Evaluation of structural changes of Echinococcus granulosus protoscoleces following exposure to different protoscolicidal solutions evaluated by differential interference contrast microscopy.

The present study was aimed to assess the structural changes in protoscoleces of Echinococcus granulosus sensu stricto following exposure to different natural and chemical protoscolicidal agents using differential interference contrast (DIC)/Nomarski microscopy. Protoscoleces of sheep's liver cysts were collected aseptically. Individually, about 1000 protoscoleces were exposed to 0.5% silver nitrate, 20% hypertonic saline solution, 0.5% cetrimide solution and two different concentrations of garlic chloroformic extraction as well as phosphate-buffered saline (PBS). The protoscoleces viability was assessed using 0.1% eosin solution, and structural modifications in the protoscoleces were examined by DIC/Nomarski microscopy. The results revealed the degeneration of the tegument, disorganization of the hooks, and reduction of the size of the protoscoleces exposed to cetrimide, hypertonic sodium chloride, and silver nitrate. Furthermore, calcareous corpuscles became blurred and opaque and their numbers decreased in all the exposed samples except, those in PBS. The exposed protoscoleces to cetrimide and hypertonic sodium chloride solution showed extensive degeneration of the tegument and disorganization of the hooks. In the group exposed to 200 mg/ml chloroformic garlic extract, the protoscoleces' width decreased. The length, width, and number of calcareous corpuscles also decreased significantly in the silver nitrate-exposed protoscoleces. The study concludes that protoscoleces exposed to different solutions; cetrimide 0.5% and hypertonic sodium chloride 20% caused more pronounced structural changes in the exposed protoscoleces. These changes were well demonstrated by DIC microscopy and can be used as a supplementary tool to evaluate the effects of protoscolicidal agents. Supplementary Information: The online version contains supplementary material available at 10.1007/s12639-023-01632-4.

A comparison of the effects of Stevia extract and metformin on metabolic syndrome indices in rats fed with a high-fat, high-sucrose diet.

The beneficial effects of Stevia on metabolic indices have been studied in recent years. However, controversial results emphasize the need for further investigation. We aimed to examine and compare the effects of Stevia's hydroalcoholic extract with two dosages (200, 400 mg/kg) with those of metformin (100 mg/kg) on metabolic syndrome (MetS) indices of rats fed with a high-fat, high-sucrose diet (HFHS). It was found that both Stevia extract and metformin could prevent the adverse effects of a HFHS on lipid profile, liver enzymes, total antioxidant capacity (TAC), and histopathologic factors. Except for the finding that metformin showed a greater potential to alleviate insulin resistance than did Stevia extract, no significant difference was observed between the rats receiving metformin or Stevia extract. In addition, using a high treatment dosage of Stevia extract did not lead to better results than a low dosage. Collectively, the efficacy of Stevia extracts to modify metabolic, oxidative, and histopathological indices in a MetS model was comparable to that of the metformin. PRACTICAL APPLICATIONS: This study was aimed to compare the efficiency of Stevia hydroalcoholic extract with metformin in attenuating MetS abnormalities of rats induced by a high-fat, high-sucrose diet. The results showed the beneficial changes caused due to the administration of Stevia extract on lipid profile, antioxidant capacity, liver enzyme, and liver histopathological indices. The changes were comparable with the results of metformin group. Despite some promising results, further investigation is suggested to evaluate the effectiveness of Stevia extract on human subjects.

Liposomal and Non-Liposomal Formulations of Vitamin C: Comparison of the Antihypertensive and Vascular Modifying Activity in Renovascular Hypertensive Rats.

