Nephroprotective effect of exogenous hydrogen sulfide donor against cyclophosphamide-induced toxicity is mediated by Nrf2/HO-1/NF-κB signaling pathway.

AIM: Cyclophosphamide (CP) is an effective anticancer and immunosuppressive agent. However, it induces nephrotoxicity that limits its use. This study explored the effect of H2S, an important biological signaling molecule with a cytoprotective activity, on CP-induced nephrotoxicity. METHODS: Male Wistar rats were treated with saline or NaHS (100 µM/kg/day, H2S donor) or dl-propargylglycine (PAG) (30 mg/kg/day, H2S blocker) for 10 days before a single i.p injection of CP (200 mg/kg). Then, rats were sacrificed, and renal functions were assessed in serum. Histopathological changes, as well as oxidant defenses, inflammatory and apoptotic markers in the renal tissue, were evaluated. KEY FINDINGS: Pretreatment with NaHS significantly reduced the urea and creatinine levels that were elevated in CP-intoxicated rats. NaHS increased the expression of the cytoprotective nuclear factor erythroid 2-related factor 2 (Nrf2) and its subsequent antioxidant proteins; heme oxygenase-1 (HO-1), NAD(P) H quinone oxidoreductase 1 (NQO1), reduced glutathione (GSH) and superoxide dismutase (SOD). Moreover, NaHS prohibited the histopathological damage induced by CP. The inhibition of caspase-3 and nuclear factor kappa B (NF-κB) supported the protective role of H2S against CP-induced kidney damage. On the other hand, blocking endogenous H2S did not provide a more significant deterioration in CP-induced nephrotoxicity in terms of oxidative stress or inflammatory status. SIGNIFICANCE: Exogenous H2S donors exhibited a protective effect against CP-induced nephrotoxicity, which may be mediated via the Nrf2/HO-1/NF-κB signaling pathway. However, endogenous H2S may be insufficient to protect the cell against the induced oxidative damage. This approach provides a novel target to prevent nephrotoxicity of CP.

Low-dose lixisenatide protects against early-onset nephropathy induced in diabetic rats.

AIM: Diabetic nephropathy (DN) is the most frequent cause of end-stage renal disease. This study was performed to investigate the possible protective effect of lixisenatide, a glucagon-like peptide-1 (GLP-1) receptor agonist, on early diabetic nephropathy induced in diabetic rats and explore the various mechanisms underlie this postulated effect. MAIN METHODS: Early DN was induced after 3 weeks in diabetic rats fed with a high-fat diet (HFD) and treated with low dose STZ. One week after induction of diabetes, diabetic rats were administered lixisenatide at two dose levels (1 and 10 nmole/kg/day, ip) or glimepiride (2 mg/kg/day, p.o.) for 2 weeks. KEY FINDINGS: Lixisenatide, in a low dose regimen, induced a nephroprotective effect evident by significant decreases in serum creatinine and serum urea along with improved renal histology. Low lixisenatide dose showed an antioxidant effect, exhibited by a significant decrease in renal malondialdehyde and total NOx- levels along with a marked rise in total antioxidant capacity. Apart from ameliorating glucose intolerance and insulin resistance, significant down-regulation in renal expressions of iNOS, COX-2, and TGF-B1 were recorded in the diabetic group treated with low dose lixisenatide. Furthermore, low dose lixisenatide was reported to be superior to glimepiride as a nephroprotective. On the contrary, treatment with large dose lixisenatide was founded to be deleterious. SIGNIFICANCE: Low-dose lixisenatide treatment was able to protect against early diabetic nephropathy, which might represent a promising approach in the management of diabetes and its renal complication however, further clinical studies are warranted.

Empagliflozin alleviates neuronal apoptosis induced by cerebral ischemia/reperfusion injury through HIF-1α/VEGF signaling pathway.

Ischemic stroke is a serious condition associated with severe functional disability and high mortality, however; effective therapy remains elusive. Empagliflozin, a sodium-glucose cotransporter 2 inhibitor, has been shown to exert additional non-glycemic benefits including anti-apoptotic effects in different disease settings. Thereby, this study was designed to investigate the ameliorative effect of empagliflozin on the neuronal apoptosis exhibited in cerebral ischemia/reperfusion (I/R) in a rat model targeting HIF-1α/VEGF signaling which is involved in this insult. Global cerebral I/R injury was induced in male Wistar rats through occlusion of the bilateral common carotid arteries for 30 min followed by one-hour reperfusion. Empagliflozin doses of 1 and 10 mg/kg were administered 1 and 24 h after reperfusion. In I/R-injured rats, empagliflozin treatments significantly reduced infarct size and enhanced neurobehavioral functions in a dose-dependent manner. The drug alleviated neuronal death and cerebral injury inflicted by global ischemia as it suppressed neuronal caspase-3 protein expression. In parallel, protein expressions of HIF-1α and its downstream mediator VEGF were upregulated in the ischemic brain following empagliflozin treatment. The results indicated that empagliflozin attenuates cerebral I/R-induced neuronal death via the HIF-1α/VEGF cascade.

