Loganin attenuates diabetic nephropathy in C57BL/6J mice with diabetes induced by streptozotocin and fed with diets containing high level of advanced glycation end products.

AIMS: 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. MAIN METHODS: 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. KEY FINDINGS: 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. SIGNIFICANCE: Loganin improved diabetic nephropathy in vivo associated with inhibition of AGE pathways, and could be a promising remedy for diabetic nephropathy.

Protection of Tong-Sai-Mai Decoction against Apoptosis Induced by H2O2 in PC12 Cells: Mechanisms via Bcl-2-Mitochondria-ROS-INOS Pathway.

Tong-Sai-Mai decoction (TSM) is a Chinese materia medica polyherbal formulation that has been applied in treating brain ischemia for hundreds of years. Because it could repress the oxidative stress in in vivo studies, now we focus on the in vitro studies to investigate the mechanism by targeting the oxidative stress dependent signaling. The relation between the neurogenesis and the reactive oxygen species (ROS) production remains largely unexamined. PC12 cells are excitable cell types widely used as in vitro model for neuronal cells. Most marker genes that are related to neurotoxicity, apoptosis, and cell cycles are expressed at high levels in these cells. The aim of the present study is to explore the cytoprotection of TSM against hydrogen peroxide- (H2O2-) induced apoptosis and the molecular mechanisms underlying PC12 cells. Our findings revealed that TSM cotreatment with H2O2 restores the expression of bcl-2, inducible nitric oxide synthase (INOS), and mitochondria membrane potential. Meanwhile, it reduces intracellular [Ca(2+)] concentration, lactate dehydrogenase (LDH) release, and the expression of caspase-3 and bax. The results of the present study suggested that the cytoprotective effects of the TSM might be mediated, at least in part, by the bcl-2-mitochondria-ROS-INOS pathway. Due to its nontoxic characteristics, TSM could be further developed to treat the neurodegenerative diseases which are closely associated with the oxidative stress.