BACKGROUND: Liposomes constitute a promising drug delivery vehicle, and are believed to improve drugs' effectiveness. This study was aimed to compare antihypertensive and vascular modifying activities of liposomal and non-liposomal forms of ascorbic acid. METHODS: Forty-nine male Sprague-Dawley rats were randomly divided into seven groups (n=7): A sham vehicle-receiving (Sham-veh), hypertensive (HTN), vehicle-receiving hypertensive (HTN-Veh), two liposomal Ascorbic acid-treated hypertensive at 50 or 100 mg/kg/day (LVC-50 and LVC-100), and two non-liposomal Ascorbic acid-treated hypertensive at 50 or 100 mg/kg/day (VC-50 and VC-100). Systolic blood pressure (SBP) and heart rate (HR) were measured weekly; after 4 weeks, dose-responses to phenylephrine (PE) in the absence and presence of nitro-L-arginine methyl ester (L-NAME), acetylcholine (Ach), and sodium nitroprusside (SNP) were obtained on aortic rings. Data were analyzed with one-way ANOVA and Duncan's multiple range test at a P value of <0.05 using Sigmastat statistical software. RESULTS: Compared to the non-liposomal form, the liposomal one was associated with more prominent effects on the final SBP. Both forms of Ascorbic acid decreased SBP dose-dependently. The basal and stimulated release of Nitric Oxide (NO) was significantly recovered by both forms of Ascorbic acid. The PE maximal responses were not significantly different between the liposomal and non-liposomal groups (P=0.08). Although the Emax of Ach-relaxation response was not different in two preparation forms, Ach-relaxation response induced a lower concentration of the liposomal form of Ascorbic acid (P=0.03. CONCLUSION: The liposomal Ascorbic acid exhibited relaxation activity in significantly lower concentrations. The observed effects were partly mediated by the increased basal release of NO.

The Healing Effects of Hydroalcoholic Extract of Carum copticum L. on Experimental Colitis in Rats.

BACKGROUND: Ulcerative colitis is an inflammatory disease with indefinite treatment. The present study aimed to assess the anti-inflammatory and antioxidant effects of Carum copticum L. (CC) extract on induced colitis in rats. METHODS: Sixty male rats were randomly divided into six groups (n=10 per group). Acetic acid-induced colitis rats were orally administered with doses of 100, 200, and 400 mg/kg CC extract, and 100 mg/kg sulfasalazine for seven consecutive days, respectively. Colonic biopsies were taken to measure histopathological parameters as well as the tumor necrosis factor (TNF-α), interleukin-6 (IL-6), myeloperoxidase (MPO), malondialdehyde (MDA), and glutathione (GSH). Data analysis was performed using the one-way ANOVA and Tukey's test for normally distributed data. Kruskal-Wallis test followed by Dunn's test was used for non-normally distributed data. The analysis was performed at P≤0.05 using SigmaStat software (version 10.0). RESULTS: The control colitis group had a significantly higher total colitis index (P=0.01), TNF-α (P=0.01), IL-6 (P=0.01), MPO (P=0.01), and MDA (P=0.01); and lower GSH (P=0.01) than those of the sham group. The colitis group receiving a dose of 200 mg/kg/day CC extract had a significantly lower total colitis index (P=0.01), TNF-α (P=0.01), IL-6 (P=0.01), MPO (P=0.01), and MDA (P=0.01); and higher GSH (P=0.01) than those of the control colitis group. The colitis group receiving a dose of 200 mg/kg/day CC extract had a significantly lower total colitis index (P=0.04), TNF-α (P=0.03), IL-6 (P=0.04), MPO (P=0.03), and MDA (P=0.03); and higher GSH (P=0.01) than those of the colitis group receiving sulfasalazine. CONCLUSION: The present study revealed that CC extract had healing effects on colitis, possibly due to its antioxidant and anti-inflammatory properties.

Antihypertensive Effects of Hydroalcoholic Extract of Crataegus Azarolus Subspecies Aronia Fruit in Rats with Renovascular Hypertension: An Experimental Mechanistic Study.

