RESUMO
SCOPE: Dietary supplementation with polyphenol-rich propolis can protect against experimentally induced colitis. We examined whether different polyphenol compositions of Chinese propolis (CP) and Brazilian propolis (BP) influence their ability to protect against dextran sulfate sodium (DSS)-induced colitis in rats. METHODS AND RESULTS: HPLC-DAD/Q-TOF-MS analysis confirmed that polyphenol compositions of CP and BP were dissimilar. Rats were given CP or BP by gavage (300 mg kg-1 body weight) throughout the study, starting 1 week prior to DSS treatment for 1 week followed by 3 d without DSS. CP and BP significantly reduced the colitis disease activity index relative to controls not receiving propolis, prevented significant DSS-induced colonic tissue damage, and increased resistance to DSS-induced colonic oxidative stress as shown by reduced malonaldehyde levels and increased T-AOC levels. CP and BP significantly reduced DSS-induced colonic apoptosis. Colonic inflammatory markers IL-1ß, IL-6, and MCP-1 were suppressed by CP and BP, whereas only BP-induced expression of TGF-ß. CP, not BP, increased the diversity and richness of gut microbiota populations. Both forms of propolis significantly reduced populations of Bacteroides spp. CONCLUSIONS: Despite the dissimilar polyphenol compositions of CP and BP, their ability to protect against DSS-induced colitis is similar. Nevertheless, some different physiological impacts were observed.
Assuntos
Bacteroides/efeitos dos fármacos , Colite/tratamento farmacológico , Microbioma Gastrointestinal/efeitos dos fármacos , Própole/química , Própole/farmacologia , Animais , Brasil , China , Colite/induzido quimicamente , Colite/genética , Colo/efeitos dos fármacos , Colo/microbiologia , Colo/patologia , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Microbioma Gastrointestinal/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Masculino , Estresse Oxidativo/efeitos dos fármacos , Ratos Sprague-DawleyRESUMO
Se and green tea have been shown in epidemiological, observational and preclinical studies to be inversely related to the risk of developing colorectal cancer (CRC). However, there are limited studies to evaluate their regulatory effects on genes/proteins that relate to CRC oncogenesis in human subjects, such as selenoproteins, WNT signalling pathway, inflammation and methylation. This study examined the effects of supplementation of Se using Brazil nuts and green tea extract (GTE) capsules, alone and in combination, on targeted biomarkers. In total, thirty-two volunteers (>50 years of age) with plasma Se≤1·36 µmol/l were randomised to one of three treatment groups: nine to Se (approximately 48 µg/d) as six Brazil nuts, eleven to four GTE capsules (800 mg (-)-epigallocatechin-3-gallate) and twelve to a combination of Brazil nuts and GTE. Blood and rectal biopsies were obtained before and after each intervention. Plasma Se levels, rectal selenoprotein P (SePP) and ß-catenin mRNA increased significantly in subjects consuming Brazil nuts alone or in combination, whereas rectal DNA methyltransferase (DNMT1) and NF-κB mRNA were reduced significantly in subjects consuming GTE alone or in combination. None of the interventions significantly affected rectal acetylated histone H3 or Ki-67 expression at the protein level or plasma C-reactive protein. Effects of the combination of Brazil nuts and GTE did not differ from what would be expected from either agent alone. In conclusion, supplementation of Brazil nuts and/or GTE regulates targeted biomarkers related to CRC oncogenesis, specifically genes associated with selenoproteins (SePP), WNT signalling (ß-catenin), inflammation (NF-κB) and methylation (DNMT1). Their combination does not appear to provide additional effects compared with either agent alone.