Healthy effects of prebiotics and their metabolites against intestinal diseases and colorectal cancer

A specific group of plant and animal oligosaccharides does not suffer enzymatic digestion in the human upper intestinal tract, achieving the colon microbial ecosystem in intact form. The reason for that is their diverse glycosidic bond structure, in comparison with common energetic polysaccharides as starch or glycogen. In this complex ecosystem, these molecules serve as energy sources, via fermentation, of distinctive beneficial bacterial groups, mainly belonging to the Anaerostipes, Bifidobacterium, Coprococcus, Faecalibacterium, Lactobacillus, Roseburia and other genera. The main catabolic products of these fermentations are short-chain fatty acids (SCFA) as acetate, propionate and butyrate, which appear in high concentrations in the lumen around the colon mucosa. Acetate and propionate are associated to energetic purposes for enterocytes, hepatocytes and other cells. Butyrate is the preferred energy source for colonocytes where it controls their cell cycle; butyrate is able to induce cell cycle arrest and apoptosis in tumor colonocytes. These oligosaccharides that increase beneficial colon bacterial populations and induce SCFA production in this ecosystem are called prebiotics. Here, different sources and chemical structures for prebiotics are described, as well as their modulatory effect on the growth of specific probiotic bacterial groups in the colon, and how their fermentation renders diverse SCFA, with beneficial effects in gut healt

Modulación de la apoptosis en líneas celulares de cáncer de colon mediante compuestos bioactivos

El cáncer colorrectal es una enfermedad muy heterogénea causada por la interacción de factores genéticos y ambientales. Es uno de los cánceres con mayor incidencia en todo el mundo, especialmente en países desarrollados. El tratamiento se basa en cirugía durante las etapas iniciales, acompañada de quimio y radioterapia a partir del estadio III. Para estos tratamientos adyuvantes se utilizan fármacos como el 5-fluorouracilo, con fuertes efectos secundarios y una tasa de respuesta relativamente baja. Las aproximaciones combinatorias en el manejo del cáncer tienen como objetivo diseñar combinaciones de fármacos y compuestos moduladores que potencien el efecto del tratamiento. Así, en este trabajo Fin de Máster se propone que distintos nutracéuticos, como la quercetina, el kaempferol y el resveratrol, podrían potenciar el efecto antitumoral del 5-fluorouracilo. Los resultados indican que el resveratrol, una molécula que ha demostrado tener propiedades quimiopreventivas y antitumorales, modula el efecto del 5-fluorouracilo en la línea de cáncer de colon HCT116, potenciando la producción de muerte celular e induciendo una disminución en la fase S del ciclo celular

Chlorosphaerolactylates A-D: The Natural Chlorinated Lactylates Isolated from the Portuguese Cyanobacterium Sphaerospermopsis Sp. LEGE 00249

The unprecedented natural chlorinated lactylates, chlorosphaerolactylates A-D (1-4), were isolated from the methanolic extract of the cyanobacterium Sphaerospermopsis sp. LEGE 00249 through a combination of bioassay-guided and MS-guided approaches. Compounds 1-4 are esters of (mono-, di- or tri-)chlorinated lauric acid and lactic acid, whose structures were assigned on the basis of spectrometric and spectroscopic methods inclusive of 1D and 2D NMR experiments. High-resolution mass-spectrometry datasets also demonstrated the existence of other minor components that were identified as chlorosphaero(bis)lactylate analogues. The chlorosphaerolactylates were tested for potential antibacterial, antifungal and antibiofilm properties using bacterial and fungal clinical isolates. Compounds 1-4 inhibited the growth of Staphylococcus aureus S54F9 and Candida parapsilosis SMI416, as well as, affected the biofilm formation of coagulase-negative Staphylococcus hominis FI31

Microalgae and Cyanobacteria Strains as Producers of Lipids with Antibacterial and Antibiofilm Activity

Lipids are one of the primary metabolites of microalgae and cyanobacteria, which enrich their utility in the pharmaceutical, feed, cosmetic, and chemistry sectors. This work describes the isolation, structural elucidation, and the antibiotic and antibiofilm activities of diverse lipids produced by different microalgae and cyanobacteria strains from two European collections (ACOI and LEGE-CC). Three microalgae strains and one cyanobacteria strain were selected for their antibacterial and/or antibiofilm activity after the screening of about 600 strains carried out under the NoMorFilm European project. The total organic extracts were firstly fractionated using solid phase extraction methods, and the minimum inhibitory concentration and minimal biofilm inhibitory concentration against an array of human pathogens were determined. The isolation was carried out by bioassay-guided HPLC-DAD purification, and the structure of the isolated molecules responsible for the observed activities was determined by HPLC-HRESIMS and NMR methods. Sulfoquinovosyldiacylglycerol, monogalactosylmonoacylglycerol, sulfoquinovosyl-monoacylglycerol, α-linolenic acid, hexadeca-4,7,10,13-tetraenoic acid (HDTA), palmitoleic acid, and lysophosphatidylcholine were found among the different active sub-fractions selected. In conclusion, cyanobacteria and microalgae produce a great variety of lipids with antibiotic and antibiofilm activity against the most important pathogens causing severe infections in humans. The use of these lipids in clinical treatments alone or in combination with antibiotics may provide an alternative to the current treatments. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This research was funded by the European Union’s Horizon 2020 research and innovation program under grant agreement no. 634588 (NOMORFILM). We thank Programa Severo Ochoa de Ayudas Predoctorales para la investigación y docencia from Principado de Asturias (grant BP16023 to I.G.-D.-R.). ISGlobal is a CERCA center from the Generalitat of Catalunya and a Severo Ochoa Center (Spanish Ministry of Science, Innovations, and Universities)