BACKGROUND: Hawthorn species decreases blood pressure and relaxes precontracted vessels. This study aimed at examining the antihypertensive effect and related mechanisms of hydroalcoholic extract of Crataegus azarolus subspecies aronia fruit in rats with renovascular hypertension. METHODS: Six groups of male Sprague-Dawley rats, each containing 6 to 8 rats, were studied. The groups comprised of one sham group and 5 renal artery-clipped groups. The sham group received vehicle (distilled water 0.5 ml/day) and the renal artery-clipped groups received vehicle or the extract at 5, 10, 20 or 30 mg/kg/day. Oral vehicle or extract was administered daily for 4 weeks following sham-operation or induction of hypertension. Systolic blood pressure and heart rate were measured weekly. Isolated aorta study was performed by last week and serum superoxide dismutase and glutathione reductase were measured. The findings were analyzed using one-way analysis of variance and Duncan's multiple range tests at P≤0.05 using SigmaStat software. RESULTS: The data obtained after 4 weeks of treatment showed that the renal artery-clipped group receiving vehicle had significantly higher systolic blood pressure (P=0.002) and phenylephrine maximal response (P=0.01); and lower acetylcholine maximal response (P=0.01), serum superoxide dismutase (P=0.006) and serum glutathione reductase (P=0.006) than those of the sham group. The renal artery-clipped group receiving extract had significantly lower systolic blood pressure (P=0.03) and phenylephrine maximal response (P=0.01); and significantly higher acetylcholine maximal response (P=0.01), serum superoxide dismutase (P=0.015), and serum glutathione reductase (P=0.015) than those of the renal artery-clipped group receiving vehicle. CONCLUSION: Our findings show that the hydroalcoholic extract of Crataegus azarolus subspecies aronia fruit has antihypertensive effects, which may be partly due to antioxidant and nitric oxide releasing effects.

Oleuropein improves glucose tolerance and lipid profile in rats with simultaneous renovascular hypertension and type 2 diabetes.

Oleuropein mediates most of the beneficial effects of olive products. This study examined the role of oxidative stress in the effects of oleuropein on lipid profile and blood glucose in rats with simultaneous renovascular hypertension and type 2 diabetes. Eight groups (n = 7-9 each) of male Sprague-Dawley rats including a control, a type 2 diabetic, a renovascular hypertensive, a sham, a simultaneously hypertensive diabetic receiving vehicle, and 3 simultaneously hypertensive-diabetic receiving 20, 40, or 60 mg/kg/day oleuropein were used. Four weeks after treatment, blood glucose, lipid profile, and biomarkers of oxidative stress were measured, and glucose tolerance test (GTT) was performed. Simultaneously hypertensive diabetic rats had significantly higher blood pressure, blood glucose, and serum total cholesterol, low-density lipoprotein cholesterol (LDL-C), triglyceride and malondialdehyde. They also had lower serum high-density lipoprotein cholesterol, erythrocyte superoxide dismutase, and impaired glucose tolerance. Oleuropein significantly reduced blood pressure, blood glucose, and serum total cholesterol, LDL-C, triglyceride and malondoaldehyde. It also increased serum high-density lipoprotein cholesterol, erythrocyte superoxide dismutase, and improved glucose tolerance. The findings show that the model is associated with impaired glucose tolerance, and adverse lipid profile. They also show that oleuropein, partly by an antioxidant mechanism, improves glucose tolerance and changed lipid profile favorably.

Oleuropein attenuates the progression of heart failure in rats by antioxidant and antiinflammatory effects.

Much of the beneficial effects of olive products have been attributed to oleuropein. This study examined the effects of oleuropein in rats with heart failure induced by permanent ligation of left coronary arteries. Twenty-four hours after the operation, the rats were assigned to five groups including a sham assigned to receive vehicle (1 ml/day) and four coronary ligated groups assigned to receive vehicle or oleuropein at 5, 10, or 20 mg/kg/day. Five weeks later, echocardiographic and hemodynamic parameters, serum concentrations of oxidative stress, and inflammatory markers were determined. Myocardial infarction group receiving vehicle showed impaired hemodynamic and echocardiographic parameters as evidenced by decreased left ventricular systolic pressure, rate of rise and decrease of left ventricular pressure, stroke volume, ejection fraction, and cardiac output. In addition, significant reduction in superoxide dismutase and glutathione reductase was observed. Oleuropein treatment prevented the reduction of these variables. Moreover, the group had a significantly higher infarct size and serum malondialdehyde, interleukin-1ß, and tumor necrosis factor-α than those of the sham group. Treatment with oleuropein prevented the increase of these variables. The results show that oleuropein attenuates the progression of heart failure, possibly by antioxidative and antiinflammatory effects.

Antihypertensive effects of new dihydropyridine derivatives on phenylephrine-raised blood pressure in rats.

