Fahaid H. Al-Hashem

Resveratrol reverses cadmium chloride-induced testicular damage and subfertility by downregulating p53 and Bax and upregulating gonadotropins and Bcl-2 gene expression.

This study was performed to investigate the protective and therapeutic effects of resveratrol (RES) against CdCl2-induced toxicity in rat testes. Seven experimental groups of adult male rats were formulated as follows: A) controls+NS, B) control+vehicle (saline solution of hydroxypropyl cyclodextrin), C) RES treated, D) CdCl2+NS, E) CdCl2+vehicle, F) RES followed by CdCl2 and M) CdCl2 followed by RES. At the end of the protocol, serum levels of FSH, LH and testosterone were measured in all groups, and testicular levels of TBARS and superoxide dismutase (SOD) activity were measured. Epididymal semen analysis was performed, and testicular expression of Bcl-2, p53 and Bax was assessed by RT-PCR. Also, histopathological changes of the testes were examined microscopically. Administration of RES before or after cadmium chloride in rats improved semen parameters including count, motility, daily sperm production and morphology, increased serum concentrations of gonadotropins and testosterone, decreased testicular lipid peroxidation and increased SOD activity. RES not only attenuated cadmium chloride-induced testicular histopathology but was also able to protect against the onset of cadmium chloride testicular toxicity. Cadmium chloride downregulated the anti-apoptotic gene Bcl2 and upregulated the expression of pro-apoptotic genes p53 and Bax. Resveratrol protected against and partially reversed cadmium chloride testicular toxicity via upregulation of Bcl2 and downregulation of p53 and Bax gene expression. The antioxidant activity of RES protects against cadmium chloride testicular toxicity and partially reverses its effect via upregulation of BCl2 and downregulation of p53 and Bax expression.

Effect of Hawthorn (Crataegus aronia syn. Azarolus (L)) on Platelet Function in Albino Wistar Rats

OBJECTIVE This study was designed to investigate the possible antiplatelet effect of aqueous whole-plant C. aronia syn: Azarolus (L) extract using Wistar albino rats as a model. MATERIALS AND METHODS Forty-two male albino Wistar rats weighing 200 to 250 g were divided into seven groups with six rats in each group. Group 1 served as the control and received equal volumes of distilled water. Groups 2-6 served as the experimental groups and were given C. aronia extract at doses of 100, 200, 500, 1,000, and 2,000 mg/kg, while group 7 served as a positive control and was given aspirin (25mg/kg). All the doses were administered orally once a day and the treatment was continued for seven days. In all groups, at the end of the experimental procedure, blood samples were obtained for platelet function measurements, including PFA-100, thromboxane B2 levels, platelet count, and haematocrit. The bleeding time was determined using a modified tail cutting method described previously. RESULTS The aqueous C. aronia syn. Azarolus (L) extract significantly altered the bleeding time and the closure time, as determined by the PFA-100 and thromboxane B2 levels, suggesting significant platelet function inhibition. These effects were observed with C. aronia doses between 100 - 500 mg/kg, which yielded thromboxane B2 levels of 1,000 mg/kg, whereas the higher dose (2,000 mg/kg) produced opposite effects on these parameters. CONCLUSION C. aronia syn. Azarolus (L) aqueous extract has antiplatelet effects in Wistar albino rats.

Cardiac Adaptive Responses After Hypoxia in an Experimental Model

The role of vascular endothelial growth factor (VEGF) and erythropoietin (EPO) in mediating hypoxic preconditioning under the acute intermittent hypoxic condition (AIH) was investigated in this study. Male Wistar rats were randomly assigned and kept in normoxic conditions, (Nx) or in AIH conditions and subjected to brief cycles hypoxia/reoxygenation. Hearts were isolated, perfused, and subjected to in vitro global ischemia followed by reperfusion. During and at the end of reperfusion, left ventricular developed pressure (LVDP); LV end diastolic pressure (LVEDP); rate pressure product (RPP); peak left ventricular pressure rise (ΔP/Δt max ) and heart rate (HR) were measured. Hearts subjected to AIH displayed a significant higher LVDP (P < .001), RPP (P < .001), and ΔP/Δt max (P < .001). Expression of VEGF and EPO were significantly increased at 3, 8, and 24 hours after AIH. Hypoxic training could provide a new approach to enhance endogenous cardioprotective mechanisms.

