Antioxidant activity, total phenolic and flavonoid contents of Anthocleista djalonensis root extracts

Background: Anthocleista djalonensis (Chev.), a plant native to tropical West Africa, is used ethnomedicinally in the management of several diseases.

Objectives: This study seeks to determine the free radical scavenging ability of the methanol, ethyl acetate and aqueous root extracts of A. djalonensis on 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and hydrogen peroxide radicals and to determine the total phenolic and flavonoid contents of the extracts.

Method: The antioxidant effect of A. djalonensis root extracts was compared with that of ascorbic acid using DPPH (2, 2- diphenyl-2- picrylhydrazyl) assay and hydrogen peroxide scavenging assay methods. Percentage antioxidant activity (AA %), IC50, total phenolic content and total flavonoid of extracts were determined.

Result: The total phenolic content of the extracts ranges from 132.73 ± 20.25 to 207.93 ± 11.7 mgGAE/g of dry plant extract while the total flavonoid content of the extracts ranges from 78.2 ± 0.12 to 100.6 ± 2.08 mg QE/g dry plant extract. The extracts showed a good but lower DPPH radical scavenging activity compared to ascorbic acid. The methanol extract showed a maximum percentage radical scavenging of 94.76 ± 0.05% (IC50 = 148.54 µ/ml) on DPPH radicals at concentration of 1000 µg/ml among the three extracts. The extracts showed a non-significant (P ˃ 0.05) radical scavenging activity on hydrogen peroxide compared to ascorbic acid (74.14 ± 0.05 %). The methanol extract have the highest hydrogen peroxide scavenging activity (79.24 ± 0.07 %).

Conclusion: This result indicate that the root extracts of Anthocleista djalonensis possesses antioxidant phytochemicals and can be a good source of antioxidants to ameliorate conditions that are caused by oxidative effects of free radicals.