||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.