No abstract

The main aim of this study was to investigate the effect of Grape seed extract (GSE) on Campylobacter induced-cytokine production by human intestinal cell lines. With this purpose, Caco-2 and HT-29 cells were challenged with culture supernatants from several strains of C. jejuni and levels of secreted IL-6, IL-8, and MCP-1 were measured. Cytokine production was higher in HT-29 than in Caco-2 cells, showing different levels of secretion depending of the epithelial cells origin. Also, infective isolates coming from campylobacteriosis patients rendered higher levels of proinflammatory cytokines. Co-treatment and pre-treatment of HT-29 cells with GSE and C. jejuni significantly reduced cytokines production in a dose-dependent manner. These results make this natural product a putative nutritional tool for use in the treatment of campylobacteriosis, which could contribute to improve disease prevention or reduce disease severity.

The feasibility of winemaking waste (WW) as source of active phenolic compounds against Campylobacter was evaluated using a mixture of ethanol-water (50% v/v) as extraction solvent. The winemaking waste extract (WWE) was active against all the strains tested, and most of them were inhibited at WWE concentrations between 40-100 mg GAE/L. However, different lactic acid bacteria (LAB) strains were practically unaffected by WWE, suggesting a selective antibacterial effect of WWE against Campylobacter. The fractioning and phenolic characterization of WWE using HPLC-MS showed that catechins and proanthocyanidins were the main compounds involved in the antibacterial effect. Among them, the structural verification using pure phenolic standards showed that epicatechin gallate and resveratrol were the most active compounds against Campylobacter. We conclude that the study of the main mechanisms involved in the antibacterial activity against Campylobacter of epicatechin gallate, resveratrol, and other related compounds presenting gallate side-chain, can contribute for future design of useful antibacterials against this pathogen.