Ameliorative Role Of Melatonin Research Articles

Ameliorative role of melatonin against adrenaline induced oxidative stress mediated cardiac and hepatic tissue injuries through preserving pyridoxine metabolism in male Wistar rats: A mechanistic insight

Adrenaline (AD) is a naturally occurring catecholamine, synthesised in the adrenal medulla to prepare the organisms for a "fight or flight" response. Under stressful circumstances, the circulatory catecholamine undergoes auto-oxidation, resulting in the formation of free radicals. Chronic stress results in the depletion of micronutrient stores in the body. Pyridoxine, often known as vitamin B6, is an essential water-soluble vitamin that acts as a coenzyme in many metabolic processes. Therefore, our current investigation has prioritized the regulation of pyridoxine metabolism during the period of chronic stress and the precise role of melatonin, as a natural antioxidant, in preventing the alterations generated by adrenaline in cardiac and hepatic tissues. Adrenaline augmented the oxidative stress indices, leading to an imbalance in the antioxidative state resulting in changes in the levels of certain organ-specific serum markers, modifications in the levels of PL (pyridoxal), PLP (pyridoxal-5-phosphate), and the enzymes responsible for their metabolism and breakdown. The foregoing results were corroborated by the histochemical and histological examinations. Melatonin efficiently counteracted all these harmful changes. Besides, the current study demonstrates that both PLP and melatonin show efficacy in scavenging free radicals, including superoxide anion free radicals and hydroxyl radicals, in the chemical system. However, the in vitro studies demonstrated that when administered together, melatonin and PLP more effectively mitigate free radical generation than the individual molecule. These findings were further confirmed by the ITC binding study. These results suggest that a combination of melatonin and PLP could be a better therapeutic approach for the amelioration of stress induced oxidative damages in cardiac and hepatic tissues with an improved pyridoxine metabolism.

Analysis of Melatonin-Modulating Effects Against Tartrazine-Induced Neurotoxicity in Male Rats: Biochemical, Pathological and Immunohistochemical Markers

Tartrazine (E-102) is one of the most widely used artificial food azo-colors that can be metabolized to highly sensitizing aromatic amines such as sulphanilic acid. These metabolites are oxidized to N-hydroxy derivatives that cause neurotoxicity. Melatonin is a neurohormone. That possesses a free-radical scavenging effect. The present work was mainly designed to evaluate the possible ameliorative role of melatonin against tartrazine induced neurotoxicity in cerebral cortex and cerebellum of male rats. Adult male rats were administered orally with tartrazine (7.5 mg/kg) with or without melatonin (10 mg/kg) daily for four weeks. The data revealed that tartrazine induced redox disruptions as measured by significant (p < 0.05) increased malondialdehyde (MDA) level and inhibition of (GSH) concentration and catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GPx) antioxidant enzyme activities. Besides, brain acetyl cholin (Ach) and gamma-aminobutyric acid (GABA) were elevated while, dopamine (DA) was depleted in trtrazine -treated rats. Moreover, tartrazine caused a significant (p < 0.05) increase in the brain interleukin-6 (IL-6), interleukin-1β (IL-1 β) and tumor necrosis factor-α (TNFα). At the tissue level, tartrazine caused severe histopathological changes in the cerebellum and cerebral cortex of rats. The immunohistochemical results elucidated strong positive expression for Caspase-3 and GFAP and weak immune reaction for BcL2 and synaptophysin in tatrazine- treated rats. The administration of melatonin to tartrazine -administered rats remarkably alleviated all the aforementioned tartrzine-induced effects. It could be concluded that, melatonin has a potent ameliorative effect against tartrazine induced neurotoxicity via the attenuation of oxidative/antioxidative responses.

Ameliorative role of melatonin against cypermethrin or gamma irradiation induced testicular damage in male rats

Ameliorative role of melatonin against cypermethrin or gamma irradiation induced testicular damage in male rats

Ameliorative Role of Melatonin on CA1 of Hippocampus and Frontal Cortex in Induced Social Isolation in Adult Male Albino Rat

Abstract Background: Social Isolation (SI) which means absence or insufficient contact with others is a key factor in psychiatric disorders development, which might be necessary for effective psychological treatment as social rehabilitation. Social expe-rience during the infantile period affects brain function and behaviour in rodents, dogs and human. Aim of Study: The current study was designed to elucidate the neuroprotective role of MT on experimentally-induced SI on CA1of rat hippocampus and frontal cortex. Material and Methods: Twenty adult albino rats were divided into four groups, control, sham control, SI and SI + MT. The Body Weight (BW), Brain Weight (BrW) were determined. Brain sections were subjected to histological, morphometric, biochemical and statistical studies. Results: SI induced various histological changes in both hippocampus and frontal cortex in the form of degeneration and absent neurons. SI also caused a significant (sig) increase in area % of caspase 3 and TNF Immunoexpression (IE) were recorded. Sig decrease in the activity of Total Antioxidant Capacity (TAC), Brain Derived Neurotropic Factor (BDNF), Superoxide Dismutase (SOD) activity, Acetyle Choline Este-rase (ACHE), dopamine level as well ARC gene, and a sig increase in Malondialdehyde (MDA) levels, FOS gene, sero-tonin and AB-42. Concomitant administration with MT im-proved sig the previously mentioned changes. Conclusion: SI might lead to various neurological degen-erations as indicated by the histological, morphometric, biochemical changes. These changes were ameliorated by concomitant administration with MT.

