Neuroprotective Properties of Peptides

The development of a treatment strategy for neurodegenerative disorders is a serious issue for the healthcare world and a crucial subject of discussion. In the past two decades, a lot of focus has been placed on identifying the pathophysiological processes involved in neuronal death linked to neurodegenerative disorders and developing a variety of treatment options for neuroprotection. Numerous research teams have studied the use of peptides as neuroprotective treatments for different types of neurodegenerative disorders for a long time. The review aims to provide details about the roles of erythropoietin (EPO), glucagon-like peptide-1 (GLP-1), granulocyte colony-stimulating factor (G-CSF), and oxytocin (OXT) in neurodegenerative disorders as well as what cellular and molecular mechanisms they trigger to elicit the neuroprotective action, with a focus on neurodegenerative disorders

Rebaudioside A inhibits pentylenetetrazol-induced convulsions in rats

AbstractThe safety of patients with epilepsy consuming sweetening agents, which is becoming increasingly prevalent for various reasons, is a topic that should be emphasized as sensitively as it is for other diseases. Patients with epilepsy consume sweetening agents for different reasons such being diabetic or overweight. They can occasionally be exposed to sweetening agents unrestrainedly through consuming convenience food, primarily beverages. This study aimed to investigate the effects of rebaudioside A (Reb-A), which is a steviol glycoside produced from the herb Stevia rebaudiana (Bertoni), on epileptic seizures and convulsions induced by pentylenetetrazole (PTZ). Forty-eight male rats were used. Twenty-four rats were administered 35 mg/kg PTZ to trigger epileptiform activity; the remaining 24 rats were administered 70 mg/kg PTZ to trigger the convulsion model. The epileptiform activity was evaluated by spike percentage, whereas convulsion was evaluated by Racine's Convulsion Scale and the onset time of the first myoclonic jerk. Statistical analysis revealed a statistically significant decrease in the Racine's Convulsion Scale score and increase in the latency of first myoclonic jerk in a dose-dependent manner for the rat groups in which PTZ epilepsy had been induced and Reb-A had been administered. For the groups that were administered Reb-A, the spike decrease was apparent in a dose-dependent manner, based on the spike percentage calculation. These results indicated that Reb-A has positive effects on PTZ-induced convulsions

The Relationship Between The Level Of Attachment In Romantic Relations, Affective Commitment And Continuance Commitment Towards Organization : A Field Research

Romantic relationship/love is the expression of the intensive desire of being an entity with someone else, in a cognitive, behavioral and emotional aspect. Organizational commitment is clarified by the acceptance of organizational aims and values, employees' willingness to stay in their own organization and their intention to display more efforts. In this study, it was analysed whether there is a relation between the level of attachment / passionate love felt by the employees within their romantic relationships, the affective commitment and continuance commitment of the employees towards their organizations. The survey method was used as a data collection tool. With the use of "Organizational Commitment Scale'' and "Passionate Love Scale'', surveys were applied to doctors and nurses selected from a health institution. Surveys were analysed via the package programme of STATA-11/EVIEWS-7/SPSS-21. According to the result of the analysis, it was determined that a positive side and weak relation exist between the level of passionate love, affective commitment and continuance commitment. (C) 2015 The Authors. Published by Elsevier B.V

Levetiracetam attenuates rotenone-induced toxicity: A rat model of Parkinson's disease

WOS: 000372763600029PubMed ID: 26896611Levetiracetam (LEV), a second-generation anti-epileptic drug, is used for treatment of both focal and generalized epilepsy. Growing body of evidence suggests that LEV may have neuroprotective effects. The present study was undertaken to investigate the neuroprotective effects of LEV on rotenone-induced Parkinson's disease (PD) in rats. Twenty-four adult Sprague-Dawley rats were infused with rotenone (3 mu g/mu l in DMSO) or vehicle (1 mu l DMSO) into the left substantia nigra pars compacta (SNc) under stereotaxic surgery. PD model was assessed by rotational test ten days after drug infusion. The valid PD rats were randomly distributed into two groups; Group 1 (n =8) and Group 2 (n=8) were administered saline (1 ml/kg/day, i.p.) and LEV (600 mg/kg/day, i.p.) through 21 days, respectively. The effects of LEV treatment were evaluated by behavioral (rotation score), biochemical (brain homovalinic acid level and oxidant/antioxidant status) and immunohistochemical (tyrosine hydroxylase) parameters. Apomorphine-induced rotations in PD rats were significantly suppressed by LEV treatment. While unilateral rotenone lesion induced a dramatic loss of dopaminergic neurons both in the striatum and SNc, LEV treatment significantly attenuated the degenerative changes in dopaminergic neurons. Furthermore, LEV significantly decreased lipid peroxide levels, a marker of lipid peroxidation, and induced glutathione levels, catalase and superoxide dismutase activity in PD rats compared with saline group. We conclude that LEV may have beneficial effects on dopaminergic neurons against rotenone-induced injury. The underlying mechanism may be associated with the attenuation of oxidative stress. (C) 2016 Elsevier B.V. All rights reserved