Exercise protects against obesity induced semen abnormalities via downregulating stem cell factor, upregulating Ghrelin and normalizing oxidative stress

Increased oxidative stress and hormonal imbalance have been hypothesized to underlie infertility in obese animals. However, recent evidence suggests that Ghrelin and Stem Cell Factor (SCF) play an important role in fertility, in lean individuals. Therefore, this study aimed at investigating whether changes in the levels of Ghrelin and SCF in rat testes underlie semen abnormal parameters observed in obese rats, and secondly, whether endurance exercise or Orlistat can protect against changes in Ghrelin, SCF, and/or semen parameters in diet induced obese rats. Obesity was modelled in male Wistar rats using High Fat Diet (HFD) 12-week protocol. Eight week-old rats (n=40) were divided into four groups, namely, Group I: fed with a standard diet (12 % of calories as fat); Group II: fed HFD (40 % of calories as fat); Group III: fed the HFD with a concomitant dose of Orlistat (200 mg/kg); and Group IV: fed the HFD and underwent 30 min daily swimming exercise. The model was validated by measuring the levels of testosterone, FSH, LH, estradiol, leptin, triglycerides, total, HDL, and LDL cholesterol, and final change in body weight. Levels were consistent with published obesity models (see Results). As predicted, the HFD group had a 76.8 % decrease in sperm count, 44.72 % decrease in sperm motility, as well as 47.09 % increase in abnormal sperm morphology. Unlike the control group, in the HFD group (i.e. obese rats) Ghrelin mRNA and protein were elevated, while SCF mRNA and protein were diminished in the testes. Furthermore, in the HFD group, SOD and GPx activities were significantly reduced, 48.5±5.8 % (P=0.0012) and 45.6±4.6 % (P=0.0019), respectively, while TBARS levels were significantly increased (112.7±8.9 %, P=0.0001). Finally, endurance exercise training and Orlistat administration individually and differentially protected semen parameters in obese rats. The mechanism includes, but is not limited to, normalizing the levels of Ghrelin, SCF, SOD, GPx and TBARS. In rat testes, diet induced obesity down regulates SCF expression, upregulates Ghrelin expression, and deteriorate oxidative stress levels, which are collectively detrimental to semen parameters. Exercise, and to a lesser extent Orlistat administration, protected effectively against this detrimental effect.

EC50 of adrenaline-atenolol: Functional agonist assay using Langendorff isolated rabbit heart tethered to powerLab data acquisition system

The purpose of this study was to determine the mean EC50 of adrenaline on heart rate and force of contraction of isolated New Zealand white rabbit hearts and to determine the concentration of atenolol that completely blocks the effect of adrenaline using one of modern physiological acquisition system, PowerLab, AD instrumnets. Twelve Isolated hearts from New Zealand white rabbits were perfused through aorta in a Langendorff mode. Heart rate and contractility were determined for 5 minutes after bolus injection of 5 different concentrations of adrenaline (1.0, 2.5, 5.0, 7.5 and 10 μg/mL). The changes in heart rate and contractility after each treatment were compared with their baseline values. These data were used to calculate the mean EC50 of adrenaline on heart rate and force of contraction. This EC 50 was then used after perfusion of different concentrations of atenolol (1.0, 2.5, 5.0 and 10μg/mL). Data were collected with the help of PowerLab data acquisition and analyzed by Labchart pro7 software. Adrenaline resulted in a stimulatory effect on the heart rate and the amplitude of the heart contraction. The maximum increases in both heart rate and force of contraction were seen at adrenaline dose of 7.5 μg/mL and the plateau phase was achieved at a dose of 10 μg/mL. The average EC50 of adrenaline was 3.5 μg/mL. The positive inotropic effect of adrenaline was antagonized only at atenolol concentrations of 5.0 and 10 μg/mL and complete inhibition of adrenaline effect on heart rate was achieved at atenolol concentrations of 10 μg/mL. These data showed that atenolol must be used at a concentration no less than 7.5 μg/mL to demonstrate if β adrenergic receptors are involved in the mechanism of action of any newly tested positive inotropic or choronotroic drug.

