Renoprotective effect of benazepril on diabetic nephropathy mediated by P42/44MAPK

Protective effects of allicin on streptozotocin-induced diabetic nephropathy in rats

BACKGROUND

Studies in animal models have shown that allicin, a major biologically active component of garlic, can play a role in the prevention of tissue fibrosis in the liver, lung and heart, mainly related to the inhibition of fibroblast proliferation, fibrogenic cytokine secretion and extracellular matrix synthesis. This study aimed to investigate the protective effects of allicin on renal damage in streptozotocin (STZ)-induced diabetic rats. STZ-induced diabetic rats were administered allicin (15, 30 and 45 mg · kg^-1  · day^-1 ) via daily intra-gastric gavage for 12 weeks. The levels of fasting blood glucose (FBG), blood urea nitrogen (BUN), serum creatinine (sCr), lipid and 24 h urine albumin excretion (UAE) were measured at the end of weeks 4, 8 and 12. The renal histopathology and the expression levels of collagen I, transforming growth factor β1 (TGF-β1) and phosphorylated extracellular signal-regulated kinase 1/2 (p-ERK1/2) were measured using immunohistochemistry and/or western blotting.

RESULTS

In 12 week STZ-induced diabetic rats, severe hyperglycemia and albuminuria were markedly developed. Treatment with allicin for 12 weeks ameliorated diabetes-induced morphological alterations of the kidney and decreased FBG, BUN, sCr, triglyceride (TG) and 24 h UAE in diabetic rats. The expression levels of collagen I, TGF-β1 and p-ERK1/2 were significantly decreased by allicin treatment.

CONCLUSION

These results suggested that allicin may play a protective role in diabetic nephropathy via the TGF-β1/ERK pathway in diabetic rats. © 2016 Society of Chemical Industry.

New molecular insights in diabetic nephropathy

Diabetes mellitus represents one of the major causes of functional kidney impairment. The review highlights the most significant steps made over the last decades in understanding the molecular basis of diabetic nephropathy (DN), which may provide reliable biomarkers for early diagnosis and prognosis, along with new molecular targets for personalized medicine. There is an increased interest in developing new therapeutic strategies to slow DN progression for improving patients' quality of life and reducing all-cause morbidity and disease-associated mortality. It is highly important to have a science-based medical attitude when facing diabetic patients with associated comorbidities and risk of rapid evolution toward end-stage renal disease. The data discussed herein were mainly from MEDLINE and PubMed articles published in English from 1990 to 2015 and from up-to-date. The search term was "diabetic nephropathy and oxidative stress".

Smoking in diabetic nephropathy: sparks in the fuel tank?

Diabetic nephropathy is associated with high morbidity and mortality and the prevalence of this disease is continuously increasing worldwide. Long-term diabetes increases the likelihood of developing secondary complications like nephropathy, the most common cause of end stage renal disease. Usually, other factors like hypertension, alcoholism and smoking also partly contribute to the progression of diabetic nephropathy. Among this, cigarette smoking in diabetes has been repeatedly confirmed as an independent risk factor for the onset and progression of diabetic nephropathy. Various studies suggest that smoking is a major fuel in the development of high oxidative stress and subsequently hyperlipidemia, accumulation of advanced glycation end products, activation of the renin angiotensin system and Rho-kinase, which are observed to play a pathogenic role in the progression of diabetic nephropathy. Furthermore, cigarette smoking in diabetic patients with vascular complications produces a variety of pathological changes in the kidney, such as thickening of the glomerular basement membrane and mesangial expansion with progression in glomerulosclerosis and interstitial fibrosis, which ultimately results in end stage renal failure. Strong associations are consistently found between chronic cigarette smoking and diabetic microvascular complications. A diverse group of studies unveil potential mechanisms that may explain the role of cigarette smoking in the progression of diabetic nephropathy. Tremendous efforts are being made to control smoking mediated progression of diabetic nephropathy, but no promising therapy is yet available. The present review critically discusses the possible detrimental role of chronic cigarette smoking in the progression of diabetic nephropathy and various possible pharmacological interventions to attenuate the exacerbation of diabetic nephropathy.