Evaluation of the antioxidant and antibacterial activity of aqueous and ethanoic extracts of two medicinal plants used to treat diarrhea in Côte d’Ivoire

Abstract

This study was initiated to evaluate the antioxidant and antibacterial activities of aqueous and ethanoic extracts of Anthocleista djalonensis and Uvaria chamae, two plants of the African pharmacopoeia used by the peoples of the northern Côte d’Ivoire to treat severe cases of diarrhea. A series of extraction by maceration was carried out. The extracts obtained were assayed by the colorimetric method and their antioxidant activity determined by spectrophotometer using the free radical scavenging (DPPH) and iron reduction (FRAP) methods. Dilution and agar diffusion methods on Mueller Hinton medium were used to determine MICs and inhibition diameters. The assay of the extracts determined the polyphenol content ranging from 6.8 to 21.1 mg. The total phenol content of the ethanol extract of Uvaria chamae was the highest. Evaluation of the free radical scavenging activity and the reducing power of ferric ions to ferrous ions of the extracts of both plants indicated variable IC50 values ranging from 4 to 14 (μg/mL). The lowest value (4 μg/mL) close to that of vitamin C (reference molecule) (3.5 μg/mL) was obtained with the aqueous and ethanoic extracts of Anthocleista djalomensis and Uvaria chamae respectively. Furthermore, all germs were found to be sensitive to the action of the extracts with inhibition diameters greater than 10 mm and MICs greater than 3.12 mg/mL. This sensitivity could be due to the presence of phytochemicals such as total phenols, flavonoids, tannins, alkaloids, saponins whose antimicrobial activities have already been shown. These investigations justify the traditional use of these plants in the treatment of diarrhea and dysentery.

Chemical characterization and biological abilities of Anthocleista djalonensis collected from two locations of Ivory Coast

“…In another study by Awah et al (2010), the total flavonoid content in the methanol extract of leaves of A. djalonensis were found to be 48.52 mg RE/g, which was higher than in our tested leaf extracts. However, the total phenolic level of ethanolic extract of A. djalonensis root barks (10.1 mg GAE/g) was lower than that of our tested extracts (14.17-46.95 mg GAE/g) in a previous study by Monon Kone et al (2022). The differences could be explained by geographical and climatic factors including altitude, rainfall, or plant collection stages.…”

In-vitro comparative study of solvent effect on antioxidant properties of leaf extracts of Anthocleista djalonensis

“…Various parts of this plant have been shown in scientific reports to have anti-inflammatory, antidiabetic, analgesic, antifungal, and antimalarial properties [2][3][4]. Also, the plant has been proven to scavenge free radicals, identifying it as a powerful antioxidant agent [5].…”