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

• Published in: Journal of ethnopharmacology Vol. 266; no. NA; p. 113423
• Main Authors: Nizer, Waleska Stephanie da Cruz, Ferraz, Ariane Coelho, Moraes, Thaís de Fátima Silva, Lima, William Gustavo, Santos, Josana Pereira dos, Duarte, Lucienir Pains, Ferreira, Jaqueline Maria Siqueira, de Brito Magalhães, Cintia Lopes, Vieira-Filho, Sidney Augusto, Andrade, Ana Claúdia dos Santos Pereira, Rodrigues, Rodrigo Araújo Lima, Abrahão, Jonatas Santos, Magalhães, José Carlos de
• Format: Journal Article
• Language: English
• Published: Ireland Elsevier B.V 10.02.2021
• Subjects: Animals; Anti-Bacterial Agents - isolation & purification; Anti-Bacterial Agents - pharmacology; Anti-staphylococcal; Antibacterial activity; antibacterial properties; antibiotics; biofilm; Biofilms - drug effects; Chlorocebus aethiops; computer simulation; computer software; cytotoxicity; dose response; gentian violet; Gram-Positive Bacteria - drug effects; hexane; mechanism of action; membrane permeability; Microbial Sensitivity Tests; minimum inhibitory concentration; Plant Roots; Pristimerin; S. aureus biofilm; Salacia; Salacia - chemistry; Salacia crassifolia; Staphylococcal Infections - drug therapy; Staphylococcus aureus; Staphylococcus aureus - drug effects; Synergic effect; synergism; traditional medicine; transmission electron microscopy; Triterpenes - isolation & purification; Triterpenes - pharmacology; triterpenoids; Vero Cells; CLSI; FIC; CI; MIC; FICI; Pristimerin; Anti-staphylococcal; MTT; ATCC; MBC; S. aureus biofilm; HER; PASS; ANOVA; OD; SI; Synergic effect; MRSA; Salacia crassifolia; Antibacterial activity; MH; TEM; WHO
• DOI: 10.1016/j.jep.2020.113423
• ISSN: 0378-8741; 1872-7573

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. This study aimed to evaluate the antibacterial activity of the hexane extract of Salacia crassifolia roots (HER) and its isolate, pristimerin, against pathogenic bacteria. 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. 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. Overall, HER and pristimerin showed a promising antibacterial effect in vitro through the alteration of membrane permeability of S. aureus. [Display omitted] •The hexane extract of roots of Salacia crassifolia and pristimerin are promising anti-Gram-positive agents.•The hexane extract of roots of Salacia crassifolia and pristimerin disrupt cell membranes of Gram-positive bacteria.•The hexane extract of roots of Salacia crassifolia and pristimerin showed antibiofilm effect against Staphylococcus aureus.•The combination of the extract of roots of Salacia crassifolia and pristimerin with antibiotics produced a synergic effect.