Combination of Vildagliptin and Pioglitazone in Experimental Type 2 Diabetes in Male Rats.

Preclinical Research The majority of studies on vildagliptin and pioglitazone have focused on their combination in glycemic control. The aim of the present study was to investigate their effects in combination on (i) hyperglycemia-induced oxidative stress and inflammation and (ii) on organs involved in the pathophysiology of diabetes, pancreas, kidney and liver. Type 2 diabetes was induced using low-dose streptozotocin in male Wistar rats. Diabetic rats were treated for 4 weeks, with vildagliptin (10 mg/kg/day), pioglitazone (10 mg/kg/day) and their combination. Diabetic rats showed elevated fasting serum glucose, fasting serum insulin, serum transaminases together with a deleterious lipid profile and elevated serum creatinine and urea concentrations. Serum levels of the inflammatory markers tumor necrosis factor-α (TNF-α) and nitrite/nitrate were also elevated compared to normal rats. Oxidative stress was manifested by lowered hepatic reduced glutathione (GSH) and increased malondialdehyde (MDA) levels. Pancreatic sections from diabetic rats showed degenerated islets with poorly maintained architecture that was prevented by drug treatment. Pioglitazone was generally more effective than vildagliptin in the studied parameters except for the lipid profile where the effect of both drugs was comparable and for the liver enzymes and renal parameters where vildagliptin was more effective. The combination of vildagliptin and pioglitazone produced superior effects than either drug alone. Drug Dev Res 77 : 251-257, 2016. © 2016 Wiley Periodicals, Inc.

The combined effect of metformin and L-cysteine on inflammation, oxidative stress and insulin resistance in streptozotocin-induced type 2 diabetes in rats.

Increasing evidence has established causative links between obesity, chronic inflammation and insulin resistance; the core pathophysiological feature in type 2 diabetes mellitus. This study was designed to examine whether the combination of L-cysteine and metformin would provide additional benefits in reducing oxidative stress, inflammation and insulin resistance in streptozotocin-induced type 2 diabetes in rats. Male Wistar rats were fed a high-fat diet (HFD) for 8 weeks to induce insulin resistance after which they were rendered diabetic with low-dose streptozotocin. Diabetic rats were treated with metformin (300 mg/kg/day), L-cysteine (300 mg/kg/day) and their combination along with HFD for another 2 weeks. Control rats were fed normal rat chow throughout the experiment. At the end of treatment, fasting blood glucose, fasting serum insulin, homeostasis model assessment-insulin resistance index (HOMA-IR) and serum free fatty acids (FFAs) were measured. Serum levels of the inflammatory markers; monocyte chemoattractant protein-1 (MCP-1), C-reactive protein (CRP) and nitrite/nitrate were also determined. The liver was isolated and used for determination of malondialdehyde (MDA), reduced glutathione (GSH), caspase-3 and cytochrome c levels. The hypoglycemic effect of the combination therapy exceeded that of metformin and L-cysteine monotherapies with more improvement in insulin resistance. All treated groups exhibited significant reductions in serum FFAs, oxidative stress and inflammatory parameters, caspase-3 and cytochrome c levels compared to untreated diabetic rats with the highest improvement observed in the combination group. In conclusion, the present results clearly suggest that L-cysteine can be strongly considered as an adjunct to metformin in management of type 2 diabetes.

Evaluation of the effect of losartan and methotrexate combined therapy in adjuvant-induced arthritis in rats.

There is increasing body of evidence documenting the involvement of angiotensin II in inflammatory diseases. Moreover the up-regulation of angiotensin II AT(1) receptors in the synovium of rheumatoid arthritis patients has been previously described. This study aimed at investigating the anti-inflammatory effect of losartan, the selective angiotensin II AT(1) receptor blocker, and comparing the efficacy of methotrexate alone and in combination with losartan in adjuvant arthritis in rats. Twelve days post adjuvant injection, Sprague-Dawley rats were treated with methotrexate (1mg/kg/week), losartan (20mg/kg/day) and their combination for 15 days. Severity of arthritis was assessed by hind paw swelling, arthrogram scores. Serum was analyzed for measurement of albumin, C-reactive protein (CRP), nitrite/nitrate concentrations, interleukin 1ß (IL-1ß), tumor necrosis factor-α (TNF-α), vascular endothelial growth factor (VEGF), aspartate transaminase (AST) and alanine transaminase (ALT). Histopathological examination was done for hind paws and livers. Methotrexate and losartan monotherapies significantly reduced all parameters of inflammation and arthritis with better results in the methotrexate group except for the transaminases where losartan caused more significant reduction in their serum levels. The combined therapy showed better results than methotrexate and losartan alone. Hind paws showed better improvement of inflammatory cell infiltration and bone resorption in the combined therapy group. Disturbances in liver architecture and fibrosis caused by adjuvant arthritis were reverted to normal status in the combined therapy group in contrast to losartan and methotrexate monotherapies. In conclusion, methotrexate and losartan combined therapy provided more effective anti-inflammatory and hepatoprotective effects than either drug alone.

Serum sFas and tumor tissue FasL negatively correlated with survival in Egyptian patients suffering from breast ductal carcinoma.

Fas (CD95-APO-1), a member of tumor necrosis factor receptor super-family, exists in two forms, transmembrane and soluble (sFas). It had been suggested that circulating sFas levels and/or tissue FasL may reflect the severity of invasive breast ductal carcinoma. Few studies showed that neither DNA-index nor ploidy is an independent prognostic indicator, and there is no correlation with clinical outcome. The S-phase fraction (SPF) has been shown to be useful prognostic factor in both node-negative and node-positive tumors. The present work was done to find a correlation between sFas, tissue FasL, ploidy and SPF with prognostic factors and survival of breast ductal carcinoma patients. The present study included two groups; a patients group comprised 30 patients with breast ductal carcinoma and a control group that comprised 15 patients with benign breast swellings. Serum sFas was measured using commercially available ELISA kit and tissue FasL expression was studied using avidin-biotine immunohistochemical staining technique. Cell cycle studies were performed using flow cytometry. Serum sFas was significantly higher in breast ductal carcinoma group than in the benign breast swelling control group. A significant negative correlation between serum sFas and overall survival was found. Tissue FasL expression was directly correlated with distant metastasis and poor overall survival. A significant direct correlation was found between moderate and high SPF with worse pathologic parameters. Serum sFas level, tissue FasL immuno-expression and S-phase fraction are independent prognostic factors in breast ductal carcinoma cases.