Combined treatments with metformin and phosphodiesterase inhibitors alleviate nonalcoholic fatty liver disease in high-fat diet fed rats: a comparative study.

Nonalcoholic fatty liver disease (NAFLD) is an excessive accumulation of fats in the liver resulting in hepatic inflammation and fibrous tissue formation along with insulin resistance. This study was designed to investigate the possible protective effects of metformin alone and in combination with different phosphodiesterase inhibitors (PDEIs). Rats were fed a high-fat diet (HFD) for 16 weeks to induce NAFLD. Starting from week 12, rats received metformin alone or in combination with pentoxifylline, cilostazol, or sildenafil. HFD administration resulted in hepatic steatosis and inflammation in rats. In addition, liver index, body composition index, activities of liver enzymes, and serum lipids deviated from normal. Further, significant elevations were recorded compared to control in terms of serum glucose, insulin, and HOMA-IR (homeostasis model assessment index for insulin resistance), oxidative stress parameters, hepatic TNF-α and NF-κB gene expression, and iNOS protein expression. Rats treated with metformin showed a significant improvement in the aforementioned parameters. However, the addition of pentoxifylline to metformin treatment synergized its action and produced a fortified effect against HFD-induced NAFLD better than other PDEIs. Data from this study indicated that combined treatment of metformin and pentoxifylline had the most remarkable ameliorated effects against HFD-induced NAFLD; further clinical investigations are needed to approve PDEIs for NAFLD treatment.

Empagliflozin attenuates transient cerebral ischemia/reperfusion injury in hyperglycemic rats via repressing oxidative-inflammatory-apoptotic pathway.

Hyperglycemia is one of the ischemic neuronal damage triggers that exacerbate the response to oxidative stress, inflammation, and apoptosis induced by cerebral ischemia/reperfusion (I/R) injury. Empagliflozin, a sodium-glucose cotransporter 2 (SGLT 2) inhibitor, was shown to effectively reduce hyperglycemia and glucotoxicity besides improving glycemic control in diabetics. Therefore, the present study was conducted to investigate the neuroprotective effect of empagliflozin against cerebral I/R injury in hyperglycemic rats. Hyperglycemia was induced by streptozotocin (55 mg/kg), and transient cerebral I/R was induced by bilateral common carotid occlusion for 30 min followed by 24-h reperfusion. Either empagliflozin (10 mg/kg; i.p.) or gliclazide (2 mg/kg, p.o.) was administered at 1 and 24 h after reperfusion. Treatment with empagliflozin showed a significant amelioration of behavioral/neurological functions and histopathological changes observed in brain tissues of hyperglycemic rats subjected to cerebral I/R injury. Comparable to gliclazide, empagliflozin decreased cerebral infarct volume along with suppression of cerebral oxidative stress, inflammatory, and apoptotic markers in brain tissues of hyperglycemic I/R-injured rats. These findings suggested that empagliflozin can significantly alleviate neuronal damage resulting from global I/R injury induced in hyperglycemic rats. The proposed neuroprotective effect of empagliflozin may be attributed to its glycemic control effect and related antioxidant, anti-inflammatory, and antiapoptotic effects.

Comparative effectiveness of phosphodiesterase 3, 4, and 5 inhibitors in amelioration of high-fat diet-induced nonalcoholic fatty liver in rats.

