Shimaa M. Elshazly

Piracetam and vinpocetine ameliorate rotenone-induced Parkinsonism in rats.

Objective: To evaluate the neuroprotective effect of the nootropic drugs, piracetam (PIR) and vinpocetine (VIN), in rotenone-induced Parkinsonism in rats. Materials and Methods: Sixty male rats were divided into 6 groups of 10 rats each. The groups were administered vehicle, control (rotenone, 1.5 mg/kg/48 h/6 doses, s.c.), PIR (100 and 200 mg/kg/day, p.o.) and VIN (3 and 6 mg/kg/day, p.o.). The motor performance of the rats was evaluated by the open field and pole test. Striatal dopamine level, malondialdehyde (MDA), reduced glutathione (GSH) and tumor necrosis factor-α (TNF-α) were assayed. Histopathological study of the substantia nigra was also done. Results: Results showed that rotenone-treated rats exhibited bradykinesia and motor impairment in the open-field test. In addition, GSH level was decreased whereas MDA and TNF-α increased in striata of rotenone-treated rats as compared to vehicle-treated rats. Marked degeneration of the substantia nigra pars compacta (SNpc) neurons and depletion of striatal dopamine was also observed in the rotenone-treated rats. Treatment with PIR or VIN significantly reversed the locomotor deficits and increased striatal dopamine level. Treatment with VIN significantly (P < 0.05) reduced the striatal level of MDA and GSH in comparison to rotenone group whereas TNF-α production was found to be significantly decreased in PIR group (P < 0.05). Conclusion: VIN and PIR exhibit neuroprotective activity in rotenone-induced Parkinsonism. Hence, these nootropic agents may be considered as possible candidates in the treatment of Parkinsons disease.

Renoprotective effect of sitagliptin against hypertensive nephropathy induced by chronic administration of L-NAME in rats: Role of GLP-1 and GLP-1 receptor

The present study was undertaken to assess the possible protective effects of sitagliptin, a dipeptidyl peptidase 4-inhibitor (DPP4), against Nω-nitro-L-arginine methyl ester (L-NAME) induced hypertensive nephropathy in rats. Hypertension was induced in adult rats by administration of L-NAME for 6 weeks. Rats were treated with sitagliptin (10mg/kg/day or 30 mg/kg/day) for six weeks. Chronic L-NAME administration resulted in depletion of serum nitric oxide (NO) associated with elevation in the mean arterial pressure. When compared with the control group; serum urea, serum creatinine, albuminuria, urinary N-acetyl-ß-d-glucosaminidase (NAG) level and renal tissue malondialdhyde (MDA) content were significantly elevated, while creatinine clearance, serum level of glucagon like peptide-1 (GLP-1) as well as renal tissue superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were signifcantly decreased in L-NAME treated group. Renal expression of mRNA for eNOS and GLP-1 receptors were reduced in the L-NAME treated group as compared with the control group. Treatment with sitagliptin (10mg/kg or 30 mg/kg) successfully ameliorated the deleterious effects of L-NAME on the all tested parameters. Our study indicates a novel protective effect of sitagliptin against L-NAME induced hypertensive nephropathy. An effect which is mediated through, increasing serum level of GLP-1, upregulation of GLP-1 receptors, which in turn, lead to induction of expression eNOS, increased serum NO level, tandem with decreased lipid perodixation and restore the antioxidant defense mechanisms. It is worth mentioning that the effects produced by sitaglipin (30 mg/kg) were superior to the effects obtained by the lower dose.

