponins, quinones, tannins, terpenoids, proteins and amino acids etc. However, relatively less amount of phytochemicals like flavonoids, phenolic compounds, terpenoids, tannins were found to be present in the hexane extract implying that methanol is better solvent for phytochemical extraction. Similarly, in the hexane extract alkaloids, carbohydrates, glycosides, coumarins, saponins, quinones, protein and amino acids were absent. However coumarins were absent in both extracts of Ipomoea aquatica. The hexane extract showed less antioxidant activity (IC50 = 70.47µg/mL) whereas for methanol extract IC50 = 49.49 µg/mL. For standard antioxidant ascorbic acid IC50 = 53.99 µg/mL. The present study demonstrated higher antioxidant activity of methanol extract of Ipomoea aquatica was due to wide range of phytochemicals extracted in methanol in comparison to hexane as a solvent. This research also justifies Ipomoea aquatica as antioxidant rich green leafy vegetable available in wild nature.