Tarek K. Motawi

Protective effect of vitamin E, β-carotene and N-acetylcysteine from the brain oxidative stress induced in rats by lipopolysaccharide

The major goal of this study was to examine the ability of several antioxidants namely, vitamin E, beta-carotene and N-acetylcysteine, to protect the brain from oxidative stress induced by lipopolysaccharide (LPS, endotoxin). LPS, a component of the bacterial wall of gram-negative bacteria, has been recognized as one of the most potent bacterial products in the induction of host inflammatory responses and tissue injury and was used in this study to mimic infections. LPS injection resulted in a significant increase in the stress indices, plasma corticosterone and glucose concentration, a significant alteration of the brain oxidative status observed as elevation of the level of malondialdehyde (MDA, index of lipid peroxidation) and reduction of reduced glutathione (GSH), and a disturbance in the brain energy metabolism presented as a reduction in the ATP/ADP ratio and an increase in the mitochondrial/cytosolic hexokinase ratio. However, the activities of brain superoxide dismutase and Na+, K+-ATPase and contents of cholesterol and phospholipids were not altered. Administration of the aforementioned antioxidants prior to LPS injection ameliorated the oxidative stress by reducing levels of MDA, restoring GSH content and normalizing the mitochondrial/cytosolic hexokinase ratio in the brain in addition to lowering levels of plasma corticosterone and glucose. In conclusion, this study showed the increased free radical generation during infections and LPS-induced stress. It also suggests that brain oxidative status and energy is disturbed.

Cytoprotective effects of DL-alpha-lipoic acid or squalene on cyclophosphamide-induced oxidative injury: An experimental study on rat myocardium, testicles and urinary bladder

The present study aimed to evaluate the role of DL-alpha-lipoic acid (LA) and squalene (SQ) on oxidative cardiac, testicular and urotoxic damage induced by cyclophosphamide (CP). Male Wistar rats were divided into four groups; three groups received a single intraperitoneal injection of CP (200mg/kg BW) to induce toxicity, and two of these groups received either LA (35 mg/kg BW) or SQ (0.4 ml/rat) orally 7 days before and 7 days after CP injection. A vehicle-treated control group was also included. Oxidative damage was observed by decreased serum total antioxidant capacity (TAC) level and abnormal alterations in glutathione peroxidase (GPx) and glutathione reductase (GR) activities, levels of glutathione (GSH), malondialdehyde (MDA), nitric oxide (NO) and calcium (Ca(+2)) in the heart, testes and urinary bladder of CP-administered rats. Cardiac marker enzyme activities; creatine phosphokinase (CPK), lactate dehydrogenase (LDH), and aspartate transaminase (AST) showed severe declines whereas testicular markers; sorbitol dehydrogenase (SDH), gamma-glutamyl transferase (gamma-GT), acid and alkaline phosphatases (ACP and ALP), serum testosterone (T) level and haemoglobin (Hb) absorbance were abnormal. Histopathological observations were also altered. These CP-induced pathological alterations were attenuated by treatment with LA or SQ. These findings highlight the efficacy of LA and SQ as cytoprotectants in CP-induced toxicity.

Gastroprotective effect of leptin in indomethacin-induced gastric injury.

This study investigated the involvement of neutrophil infiltration, disturbances in nitric oxide (NO) generation and oxidative stress in indomethacin-induced gastric ulcer, and the possible gastroprotective potentials of leptin, known for its angiogenic effect. Male Wistar albino rats (180-220 g) were allocated into a normal control group, ulcer control group (received a single dose of indomethacin 40 mg/kg p.o.) and an ulcer group pretreated with leptin (10 microg/kg i.p. 30 min before ulcer induction). The animals were killed 6 h after indomethacin administration and their gastric juice, serum and mucosal tissue were used for gastric injury evaluation. Indomethacin produced multiple lesions in glandular mucosa, evidenced by marked increase in gastric ulcer index (GUI) accompanied by significant increases in gastric juice acidity, tissue myeloperoxidase (MPO) activity, serum NO and tissue conjugated diene (CD), and marked decreases in tissue NO and glutathione (GSH) as well as glutathione reductase (GR) and superoxide dismutase (SOD) activities, while gastric juice mucin and tissue glutathione peroxidase (GPx) were not affected. Leptin exerted significant gastroprotection as evidenced by significantly decreased GUI and attenuated neutrophil infiltration. Leptin significantly increased mucin and tissue NO, restored GR and SOD activities and up-regulated GPx activity. It failed to affect acidity, serum NO, GSH and CD. These results suggest that leptin confers significant gastroprotection against indomethacin-induced injury through interfering with neutrophil infiltration, NO production and oxidative stress.