Ursodeoxycholic Acid Ameliorates Fructose-Induced Metabolic Syndrome in Rats

The metabolic syndrome (MS) is characterized by insulin resistance, dyslipidemia and hypertension. It is associated with increased risk of cardiovascular diseases and type-2 diabetes. Consumption of fructose is linked to increased prevalence of MS. Ursodeoxycholic acid (UDCA) is a steroid bile acid with antioxidant, anti-inflammatory activities and has been shown to improve insulin resistance. The current study aims to investigate the effect of UDCA (150 mg/kg) on MS induced in rats by fructose administration (10%) in drinking water for 12 weeks. The effects of UDCA were compared to fenofibrate (100 mg/kg), an agonist of PPAR-α receptors. Treatment with UDCA or fenofibrate started from the 6th week after fructose administration once daily. Fructose administration resulted in significant increase in body weight, elevations of blood glucose, serum insulin, cholesterol, triglycerides, advanced glycation end products (AGEs), uric acid levels, insulin resistance index and blood pressure compared to control rats. Moreover, fructose increased oxidative stress in aortic tissues indicated by significant increases of malondialdehyde (MDA), expression of iNOS and reduction of reduced glutathione (GSH) content. These disturbances were associated with decreased eNOS expression, increased infiltration of leukocytes and loss of aortic vascular elasticity. Treatment with UDCA successfully ameliorated the deleterious effects of fructose. The protective effect of UDCA could be attributed to its ability to decrease uric acid level, improve insulin resistance and diminish oxidative stress in vascular tissues. These results might support possible clinical application of UDCA in MS patients especially those present with liver diseases, taking into account its tolerability and safety. However, further investigations on human subjects are needed before the clinical application of UDCA for this indication.

Ameliorative effect of nicorandil on high fat diet induced non-alcoholic fatty liver disease in rats

Nonalcoholic fatty liver disease (NAFLD) is an accumulation of excessive amounts of fats in the liver that is not caused by alcohol consumption. It is considered as the most common liver disease in Western societies. The aim of this study is to investigate the possible protective effects of nicorandil and pioglitazone, the benefits of their combination and the possible mechanism underlie these effects in NAFLD. Rats were fed a high-fat diet (HFD) for eight weeks to induce NAFLD. In the next eight weeks, rats were fed the HFD along with pioglitazone (4 mg/kg) or nicorandil in two dose levels (3 or 15 mg/kg), alone or in combination. Chronic HFD administration resulted in significant elevations in serum levels of liver enzymes, total cholesterol, triglycerides, glucose, insulin and HOMA-IR index as compared with the control group. This was coupled with significant increments in liver triglycerides, MDA content and TNF-α as well as a significant reduction in liver GSH content. In comparison with the control group; liver expression of NF-κB was significantly elevated while liver eNOS expression and nitric oxide content were significantly decreased in HFD group. Treatment with pioglitazone or nicorandil either alone or in combination successfully ameliorated the deleterious effects of HFD on the all previous parameters. In conclusion, this investigation indicates a novel role of nicorandil in rats with NAFLD. This effect is mediated through, nitric oxide donor, antioxidant and anti-inflammatory properties, leading to improvement of insulin resistance. It is worth mentioning that the combinations were more effective than the individual drugs.

Therapeutic effect of captopril, pentoxifylline, and cordyceps sinensis in pre-hepatic portal hypertensive rats.

Background/Aim: Portal hypertension is an important and potentially fatal complication of liver disease whereby cellular and fibrotic alterations manifest to increase portal venous pressure. The aim of this study is to investigate the effect of captopril, pentoxifylline (PTX), and cordyceps sinensis in pre-hepatic portal hypertensive rats. Settings and Design: Wister male rats were divided at random into 3 main groups: the first group: control rats. The second group: sham-operated rats and the third group: prehepatic portal hypertensive rats (PHPHT) induced by regulated pre-hepatic portal vein ligation. After 14 days, Group 3 was subdivided into 5 subgroups. Subgroup (1): portal vein-ligated (PVL) was killed at once; Subgroup (2): received distilled water for 30 days (untreated PVL group); subgroups 3-5 were treated with captopril (60 mg/kg, orally); PTX (100 mg/kg, orally); and C. sinensis (200 mg/kg, orally), respectively, as a single daily dose for 30 days. Patients and Methods: Portal pressure, nitric oxide (NO), antioxidant enzymes, Liver enzymes, and creatinine levels were measured to evaluate the status of the liver state. Results: Portal vein ligation produced significant increments in liver enzymes, NO, creatinine and portal pressure concomitant with significant decrements in glutathione content and superoxide dismutase activity. Treatment with captopril, PTX, and C. sinensis resulted in a significant reduction in liver enzymes, NO, creatinine and portal pressure and observable increase in antioxidant enzymes. Conclusions: captopril, PTX, and C. sinensis have promising effect in controlling PHPHT and reducing hyperdynamic circulatory state through reduction of portal pressure and NO level.

