Potential of chambá (Justicia Pectoralis Jacq.) leaves extracts as a source of bioactive compounds and natural antimicrobial agent

Abstract

This study aimed to produce different chambá (Justicia pectoralis Jacq.) extracts, determinate their biocompounds and antimicrobial activity against several foodborne bacterias. Aqueous and hydroalcoholic extracts were prepared using the decoction and maceration method, respectively, and were submitted to cytotoxicity analysis. The samples were submitted to bioactive compound analysis and antimicrobial tests. The effects of the extract on the bacterial cell structures were visualized using Transmission Electron Microscope. Between the samples, the aqueous extract presented higher levels of umbelliferone (8.99 mg/g), total phenolic compounds (17.7 g AGE/100g) and antioxidant activity (765.3 μM TE/g) compared hydroalcoholic extracts. All extracts presented antimicrobial activity against Gram-Positive bacteria group, being the aqueous sample the one most effective presenting the lowest values for minimum inhibitory (MIC) and bactericidal (MIB) concentrations for all microorganisms evaluated, highlighting its action against Staphyloccocus aureaus (MIC = 0.84 and MIB = 1). The bactericidal action of the aqueous extract against the bacteria was observed by the microphotographs with evidenced by a rupture of the bacterial cell wall caused by the exposition to phenolics presented in the extract. Thus, this research demonstrated that beyond being a source of phenolics, chambá presents great potential as a new natural antimicrobial agent, which reinforces the development of more studies to evaluate its effective application in food systems.