Serum MicroRNAs as Potential Biomarkers for Early Diagnosis of Hepatitis C Virus-Related Hepatocellular Carcinoma in Egyptian Patients

Circulating microRNAs are deregulated in liver fibrosis and hepatocellular carcinoma (HCC) and are candidate biomarkers. This study investigated the potential of serum microRNAs; miR-19a, miR-296, miR-130a, miR-195, miR-192, miR-34a, and miR-146a as early diagnostic biomarkers for hepatitis C virus (HCV)-related HCC. As how these microRNAs change during liver fibrosis progression is not clear, we explored their serum levels during fibrosis progression in HCV-associated chronic liver disease (CLD) and if they could serve as non-invasive biomarkers for fibrosis progression to HCC. 112 Egyptian HCV-HCC patients, 125 non-malignant HCV-CLD patients, and 42 healthy controls were included. CLD patients were subdivided according to Metavir fibrosis-scoring. Serum microRNAs were measured by qRT-PCR custom array. Serum microRNAs were deregulated in HCC versus controls, and except miR-130a, they were differentially expressed between HCC and CLD or late fibrosis (F3-F4) subgroup. Serum microRNAs were not significantly different between individual fibrosis-stages or between F1-F2 (early/moderate fibrosis) and F3-F4. Only miR-19a was significantly downregulated from liver fibrosis (F1-F3) to cirrhosis (F4) to HCC. Individual microRNAs discriminated HCC from controls, and except miR-130a, they distinguished HCC from CLD or F3-F4 patients by receiver-operating-characteristic analysis. Multivariate logistic analysis revealed a panel of four microRNAs (miR-19a, miR-195, miR-192, and miR-146a) with high diagnostic accuracy for HCC (AUC = 0.946). The microRNA panel also discriminated HCC from controls (AUC = 0.949), CLD (AUC = 0.945), and F3-F4 (AUC = 0.955). Studied microRNAs were positively correlated in HCC group. miR-19a and miR-34a were correlated with portal vein thrombosis and HCC staging scores, respectively. In conclusion, studied microRNAs, but not miR-130a, could serve as potential early biomarkers for HCC in high-risk groups, with miR-19a as a biomarker for liver fibrosis progression to cirrhosis to HCC. We identified a panel of four serum microRNAs with high accuracy in HCC diagnosis. Additional studies are required to confirm this panel and test its prognostic significance.

Effects of a Water‐Soluble Curcumin Protein Conjugate vs. Pure Curcumin in a Diabetic Model of Erectile Dysfunction