Spirulina platensis Lacks Antitumor Effect against Solid Ehrlich Carcinoma in Female Mice

Spirulina is a blue-green alga used as a dietary supplement. It has been shown to possess anti-inflammatory, antioxidant, and hepatoprotective properties. This study was designed to evaluate the antitumor effect of spirulina (200 and 800 mg/kg) against a murine model of solid Ehrlich carcinoma compared to a standard chemotherapeutic drug, 5-fluorouracil (20 mg/kg). Untreated mice developed a palpable solid tumor after 13 days. Unlike fluorouracil, spirulina at the investigated two dose levels failed to exert any protective effect. In addition, spirulina did not potentiate the antitumor effect of fluorouracil when they were administered concurrently. Interestingly, their combined administration resulted in a dose-dependent increase in mortality. The present study demonstrates that spirulina lacks antitumor effect against this model of solid Ehrlich carcinoma and increased mortality when combined with fluorouracil. However, the implicated mechanism is still elusive.

Ameliorative effects of clonidine on ethanol induced kidney injury in rats: Potential role for imidazoline-1 receptor

&NA; Chronic alcoholism is a risk factor for kidney injury. Clonidine is an &agr;2‐adrenergic receptor/imidazoline‐1 receptor agonist that can reduce blood pressure and maintain renal functions. This study aims to investigate the possible ameliorative effects of clonidine on ethanol induced kidney injury and its mechanism of action. Kidney injury was induced in rats by adding ethanol to drinking water for eight weeks. Clonidine effects on kidney functions and histopathology were measured. Moreover, phentolamine (&agr;‐adrenergic receptor antagonist), efaroxan (imidazoline‐1 receptor antagonist) and rilmenidine (imidazoline‐1 receptor agonist) were used to clarify the role of imidazoline‐1 receptor in mediating renal ameliorative effects. Also, the effect of clonidine on liver functions and metabolic changes, in addition to renal oxidative stress, inflammatory and apoptotic pathways were measured. Results showed that, clonidine improved renal functions and reduced ethanol induced renal inflammation and fibrosis. On the other hand, efaroxan, only, blocked clonidine effects on kidney functions. Rilmenidine decreased kidney injury like clonidine. Both clonidine and rilmenidine increased renal nischarin gene expression. Furthermore, clonidine improved liver functions, increased serum insulin and decreased serum advanced glycation end products (metabolic markers). Also, clonidine reduced renal oxidative stress as reflected by decreased myeloperoxidase, malondialdehyde, inducible nitric oxide synthase and total nitric oxide levels and increased superoxide dismutase level. Moreover, clonidine reduced renal tumor necrosis factor‐&agr; (inflammatory marker) and caspase‐3 (apoptotic marker) levels, while increased renal prostaglandine E2 and interleukin‐10 levels (anti‐inflammatory markers). In conclusion, clonidine can reduce ethanol induced kidney injury, at least in part, by stimulating imidazoline‐1 receptor signaling.

Sildenafil protects against bile duct ligation induced hepatic fibrosis in rats: Potential role for silent information regulator 1 (SIRT1)

