rutin and Insulin-Resistance

Topics: Animals; Antioxidants; Brain; Cholesterol; Cognition Disorders; Humans; Hydroxyethylrutoside; Insulin Resistance; Mice

Troxerutin (TRX) has a beneficial effect on blood viscosity and platelet aggregation, and is currently used for the treatment of chronic varicosity. Recently, TRX can improve lipid abnormalities, glucose intolerance and oxidative stress in high-fat diet-induced metabolic disorders. In this study, we tested the effect of TRX on metabolic syndrome-associated disorders using a non-obese model of metabolic syndrome-the Hereditary Hypertriglyceridaemic rats (HHTg).. Adult male HHTg rats were fed standard diet without or with TRX (150 mg/kg bwt/day for 4 weeks).. Compared to untreated rats, TRX supplementation in HHTg rats decreased serum glucose (p<0.05) and insulin (p<0.05). Although blood lipids were not affected, TRX decreased hepatic cholesterol concentrations (p<0.01) and reduced gene expression of HMGCR, SREBP2 and SCD1 (p<0.01), involved in cholesterol synthesis and lipid homeostasis. TRX-treated rats exhibited decreased lipoperoxidation and increased activity of antioxidant enzymes SOD and GPx (p<0.05) in the liver. In addition, TRX supplementation increased insulin sensitivity in muscles and epididymal adipose tissue (p<0.05). Elevated serum adiponectin (p<0.05) and decreased muscle triglyceride (p<0.05) helped improve insulin sensitivity. Among the beneficial effects of TRX were changes to cytochrome P450 family enzymes. Hepatic gene expression of CYP4A1, CYP4A3 and CYP5A1 (p<0.01) decreased, while there was a marked elevation in gene expression of CYP1A1 (p<0.01).. Our results indicate that TRX improves hepatic lipid metabolism and insulin sensitivity in peripheral tissues. As well as ameliorating oxidative stress, TRX can reduce ectopic lipid deposition, affect genes involved in lipid metabolism, and influence the activity of CYP family enzymes.

Topics: Animals; Disease Models, Animal; Glucose; Glycogen; Hydroxyethylrutoside; Hypolipidemic Agents; Insulin Resistance; Lipid Metabolism; Male; Metabolic Syndrome; Muscle, Skeletal; Oxidative Stress; Rats; Rats, Inbred Strains; Real-Time Polymerase Chain Reaction; Transcriptome

A previous study from our laboratory showed that troxerutin (TX) provides cardioprotection by mitigating lipid abnormalities in a high-fat high-fructose diet (HFFD)-fed mice model of metabolic syndrome (MS). The present study aims to investigate the reversal effect of TX on the fibrogenic changes in the myocardium of HFFD-fed mice. Adult male Mus musculus mice were grouped into four and fed either control diet or HFFD for 60 days. Each group was divided into two, and the mice were either treated or untreated with TX (150 mg/kg bw, p.o) from the 16th day. HFFD-fed mice showed marked changes in the electrocardiographic data. Increased levels of myocardial superoxide, p22phox subunit of NADPH oxidase, transforming growth factor (TGF), smooth muscle actin (α-SMA), and matrix metalloproteinases (MMPs)-9 and -2, and decreased levels of tissue inhibitors of MMPs-1 and -2 were observed. Furthermore, degradation products of troponin I and myosin light chain-1 were observed in the myocardium by immunoblotting. Rise in collagen was observed by hydroxyproline assay, while fibrotic changes were noticed by histology and Western blotting. Hypertrophy of cardiomyocytes and myocardial calcium accumulation were also observed in HFFD-fed mice. TX treatment exerted cardioprotective and anti-fibrotic effects in HFFD-fed mice by improving cardiac contractile function, reducing superoxide production and by favorably modifying the fibrosis markers. These findings suggest that TX could be cardioprotective through its antioxidant and antifibrogenic actions. This new finding could pave way for translation studies to human MS.

Topics: Animals; Calcium; Diet, High-Fat; Disease Models, Animal; Fibrosis; Fructose; Gene Expression Regulation; Hydroxyethylrutoside; Insulin Resistance; Male; Metabolic Syndrome; Mice; Myocytes, Cardiac

Topics: Animals; Antineoplastic Agents; Antitubercular Agents; Diabetes Mellitus; Humans; Hypoglycemic Agents; Insulin Resistance; Isoenzymes; Models, Molecular; Molecular Targeted Therapy; Mycobacterium tuberculosis; Neoplasms; Protein Conformation; Protein Tyrosine Phosphatases; Proto-Oncogene Proteins

Recent findings suggest that neurotoxicity is the mechanism underlying the induction of neuronal insulin resistance by a high cholesterol diet. Troxerutin, a naturally occurring flavonoid, has been reported to possess biological activity beneficial to human health. Our recent studies have demonstrated that troxerutin attenuates cognitive impairment and oxidative stress induced by D-galactose in mouse brain through decreasing advanced glycation end products, reactive oxygen species and protein carbonyl levels and enhancing phosphoinositide 3-kinase/Akt activation. In this study, we evaluated the effect of troxerutin on cognitive impairment induced by brain insulin resistance in mice fed a high-cholesterol diet, and explored its potential mechanism. Our results showed that oral administration of troxerutin to these mice significantly improved behavioural performance in a step-through passive avoidance task and a Morris water maze task, at least in part, by decreasing the levels of reactive oxygen species, protein carbonyl and advanced glycation end products and blocking endoplasmic reticulum stress via reduced phosphorylation of the pancreatic endoplasmic reticulum-resident kinase and eukaryotic translation initiation factor 2α. Furthermore, troxerutin significantly inhibited the activation of c-jun N-terminal kinase 1 and IκB kinase β/nuclear factor-κB induced by endoplasmic reticulum stress and enhanced insulin signalling pathway, which prevented obesity, restored normal levels of blood glucose, fatty acids and cholesterol and increased the phosphorylation of cyclic adenosine monophosphate response element-binding protein and the expression levels of c-fos in the hippocampus. Moreover, troxerutin significantly inhibited endoplasmic reticulum stress-induced apoptosis and decreased the activation of caspase-12 and caspase-3, and reduced the mean optical density of the terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end label-positive cells in the hippocampus. However, intra-cerebroventricular infusion of PI-103, a specific phosphoinositide 3-kinase 110α inhibitor, significantly inhibited the expression levels of phosphoinositide 3-kinase 110α and phosphoinositide 3-kinase downstream signalling in the hippocampus of mice co-treated with high cholesterol and troxerutin and vehicle control mice. These results suggest that troxerutin could be recommended as a possible candidate for the prevention and therapy of cognitive deficits in typ

Topics: Animals; Avoidance Learning; Blood Glucose; Body Weight; Brain; Cholesterol; Cognition Disorders; CREB-Binding Protein; Disease Models, Animal; Enzyme-Linked Immunosorbent Assay; Fatty Acids, Nonesterified; Gene Expression Regulation; Glycation End Products, Advanced; Hydroxyethylrutoside; Immunoprecipitation; In Situ Nick-End Labeling; Infusions, Intraventricular; Insulin Resistance; Male; Maze Learning; Mice; Mice, Inbred C57BL; Neuroprostanes; Phosphorylation; Protein Carbonylation; Reactive Oxygen Species; Signal Transduction; Triglycerides