Granulocyte colony-stimulating factor provides protection against cardiovascular autonomic neuropathy in streptozotocin-induced diabetes in rats

WOS: 000349959600012PubMed ID: 25638453Aims: Cardiovascular autonomic neuropathy (CAN) is a relatively common and detrimental complication of diabetes mellitus (DM). Dysregulation of neuropeptides, such as calcitonin gene-related peptide (CGRP) and vasoactive intestinal peptide (VIP), are thought to play significant roles in diabetes-related cardiovascular disease. Accumulating evidence indicates the neuroprotective effects of granulocyte-colony stimulating factor (G-CSF) in different neurological disorders. The purpose of the study is to investigate the role of CGRP and VIP and possible effects of G-CSF on CAN in type I DM model in rats. Methods: Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) for 14 rats. Seven rats served as controls and 6 rats were administered G-CSF alone. DM group was randomly divided into 2 groups and received either 1 mL/kg saline (DM + saline group) or 100 mu g/kg/day G-CSF (DM + G-CSF group) for 4 weeks. Following electrocardiography (ECG), GCRP and VIP levels were measured in plasma samples. Results: Diabetes promoted a significant prolongation in the corrected QT interval (cQT) (P < 0.001) whereas G-CSF administration significantly shortened cQT interval (P < 0.05). Plasma VIP and CGRP levels of saline treated DM group were significantly lower than those of control group (P < 0.05). G-CSF treatment significantly prevented the reduction in plasma VIP and CGRP levels (P < 0.01 and P < 0.05, respectively). Also, correlation analysis showed a significant negative correlation between the cQT and neuropeptide levels. Conclusions: This study suggests that G-CSF can be effective in CAN by means of neuro-protection, and plasma VIP and CGRP levels can be used for the assessment of autonomic and sensory functions in diabetes. (C) 2015 Elsevier Ireland Ltd. All rights reserved

The efficacy of Aesculus hippocastanum seeds on diabetic nephropathy in a streptozotocin-induced diabetic rat model

WOS: 000390433400047PubMed ID: 27424320Cytokines, such as transforming growth factor (TGF)-beta 1, and increased oxidative stress are considered to be responsible for the development of diabetic nephropathy. We hypothesized that Aesculus hippocastanum (AH) seeds may have preventive effects on oxidative stress and TGF-beta-related diabetic nephropathy in streptozotocin (STZ)-induced diabetic nephropathy in rats. Twenty-one male Sprague-Dawley albino rats were divided into three groups (n = 7). Except for the control group, they all had diabetic nephropathy induced by an intraperitoneal injection of STZ. While the diabetes group did not receive any medication, the diabetes + AH group was given the medication for 4 weeks. After the experiment, analyses were performed to evaluate the glomerular area, severity of sclerosis, and fibronectin immunoexpression, as well as levels of malondialdehyde (MDA), TGF-beta, blood urea nitrogen (BUN), blood glucose, creatinine, and proteinuria. It was found that glomerular area, severity of sclerosis, fibronectin immunoexpression, and levels of MDA, TGF-beta, BUN, creatinine, and proteinuria were decreased in the diabetes + AH group. It is known that diabetic nephropathy is induced, to a large extent, by hyperglycemia. In the present study, AH extract ameliorated diabetic nephropathy without decrease in blood glucose levels. In the study, AH seeds showed beneficial effects on the functional properties of the kidney and microscopic improvements in diabetic nephropathy. (C) 2016 Elsevier Masson SAS. All rights reserved

The Investigation of the Protective Effect of Glucagon-like peptide (GLP-1) Analogue Exenatide on Glucose and Fructose-induced Neurotoxicity

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