iridoids and Proteinuria

Diabetic nephropathy is the most common cause of end-stage renal disease in patients with diabetes. Advanced glycation end-products (AGEs) play a prominent role in the development of diabetic nephropathy. We herein evaluated the effects of loganin on diabetic nephropathy in vivo.. We established a diabetic nephropathy model in C57BL/6J mice with diabetes induced by streptozotocin and fed with diets containing high level of AGEs. Diabetic symptoms, renal functions, and pathohistology of pancreas and kidney were evaluated. AGE-RAGE pathway and oxidative stress parameters were determined.. The model mice exhibited characteristic symptoms of diabetes including weight loss, polydipsia, polyphagia, polyuria, elevated blood glucose levels and low serum insulin levels during the experiments. However, loganin at doses of 0.02 and 0.1g/kg effectively improved these diabetic symptoms. Loganin reduced kidney/body weight ratio, 24h urine protein levels, and serum levels of urea nitrogen and creatinine in diabetic mice to different degrees compared to positive controls. Moreover, loganin improved the histology of pancreas and kidney, and alleviated the structural alterations in endothelial cells, mesangial cells and podocytes in renal cortex. Finally, we found that loganin reduced AGE levels in serum and kidney and downregulated mRNA and protein expression of receptors for AGEs in kidney in diabetic mice. Loganin also reduced the levels of malondialdehyde and increased the levels of superoxide dismutase in serum and kidney.. Loganin improved diabetic nephropathy in vivo associated with inhibition of AGE pathways, and could be a promising remedy for diabetic nephropathy.

Topics: Analysis of Variance; Animals; Blood Urea Nitrogen; Blotting, Western; Diabetes Mellitus, Experimental; Diabetic Nephropathies; Disease Models, Animal; DNA Primers; Dose-Response Relationship, Drug; Gene Expression Regulation; Glycation End Products, Advanced; Iridoids; Kidney; Malondialdehyde; Mice; Mice, Inbred C57BL; Microscopy, Electron, Transmission; Molecular Structure; Oxidative Stress; Pancreas; Proteinuria; Receptor for Advanced Glycation End Products; Receptors, Immunologic; Reverse Transcriptase Polymerase Chain Reaction; Superoxide Dismutase

Renal damage precedes occurrence of stroke in high-sodium/low-potassium-fed stroke-prone spontaneously hypertensive rat (SHRSP). We previously reported a marked suppression of uncoupling protein-2 (UCP2) upon high-salt Japanese-style diet in SHRSP kidneys. Vegetable compounds are known to exert protective effects in cardiovascular diseases. We aimed at evaluating the impact of Brassica oleracea sprouts juice toward renal damage in Japanese diet-fed SHRSP and exploring the role of 5'-adenosine monophosphate-activated protein kinase (AMPK)/NAD-dependent deacetylase sirtuin-1 (SIRT1)/peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α)/peroxisome proliferator-activated receptor-α (PPARα)/UCP2 axis.. SHRSP received Japanese diet for 4 weeks. A group of SHRSP received Japanese diet and B. oleracea. A third group received Japanese diet, B. oleracea, and PPARα inhibitor (GW6471). A group of SHRSP fed with regular diet served as control.. Japanese diet induced marked increases of oxidative stress, inflammation, and proteinuria, along with glomerular and tubular damage, as compared with regular diet. A significant suppression of AMPK/UCP2 pathway was observed. Despite Japanese diet feeding, concomitant administration of B. oleracea prevented oxidative stress accumulation, inflammation, renal damage, and proteinuria. All components of the UCP2 regulatory pathway were significantly increased by B. oleracea. Superoxide dismutase 2 and phosphoendothelial nitric oxide synthase were also stimulated. Addition of PPARα inhibitor to B. oleracea and Japanese diet significantly reduced the B. oleracea beneficial effects. SBP levels were comparable among the different groups of rats.In vitro, UCP2 inhibition by genipin offset the antioxidant effect of B. oleracea in renal mesangial and proximal tubular cells.. B. oleracea administration prevented renal damage in salt-loaded SHRSP, independently from SBP, with parallel stimulation of AMPK/SIRT1/PGC1α/PPARα/UCP2 axis. Stimulation of the latter mechanism may provide relevant renal protective effect and play a therapeutic role in target organ damage progression in hypertension.

Topics: AMP-Activated Protein Kinases; Animals; Antioxidants; Blood Pressure; Brassica; Diet; Glomerular Mesangium; Hypertension; Ion Channels; Iridoids; Kidney Diseases; Kidney Glomerulus; Kidney Tubules, Proximal; Mitochondrial Proteins; Oxidative Stress; Plant Extracts; PPAR alpha; Proteinuria; Rats; Rats, Inbred SHR; Seedlings; Sodium Chloride, Dietary; Stroke; Uncoupling Protein 2