Ghrelin prevents cardiac cell apoptosis during cardiac remodelling post experimentally induced myocardial infarction in rats via activation of Raf-MEK1/2-ERK1/2 signalling

Abstract Context: Mechanisms by which ghrelin affords its cardioprotection in mammals remained unclear. Objective: To examine if ghrelin confers cardio-protection during cardiac remodelling post-MI by modulating the RAF-1-MEK1/2-ERK1/2 signalling pathway. Materials and methods: Rats were divided into control, sham, sham + ghrelin, myocardial infarction (MI), and MI + ghrelin groups. Ghrelin (100 µg/kg) was administered for 21 days, starting one-day post-MI. Results: Ghrelin enhanced cardiac contractility and the activities of antioxidant enzymes, lowered serum levels of enzyme markers of cardiac dysfunction, and lowered inflammatory mediator levels. Ghrelin increased levels of phospho-Raf-1 (Ser338), phospho-MEK1/2 (Ser217/221), phospho-ERK1/2 (Thr202/Tyr204), and of their downstream target p-BAD (Ser112) and inhibited the cleavage of caspase-3. Concomitantly, ghrelin prevented the increases in the levels of fibrotic markers, including α-smooth muscle actin (α-SMA), metalloproteinase-9 (MPP-9), and type III collagen. Conclusion: Post-MI in rats, ghrelin stimulated Raf-1-MEK1/2-ERK1/2-BAD signalling in the LV infarct areas, accounting for its anti-apoptotic effect, enhancing cardiac function, and inhibiting cardiac fibrosis during cardiac remodelling.

Exercise protects against insulin-dependent diabetes-induced osteoarthritis in rats: A scanning electron microscopy study

ABSTRACT We tested the hypothesis that swim exercise can protect the articular cartilage from damages induced secondary to insulin-dependent diabetes mellitus in rats using the scanning electron microscopy and to monitor the blood levels of oxidative and antioxidative stress biomarkers that are known to be modulated in osteoarthritis (OA). A profound damage to the cartilage was observed in the diabetic rats. Our findings also show that swim exercise protects the knee joints from damage induced by diabetes as well as significantly inhibiting OA-induced upregulation of thiobarbituric acid reactive substances (TBARS) and tumor necrosis factor alpha (TNF-α) and augmented superoxide dismutase (SOD) inhibition by OA. Thus, we demonstrated an effective protection by swim exercise against diabetes-induced OA in a rat model of the disease.

Exhaustive exercise and vitamins C and E modulate thyroid hormone levels at low and high altitudes

Thyroid hormones play an important role in cell growth and differentiation and regulation of oxygen consumption and thermogenesis. The effect of altitude and vitamin supplementation on thyroid hormone levels in animals or humans performing acute exhaustive exercise have not been investigated before. Therefore, we thought to test whether exhaustive exercise-induced stress with antioxidant supplementation was capable of modulating the level of thyroid hormones at different altitudes. Serum levels of T4 (Thyroxin), T3 (Triiodothyronine), and TSH (Thyroid Stimulating Hormone) were measured in rats (N=36) born and bred in low altitude (600 m above sea level) and high altitude (2200 m above sea level) following forced swimming with or without vitamins C and E (25 mg/kg) pre-treatments. Thyroid levels were significantly decreased in resting rats at high altitude compared to low altitude, and swimming exercise moderately increased T3 and TSH at both high and low altitudes, whereas T4 was markedly increased (62 %) at low altitude compared to a moderate high altitude increase (28 %). Co-administration of vitamins C and E augmented the observed forced swimming-induced thyroid release. However, the conversion of T4 to T3 was reduced in both altitude areas following swimming exercise and vitamin pre-treatment had no effect. We conclude that acute stress induced thyroidal hormones in rats, which was augmented by antioxidant drugs in both high and low altitude areas. These findings may play an important role in the human pathophysiology of thyroid gland at different altitudes.

