Phytochemical Characterization and Evaluation of the Antibacterial Activity of Leaf Extracts of Mitragyna inermis (Willd.) O. Ktze on the in Vitro Growth of Clinical Strains Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa Involved in Gastro Enteritis

Gastroenteritis constitutes a group of diarrheal diseases of infectious origin, responsible for absenteeism from work, morbidity and mortality, especially among aged people. This study aimed to evaluate the antibacterial activity of Mitragyna inermis extracts on the in vitro growth of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa involved in gastroenteritis. Phytochemical screening was carried out using two distinct methods. The detection of phytochemical compounds by tube coloring and chromatography on a thin layer of silica gel. The sensitivity of organisms was evaluated by the agar well method. The dilution method in liquid medium coupled with spreading on Mueller Hinton agar helped determine the CMB/MIC activity ratios. The investigations show that the extract has the best extraction yield (75.86% ± 0.20%) compared to the aqueous macerated (61.8% ± 0.08%) and decocted (66.6% ± 0.12%). These extracts contain several phytochemical compounds such as flavonoids, polyphenols, tannins, alkaloids, saponosides, coumarins and sterols and terpenes. These substances are endowed with biological activities and could be at the origin of antibacterial activity observed with M. inermis extracts. The analysis of antibacterial activity showed that the germs are sensitive to the extracts with inhibition diameters ranging from 8.30 ± 0.53 to 17.87 ± 0.58 mm. The ethanolic extract was the most active with diameters varying from 15.07 ± 0.62 to 17.87 ± 0.58 mm on all the germs tested. E. coli and S. aureus were the most sensitive germs to the extracts. P. aeruginosa was the least sensitive germ. Activity reports indicate that the extracts exert bactericidal activity on E. coli and S. aureus but bacteriostatic activity on P. aeruginosa. These results justify the use of M. inermis leaves in a traditional environment to treat gastroenteritis.