Phytochemistry and Anti-Bacterial Activity of Thirteen Plants Used in Traditional Medicine to Treat Typhoid Fever in Benin

The objective of this study is to study the phytochemistry of the anti-bacterial activity of thirteen plants used in traditional medicine to treat typhoid fever in Benin. For this fact, we carried out the phytochemical screening, then the antibacterial activity was carried out by the micro-dilution method. The dosage of polyphenols was made on the extracts having exhibited good anti-salmonella activity. Phytochemical screening has revealed the presence of alkaloids, tannins (gallic and catechic) and flavonoids for all plants, as for other secondary metabolites, they vary from one plant to another. For the forty-five [H2O, EtOH (96%), CH2Cl2-MeOH (V / V)] extracts, the extraction yield ranged from 3.3% to 23.78%; the CH2Cl2-MeOH extracts have the best yields followed by ethanolic extracts. The evaluation of the anti-salmonella activity of the forty-five extracts on seven strains of Salmonella (clinical isolate and reference) made it possible to determine the minimum inhibitory concentration (MIC) of the active extracts following the biological screening. The ethanolic extract of Zanthoxylum zanthoxyloides and CH2Cl2-MeOH from Azadirachta indica are the most active in inhibiting four types of salmonella with MICs ranging from 250 to 500 μg / mL. The determination of the polyphenol contents showed the richness of these plants in these compounds and we noticed that the activity of the extracts varies according to their content of flavonoids. The results obtained confirmed the anti-salmonella potential of certain plants at the concentration tested and constitute a scientific database for the research of phytomedicines.