INTRODUCTION Curcumin is involved in erectile signaling via elevation of cyclic guanosine monophosphate (cGMP). AIM Assessment of the effects of water-soluble curcumin in erectile dysfunction (ED). METHODS One hundred twenty male white albino rats were divided into: 1st and 2nd control groups with or without administration of Zinc protoporphyrin (ZnPP), 3rd and 4th diabetic groups with or without ZnPP, 5th diabetic group on single oral dose of pure curcumin, 6th diabetic group on pure curcumin administered daily for 12 weeks, 7th and 8th diabetic groups on single dose of water-soluble curcumin administered with or without ZnPP, 9th and 10th diabetic groups on water-soluble curcumin administered daily for 12 weeks with or without ZnPP. All curcumin dosage schedules were administered after induction of diabetes. MAIN OUTCOME MEASURES Quantitative gene expression of endothelial nitric oxide synthase (eNOS), neuronal NOS (nNOS), inducible NOS (iNOS), heme oxygenase-1 (HO-1), nuclear transcription factor-erythroid2 (Nrf2), NF-Кβ, and p38. Cavernous tissue levels of HO and NOS enzyme activities, cGMP and intracavernosal pressure (ICP). RESULTS Twelve weeks after induction of diabetes, ED was confirmed by the significant decrease in ICP. There was a significant decrease in cGMP, NOS, HO enzymes, a significant decrease in eNOS, nNOS, HO-1 genes and a significant elevation of NF-Кβ, p38, iNOS genes. Administration of pure curcumin or its water-soluble conjugate led to a significant elevation in ICP, cGMP levels, a significant increase in HO-1 and NOS enzymes, a significant increase in eNOS, nNOS, HO-1, and Nrf2 genes, and a significant decrease in NF-Кβ, p38, and iNOS genes. Water-soluble curcumin showed significant superiority and more prolonged duration of action. Repeated doses regimens were superior to single dose regimen. Administration of ZnPP significantly reduced HO enzyme, cGMP, ICP/ mean arterial pressure (MAP), HO-1 genes in diabetic groups. CONCLUSION Water-soluble curcumin could enhance erectile function with more effectiveness and with more prolonged duration of action.

Effects of caffeic acid phenethyl ester on endotoxin-induced cardiac stress in rats: A possible mechanism of protection

Endotoxins (lipopolysaccharides; LPS) are known to cause multiple organ failure, including myocardial dysfunction. The present study aimed to investigate the mechanism of caffeic acid phenethyl ester (CAPE) protection against LPS‐induced cardiac stress. Rats were allocated into three groups; group 1 served as a normal control group, group 2 (LPS) received a single intraperitoneal injection of LPS (10 mg/kg), group 3 (LPS + CAPE) was injected intraperitoneally with CAPE (10 mg/kg/day; solubilized in saline containing 20% tween 20) throughout a period of 10 days prior to LPS injection. Rats were maintained 4 h before sacrifice. Caffeic acid phenethyl ester pretreatment normalized LPS‐enhanced activities of serum creatine kinase (CK) and lactate dehydrogenase (LDH) as well as glutathione peroxidase (GPx), and myeloperoxidase (MPO) in cardiac tissue. A significant reduction of the elevated levels of serum tumor necrosis factor‐alpha (TNF‐α) as well as serum and cardiac nitrite/nitrate (NOx) was achieved after CAPE pretreatment. CAPE also restored malondialdelyde (MDA), reduced glutathione (GSH), and cytosolic calcium (Ca2+) levels in the heart. A marked induction of cardiac heme oxygenase‐1 (HO‐1) protein level was detected in CAPE‐pretreated group. Whereas, LPS‐induced reduction of adenosine triphosphate (ATP) and phosphocreatine (PCr) levels was insignificantly changed. Conclusively, the early treatment with CAPE maintained antioxidant defences, reduced oxidative injury, cytokine damage, and inflammation but did not markedly improve energy status in cardiac tissue. The beneficial effect of CAPE might be mediated, at least in part, by the superinduction of HO‐1.

Comparative study between the effect of the peroxisome proliferator activated receptor-α ligands fenofibrate and n-3 polyunsaturated fatty acids on activation of 5'-AMP-activated protein kinase-α1 in high-fat fed rats

Objectives Obesity is a risk factor for type 2 diabetes mellitus. It results from an energy imbalance in which energy intake exceeds energy expenditure. The cellular fuel gauge 5′‐AMP‐activated protein kinase (AMPK) is a heterotrimeric protein consisting of one catalytic subunit (α) and two non‐catalytic subunits (β and γ), and approximately equal levels of α1 and α2 complexes are present in the liver. AMPK regulates metabolic pathways in response to metabolic stress and in particular ATP depletion to switch on energy‐producing catabolic pathways such as β‐oxidation of fatty acids and switch off energy‐depleting processes such as synthesis of fatty acid and cholesterol. A high‐fat diet alters AMPK‐α1 gene expression in the liver and skeletal muscle of rats and results in body weight gain and hyperglycaemia. The aim of this study was to investigate and compare the potential effects of peroxisome proliferator‐activated receptor (PPAR)‐α agonists fenofibrate and n‐3 polyunsaturated fatty acids (PUFAs) in modulation of AMPK‐α1 activity in liver and skeletal muscle of high‐fat diet fed rats.