Changes in the substitutions at C-3 and C-5 positions of 4-(1-methyl-5-nitro-2-imidazolyl) dihydropyridine analogs of nifedipine have led to changes in potency of the compounds. The objective of the present study was to examine the hypotensive effects of 5 newly synthesized dihydropyridine derivatives of nifedipine in rats with phenylephrine-raised blood pressure. Anesthetized Sprague-Dawley rats were randomly assigned to 19 groups of 7 animals each. Control group received the vehicle dimethylsulfoxide (0.05 mL), 3 groups were given nifedipine at 100, 300, or 1000 µg/kg, and 5 other groups each composed of 3 subgroups administered one of the 5 new dihydropyridine compound at 100, 300, or 1000 µg/kg. All animals were initially infused with 20 µg/kg/min phenylephrine for 45 min, and were then given a bolus of either dimethylsulfoxide, nifedipine, or new dihydropyridine compounds 20 min after the commencement of phenylephrine infusion. Blood pressure and heart rate (HR) of the animals were measured before and at the end of phenylephrine infusion, or 25 min after injection of vehicle or compounds. Compared to dimethylsulfoxide, nifedipine, and new 1, 4-dihydropyridine derivatives caused significant reductions in MBP. Moreover, cyclohexyl propyl, phenyl butyl, and cyclohexyl methyl analogs of 1, 4-dihydro-2,6-dimethyl-4-(1-methyl-5-nitro-2-imidazoyl)-3,5-pyridinedicarboxylase at 100 µg/kg, phenyl butyl, and cyclohexyl methyl analogs at 300 µg/kg, and cyclohexyl methyl analogs at 1000 µg/kg reduced MBP similar to nifedipine. There was no significant difference between HR of all groups before and after administration of the compounds. The findings indicated that changes in substitution at C-3 and C-5 positions of 2-(1-methyl-5-nitro-2-imidazolyl) dihydropyridine analogs of nifedipine were associated with changes in hypotensive activity of the compounds.

Acute and chronic effects of lithium on BDNF and GDNF mRNA and protein levels in rat primary neuronal, astroglial and neuroastroglia cultures.

OBJECTIVES: The neuroprotective effect of lithium has been attributed to its therapeutic action. However, the role of glial cells particularly astrocytes, and the possible interactions between neurons and astrocytes in neuroprotective effects of lithium have been disregarded. Thus, the aim of this study was to evaluate the direct effects of lithium on brain derived neurotrophic factor (BDNF) and glial cell line derived neurotrophic factor (GDNF) in rat primary neuronal, astrocytes, and mixed neuro-astroglial cultures to assess the possible effects of lithium on astrocytes and neuro-astroglia interactions. MATERIALS AND METHODS: Rat primary astrocyte, neuronal and mixed neuro-astrocyte cultures were prepared from cortices of 18-day embryos. Cell cultures were exposed to lithium (1 mM) or vehicle for 1 day (acute) or 7 days (chronic). BDNF and GDNF mRNA and protein levels were determined by RT-PCR and ELISA, respectively. RESULTS: Chronic but not acute lithium treatment increased intracellular BDNF and GDNF protein levels in rat primary neuronal and astrocyte cultures, respectively (P<0.05). However, chronic lithium treatment had no significant effect on intracellular BDNF protein level in astrocyte and mixed neuron-astrocyte cultures or GDNF protein levels in mixed neuron-astrocyte culture. Furthermore, acute and chronic lithium treatment had no significant effect on mRNA and extracellular BDNF and GDNF protein levels in three studied cultures. CONCLUSION: Present study showed that chronic lithium treatment affected neurotrophins both in neurons and astrocytes in a cell-type specific manner with no effect on neuron-astrocyte interactions. The findings of this study also highlighted the importance of astrocytes as drug targets involved in the neuroprotective action of lithium.

The cardioprotective effects of resveratrol in rats with simultaneous type 2 diabetes and renal hypertension.

