Dihydroxylated phenolic acids derived from microbial metabolism reduce lipopolysaccharide-stimulated cytokine secretion by human peripheral blood mononuclear cells

Oligomers and polymers of flavan-3-ols (proanthocyanidins) are very abundant in the Mediterranean diet, but are poorly absorbed. However, when these polyphenols reach the colon, they are metabolised by the intestinal microbiota into various phenolic acids, including phenylpropionic, phenylacetic and benzoic acid derivatives. Since the biological properties of these metabolites are not completely known, in the present study, we investigated the effect of the following microbial phenolic metabolites: 3,4-dihydroxyphenylpropionic acid (3,4-DHPPA), 3-hydroxyphenylpropionic acid, 3,4-dihydroxyphenylacetic acid (3,4-DHPAA), 3-hydroxyphenylacetic acid, 4-hydroxybenzoic acid and 4-hydroxyhippuric acid (4-HHA), on modulation of the production of the main pro-inflammatory cytokines (TNF-alpha, IL-1beta and IL-6). The production of these cytokines by lipopolysaccharide (LPS)-stimulated peripheral blood mononuclear cells (PBMC) pre-treated with the phenolic metabolites was studied in six healthy volunteers. With the exception of 4-HHA for TNF-alpha secretion, only the dihydroxylated compounds, 3,4-DHPPA and 3,4-DHPAA, significantly inhibited the secretion of these pro-inflammatory cytokines in LPS-stimulated PBMC. Mean inhibition of the secretion of TNF-alpha by 3,4-DHPPA and 3,4-DHPAA was 84.9 and 86.4 %, respectively. The concentrations of IL-6 in the culture supernatant were reduced by 88.8 and 92.3 % with 3,4-DHPPA and 3,4-DHPAA pre-treatment, respectively. Finally, inhibition was slightly higher for IL-1beta, 93.1 % by 3,4-DHPPA and 97.9 % by 3,4-DHPAA. These results indicate that dihydroxylated phenolic acids derived from microbial metabolism present marked anti-inflammatory properties, providing additional information about the health benefits of dietary polyphenols and their potential value as therapeutic agents

OBSERVADORES DEL MAR - A MARINE CITIZEN SCIENCE PLATFORM WORKING FOR A HEALTHY OCEAN

Observadores del Mar is a marine citizen science platform launched in 2012 devoted to enhancing the understanding of the conservation status of marine ecosystems. The platform hosts different projects reporting information on two main topics: i) biodiversity data focusing mainly on species distribution and abundance, and ii) the impacts of anthropogenic activities, including both the occurrence of episodic events (e.g. jellyfish blooms) and associated mid- to long-term changes (e.g. colonization of invasive species)

Antioxidative stress actions of cocoa in colonic cancer: Revisited

Colorectal cancer is the third most common cancer in the world and is one of the major causes of cancer-related mortality in the world. Cancer is defined as a multistage process and divided into the following stages: initiation, promotion, and progression. In this disease, oxidative stress is involved in a large array of carcinogenic pathways associated with the proliferation of initiated cells and cellular malignancy. Therefore, the suppression of oxidative stress by natural antioxidant compounds has gained interest as an effective approach in colorectal cancer prevention. Accordingly, cocoa and its phenolic components have demonstrated to exert antioxidant activity and to be able to interfere with multiple carcinogenic signaling pathways. In this chapter, we reviewed the different in vitro and in vivo studies that have identified potential targets and mechanisms whereby cocoa and their flavonoid compounds could interfere with colonic cancer cells. In addition, recent evidence from human studies is also illustrated.This work was supported by the grants AGL2015-67087-R and RTI2018-095059-B-I00 (MINECO/FEDER, UE).Peer reviewe