Red pepper peptide coatings control Staphylococcus epidermidis adhesion and biofilm formation.

Medical devices (indwelling) have greatly improved healthcare. Nevertheless, infections related to the use of these apparatuses continue to be a major clinical concern. Biofilms form on surfaces after bacterial adhesion, and they function as bacterial reservoirs and as resistance and tolerance factors against antibiotics and the host immune response. Technological strategies to control biofilms and bacterial adhesion, such as the use of surface coatings, are being explored more frequently, and natural peptides may promote their development. In this study, we purified and identified antibiofilm peptides from Capsicum baccatum (red pepper) using chromatography-tandem mass spectrometry, MALDI-MS, MS/MS and bioinformatics. These peptides strongly controlled biofilm formation by Staphylococcus epidermidis, the most prevalent pathogen in device-related infections, without any antibiotic activity. Furthermore, natural peptide-coated surfaces dislayed effective antiadhesive proprieties and showed no cytotoxic effects against different representative human cell lines. Finally, we determined the lead peptide predicted by Mascot and identified CSP37, which may be useful as a prime structure for the design of new antibiofilm agents. Together, these results shed light on natural Capsicum peptides as a possible antiadhesive coat to prevent medical device colonization.

Anti-inflammatory and immunomodulatory effects of Baccharis trimera aqueous extract on induced pleurisy in rats and lymphoproliferation in vitro.

Baccharis trimera is a widespread South American plant known as "carqueja". Medicinal teas prepared from the aerial parts of this plant are used in folk medicine in cases of liver diseases and inflammatory processes. We evaluated the effects of aqueous extract of B. trimera in the experimental inflammatory model of carrageenan-induced pleurisy in rat. The injection of carrageenan into the pleural cavity induces an influx of cells and fluid accumulation with a large number of polymorphonuclear leukocytes and increase of protein levels. The inflammation parameters were attenuated when B. trimera (400 and 800 mg/kg, i.p.) was administrated 30 min before the carrageenan. The immunomodulatory effects were evaluated in vitro on human peripheral blood mononuclear cells. The extract in concentration of 25, 50 and 100 mg/mL presented inhibited the T-lymphocytes proliferation stimulated by phytohemagglutinin, but these extract concentrations also presented cytotoxic effect. These results showed that the aqueous extract of B. trimera has anti-inflammatory effect.