ABSTRACT Hepatic fibrosis is a potential health problem that may end with life‐threatening cirrhosis and primary liver cancer. Recent studies point out to the protective effects of silent information regulator1 (SIRT1), against different models of organs fibrosis. This work aimed to investigate the possible protective effect of sildenafil (SIRT1 activator) against hepatic fibrosis induced by bile duct ligation (BDL). Firstly, three different doses of sildenafil (5, 10, 20 mg/kg/day) were investigated; to detect the most protective one against BDL induced liver dysfunction and hepatic fibrosis. The most protective dose is then used; to study its effect on BDL induced SIRT1 downregulation, imbalance of oxidant/antioxidant status, increased inflammatory cytokines and fibrosis. Sildenafil (20 mg/kg/day) was the most protective one, it caused upregulation of SIRT1, reduction of hepatic malondialdehyde (MDA) content, increase in expression of nuclear factor erythroid 2‐related factor 2 (Nrf2), hemeoxygenease (HO)‐1, reduced glutathione (GSH) content and superoxide dismutase (SOD) activity. Hepatic content of tumor necrosis factor‐&agr; (TNF‐&agr;) and nuclear factor &kgr;B (NF&kgr;B) expression & content displayed significant reductions with sildenafil treatment, Furthermore, sildenafil caused marked reductions of transforming growth factor (TGF)‐&bgr; content, expression of plasminogen activator inhibitor‐1 (PAI‐1), matrix metalloproteinase‐9 (MMP‐9), tissue inhibitor of metalloproteinase‐1 (TIMP‐1), &agr;‐smooth muscle actin (&agr;‐SMA), fibronectin, collagen I (&agr;1) and hydroxyproline content. However, sildenafil protective effects were significantly reduced by co‐administration of EX527 (SIRT1 inhibitor). Our work showed, for the first time that, sildenafil has promising protective effects against BDL induced liver dysfunction and hepatic fibrosis. These effects may be, in part, mediated by up regulation of SIRT1. HighlightsBile duct ligation induced hepatic fibrosis associated with down regulation of SIRT1.Sildenafil reduced hepatic fibrosis induced by bile duct ligation.Sildenafil upregulated SIRT1 in the liver after bile duct ligation.EX527, SIRT1 inhibitor, reduced sildenafil hepatoprotective effects.Sildenafil hepatoprotective effects are SIRT1 dependent.

Anticancer activity of salicin and fenofibrate

Cancer refers to a disorder of cell proliferation that leads to tumor production. Cancer is usually treated by surgery, chemotherapeutic drugs, and radiation. Despite the presence of many anticancer drugs, cancer is still an uncontrolled disease and is a major cause of death worldwide. In addition, most anticancer drugs have severe side effects that can limit their use in some patients. This study aims to investigate the possible anticancer activity of two clinically used drugs: a natural antioxidant agent (salicin) and an antihyperlipidemic agent (fenofibrate) against two breast cancer models (in vivo EAC and in vitro MCF7) and the pancreatic cancer cell line (Panc-1).Our results have shown that both salicin and fenofibrate exerted an in vivo anticancer activity as evidenced by the decrease in tumor weight, tumor volume, CEA level, and reduced tumor cholesterol content through an antioxidant (reduced MDA level and increased GSH and catalase content) and an antiinflammatory activity (reduced TNF-∝ level). In addition, both salicin and fenofibrate were shown to be cytotoxic to MCF-7 and Panc-1 cell lines through activation of the caspase 3/7 apoptotic pathway.In conclusion, salicin and fenofibrate are promising anticancer drugs that are already used clinically with acceptable safety profile which can be incorporated into clinical trials to determine their possible application in cancer treatment.

Pentoxifylline abrogates cardiotoxicity induced by the administration of a single high dose or multiple low doses of doxorubicin in rats.

Doxorubicin (DOX) possesses a broad-spectrum antineoplastic activity; however, its clinical application is impeded by cardiotoxicity. This study aimed to investigate the protective effect of pentoxifylline (PXF), which possesses antioxidant and anti-inflammatory properties against cardiotoxicity induced by a single high dose (15 mg/kg, i.p.) or multiple low doses (2.5 mg/kg, i.p., three times per week for 2 weeks) of DOX. At the end of the experimental period, the serum creatine kinase (CK)-MB and lactate dehydrogenase (LDH) activities were measured. The hearts were then removed for evaluating TNF-α, NO, malondialdehyde (MDA), and reduced glutathione (GSH) levels, superoxide dismutase (SOD) and catalase (CAT) activities, and the expression of iNOS, NF-κB, Fas ligand (FasL), and caspase-3. The administration of DOX in both dose regimens caused increases in serum CK-MB and LDH activities, in cardiac TNF-α, NO and MDA levels, as well as in the cardiac expression of iNOS, NF-κB, FasL and caspase-3, whereas it significantly reduced the cardiac GSH level, as well as SOD and CAT activities (P < 0.05). Prophylactic treatment of rats with PXF diminished DOX-induced alterations in theses parameters. Our results warrant the clinical use of PXF as an adjuvant therapy to abrogate cardiotoxicity of DOX and extend its clinical applications.