procyanidin-b1 and Disease-Models--Animal

The p38 MAPK signaling pathway plays a key role in lung inflammation and the development of acute lung injury (ALI). We previously reported that the phenolic compound procyanidin B1 inhibits inflammation by suppressing the p38 MAPK signaling pathway. Here, we asked whether the monomer of procyanidin B1, epicatechin (EC), can alleviate LPS-induced ALI in mice, and if so, whether EC acts by inhibiting p38 MAPK. C57BL/6 mice were randomly divided into four groups (n = 8) and received EC alone, vehicle (sham group), LPS alone, or LPS and EC. LPS was administered via intraperitoneal injection and EC via nasogastric feeding. Lung histopathology, alveolocapillary membrane permeability, inflammation, and p38 MAPK pathway activation were assessed by immunohistochemistry, tissue wet/dry weight analysis, quantitative PCR, protein assays, ELISA, and western blot analysis using lung tissue and/or bronchoalveolar fluid. We also performed molecular modeling and in vitro enzymatic assays to examine the potential interaction between EC and p38 MAPK at the molecular level. We found that LPS caused an increase in ALI-associated lung pathology accompanied by activation of p-p38 pathway components and the transcription factor AP1. All of these effects were substantially reduced by treatment with EC. Furthermore, molecular modeling suggested that EC suppressed p38 MAPK signaling by hydrogen bonding with Glu71, Ala 111, Asp112, and Leu171 in the active site of p38α. In vitro kinase assays confirmed the ability of EC to directly inhibit purified p38 MAPK. Collectively, our data suggest that the naturally occurring compound EC could be a new therapeutic option for ALI.

Topics: Acute Lung Injury; Animals; Anti-Inflammatory Agents; Biflavonoids; Catechin; Disease Models, Animal; Humans; Inflammation; Lipopolysaccharides; Male; MAP Kinase Signaling System; Mice; Mice, Inbred C57BL; p38 Mitogen-Activated Protein Kinases; Proanthocyanidins; Protein Binding

Flavangenol, one of several pine bark extract products, is expected to prevent metabolic diseases with its potent antioxidant effect, its anti-obesity effect and its improvement of insulin sensitivity. In this study, targeting the liver as one of the organs that plays an important role in energy metabolism, Flavangenol was investigated for its effect on non-alcoholic fatty liver disease (NAFLD), its action mechanism and its active ingredients, using in vivo and in vitro experiment systems. Flavangenol suppressed intrahepatic fat accumulation in Western diet-loaded Tsumura Suzuki Obese Diabetes (TSOD) mice, which develop various metabolic diseases. In addition, Flavangenol significantly increased the mRNA expression levels of fatty acid oxidative enzymes (peroxisomal proliferator-activated receptor α, acyl-CoA oxidase, carnitine palmitoyltransferase). In order to investigate the direct effect of Flavangenol on the liver, an in vitro fatty liver model prepared by adding a free fatty acid to human liver cancer cells (HepG2 cells) was used. In this model, Flavangenol significantly suppressed intracellular fat accumulation. Procyanidin B1, one of the major components of Flavangenol, also suppressed fat accumulation and induced mRNA expression of the fatty acid oxidative enzymes. As mentioned above, Flavangenol showed a significant suppressive effect in the NAFLD model, and it was suggested that the molecular mechanism is induction of fatty acid oxidation, with the effect mainly attributed to procyanidin B1.

Topics: Animals; Biflavonoids; Catechin; Diabetes Mellitus; Disease Models, Animal; Fatty Acids; Fatty Liver; Gene Expression Regulation, Enzymologic; Hep G2 Cells; Humans; Lipid Metabolism; Liver; Liver Function Tests; Male; Mice; Non-alcoholic Fatty Liver Disease; Obesity; Oxidation-Reduction; Pinus; Plant Bark; Plant Extracts; Proanthocyanidins; RNA, Messenger; Tomography, X-Ray Computed