Antibacterial capacity interactions between Aristotelia chilensis (Mol.) Stuntz leaf extract and commercial antibiotics

Antibiotic-resistant bacteria are continuously increasing the prevalent level of bacterial infection, making it a serious public health threat. In the search for solutions, natural products have emerged as promising allies that could enhance the efficacy of conventional antibiotics. This study examined the antibacterial interactions between the leaf extracts of Aristotelia chilensis (Mol.) Stuntz (maqui) and the antibiotics ampicillin and chloramphenicol using a checkerboard assay; the test were conducted against the pathogenic bacteria Escherichia coli, Staphylococcus aureus, and Salmonella typhi. The minimum inhibitory concentrations (MIC) of maqui leaf extract were 12.5, 0.04, and 1.56 mg/mL against E. coli, S. aureus, and S. typhi, respectively. Combining the extract with ampicillin or chloramphenicol, the extract reduced the MICs of the antibiotics by up to six-fold. The interaction of maqui leaf extracts with conventional antibiotics was found to significantly enhance antibacterial activity, reducing required antibiotic doses and highlighting their relevance in combating antimicrobial resistance.