rhodanine and Inflammation

Lipopolysaccharide (LPS) is a potent inducer of inflammatory response. Inflammation is a major risk factor for many diseases. Regulation of inflammatory mediator and pro-inflammatory cytokine levels could be a potential therapeutic approach to treat inflammatory injury. The purpose of the present study was to determine whether epalrestat (EPS), which is used for the treatment of diabetic neuropathy, suppresses inflammatory response in LPS-stimulated RAW264.7 cells.. The effects of EPS at near-plasma concentration on the levels of pro-inflammatory cytokines and inflammatory mediators was examined using by MTS assay, quantitative RT-PCR analysis, and western blotting in LPS-stimulated RAW264.7 cells.. EPS suppressed mRNA and protein expression levels of pro-inflammatory cytokines, including IL-1β, IL-6, and TNFα, in RAW264.7 cells stimulated with LPS. EPS also affected inflammatory mediators such as iNOS and NF-κB in LPS-stimulated RAW264.7 cells.. In this study, we demonstrated for the first time that EPS suppresses inflammatory response in LPS-stimulated RAW264.7 cells. From these results, we propose that targeting the regulation of pro-inflammatory cytokine levels and inflammatory mediators by EPS is a promising therapeutic approach to treat inflammatory injury. It is expected that EPS, whose safety and pharmacokinetics have been confirmed clinically, would be useful for the treatment of inflammatory diseases.

Topics: Animals; Cytokines; Inflammation; Inflammation Mediators; Lipopolysaccharides; Mice; Nitric Oxide; RAW 264.7 Cells; Rhodanine; Thiazolidines

Type-2 diabetes mellitus (DM) is associated with cognitive impairment. Increasing evidence establishes that neuro-inflammatory and oxidative stress condition plays a main role in the development of neurodegeneration. Epalrestat, an aldose reductase inhibitor is commonly prescribed for the treatment of diabetic peripheral neuropathy. Its beneficial effects for antioxidant, anti-inflammatory potential and being rhodanine structure containing compound suggests possible role for treatment of DM associated with cognitive dysfunction.. In the present study, we evaluated the effect of epalrestat (54, 27, 13.5 mg/kg, p.o.) and donepezil (1 mg/kg, p.o.) on Tau protein levels, oxidative stress and inflammatory markers in high fat diet (HFD) and Streptozotocin (STZ; 35 mg/kg, i.p.) induced cognitive impairment in diabetic rats.. The epalrestat - 54, 27 mg/kg p.o. and donepezil treatment significantly increased CAT (p < 0.001, p < 0.01, p < 0.001) and GSH (p < 0.001, p < 0.01, p < 0.001) activities respectively as compared to diabetic control rats. In addition, similar dose of epalrestat treatment indicated considerably lowered TAU protein levels (p < 0.001, p < 0.05) while no significant effect was noted with donepezil. These treatments significantly decreased gene expression of TNF-α (1.6, 1.6, 1.7 fold change) and IL-6 (2.5, 1.9, 1.7 fold change). Histopathological examination indicated that epalrestat could attenuate apoptosis of neurons, vacuolations and clumped processes, disorganization and thinning of all the layers.. Our findings suggest that diabetic rats treated with epalrestat could ameliorate the cognition deficits and might act as a beneficial agent for prevention and treatment of cognitive impairment in diabetes.

Topics: Animals; Antioxidants; Blood Glucose; Body Weight; Cognition Disorders; Cytokines; Diabetes Mellitus, Experimental; Diabetic Neuropathies; Diet, High-Fat; Hippocampus; Inflammation; Male; Neuroprotective Agents; Oxidative Stress; Rats; Rats, Wistar; Rhodanine; tau Proteins; Thiazolidines

