Free radical scavenging and antibacterial potential of two plants extracts (Khaya senegalensis and Pseudocedrela kotschyi) used in veterinary

Abstract

In all developing countries like Benin, medicinal plants were the most widely used especially in rural areas to solve health problems in humans and in animal’s life. But despite this use, all the mysteries of nature were not yet perceived by human. This paper reports the results of the chemical and biological studies of two plants, Khaya senegalensis and Pseudocedrela kotschyi used by farmers in Benin in the treatment of gastro-intestinal diseases in livestock. Throughout the results, we noted in both samples the presence of several secondary metabolites such as saponins, catechic tannins, polyphenols, mucilages, flavonoids, anthocyanins, leuco anthocyanin, reducing compounds, sterols and terpenes. Concerning the extraction yield of metabolites, the binary water-ethanol (50/50) showed the best results compared to each of the two solvents used separately. Concerning the polyphenols content, it varied in the same plant depending of the extraction solvent nature. The test results of the scavenging activity showed a better one with the ethanolic extract of the stem bark of P. kotschyi whereas the stem bark of Khaya senegalensis extracted with semi-ethanol was the most active. Both extracts displayed similar activities (CI50= 4 μg/ml) more pronounced than that of the reference compound used in this study, the BHA (CI50=4.8 μg/mL). The results of antibacterial activity of the ethanolic and hydroethanolic extracts of trunk bark of P. kotschyi had bactericidal activity against Staphylococcus aureus, Salmonella typhi, Escherichia coli and Klebsiella pneumoniae. Concerning K. senegalensis, the ethanolic and hydroethanolic extracts showed an interesting antibacterial activity against Salmonella typhi, Escherichia coli and Klebsiella pneumonia.