A Study of Phenolic Contents and in vitro Antioxidant Activity of Different Solvent Leaf Extracts Obtained from Heen Kekiri/Len Kekiri (Mukia maderaspatana L.) Grown in Sri Lanka

Abstract

Background: Hyperphysiological burden of free radicals causes the imbalance between free radicals and antioxidants and results in the oxidation of biomolecules. Hence, there is a need to supply exogenous supply of antioxidants of natural origin, where synthetic antioxidant were reported to be carcinogenic. Objectives: To perform qualitative analysis to test the phytochemicals present in different solvent extracts namely, 80% ethanol and water obtained from Mukia maderaspatana leaves. The quantitative tests were performed to determine the total phenolic content (TPC), total flavonoid content (TFC) and antioxidant activity of two solvent extracts obtained from plant Mukia maderaspatana leaves. Methodology: The defatted crude extracts were prepared into 80% aqueous ethanol and water by steeping method and subjected to preliminary phytochemical screening tests. TPC and TFC were evaluated by using Folin-Ciocalteu assay and aluminium chloride colorimetric method respectively. The antioxidant activity was evaluated by using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay. Results: The leaf extracts of ethanolic and water obtaıned from M. maderaspatana revealed the presence of phenolic compounds, flavonoids, saponins, alkaloids and carbohydrates in both extracts. The TPC values for two extraction solvents were 455.608±64.743 mg GAE/100 g DW of leaves (for water extract) and 269.608±34.050 mg GAE/100 g DW of leaves (for 80% ethanol) respectively. The TFC of the solvent extracts tested were 445.663±101.215 (for water extract) and 100.516±745 mg CAE/100 g DW of the leaves (for 80% ethanol extract). Antioxidant capacity performed by DPPH assay for the different extraction solvents were 0.574±0.062 (for water extract) and 0.286±0.020 (for 80% ethanol extraction) mmol Trolox equivalents/100 g DW of the leaves. Conclusions: Both extracts of M. maderaspatana leaves showed less antioxidant activity and need further investigation.