This study aimed at examining the cardioprotective effects of resveratrol in rats with simultaneous type 2 diabetes and renal hypertension. Eight groups (8-10 each) of male Sprague-Dawley rats, including a control, a diabetic, a renal hypertensive, a sham, a simultaneously hypertensive-diabetic receiving vehicle, and 3 simultaneously hypertensive-diabetic receiving resveratrol at 5, 10 or 20 mg/kg/day were used. After 4 weeks of treatment, blood pressure and glucose, and serum markers of oxidative stress were measured, and animals' hearts were used for isolated studies. Resveratrol prevented the increase of systolic blood pressure, serum malondialdehyde, fasting blood glucose, infarct size, coronary resistance, and coronary effluent creatine kinase-MB. Moreover, it prevented the decrease of serum superoxide dismutase and glutathione reductase, heart rate, left ventricular developed pressure, rate of increase of ventricular pressure, and rate of decrease of ventricular pressure. In conclusion, our findings show that resveratrol alleviates cardiac dysfunction in diabetic-hypertensive rats by virtue of antioxidant, antihypertensive, and coronary vasodilating activities.

Chronic lithium treatment increased intracellular S100ß levels in rat primary neuronal culture.

S100ß a neurotrophic factor mainly released by astrocytes, has been implicated in the pathogenesis of bipolar disorder. Thus, lithium may exert its neuroprotective effects to some extent through S100ß. Furthermore, the possible effects of lithium on astrocytes as well as on interactions between neurons and astrocytes as a part of its mechanisms of actions are unknown. This study was undertaken to determine the effect of lithium on S100ß in neurons, astrocytes and a mixture of neurons and astrocytes. Rat primary astrocyte, neuronal and mixed neuro-astroglia cultures were prepared from cortices of 18-day's embryos. Cell cultures were exposed to lithium (1mM) or vehicle for 1day (acute) or 7 days (chronic). RT-PCR and ELISA determined S100ß mRNA and intra- and extracellular protein levels. Chronic lithium treatment significantly increased intracellular S100ß in neuronal and neuro-astroglia cultures in comparison to control cultures (P<0.05). Acute and chronic lithium treatments exerted no significant effects on intracellular S100ß protein levels in astrocytes, and extracellular S100ß protein levels in three studied cultures as compared to control cultures. Acute and chronic lithium treatments did not significantly alter S100ß mRNA levels in three studied cultures, compared to control cultures. Chronic lithium treatment increased intracellular S100ß protein levels in a cell-type specific manner which may favor its neuroprotective action. The findings of this study suggest that lithium may exert its neuroprotective action, at least partly, by increasing neuronal S100ß level, with no effect on astrocytes or interaction between neurons and astrocytes.

The effects of resveratrol in rats with simultaneous type 2 diabetes and renal hypertension: a study of antihypertensive mechanisms.

BACKGROUND: Resveratrol has beneficial effects on cardiovascular system. This study aimed at examining antidiabetic and antihypertensive effects of resveratrol in rats with simultaneous type 2 diabetes and renal hypertension. METHODS: Eight groups (8-10 each) of male Spargue-Dawley rats, including a control, a diabetic (induced by streptozotocin and nicotinamide), a renal hypertensive (induced by placing plexiglas clips on the left renal arteries), a sham, a simultaneously hypertensive-diabetic receiving vehicle, and 3 simultaneous hypertensive-diabetic receiving resveratrol at 5, 10 or 20 mg/kg/day were used. Four weeks after the induction of diabetes, renal hypertension was induced and animals were given vehicle or resveratrol for the next four weeks. Afterwards, blood pressure and glucose, serum markers of oxidative stress were measured and animal's aortic rings were used for isolated studies. RESULTS: Serum malondialdehyde, systolic blood pressure, heart rate, fasting blood glucose, maximal response and effective concentration 50 of phenylephrine, and inhibitory concentration 50 of acetylcholine of hypertensive-diabetic group receiving vehicle were significantly higher than those of the control group, and treatment with resveratrol caused significant reduction of these variables. Moreover, serum superoxide dismutase, glutathione reductase, and maximal response to acetylcholine of hypertensive-diabetic group receiving vehicle were significantly lower than those of the control group, and treatment with resveratrol caused significant increase of these variables. CONCLUSION: The findings indicate that resveratrol has antidiabetic and antihypertensive effects, which may be partly due to antioxidant mechanism. They also show that antihypertensive effect of resveratrol may be additionally mediated by improving the release of nitric oxide and sympathoplegic activities.

