Antimicrobial screening and hemolytic activity of products obtained from Piper montealegreanum Yuncker and effect in vitro on growth of Staphylococcus aureus

Abstract

This study aimed to determine spectrum of antimicrobial activity of crude ethanolic extract (CEE), chloroform (CHCl3) and ethyl acetate (EtOAc) fractions, to determine influence of CHCl3 fraction on Staphylococcus aureus growth and hemolytic activity. Antimicrobial screening of CEE, CHCl3 and EtOAc fractions was carried out using broth microdilution technique against standard strains: Staphyloccocus aureus ATCC25923, Escherichia coli ATCC25922, Pseudomonas aeruginosa ATCC27853 and Candida albicans ATCC76645 to determine the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). Time kill curves were performed to determine influence of CHCl3 fraction on MIC and ½ MIC concentrations on S. aureus growth. Hemolytic activity of CHCl3 was performed in human erythrocytes to report the cytotoxic effect. CHCl3 fraction showed activity against S. aureus with MIC=1024 µg mL-1 and MBC=2048 µg mL-1. This fraction did not show activity against other tested strains, as well as the CEE and EtOAc fraction. Time kill curve of S. aureus treated with CHCl3 fraction showed that at MIC this fraction has bacteriostatic activity, which was not observed with the ½ MIC. Hemolytic activity demonstrated that when CHCl3 fraction in MIC does not present membrane damage of erythrocytes, since it did not cause hemolysis. Studies should be conducted to evaluate the activity of CHCl3 fraction against S. aureus with different antimicrobial resistance profiles, in addition to evaluating the potential for resistance reversion by in vitro combination studies. The study demonstrated that the species P. montealegreanum can be an important source of compounds of importance for combating microorganisms of clinical importance.

Investigação da atividade antimicrobiana de extratos e frações de espécies de Piper usando bioautografia

“…There are reports of antimicrobial activity of Piper species that show activity against S. aureus, but demonstrate that the same extracts do not show activity against Gram-negative bacteria (Alves et al, 2016;Rocha et al, 2020) and corroborate with the results found in this study, since the results indicate that the products eluted in chromatoplates did not show activity against E. coli and P. aeruginosa. Holley and Patel (2005) suggest that the dual membrane presented by Gram-negative bacteria forms a complex envelope, being responsible for the lower sensitivity of these microorganisms to plant extracts.…”

“…Previous studies have shown the isolation of secondary metabolites in different Piper species, such as extracts of Piper montealegreanum that showed activity against Staphylococcus aureus, Bacillus subtillis, Pseudomonas aeruginosa and Escherichia coli, furthermore isolated molecules of Piper glandulosissimum that showed antifungal activity against Trichophyton mentagrophytes and Microsporum canis, in addition to presenting antibacterial activity against Staphylococcus aureus and S. epidermidis (Pinto et al, 2012;Cordova, Benfatti, Magina, Guedes & Cordova, 2010). Studies also reporting antibacterial and antifungal activity of products obtained from P. caldense, P. mollicomum and P. arboreum against S. aureus and Candida albicans, C. glabrata and C. tropicalis (Rocha, Nunes, Fernandes, Catão & Alves, 2020;Alves et al, 2016). Rocha et al (2018) report that although the extractive products of P. montealegreanum have no activity against E. coli ATCC 25922, these extracts when evaluated in association with antimicrobials such as quinolones, tetracyclines and betalactams were able to increase diameter of the halos of inhibition of these substances when compared to the values of antibiotics alone, indicating a possible in vitro synergism between the products and antimicrobials agents.…”

Caracterização morfológica de piperáceas nativas conservadas em casa de vegetação

“…A literatura cita que Piper montealegreanum Yunk. tem componentes com ação antibacteriana e hemolítica (Pinto et al, 2012;Rocha et al, 2020). Essa espécie apresentou hábito de crescimento arbustivo, folhas em formato oval lanceolada, caule em formato cilíndrico, filotaxia alterna e com ausência de lenticelas.…”