Antibacterial Activity from Momordica charantia L. Leaves and Flavones Enriched Phase

Momordica charantia L. (Cucurbitaceae) is a plant known in Brazil as melao de Sao Caetano, which has been related to many therapeutic applications in folk medicine. Herein, we describe antibacterial activities and related metabolites for an extract and fractions obtained from the leaves of that species. An ethanolic extract and its three fractions were used to perform in vitro antibacterial assays. In addition, liquid chromatography coupled to mass spectrometry and the molecular networking approach were used for the metabolite annotation process. Overall, 25 compounds were annotated in the ethanolic extract from M. charantia leaves, including flavones, terpenes, organic acids, and inositol pyrophosphate derivatives. The ethanolic extract exhibited low activity against Proteus mirabilis (MIC 312.5 mu g center dot mL(-1)) and Klebsiella pneumoniae (MIC 625 mu g center dot mL(-1)). The ethyl acetate phase showed interesting antibacterial activity (MIC 156.2 mu g center dot mL(-1)) against Klebsiella pneumoniae, and it was well justified by the high content of glycosylated flavones. Therefore, based on the ethyl acetate phase antibacterial result, we suggest that M. charantia leaves could be considered as an alternative antibacterial source against K. pneumoniae and can serve as a pillar for future studies as well as pharmacological application against the bacteria.

Automated summary

Momordica charantia leaves exhibit antibacterial activity, particularly against Klebsiella pneumoniae. The ethyl acetate phase has a high content of glycosylated flavones, which may contribute to its antibacterial activity. Therefore, M. charantia leaves could be considered as an alternative antibacterial source and should be further studied for potential pharmacological applications.