Iranian Journal of Basic Medical Sciences
Year:2010 | Volume:13 | Issue:2 (45)|Papers Count:9

Objective(s): Previous studies have indicated that diabetes mellitus might be accompanied by neuropathic pain. Oxidative stress is implicated as a final common pathway in development of diabetic neuropathy. Pharmacological interventions targeted at inhibiting free radical production have shown beneficial effects in diabetic neuropathy. The aim of this study was to investigate and compare the possible analgesic effects of melatonin and vitamin E in diabetic rats.Materials and MethodsThis study was performed on 32 male Wistar rats divided into 4 groups: control, diabetic, melatonin-treated diabetic and vitamin E-treated diabetic. Experimental diabetes was induced by intraperitoneal streptozotocin (50 mg/kg) injection. Melatonin (10 mg/kg, i.p.) and vitamin E (100 mg/kg, i.p.) were injected for 2 weeks after 21st day of diabetes induction. At the end of administration period, pain-related behavior was assessed using 0.5% formalin test according to two spontaneous flinching and licking responses. The levels of lipid peroxidation as well as glutathione-peroxidase and catalase activities were evaluated in lumbosacral dorsal root ganglia.Results: Formalin-evoked flinching and total time of licking were increased in both acute and chronic phases of pain in diabetic rats as compared to control rats, whereas treatment with melatonin or vitamin E significantly reduced the pain indices. Furthermore, lipid peroxidation levels increased and glutathione-peroxidase and catalase activities decreased in diabetic rats. Both antioxidants reversed the biochemical parameters toward their control values.Conclusion: These results suggest that oxidative stress may contribute to induction of pain in diabetes and further suggest that antioxidants, melatonin and vitamin E, can reduce peripheral neuropathic pain in streptozotocin-induced diabetic rats.

Objective(s): Learning is defined as the acquisition of information and skills, while subsequent retention of that information is called memory. The objective of the present study was to investigate the effect of aqueous extract of Boswellia papyrifera on learning and memory paradigms in mice and rats. Materials and Methods: This study was held at the Department of Pharmacology, Faculty of Pharmacy, Kermanshah University of Medical Science, and Kermanshah, Iran from September 2006 to March 2008. Male Wistar rats and male NMRI mice were randomly divided into control, B. papyrifera treated (50, 100, 150 mg/kg, p.o.), and piracetam (150 mg/kg) groups. Radial arm maze (RAM) and Morris water maze (MWM) were the screening tests used to assess the activity of B. papyrifera extract. Results: The mice treated with B. papyrifera (50, 100 and 150 mg/kg) or piracetam (150 mg/kg) showed a decrease in number of days required to learned (P< 0.05) and time taken to find food by the learned mice in radial arm maze (P< 0.01). In Morris water maze, rats treated with the above mentioned doses showed dose dependent improvement in spatial learning. Escape latency during swimming in water maze in piracetam and B. papyrifera treated animals was significantly lower (P< 0.01) than control. Swimming distance was also significantly lower (P< 0.05) in the treated groups. Conclusion: The results show facilitation of spatial learning and memory processes and thereby validate B. papyrifera traditional use of intelligence improving. The presence of alkaloids, flavonoids and saponins might be responsible for this activity of B. papyrifera.

Objective(s): Anxiety is a common disorder which afflicts many people in any society and is often accompanied by physiological sensations such as tachycardia, chest pain, shortness of breath, insensitivity, etc. The purpose of present study was to evaluate the putative anxiolytic-like effects of phencyclidine (1-(1-phenylcyclohexyl) piperidine, CAS 956-90-1, PCP, I) and its methyl and methoxy hydroxyl derivatives (II, III) using elevated plus maze test of anxiety.Materials and Methods: Phencyclidine as well as its methyl and methoxy hydroxyl derivatives (I, II, III) (hydrochloride, 1, 2, 5 mg/kg) were synthesized and administrated intraperitoneally (IP) on adult male Wistar rats. Results: The results of this study demonstrated that, intraperitoneal (IP) administration of PCP analogues (I, II, III) hydrochloride (1, 2, 5 mg/kg) increases the percentage of open arm time (OAT%) and percentage of open arm entries (OAE%).Conclusion: This study revealed that both derivatives of phencyclidine (II, III) were more effective than PCP (I) itself in modulation of anxiety behavior in rats.

