Phytochemical Screening, Polyphenol Content and Antioxidant Studies of Ethanol Leaf Extract of Combretum aculeatum vent.
Alioune Dior Fall *
Laboratory of Pharmacognosy and Botany, Cheikh Anta Diop University, Dakar, Senegal
Awa Ndiaye Sy
Laboratory of Pharmacology and Pharmacodynamic, Cheikh Anta Diop University, Dakar, Senegal
Jean Baptiste Hzounda Fokou
Laboratory of Pharmacognosy and Botany, Cheikh Anta Diop University, Dakar, Senegal and Department of Biochemistry, University of Yaoundé I, Yaoundé, Cameroon
Joël Olivier Ndiefi Fomi
Laboratory of Pharmacognosy and Botany, Cheikh Anta Diop University, Dakar, Senegal
Mbaye Dieng
Laboratory of Pharmacognosy and Botany, Cheikh Anta Diop University, Dakar, Senegal
Serigne Ibra Mbacké Dieng
Laboratory of Pharmacognosy and Botany, Cheikh Anta Diop University, Dakar, Senegal
Emmanuel Bassene
Laboratory of Pharmacognosy and Botany, Cheikh Anta Diop University, Dakar, Senegal
*Author to whom correspondence should be addressed.
Abstract
Objectives: The present study aimed to identify the phytochemical groups of ethanol leaf extract of Combretum aculeatum Vent., and to evaluate the phenol content of extracts and their antioxidant activity.
Materials and Methods: Collected leaves were extracted with ethanol (95°). From the dried ethanol extract, 3 fractions were obtained after a liquid/liquid fractionation (hexane, ethyl acetate and water). Phytochemical screening of the raw extract was done using standard reactions. The phenol content was determined with Folin Denis reagent. Antioxidant activity was performed using 2, 2-diphenyl-picrylhydrazyl test (DPPH), ferric reducing antioxidant power (FRAP) and nitric oxide reducing tests.
Results: Tannins, flavonoids and mucilage were the main phytochemical constituents of the leaf extract. Antioxidant assay revealed ethanol extract and its polar fractions were more active. In DPPH assay, the aqueous fraction (IC50: 61.93±5.99 μg / ml) was more active than the ethanol extract, the ethyl acetate and hexane fractions with respective IC50 values 74.1±4.47 - 81.53±6.51 - 1710.33±71.15 µg/ml. In nitric oxide test the ethyl acetate fraction (IC50: 56.66±3.09 µg/ml) had shown a better ability to inhibit nitric oxide radical than the ethanol extract, the hexane and aqueous fractions (IC50: 84.33±9.80- 451.33±1.24- 101.33±4.10 µg/ml respectively). In FRAP assay the ethyl acetate and aqueous fractions had shown a better activity than the leaf extract.
Conclusion: Ethanol leaf extract had shown antioxidant activity in the different assays. This biological activity may be due to both polar and non polar compounds.
Keywords: Combretum aculeatum, leaf extract, fractions, phytochemical, antioxidant