Correlation Between Phytochemicals and Antioxidant Activities of Different Leaf Extracts of Entada rheedii

Abstract

The main aim of this study was to determine Total Phenolic Content, Total Flavonoid Content, terpenoid content, steroid content and analyze the antioxidant activity of different leaf extracts of Entada rheedii. Correlation between antioxidant activities and total phenolic content, total flavonoids content, terpenoid content and steroid content were also analyzed. The total phenolic content in E. rheedii hexane, ethyl acetate, methanol, and aqueous leaf extracts were found to be 10.16 mg GAE/g, 24.73 mg GAE/g, 26.11 mg GAE/g, and 24.85 mg GAE/g sample dry weight respectively. The Total flavonoid content of E. rheedii hexane, ethyl acetate, methanol, and aqueous leaf extracts was found to be 8.433 mg QE/g, 8.730 mg QE/g, 8.607 mg QE/g, and 8.545 mg QE/g respectively. Hexane extract showed the highest steroid content at 32.75 g/mL, followed by ethyl acetate extract at 31.37 g/mL. The methanol extract and aqueous extract had the lowest steroid content at 22.2 g/mL and 21.21 g/mL, respectively. Terpenoid content was the highest in hexane extract with 62 mg/100 mg of dry extract, followed by the ethyl acetate extract with 45 mg/100 mg dry extract. The total content of terpenoids in the methanol extract was 25 mg/100 mg dry extract and the total content of terpenoids was lowest in the aqueous extract with 18 mg/100 mg dry extract. In 1-1-diphenyl- 2-picryl hydrazine Free Radical Scavenging (DPPH) Assay, the methanol extract displayed the highest antioxidant activity with an IC50 value of 173.581 μg/mL while the hexane extract showed the lowest activity; with IC50 value of 389.13 μg/mL. Reducing power assay was evaluated and aqueous extract was shown to possess the highest reducing power. Evaluation of total antioxidant capacity by phosphomolybdenum assay indicated that methanol extract had the highest antioxidant capacity. Significant correlations were also found between Total Phenol Content, Total flavonoid Content, and antioxidant activities of different leaf extracts of Entada rheedii.