Objective(s): Mesenchymal stem cells (MSCs) are nonhematopoietic stromal cells that are capable of differentiating into and contribute to the regeneration of mesenchymal tissues. Human mesenchymal stem cells (hMSCs) are ideal targets in cell transplantation and tissue engineering. Enhanced green fluorescent protein (EGFP) has been an important reporter gene for gene therapy. The aim of this study was establishment of MSCs expressing GFP.Materials and Methods: MSCs were isolated and characterized by Immunophenotyping. The pEGFP-N1 plasmid was extracted from previously transformed Escherichia. coli cells and transfected into MSCs using FuGENE HD transfection reagent. Stable cells were established in the presence of geneticin. Expression of GFP was detected by RTPCR, western blot analysis and immunoflorecent microscope.Results: MSCs were successfully isolated and characterized. The MSCs transfected with the pEGFP-N1 plasmid expressed GFP both in mRNA and protein levels while cells transfected with empty vector did not. Conclusion: The results suggested that this engineered cell line will be used in the future studies and can easily be traced in vivo.

Objective(s): Portulaca oleracea L. is a herbaceous weed from portulacaceae family. It can be found in many parts of the world. Modern pharmacological studies have demonstrated that P. oleracea have antioxidant effects. The protective effect of aqueous and ethanolic extract of P. oleracea against cisplatin-induced renal toxicity was studied in rats.Materials and Methods: Single intraperitoneal injection of 4 mg/kg cisplatin was administrated to rats. After 5 days, blood urea nitrogen (BUN) and serum creatinine (Scr) concentration were determined. Effect of aqueous and ethanolic extracts, before and after cisplatin injection on BUN and Scr, as well as morphological renal damage, was evaluated.Results: It was indicated that treatment with aqueous and ethanolic extracts of P. oleracea in the highest dose (0.8 and 2 g/ kg), 6 and 12 hr before cisplatin injection reduced BUN and Scr. Tubular necrotic damage was not observed either.Conclusion: Results suggest that P. oleracea extract may protect against cisplatin-induced renal toxicity and might serve as a novel combination agent with cisplan to limit renal injury.

Objective(s): Ziziphora clinopodioides Lam. is a plant widely used in Iranian traditional medicine for gastrointestinal disorders. Several reports have demonstrated antibacterial (Helicobacteria pylori), antioxidant and anti-inflammatory properties of Z. clinopodioides. The aim of this study was to investigate the effects of aqueousethanol extract of Z. clinopodioides on rat’s gastric acid output in basal, vagotomized (VX) and vagal stimulated conditions.Materials and Methods: A total of 24 male Wistar rats weighed 200-250 g were randomly divided into two groups: control and test. Tracheostomy and gastroduodenostomy procedures were performed for each rat. In the vagotomized condition the vagus nerve in the cervical region was dissected and in the vagal stimulation condition the distal portion of the vogues nerve stimulated. Gastric content was collected for 15 min by wash out technique. A volume of 1 ml of three doses (0.5, 1 and 2 mg/kg) was introduced into the stomach (i.g.) of each rat in the test group and the same volume of saline was used in the control group. Total titratable acid was measured by a titrator.Results: The extract inhibited acid secretion significantly at basal condition. At VX condition not only this inhibitory effect on acid secretion disappeared but also a stimulatory effect at the dose of 2 mg/kg was shown. In vagal stimulation condition the extract showed a significant inhibitory effect at 1 mg/kg dose. Conclusion: Taking together our data resulted from comparison of three conditions showed that the extract exerted an inhibitory effect on acid secretion in basal and vagal stimulation. Also, according to our results this inhibitory effect of the extract could be exerted via gastric vagal parasympathetic nerve.

