Pristimerin isolated from Salacia crassifolia (Mart. Ex. Schult.) G. Don. (Celastraceae) roots as a potential antibacterial agent against Staphylococcus aureus.

Affiliation

Nizer WSDC(1), Ferraz AC(2), Moraes TFS(3), Lima WG(4), Santos JPD(5), Duarte LP(6), Ferreira JMS(7), de Brito Magalhães CL(8), Vieira-Filho SA(9), Andrade ACDSP(10), Rodrigues RAL(11), Abrahão JS(12), Magalhães JC(13).
Author information:
(1)Department of Chemistry, Biotechnology, and Bioprocess Engineering, Universidade Federal de São João del-Rei, Ouro Branco, MG, Brazil; Carleton University, Ottawa, ON, Canada. Electronic address: [Email]
(2)Institute of Exact and Biological Sciences, Biological Science Research Nucleus, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil. Electronic address: [Email]
(3)Department of Microbiology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. Electronic address: [Email]
(4)Laboratory of Medical Microbiology, Campus Centro Oeste Dona Lindu, Universidade Federal de São João del-Rei, Divinópolis, MG, Brazil. Electronic address: [Email]
(5)Department of Chemistry, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. Electronic address: [Email]
(6)Department of Chemistry, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. Electronic address: [Email]
(7)Laboratory of Medical Microbiology, Campus Centro Oeste Dona Lindu, Universidade Federal de São João del-Rei, Divinópolis, MG, Brazil. Electronic address: [Email]
(8)Institute of Exact and Biological Sciences, Biological Science Research Nucleus, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil. Electronic address: [Email]
(9)Department of Pharmacy, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil. Electronic address: [Email]
(10)Department of Microbiology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. Electronic address: [Email]
(11)Institute of Exact and Biological Sciences, Biological Science Research Nucleus, Universidade Federal de Ouro Preto, Ouro Preto, MG, Brazil; Department of Microbiology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. Electronic address: [Email]
(12)Department of Microbiology, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil. Electronic address: [Email]
(13)Department of Chemistry, Biotechnology, and Bioprocess Engineering, Universidade Federal de São João del-Rei, Ouro Branco, MG, Brazil. Electronic address: [Email]

Abstract

ETHNOPHARMACOLOGICAL RELEVANCE: Pristimerin is a triterpenoid considered the main component of Salacia crassifolia extracts. This terpene has shown promising antitumor, anti-inflammatory, and antimicrobial effects. Likewise, S. crassifolia has been used in traditional medicine to treat cancer and as an antimicrobial and anti-inflammatory agent. AIM OF THE STUDY: This study aimed to evaluate the antibacterial activity of the hexane extract of Salacia crassifolia roots (HER) and its isolate, pristimerin, against pathogenic bacteria. MATERIALS AND METHODS: First, we evaluated the spectrum of action of HER and pristimerin by the determination of the minimum inhibitory concentration (MIC) and the minimal bactericidal concentration (MBC). Subsequently, we analyzed the time-kill curve of these plant-derived compounds against Staphylococcus aureus. Then, we examined their mode of action by three different assays: the crystal violet methodology, the release of intracellular material, and transmission electron microscopy methods (TEM). Finally, we evaluated the effect of HER and pristimerin on the pre-formed biofilm of S. aureus by the crystal violet assay, the synergistic effect by the checkerboard method, the cytotoxicity against Vero cells, and the in silico activity using the online software PASS. RESULTS: HER and pristimerin presented a narrow spectrum of action against Gram-positive bacteria (MIC 0.195-25 μg/mL), and their primary mode of action is the alteration of membrane permeability of S. aureus. Our results show that the compounds disrupted the pre-formed biofilm of S. aureus in a dose-dependent manner. Furthermore, HER and pristimerin presented a significant synergic effect after the combination with well-known antibiotics, which was associated with the ability of these phytomedicines to change membrane permeability. Regarding the cytotoxic effect, the selective index (SI) of HER ranged from 0.37 to 11.86, and the SI of pristimerin varied from 0.24 to 30.87, according to the bacteria tested. CONCLUSIONS: Overall, HER and pristimerin showed a promising antibacterial effect in vitro through the alteration of membrane permeability of S. aureus.