Nonalcoholic fatty liver disease (NAFLD) is a highly prevalent disease linked to insulin resistance, oxidative stress, and cytokine imbalance. Phosphodiesterase (PDE) inhibitors have shown remarkable antioxidant and anti-inflammatory potential in different disease sets including liver diseases. This study aimed to compare the ameliorative effect of different PDE inhibitors on a high-fat diet (HFD)-induced NAFLD. Male Wistar rats were fed a HFD for 16 weeks to induce NAFLD, and then, oral treatments of a vehicle or different PDE inhibitors (pentoxifylline (50 mg/kg), cilostazol (20 mg/kg), or sildenafil (5 mg/kg)) were started in the last four weeks and given on a daily basis. Rats' body composition and liver indices were recorded. Serum levels of liver enzymes, glucose, insulin, bilirubin, total cholesterol, triglycerides, and nitric oxide were measured. Liver tissues were used for histopathological examination and detecting oxidative stress and inflammatory markers. Results showed that different PDE inhibitors exhibited different efficacy against liver injury and metabolic disorders associated with HFD-induced NAFLD in rodents evident by different strength-ameliorated effects on the aforementioned parameters. Compared to cilostazol and sildenafil, insulin resistance, hepatic oxidative stress, and inflammatory markers were significantly reduced by pentoxifylline treatment. Furthermore, pentoxifylline nearly completely reversed hepatocyte steatosis and exhibited superior rectifying effect on the rats' liver status compared with other PDE inhibitors. This investigation highlighted the potential role of PDE inhibitors in NAFLD treatment. Pentoxifylline had the most remarkable ameliorative effects against NAFLD, while sildenafil was the least effective.

Preparation and Evaluation of Atorvastatin-Loaded Nanoemulgel on Wound-Healing Efficacy.

Tissue repair and wound healing are complex processes that involve inflammation, granulation, and remodeling of the tissue. The potential of various statins including atorvastatin (ATR) to improve the wound healing effect was established. The aim of this study was to formulate and evaluate the efficacy of topical application of ATR-based nanoemulgel on wound healing. The prepared formulations (ATR gel, ATR emulgel, and ATR nanoemulgel) were evaluated for their physical appearance, rheological behavior, in vitro drug release and ex vivo drug permeation. The in vivo wound healing effect was evaluated in wound-induced rats. The prepared ATR gel formulations showed good physical properties and were comparable. The release profiles of drugs from gel, emulgel, and nanoemulgel were distinct. Skin permeation potential of ATR was significantly (p < 0.05) enhanced when formulated into nanoemulgel. In vivo wound healing studies showed that ATR nanoemulgel exhibited the highest percent wound contraction. Histopathological assessment showed marked improvement in the skin histological architecture after 21 days of ATR nanoemulgel treatment. In conclusion, the data demonstrated here signify the prospective of ATR nanoemulgel as an innovative therapeutic approach in wound healing.

Modulation of eNOS/iNOS by nebivolol protects against cyclosporine A-mediated nephrotoxicity through targeting inflammatory and apoptotic pathways.

The aim of this study was to investigate effect of nitric oxide (NO) modulation on possible nephroprotective mechanisms of nebivolol (NEB) in cyclosporine A (CsA)-induced nephrotoxicity. Rats were treated with 20 mg/kg/day s.c. of CsA for 21 days, with NEB alone (10 mg/kg/day orally) or together with a NOS inhibitor, L-NAME (10 mg/kg/day i.p.). NEB conferred nephroprotection against CsA-induced toxicity, significantly decreasing serum kidney function tests and improving renal histopathology. NEB showed antioxidant effects, by significantly decreasing renal malondialdehyde levels, while increasing reduced glutathione levels and catalase activity. NEB showed anti-inflammatory and anti-apoptotic effects; reducing renal expression NF-κB and fas ligand. NEB also reversed CsA-induced effects on NO system; increasing renal NO level, with up-regulation of eNOS and down-regulation of iNOS expression. Administering L-NAME with NEB reversed all beneficial effects of NEB. Thus, NEB's modulation of NO system in CsA-induced nephrotoxicity might be the triggering mechanism controlling NEB's nephroprotective effect.

Lixisenatide ameliorates cerebral ischemia-reperfusion injury via GLP-1 receptor dependent/independent pathways.

Ischemic stroke is a major cause of neurological damage and brain dysfunction with consequent strong cerebral oxidative imbalance, inflammatory and apoptotic responses. Lixisenatide is a new potent glucagon-like peptide -1 (GLP-1) analogue that has been used clinically in the treatment of type II diabetes. Recent studies suggested the beneficial central effects of GLP-1-based therapies on different neurodegenerative diseases. This study aimed to investigate the ameliorative effect of lixisenatide in global cerebral ischemia-reperfusion (I/R) rat model and elaborate the underline mechanisms that could mediate the proposed activity. Adult male Wistar rats were subjected to sham operation or global cerebral I/R injury. Rats were administered the following drugs in two scheduled doses at 1 h and 24 h after reperfusion: lixisenatide (1 and 10 nmole/kg), lixisenatide plus GLP-1 receptor (GLP-1R) antagonist (exendin(9-39)), and pentoxiphylline. Comparable to pentoxiphylline; both doses of lixisenatide produced a significant reduction in infarct volume and amelioration of neurobehavioural functions along with suppression of oxidative stress parameters (catalase, reduced glutathione, malondialdehyde and NO), inflammatory marker (tumor necrosis factor-alpha) and apoptotic marker (caspase-3) in ischemic rat brains. However, these effects weren'tinhibited by GLP-1R antagonist, exendin(9-39), indicating that they are independent on GLP-1R mediation. Also, lixisenatide upregulated protein expression of cerebral endothelial nitric oxide synthase and the angiogenic marker, vascular endothelial growth factor. It's worth noting that this effect was blocked by exendin(9-39). Overall, these data indicated that lixisenatide may offer a promising approach for alleviating cerebral I/R injury via different mechanisms that could be mediated, in part, through GLP-1R.