Oleuropein offers cardioprotection in rats with acute myocardial infarction.

Myocardial infarction causes a cascade of events, which leads to heart failure, debilitation and death. This study examined possible cardioprotective effect of oleuropein in rats with acute myocardial infarction. Male Sprague-Dawly rats were allocated to five groups: sham, myocardial infarction receiving vehicle, and three myocardial infarction receiving oleuropein at 10, 20, and 30 mg/kg/day for 7 days, and underwent sham operation or coronary ligation. Twenty-four hours later, animals underwent echocardiographic and hemodynamic studies, and infarct areas, serum concentrations of oxidative stress and inflammatory markers were determined. Myocardial infarction group receiving vehicle had significantly lower left ventricular developed and systolic pressures, rate of rise/decrease of left ventricular pressure, stroke volume, ejection fraction and cardiac output, and serum superoxide dismutase and glutathione reductase than those of sham group. Pretreatment with oleuropein prevented the reduction of these variables. Moreover, the group had a significantly higher serum malondialdehyde, interleukin-1ß, TNF-α, creatin kinase-MB, and troponin I, lactate dehydrogenase, and infarct area than those of sham group. Pretreatment with oleuropein prevented the increase of these variables. The findings indicate that coronary ligation results in acute myocardial infarction characterized by impaired cardiac function, and oleuropein pretreatment prevented cardiac impairment partly by reducing oxidative stress and release of proinflammatory cytokines.

Blockade of Central Angiotensin II AT1 Receptor Protects the Brain from Ischemia/Reperfusion Injury in Normotensive Rats.

BACKGROUND: Stroke is the third leading cause of invalidism and death in industrialized countries. There are conflicting reports about the effects of Angiotensin II on ischemia-reperfusion brain injuries and most data have come from chronic hypertensive rats. In this study, hypotensive and non-hypotensive doses of candesartan were used to investigate the effects of angiotensin II AT1 receptor blockade by transient focal cerebral ischemia in normotensive rats. METHODS: In this experimental study, 48 male Sprague-Dawley rats were randomly divided into four groups (n=12). Sham group, the control ischemic group, and two ischemic groups received candesartan at doses of 0.1 or 0.5 mg/kg at one hour before ischemia. Transient focal cerebral ischemia was induced by 60 minutes occlusion of the middle cerebral artery, followed by 24 h reperfusion. The neurological deficit score was evaluated at the end of the reperfusion period. The total cortical and striatal infarct volumes were determined using triphenyltetrazolium chloride staining technique. Tissue swelling was calculated for the investigation of ischemic brain edema formation. RESULTS: In comparison with the control ischemic group, AT1 receptor blockade with both doses of candesartan (0.1 or 0.5 mg/kg) significantly improved neurological deficit and lowered cortical and striatal infarct sizes. In addition, pretreatment with candesartan significantly reduced ischemia induced tissue swelling. CONCLUSION: Angiotensin II by stimulating AT1 receptors, participates in ischemia-reperfusion injuries and edema formation. AT1 receptor blockade with candesartan decreased ischemic brain injury and edema and improved neurological outcome.

Candesartan attenuates ischemic brain edema and protects the blood-brain barrier integrity from ischemia/reperfusion injury in rats.

BACKGROUND: Angiotensin II (Ang II) has an important role on cerebral microcirculation; however, its direct roles in terms of ischemic brain edema need to be clarified. This study evaluated the role of central Ang II by using candesartan, as an AT1 receptor blocker, in the brain edema formation and blood-brain barrier (BBB) disruption caused by ischemia/reperfusion (I/R) injuries in rat. METHODS: Rats were exposed to 60-min middle cerebral artery (MCA) occlusion. Vehicle and non-hypotensive doses of candesartan (0.1 mg/kg) were administered one hour before ischemia. Neurological dysfunction scoring was evaluated following 24 h of reperfusion. Animals were then decapitated under deep anesthesia for the assessments of cerebral infarct size, edema formation, and BBB permeability. RESULTS: The outcomes of 24 h reperfusion after 60-min MCA occlusion were severe neurological disability, massive BBB disruption (Evans blue extravasation = 12.5 ± 1.94 µg/g tissue), 4.02% edema, and cerebral infarction (317 ± 21 mm3). Candesartan at a dose of 0.1 mg/kg, without changing arterial blood pressure, improved neurological dysfunction scoring together with significant reductions in BBB disruption (54.9%), edema (59.2%), and cerebral infarction (54.9%). CONCLUSIONS: Inactivation of central AT1 receptors, if not accompanied with arterial hypotension, protected cerebral micro-vasculatures from damaging effects of acute stroke.