Epalrestat (EPS), an aldose reductase inhibitor, is widely prescribed to manage diabetic neuropathy. It is generally believed that EPS is beneficial to diabetic patients because it can protect endothelial cells, Schwann cells, or other neural cells from oxidative stress. However, several clinical studies revealed that EPS therapy led to liver dysfunction, which limited its clinical applications. Currently, the underlying mechanism by which EPS causes liver dysfunction is unknown. This study aimed to investigate the mechanism responsible for EPS-induced liver injury. In mouse liver, EPS 1) increased oxidative stress, indicated by increased expression of manganese superoxide dismutase, Ho-1, and Nqo1, 2) induced inflammation, indicated by infiltration of inflammatory cells, and induced expression of tumor necrosis factor-alpha, CD11b, and CD11c, as well as 3) predisposed to induce fibrosis, evidenced by increased mRNA and protein expression of early profibrotic biomarker genes procollagen I and alpha-smooth muscle actin, and by increased collagen deposition. In cultured mouse and human hepatoma cells, EPS treatment induced oxidative stress, decreased cell viability, and triggered apoptosis evidenced by increased Caspase-3 cleavage/activation. In addition, EPS increased mRNA and protein expression of cytoglobin in mouse liver, indicating that EPS activated hepatic stellate cells (HSCs). Furthermore, EPS treatment in cultured human HSCs increased cell viability. In summary, EPS administration induced oxidative stress and inflammation in mouse liver, and stimulated liver fibrogenesis. Therefore, cautions should be exercised during EPS therapy.

Topics: Actins; Animals; CD11 Antigens; Cell Culture Techniques; Cell Line, Tumor; Collagen Type I; Humans; Inflammation; Liver; Liver Cirrhosis, Experimental; Male; Mice; Mice, Inbred C57BL; Oxidative Stress; Rhodanine; Thiazolidines; Tumor Necrosis Factor-alpha

Under diabetic conditions, glucose is converted to sorbitol via aldose reductase, whose process could contribute to diabetic vascular complications. However, effects of aldose reductase inhibitors are modest in diabetic patients. This may be attributed to weak inhibitory activity of aldose reductase inhibitors. We compared effects of ranirestat on endothelial cell damage with those of epalrestat.. Intracellular formations of sorbitol and superoxide were measured by liquid chromatography-mass spectrometry-mass spectrometry and dihydroethidium staining, respectively. Vascular cell adhesion molecule-1 gene expression was analysed by reverse transcription polymerase chain reaction. THP-1 cell adhesion to human umbilical vein endothelial cells was evaluated using a fluorescent probe.. High glucose significantly increased sorbitol levels, superoxide generation and vascular cell adhesion molecule-1 mRNA levels in, and THP-1 cell adhesion to, human umbilical vein endothelial cells, all of which were prevented by 500 nM ranirestat, but not epalrestat except for superoxide production.. Our present results suggest that ranirestat has a stronger inhibitory activity on aldose reductase than epalrestat and suppresses inflammatory reactions in high glucose-exposed human umbilical vein endothelial cells.

Topics: Aldehyde Reductase; Anti-Inflammatory Agents; Cell Line, Tumor; Chromatography, Liquid; Dose-Response Relationship, Drug; Enzyme Inhibitors; Glucose; Human Umbilical Vein Endothelial Cells; Humans; Inflammation; Inflammation Mediators; Pyrazines; Reverse Transcriptase Polymerase Chain Reaction; Rhodanine; Sorbitol; Spiro Compounds; Superoxides; Tandem Mass Spectrometry; Thiazolidines; Vascular Cell Adhesion Molecule-1

This protocol describes microsphere-based protease assays for use in flow cytometry and high-throughput screening. This platform measures a loss of fluorescence from the surface of a microsphere due to the cleavage of an attached fluorescent protease substrate by a suitable protease enzyme. The assay format can be adapted to any site or protein-specific protease of interest and results can be measured in both real time and as endpoint fluorescence assays on a flow cytometer. Endpoint assays are easily adapted to microplate format for flow cytometry high-throughput analysis and inhibitor screening.

Topics: Animals; Biotinylation; Flow Cytometry; Fluorescence Resonance Energy Transfer; Green Fluorescent Proteins; High-Throughput Screening Assays; Humans; Inflammation; Kinetics; Microspheres; Peptide Hydrolases; Peptides; Reproducibility of Results; Temperature