The Therapeutic Effects of Bone Marrow-Derived Mesenchymal Stem Cells and Simvastatin in a Rat Model of Liver Fibrosis

Liver fibrosis is the excessive accumulation of extracellular matrix (ECM) proteins including collagen that occurs in most types of chronic liver diseases. Studies concerning the capacity of mesenchymal stem cells (MSCs) and simvasatain (SIMV) to repair fibrotic tissues through reducing inflammation, collagen deposition, are still controversial. This study aimed to investigate the therapeutic efficacy of bone marrow (BM)-derived MSCs and SIMV on carbon tetrachloride (CCl4)-induced liver fibrosis in rats. Rats were divided into: normal, CCl4, CCl4/MSCs, CCl4/SIMV, CCl4/MSCs/SIMV, and SIMV groups. BM-derived MSCs were detected by RT-PCR of CD29 and were then infused into the tail vein of female rats that received CCl4 injection to induce liver fibrosis. Sex-determining region Y (SRY) gene on Y-chromosome gene was assessed by PCR to confirm homing of the male stem cells in liver tissue of the female recipients. Serum liver function tests, liver procollagens I and III, tissue inhibitors of metalloproteinase-1 (TIMP-1), endoglin, matrix metalloproteinase-1 (MMP-1) gene expressions, transforming growth factor-beta (TGF-β1) immunostaining, and histopathologicl examination were performed. MSCs and SIMV decreased liver procollagens I and III, TIMP-1 and endoglin gene expressions, TGF-β1 immunostaining, and serum liver function tests compared with the CCl4 group. MMP-1 expression was increased in the CCl4/MSCs group. Histopathological examination as well as fibrosis score supports the biochemical and molecular findings. It can be concluded that MSCs and SIMV were effective in the treatment of hepatic CCl4-induced fibrosis-rat model. Treatment with MSCs was superior to SIMV. This antifibrotic effect can be attributed to their effect on the MMPs/TIMPs balance which is central in fibrogenesis.

Genetic variations in E-selectin and ICAM-1: Relation to atherosclerosis

Summary Background This study aimed to investigate the association of both intercellular adhesion molecule-1 (ICAM-1) and endothelial cell adhesion molecule (E-selectin) polymorphisms using PCR technique and their role in the pathogenesis of atherosclerosis. Material/Methods The study enrolled 285 individuals, classified into 4 groups: 63 cerebrovascular atherosclerotic patients, 75 cardiovascular patients, 72 peripheral atherosclerotic patients and 75 normal healthy individuals. Results The frequency of the mutant AC genotype of E-selectin in peripheral, cerebral and cardiovascular atherosclerotic patients was significantly higher than in control subjects (29.17%, 28.53% and 28% vs. 8%, respectively). However, no significant difference was observed in the frequency of mutant CC allele between all atherosclerotic patients and control groups. The frequency of the mutant EE homozygotes of ICAM-1 in peripheral, cerebral and cardiovascular atherosclerotic patients was significantly higher compared to controls (45.8%, 42.9% and 36% vs. 12%, respectively). The frequency of EK of ICAM-1 showed no significant difference between atherosclerotic patients and the control group. The frequency of the mutant E allele of ICAM-1 was significantly higher in peripheral, cerebral and cardiovascular patients compared to controls (58.3%, 54.8% and 54% vs. 26%, respectively). Conclusions Ser 128Arg of E-selectin and the K469E of ICAM-1 polymorphisms may be involved in predisposition to atherosclerosis.

Alterations in circulating angiogenic and anti-angiogenic factors in type 2 diabetic patients with neuropathy

Diabetic peripheral neuropathy (DPN) is one of the most common diabetic chronic complications. There is an increased attention directed towards the role of angiogenic factors including vascular endothelial growth factor (VEGF) and anti‐angiogenic factors including soluble endoglin (sEng) as contributors to diabetic microvascular complications including neuropathy. The purposes of this study were to determine the role of these angiogenesis regulators in the prognosis of DPN.