Oleuropein offers cardioprotection in rats with simultaneous type 2 diabetes and renal hypertension.

OBJECTIVES: The study aimed at examining the role of oxidative stress in cadioprotective effects of oleuropein in a rat model of simultaneous type 2 diabetes and renal hypertension. MATERIALS AND METHODS: Five groups of male Sprague-Dawley rats including a control group, a diabetic-hypertensive group receiving vehicle, and three diabetic-hypertensive groups receiving oleuropein at 20, 40, or 60 mg/kg/day were used. Blood pressure and glucose, serum malondialdehyde, and erythrocyte superoxide dismutase were measured, and animal's hearts with ischemia/reperfusion injuries were used using Langendorff technique. RESULTS: Blood pressure, blood glucose, serum malondialdehyde, infarct size, coronary effluent creatine kinase-MB, and coronary resistance of diabetic-hypertensive group were significantly higher than those of the control group, while those of the oleuropein-receiving groups were significantly lower than those of the diabetic hypertensive group receiving the vehicle. Erythrocyte superoxide dismutase, left ventricular developed pressure, and rate of rise and rate of decrease of ventricular pressure of diabetic-hypertensive group were significantly lower than those of the control group. These parameters as well as heart rate of oleuropein-receiving groups were significantly higher than those of the diabetic-hypertensive group. CONCLUSION: The findings indicate that oleuropein offered cardioprotection, which might be partly mediated by its antioxidant properties.

Effects of oleuropein in rats with simultaneous type 2 diabetes and renal hypertension: a study of antihypertensive mechanisms.

The mechanism of oleuropein's antihypertensive effects was examined in rat model of simultaneous type 2 diabetes and renal hypertension (diabetic hypertensive). Five groups of male Sprague-Dawley rats including a control, a diabetic-hypertensive group receiving vehicle, and three diabetic-hypertensive groups receiving oleuropein at 20, 40, or 60 mg/kg/day were used. The duration of diabetes was 10 weeks; during the last 4 weeks of which, animals were hypertensive and received vehicle or oleuropein. Systolic blood pressure, glucose and malondialdehyde, heart rate, and maximal response to phenylephrine (PE) in the absence of nitro-L-arginine methyl ester (L-NAME) of oleuropein-treated groups were significantly lower than those of vehicle-treated group. Erythrocyte superoxide dismutase, maximal response to PE in the presence of L-NAME, and maximal response to acetylcholine (Ach) of oleuropein-treated groups were significantly higher than those of vehicle-treated group. The findings indicate that antihypertensive effects of oleuropein might be partly mediated by improving the release of nitric oxide, and antioxidant and sympathoplegic activities.

Effects of pomegranate seed oil on insulin release in rats with type 2 diabetes.

BACKGROUND: Pomegranate seed oil and its main constituent, punicic acid, have been shown to decrease plasma glucose and have antioxidant activity. The objective of the present study was to examine the effects of pomegranate seed oil on rats with type 2 diabetes mellitus. METHOD: Six groups (n=8 each) of male Sprague-Dawley rats, comprising a control, a diabetic (induced by Streptozocin and Nicotinamide) receiving water as vehicle, a diabetic receiving pomegranate seed oil (200 mg/kg/day), a diabetic receiving pomegranate seed oil (600 mg/kg/day), a diabetic receiving soybean oil (200 mg/kg/day), and a diabetic receiving soybean oil (600 mg/kg/day), were used. After 28 days of receiving vehicle or oils, blood glucose, serum levels of insulin, malondialdehyde, glutathione peroxidase, and lipid profile were determined. RESULTS: The diabetic rats had significantly higher levels of blood glucose, serum triglyceride, low-density lipoprotein cholesterol, total cholesterol, and malondialdehyde and lower levels of serum insulin and glutathione peroxidase. Rats treated with pomegranate seed oil had significantly higher levels of serum insulin and glutathione peroxidase activity, and there were no statistically significant differences in terms of blood glucose between them and the diabetic control group. CONCLUSION: The findings of the present study suggest that pomegranate seed oil improved insulin secretion without changing fasting blood glucose.