Introduction: Genetic background has known to be associated with the outcome of human T cell lymphotropic virus (HTLV) type I infection. In The present study we investigate the association between GM-CSF gene polymorphisms with the outcome of HTLV-I infection.Materials and Methods: We analyzed 3 single-nucleotide polymorphisms in the promter region of granulocyte macrophage colony stimulating factor (GM-CSF) at positions -677*A/C, -1440*A/G and -1916*T/C in 68 patients with HTLVI– associated myelopathy/tropical spastic paraparesis (HAM/TSP) and 77 HTLV-I-seropositive asymptomatic carriers and 175 healthy controls from an area in Iran, Mashhad, where HTLV-I is endemic. Results: No significant differences were observed in the distribution of GM-CSF polymorphisms between HAM/TSP patients, HTLV-I carriers and healthy controls (P> 0.05). The -677*A/C polymorphism fall within the transcriptional enhancer factor-2 (TEF-2) binding site, so an electrophoretic mobility shift assay (EMSA) was performed to determine the effects of polymorphisms on protein binding to the GM-CSF promoter. The result showed a significantly higher binding efficiency of nuclear protein to the A allele compared with the C allele.Conclusion: Our study suggests that polymorphisms in the GM-CSF promoter is not associated with the outcome of HTLV-I infection, however, GM-CSF polymorphism at position -677 could indeed influence gene expression.

Objective(s): Increased reactive oxygen species (ROS) production is implicated in the pathogenesis of arterial hypertension and the development of endothelial dysfunction. NADPH oxidase type enzyme family has been suggested to form ROS and to interfere with endothelium-dependent relaxation. However, the specific isoform of NADPH oxidases that may predominantly contribute to these events remains to be clarified. Materials and Methods: Here we investigated the expressional regulation of NADPH oxidase isoforms (NOX1, NOX2 and NOX4) in aorta of aged spontaneously hypertensive rats (SHR) in comparison to age matched Wistar Kyoto rats (WKY). Moreover, we examined the effect of in vitro inhibition of NADPH oxidase by apocynin or the novel NADPH oxidase inhibitor, VAS2870 on the vascular reactivity and ROS production. Results: Our results showed that ROS formation was largely increased in aorta of SHR as measured by dihydroethidine (DHE) fluorescence and inhibited by apocynin or VAS2870. NADPH oxidase activity, measured by lucigenin-enhanced chemiluminescence and of NOX1 and NOX2 protein levels were increased in aortic homogenates from SHR compared to WKY. However, NOX4 protein expression was not significantly changed. Furthermore, the impaired acetylcholine-induced relaxation of SHR aorta was significantly improved in the presence of either apocynin or VAS2870.Conclusion: Collectively, our data suggest that NADPH oxidases, particularly NOX1 and NOX2 are relevant sources of ROS in the aorta of aged SHR thereby cause endothelial dysfunction, and VAS2870 is effective as apocynin in reversing these consequences.

Objective(s): The purpose of the present study was to evaluate the effect of Ramadan fasting and weight-lifting training on plasma volume, glucose, and lipids profile of male weight-lifter.Materials and Methods: Forty male weight-lifters were recruited and divided into 4 groups (n=10 each) and as the following groups: control (C), fasting (F), training (T) and fasting-training (F-T). The T and F-T groups performed weightlifting technique trainings and hypertrophy body building (3 sessions/week, 90 min/session). All subjects were asked to complete a medical examination as well as a medical questionnaire to ensure that they were not taking any medication, were free of cardiac, respiratory, renal, and metabolic diseases, and were not using steroids. Blood samples were taken at 24 hr before and 24 hr after one month of fasting and weightlifting exercise. The plasma volume, fasting blood sugar (FBS), lipid profiles, and lipoproteins were analyzed in blood samples. Results: Body weight and plasma volume showed significant (P< 0.05) decrease and increase in the F group (P< 0.05) respectively. Also, a significant reduction was observed in F-T group body weight (P< 0.01). A significant increase was found in FBS level of F group (P< 0.05). The lipid profiles and lipoproteins didn’t change significantly in C, F, T and the F-T groups.Conclusion: The effect of Ramadan fasting on body weight and plasma volumes may be closely related to the nutritional diet or biochemical response to fasting.