Lixisenatide, a novel GLP-1 analog, protects against cerebral ischemia/reperfusion injury in diabetic rats.

Type 2 diabetes mellitus (T2DM) is a major risk factor for ischemic stroke accompanied by vascular dysfunction and poor cerebrovascular outcome. Lixisenatide is a glucagon like peptide-1 (GLP-1) analog that is recently used for T2DM treatment with established neuroprotective properties. This study investigated and compared the neuroprotective effect of lixisenatide against glimepiride on diabetic rats subjected to global cerebral ischemia/reperfusion (I/R) injury. T2DM-induced adult male Wistar rats were administered lixisenatide or glimepiride prior to induction of global cerebral I/R-induced injury. Results showed a disturbance in oxidative stress parameters (catalase, reduced glutathione, and malondialdehyde) along with increasing in caspase-3 and tumor necrosis factor-alpha protein expressions in ischemic diabetic brain tissues. An upregulation of protein level of inducible nitric oxide (iNOS) synthase and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase subunit, NOX2 gene expression associated with significant suppression of endothelial nitric oxide synthase (eNOS) protein expression are recorded in carotid arteries of diabetic I/R-injured rats. Apart from ameliorating glucose intolerance and insulin resistance, lixisenatide was found to be superior to glimepiride as protective treatment in terms of enhancing behavioral/neurological functions and suppressing cerebral oxidative stress, inflammation, and apoptosis in cerebral I/R-injured diabetic rats. Unlike glimepiride, lixisenatide relieved carotid endothelial dysfunction by increasing eNOS expression. It also dampened vascular nitrosative/oxidative stress via suppression of iNOS and NADPH oxidase expressions. This study supposed that lixisenatide represents a more suitable anti-diabetic therapy for patients who are at risk of ischemic stroke, and even so, the mechanisms of lixisenatide-mediated vascular protection warrant further experimental and clinical investigations.

Sildenafil protects against nitric oxide deficiency-related nephrotoxicity in cyclosporine A treated rats.

Cyclosporine A (CsA) is the most widely used immunosuppressant in organ transplant surgery and in treatment of autoimmune disease. Nevertheless, animal and clinical studies have demonstrated that nephrotoxicity is the major adverse effect limiting the prolonged CsA therapeutic use. The present study aimed to investigate possible protective effect of sildenafil, a phoshodiestrase-5 inhibitor, on CsA-induced nephrotoxicity and various mechanism(s) underlies this effect. Male Wistar rats were administered CsA (20 mg/kg/day, s.c.) for 21 days alone or in combination with sildenafil (5 mg/kg/day, p.o.). Sildenafil exhibited nephroprotective effects as evidenced by significant decrease in serum creatinine and urea levels, spot urine albumin-creatinine ratio, as well as renal level of malondialdehyde, with a concurrent increase in renal levels of reduced glutathione and nitric oxide along with catalase activity compared to CsA-treated rats. [corrected]. Additionally, immunohistochemical analysis demonstrated that sildenafil treatment markedly reduced inducible nitric oxide synthase, tumor necrosis factor-alpha, and caspase-3 expressions, while expression of endothelial nitric oxide synthase was prominently enhanced. The protective effects of sildenafil were confirmed by renal histopathological examination. Pretreatment with l-nitro-arginine methyl ester (10 mg/kg/day, i.p.), a non-selective nitric oxide synthase inhibitor, reversed the protection afforded by sildenafil. Taken together, the current study highlighted the renoprotective effects of sildenafil against CsA-induced nephrotoxicity in rats, which might be mediated, in part, through nitric oxide pathway as well as antioxidant, anti-inflammatory, and anti-apoptotic activities.