Title : Antimicrobial potential of extracts of five medicinal plants of central Mexico
Abstract:
Medicinal plants used in traditional medicine are an important resource as a primary care resource for health maintenance in developing countries; however, scientific evidence on their biological activity and phytochemical characterization is still scarce. Currently, the resistance of microorganisms that cause infectious diseases and the lack of effective antibiotics for their control are driving research into the antimicrobial potential of medicinal plants. Therefore, this study analyzed the antibacterial activity against Escherichia coli and Salmonella enterica of five species used medicinally to treat gastrointestinal infections in different locations in Mexico: Neltuma laevigata (Humb. et Bonpl. ex Willd) M.C. Johnst. (mesquite), Acacia farnesiana (L.) Willd. (huizache), Tagetes lucida Cav. (pericón), Lepidium virginicum L. (lentejilla), and Tecoma stans (L.) Juss. ex Kunth (tronadora). Extracts were obtained from the aerial parts of the plants through maceration with organic solvents (hexane, ethyl acetate, and methanol) assisted by ultrasound. Antibacterial activity was evaluated using the agar dilution method in 9 cm diameter Petri dishes, with EMB medium for E. coli and SS medium for S. enterica. The concentrations of the extracts were evaluated at 8 µg mL¹, 16 µg mL¹, 32 µg mL¹, and 64 µg mL ¹, and the bacterial inoculum concentration was 1 x 10⁸ CFU. All species showed antibacterial activity, except for L. virginicum, which did not show antibacterial activity against E. coli. The lowest MIC (16 µg mL¹) obtained against E. coli was for the extracts of A. farnesiana and T. lucida, while for S. enterica the lowest MIC (8 µg mL¹) corresponded to the extracts of A. farnesiana, T. lucida, and L. virginicum.