Acylated ghrelin protects aorta damage post-MI via activation of eNOS and inhibition of angiotensin-converting enzyme induced activation of NAD(P)H-dependent oxidase

ABSTRACT NAD(P)H dependent oxidase derived-reactive oxygen species (ROS) due to activation of the renin-angiotensin-aldosterone system (RAAS) in blood vessels postmyocardial infarction MI or during the HF leads to endothelium dysfunction and enhanced apoptosis. Acylated ghrelin (AG) is a well-reported cardioprotective and antiapoptotic agent for the heart. AG receptors are widely distributed in most of blood vessels, suggesting a role in the regulation of endothelial function and survival. This study investigated if AG can protect aorta of rats’ postmyocardial infarction (MI)-induced damage and endothelial dysfunction. Adult male rats were divided into four groups of (1) Sham, (2) Sham + AG, (3) MI, and (4) MI + AG. Vehicle (normal saline) or AG (100 µ/kg) was administered to rats for 21 consecutive days, after which, numerous biochemical markers were detected by blot. Both histological and electron microscope studies were carried on aortic samples from MI-induced rats. AG increased protein levels of both total and phosphorylated forms of endothelial nitric oxide synthase (eNOS and p-eNOS, respectively). Only in MI-treated rats, AG prevented the decreases in the levels of reduced glutathione (GSH) and superoxide dismutase (SOD) and lowered levels of malondialdehyde (MDA) and glutathione disulfide (GSSG). Concomitantly, it lowered the increased protein levels of angiotensin-converting enzyme (ACE), p22phox and cleaved caspase-3 and prevented the aorta histological and ultrustructural abnormalities induced by MI.

Metformin inhibits mTOR-HIF-1α axis and profibrogenic and inflammatory biomarkers in thioacetamide-induced hepatic tissue alterations: AL-HASHEM et al.

The potential inhibitory effect of the antidiabetic and anti‐inflammatory drug, metformin on thioacetamide (TAA)‐induced hepatotoxicity associated with the inhibition of mammalian target of rapamycin (mTOR)–hypoxia‐inducible factor‐1α (HIF‐1α) axis has not been investigated before. Therefore, we tested whether metformin can protect against liver injuries including fibrosis induced by TAA possibly via the downregulation of mTOR–HIF‐1α axis and profibrogenic and inflammatory biomarkers. Rats either injected with TAA (200 mg/kg; twice a week for 8 weeks) before being killed after 10 weeks (model group) or were pretreated with metformin (200 mg/kg) daily for 2 weeks before TAA injections and continued receiving both agents until the end of the experiment, at Week 10 (protective group). Using light and electron microscopy examinations, we observed in the model group substantial damage to the hepatocytes and liver tissue such as collagen deposition, infiltration of inflammatory cells, and degenerative cellular changes with ballooned mitochondria that were substantially ameliorated by metformin. Metformin also significantly ( p < 0.05) inhibited TAA‐induced HIF‐1α, mTOR, the profibrogenic biomarker α‐smooth muscle actin, tissue inhibitor of metalloproteinases‐1, tumor necrosis factor‐α (TNF‐α), interleukin‐6 (IL‐6), alanine aminotransferase (ALT) and aspartate aminotransferase in harvested liver homogenates and blood samples. In addition, a significant ( p < 0.01) positive correlation between hypoxia scoring (HIF‐1α) and the serum levels of TNF‐α ( r = 0.797), IL‐6 ( r = 0.859), and ALT ( r = 0.760) was observed. We conclude that metformin protects against TAA‐induced hepatic injuries in rats, which is associated with the inhibition of mTOR–HIF‐1α axis and profibrogenic and inflammatory biomarkers; thus, may offer therapeutic potential in humans.