Atividade modulatória de óleos voláteis de espécies de piperaceae em associação a antibióticos frente a staphylococcus aureus e escherichia coli

Abstract

During the COVID-19 pandemic, there was an excessive increase in the use of antibiotics, resulting in serious consequences regarding microbial resistance. One of the scientific community's alternatives to combat these resistant microorganisms has been to investigate potential drug prototypes in natural products, particularly from plant species. In the Piperaceae family, essential oils from the Piper genus have been widely investigated for their antimicrobial, antioxidant, and insecticidal effects. Considering these facts, this study aimed to investigate the chemical composition of the essential oils (EO) from Piper brachypetiolatum and Piper tuberculatum, native to the Amazon, and their antimicrobial action against strains of Staphylococcus aureus and Escherichia coli. To achieve this, the leaves of P. brachypetiolatum and P. tuberculatum were subjected to hydrodistillation in Clevenger and subsequently analyzed by GC-MS and GC-FID. The EO yield of P. brachypetiolatum was 0.85%, and GC-MS analysis detected 12 compounds, with the main components being nerolidol (24.51%) and hinesol (23.55%). The EO of P. tuberculatum had a yield of 0.17%, and 11 compounds were detected by GC-MS analysis, with its main component being β- caryophyllene (53.35%). Additionally, the obtained oils were subjected to microdilution in wells and minimum inhibitory concentration performed according to CLSI (2021) to investigate their antimicrobial potential. The EO of P. brachypetiolatum exhibited antimicrobial activity against strains of Staphylococcus aureus (CBAM 324) and Escherichia coli (CBAM 02), with average inhibition zones of 17 and 13 mm, respectively. The EO of P. tuberculatum showed no antimicrobial activity and was not further tested. On the other hand, the EO of P. brachypetiolatum exhibited a MIC of 2 mg/mL against S. aureus and E. coli. In the modulatory activity tests, the EO was tested in combination with antibiotics to which the strains showed resistance, resulting in a joint activity, suggesting a synergistic action of the oil and antibiotics. These results indicate that the essential oil of P. brachypetiolatum is promising against resistant strains.