Search Results (3)

Addressing disease remission and treatment adherence in inflammatory bowel diseases (IBDs), such as Crohn’s disease, poses significant challenges due to underlying oxidative and inflammatory processes. Nanotechnology emerges as a promising avenue for enhancing therapeutic outcomes in IBD by optimizing drug bioactivity, reducing toxicity, and extending circulation time. Gold nanoparticles, known for their resistance to gastrointestinal pH and possessing antioxidant and anti-inflammatory properties, offer particular promise. They can be produced by green synthesis with seaweed Ericaria selaginoides (ES), itself associated with gastroprotective and anti-inflammatory activities. In a murine model of Crohn’s disease induced with 8% acetic acid, pretreatment with dexamethasone (0.2 mL/30 g) or Au@ES (25 and 50 mg/kg) effectively mitigated inflammatory features. Notably, ES (50 mg/kg) and Au@ES (50 mg/kg) administration resulted in significant reductions in both macroscopic and microscopic inflammation scores compared to the disease control group. Furthermore, these treatments normalized inflammatory cytokine expression while safeguarding myenteric plexus glial cells. They also impeded neutrophil activation, leading to reduced myeloperoxidase activity and lipid peroxidation, coupled with increased glutathione levels. In conclusion, ES and Au@ES exhibit potent efficacy in counteracting inflammation and oxidation processes in an experimental Crohn’s disease model, suggesting their potential as alternative therapeutic strategies for IBD. Full article

Growing consumer demand for high-quality products coupled with minimally processed products and a minor use of synthetic food additives have increased the need to search for new sources of natural antimicrobials to ensure product safety. This study aimed to evaluate the antimicrobial activity of extracts from the brown algae Ericaria selaginoides against Bacillus cereus in typical Catalan fresh cheese (“mató”) by means of challenge testing. Three concentrations of a crude extract and its corresponding two subfractions (non-polar and mid-polar) obtained after purification showed an antimicrobial dose-dependent effect on B. cereus, from inhibition to inactivation. The best results were obtained with higher concentrations of the non-polar subfraction that caused a total inactivation of the inoculated pathogen after 2 or 4 days, followed by the mid-polar that inactivated B. cereus after 2 or 6 days. The results showed an improvement in the antimicrobial effect after purification compared with the effect observed when the crude extract was tested. Moreover, compounds of different chemical natures may be involved in this antimicrobial activity since it remained in both subfractions after purification. The results obtained in this work show the great potential of macroalgae extracts as natural food preservatives against B. cereus in fresh cheese. Full article

The search for new sources of antimicrobial compounds has become an urgent need, due to the threat that the spread of bacterial resistance represents for global health and food safety. Brown macroalgae have been proposed as a great reservoir in the search for novel antimicrobial compounds. In this study, mid-polarity extracts were performed with a selection of 20 brown macroalgae species from northern Spain. The total polyphenol, carbohydrate and protein contents were quantified by spectrophotometry. The volatile organic compounds (VOCs) of whole macroalgae were also studied as a biomarker of their metabolic state in the representative species of the tested families by gas chromatography-mass spectrometry (GC-MS). The antimicrobial potential of the extracts was assessed by a disk diffusion assay against 20 target bacteria and further determinations of the minimum inhibitory (MIC) and minimum bactericidal concentrations (MBC) were performed by a microdilution assay for the active extracts. Ericaria selaginoides, Bifurcaria bifurcata and Dictyota dichotoma showed an antimicrobial effect against six Gram-positive strains: Bacillus cereus, Bacillus subtilis, Geobacillus stearothermophilus, Listeria monocytogenes, Staphylococcus aureus and Staphylococcus haemolyticus. The phenolic content was generally higher in the extracts that showed antimicrobial activity, followed by carbohydrates and low contents of proteins. The results obtained in this study reveal the potential of brown macroalgae as a promising alternative source of antimicrobial compounds as functional ingredients for the application in industrial fields. Full article