Differential effects of low-dose fenofibrate treatment in diabetic rats with early onset nephropathy and established nephropathy

We have previously shown that low-dose fenofibrate treatment has an ability to prevent diabetes-induced nephropathy in rats. We investigated here the comparative pre- and post-treatment effects of low-dose fenofibrate (30 mg/kg/day p.o.) in diabetes-induced onset of nephropathy. Rats were made diabetics by single administration of streptozotocin (STZ, 55 mg/kg i.p.). The development of diabetic nephropathy was assessed biochemically and histologically. Moreover, lipid profile and renal oxidative stress were assessed. Diabetic rats after 8 weeks of STZ-administration developed apparent nephropathy by elevating serum creatinine, blood urea nitrogen and microproteinuria, and inducing glomerular-capsular wall distortion, mesangial expansion and tubular damage and renal oxidative stress. Fenofibrate (30 mg/kg/day p.o., 4 weeks) pretreatment (4 weeks after STZ-administration) markedly prevented diabetes-induced onset of diabetic nephropathy, while the fenofibrate (30 mg/kg/day p.o., 4 weeks) post-treatment (8 weeks after STZ-administration) was less-effective. However, both pre-and post fenofibrate treatments were effective in preventing diabetes-induced renal oxidative stress and lipid alteration in diabetic rats though the pretreatment was slightly more effective. Conversely, both pre-and post fenofibrate treatments did not alter elevated glucose levels in diabetic rats. It may be concluded that diabetes-induced oxidative stress and lipid alteration, in addition to a marked glucose elevation, play a detrimental role in the onset of nephropathy in diabetic rats. The pretreatment with low-dose fenofibrate might be a potential therapeutic approach in preventing the onset of nephropathy in diabetic subjects under the risk of renal disease induction. However, low-dose fenofibrate treatment might not be effective in treating the established nephropathy in diabetic subjects.     

Telmisartan in the management of diabetic nephropathy: a contemporary view

Diabetic nephropathy, a complex disorder with heterogeneous etiologies, remains one of the most threatening diseases worldwide. There were around 177 million people with diabetes mellitus worldwide, and it has been estimated to be increased to 360 million by 2030. Given that about 20-30% of these people develop diabetic nephropathy, the present treatment protocols primarily aim for an efficient glucose and blood pressure control to arrest the initiation and progression of diabetic nephropathy. The treatment of diabetic nephropathy near the beginning at microalbuminuria stage with angiotensin-II-AT1 receptor blockers (ARBs) improves blood pressure control and halts disease progression of diabetic nephropathy. In fact, ARBs exert renoprotective effects independently of their blood pressure lowering effect, as they have direct defensive action on the diabetic kidney. Indubitably, it would be better if an ARB has both glucose-lowering and blood pressure controlling potentials efficiently. Intriguingly, telmisartan has such possessions considering its dual role of AT1 receptor blocking action and peroxisome proliferator-activated receptor gamma (PPARγ) partial agonistic property. The additional PPARγ agonistic potential of telmisartan could make it a distinctive intervention in the ARB class to prevent the progression of diabetic nephropathy through activation of PPARγ-mediated insulin sensitization, and renal anti-inflammatory and anti-oxidant actions. Indeed, telmisartan reduced insulin resistance and glucose intolerance, and halted the progressive renal dysfunction associated with diabetic nephropathy by inhibiting the incidence of albuminuria, and preventing the progression of glomerulosclerosis, renal interstitial inflammation and fibrosis. This review will discuss the current status of therapeutic potentials of telmisartan in treating diabetic nephropathy.     

Effects of ascorbic acid and alpha-tocopherol on arsenic-induced oxidative stress

Arsenic is an ubiquitous element in the environment causing oxidative burst in the exposed individuals leading to tissue damage. Antioxidants have long been known to reduce the free radical-mediated oxidative stress. Therefore, the present study was designed to determine whether supplementation of alpha-tocopherol (400 mg/kg body weight) and ascorbic acid (200 mg/kg body weight) to arsenic-intoxicated rats (100 ppm in drinking water) for 30 days affords protection against the oxidative stress caused by the metalloid. The arsenic-treated rats showed elevated levels of lipid peroxide, decreased levels of non-enzymatic antioxidants and activities of enzymatic antioxidants. Administration of alpha-tocopherol and ascorbic acid to arsenic-exposed rats showed a decrease in the level of lipid peroxidation (LPO) and enhanced levels of total sulfhydryls, reduced glutathione, ascorbic acid and alpha-tocopherol and so do the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glucose-6-phosphate dehydrogenase to near normal. These findings suggest that alpha-tocopherol and ascorbic acid prevent LPO and protect the antioxidant system in arsenic-intoxicated rats.     

Long-term Effects of Statins,Blood Pressure-Lowering,and Both on Erectile Function in Persons at Intermediate Risk for Cardiovascular Disease: A Substudy of the Heart Outcomes Prevention Evaluation-3 (HOPE-3) Randomized Controlled Trial

Background

It is unclear whether modifying cholesterol, blood pressure, or both affect erectile dysfunction. Also, there are concerns that erectile dysfunction is worsened by common medications used to treat these risk factors. In this study, we evaluated the effect of: (1) cholesterol-lowering with a statin; (2) pharmacologic blood pressure reduction; and (3) their combination, on erectile function.