RESUMO
Objectives: Multidrug-resistant [MDR] bacterial infections, especially those caused by Gram-negative phe-notypes, have emerged as one of the major health concerns worldwide. In the present study, we investigated the antibacterial activity of methanol extracts from five Cameroonian medicinal plants [Alchornea cordifolia, Eremomastax speciosa, Laportea aestuans, Pennisetum purpureum and Spathodea campanulata] against 15 Gram-negative bacteria that included MDR phenotypes
Methods: The broth microdilution method was used to determine the minimal inhibitory concentrations [MIC] and the minimal bactericidal concentrations [MBC] of all of the samples. Standard phytochemical methods were used for a preliminary phytochemical screening of the plant extracts
Results: Phytochemical analysis showed the presence of polyphenols, tannins, triterpenes and sterols in all of the studied extracts. Other chemical classes of secondary metabolites were selectively identified. The best antibacterial activities [MICs ranges of 64-1024 microg/mL] obtained against the 15 tested bacteria were found in extracts of leaves [93.3%], bark [86.7%] and roots [80%] of A. cordifolia as well as extracts of L. aestuans [86.7%] and P. purpureum [66.7%]. The lowest MIC value of 64 microg/mL was recorded for the A. cordifolia bark extract against Pseudomonas aeruginosa PA01
Conclusions: The findings of this study provide deep insights into the possible use of the studied plants, especially A. cordifolia and L. aestuans, for the control of Gram-negative bacterial infections, especially against MDR species