Effects of Short-term Renovascular Hypertension and Type 2 Diabetes on Cardiac Functions in Rats.

BACKGROUND: The cardiac effects simultaneously occurring during experimental hypertension and diabetes have rarely been investigated. This study aimed at examining the effects of short-term renovascular hypertension and type 2 diabetes on cardiac functions. METHODS: Five groups (7 each) of male Sprague-Dawley rats, including a control group, a diabetes (induced by Streptozocin and Nicotinamide) group, a renovascular hypertensive (induced by placing Plexiglas clips on the left renal arteries) group, a sham group, and a simultaneously hypertensive-diabetic group, were used. The animals' hearts were used for isolated heart studies, and the indices of cardiac functions and coronary effluent creatine kinase MB were measured. The results were analyzed using One-way Analysis of Variance, followed by the Duncan Multiple Range test. RESULTS: The diabetic group had a significantly lower rate of rise (-29.5%) and decrease (-36.18%) in ventricular pressure, left ventricular developed pressure (-28.8%), and rate pressure product (-35%), and significantly higher creatine kinase MB (+166%) and infarct size (+36.2%) than those of the control group. The hypertensive group had a significantly higher rate of rise (+12.17%) and decrease (+16.2%) in ventricular pressure, left ventricular developed pressure (+16%), and rate pressure product (+24%), and significantly lower creatine kinase MB (-30%) and infarct size (-27%) than those of the sham group. Simultaneously, the diabetic and hypertensive rats had a significantly higher rate of rise (+32%) and decrease (+30.2%) in ventricular pressure, left ventricular developed pressure (+17.2%), and rate pressure product (+22.2%), and significantly lower creatine kinase MB (-24%) and infarct size (-16.2%) than those of the diabetic group. CONCLUSION: The findings indicated that the simultaneity of hypertension with type 2 diabetes attenuated diabetes-induced cardiac impairment.

The increased gastroprotective effect of pioglitazone in cholestatic rats: role of nitric oxide and tumour necrosis factor alpha.

The prevalence of gastric ulcers is high in cholestatic patients, but the exact mechanism of this increased frequency remains uncertain. It has been shown that pioglitazone accelerates the healing of pre-existing gastric ulcers. The present study was designed to investigate the effect of pioglitazone, on the gastric mucosal lesions in cholestatic rats. Cholestasis was induced by surgical ligation of common bile duct and sham-operated rats served as control. Different groups of sham and cholestatic animals received solvent or pioglitazone (5, 15, 30 mg/kg) for 7 days. On the day eight rats were killed after oral ethanol administration and the area of gastric lesions was measured. The serums of rats were also collected to determine serum levels of tumour necrosis factor alpha (TNF-α), IL-1ß and bilirubin. The ethanol-induced gastric mucosal damage was significantly more severe in cholestatic rats than sham-operated ones. Pretreatment with pioglitazone dose-dependently attenuated gastric lesions induced by ethanol in both sham and cholestatic rats, but this effect was more prominent in cholestatic ones. The effect of pioglitazone was associated with a significant fall in serum levels of TNF-α in cholestatic rats. L-NAME, a non-selective nitric oxide synthase (NOS) inhibitor, and decreased pioglitazone-induced gastroprotective effect in cholestatic rats, while aminoguanidine, a selective inducible NOS inhibitor, potentiated pioglitazone-induced gastroprotective effect in the cholestatic rats. Chronic treatment with pioglitazone exerts an enhanced gastroprotective effect on the stomach ulcers of cholestatic rats compared to sham rats probably due to constitutive NOS induction and/or inducible NOS inhibition and attenuating release of TNF-α.