The effects of high-fructose corn syrup consumption on testis physiopathology-The ameliorative role of melatonin.

This study investigated the ameliorative role of melatonin (MLT) and the effects of a long-term intake of high-fructose corn syrup (HFCS) on the male reproductive system. Thirty-six male Sprague Dawley rats were randomly divided into 3 groups as follows: Control, HFCS and HFCS+MLT. Testis and epididymal weights were measured. Malondialdehyde (MDA) levels, superoxide dismutase (SOD) and catalase (CAT) activities, total testosterone levels, testicular histopathological damage scores were evaluated, and immunohistochemical analyses were performed on testicular tissue. Epididymal weights were significantly lower in the HFCS+MLT group than those of the control and HFCS groups. MDA was significantly increased, while SOD and CAT activities were reduced in the HFCS group compared with the control group. Administration of melatonin significantly increased SOD and CAT activities in the HFCS+MLT group. Histopathological evaluation revealed slight hyperaemia and oedema in the stromal tissue of rat testes in the HFCS group. Sperm count and Johnsen's testicular biopsy score (JTBS) were significantly decreased in the HFCS group. Immunohistochemical analysis revealed that HSP, iNOS, MDA, OPN and VEGF values were significantly increased in the HFCS group. However, melatonin ameliorated the immunohistochemical scoring. Our results showed that a long-term intake of HFCS caused testicular damage. Melatonin may be a promising pharmacological agent against testicular toxicity induced by HFCS.

Ameliorative role of melatonin against cypermethrin induced hepatotoxicity and impaired antioxidant defense system in Wistar rats

Recently, melatonin has attracted attention because of their strong free radical scavenging and antioxidant properties. The present study was designed to investigate the role of melatonin against cypermethrin induced hepatotoxicity in rats using qualitative, quantitative and biochemical approaches. Adult female Wistar rats were randomly divided into four groups; each group consists of six animals. Control group received vehicle, corn oil; Cypermethrin (CM) (250mg/kg bw); Melatonin (MEL) (10 mg/kg bw); CM+MEL treated group. Animals were treated orally, daily for a period of 4 weeks. Animals were sacrificed by decapitation and liver was used for various biochemical and histopathological examinations. The result of this study shows that in vivo administration of cypermethrin caused a significant induction of oxidative damage in liver tissue as evidenced by depletion of proteins, glutathione (GSH) and increased lipid peroxidation in hepatic tissue. Cypermethrin administration significantly enhanced the activities of enzymatic antioxidants (superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) glutathione reductase (GR) and glutathione-S- transferase (GST). Cypermethrin intoxication exhibited elevation in the activities of liver marker enzymes such as serum glutamate pyruvate transaminase (SGPT) serum glutamate oxaloacetate transaminase (SGOT) and Lactate dehydrogenase (LDH). Furthermore, the co-administration of melatonin mitigates the hepatotoxicity of cypermethrin by normalizing the biochemical and enzymatic parameters. The biochemical observations were supported by histopathological examination of liver. The findings of this investigation suggest that the melatonin may play a protective role against cypermethrin induced hepatotoxicity and oxidative damage in female albino rats.

Consequences of Lethal-Whole-Body Gamma Radiation and Possible Ameliorative Role of Melatonin

Gamma radiation induces the generation of free radicals, leading to serious cellular damages in biological systems. Radioprotectors act as prophylactic agents that are administered to shield normal cells and tissues from the deleterious effects of radiation. Melatonin synergistically acts as an immune-stimulator and antioxidant. We investigated the possible radioprotective role of melatonin (100 mg/kg i.p.) against lethal-whole-body radiation- (10 Gy) induced sickness, body weight loss, and mortality in rats. Results of the present study suggest that exposure to lethal-whole-body radiation incurred mortality, body weight loss, and apoptosis and it also depleted the immunity and the antioxidant status of the rats. Our results show that melatonin pretreatment provides protection against radiation induced mortality, oxidative stress, and immune-suppression. The melatonin pretreated irradiated rats showed less change in body weight as compared to radiation only group. On the other hand, melatonin appeared to have another radioprotective role, suggesting that melatonin may reduce apoptosis through a caspase-3-mediated pathway by blocking caspase-3 activity.

Role of Endogenous Melatonin in Amelioration of Nonalcoholic Fatty Liver Disease (NAFLD) in Rats

Role of Endogenous Melatonin in Amelioration of Nonalcoholic Fatty Liver Disease (NAFLD) in Rats

Quantitative Microscopic evaluation of Melatonin treatment of Experimentally Atherosclerotic Rabbit Aorta

Atherosclerosis is one of the most common diseases in Egypt. The exact etiology of the disease is still vague. However, Oxidative modifications of low-density lipoprotein (LDL) have been proposed to play a critical role in atherogenesis. Antioxidants have been proposed, therefore, to have a possible role in protection and/or prevention of atherosclerosis. The pineal gland hormone, melatonin, have been reported as an antioxidant. Recently melatonin has been proposed to interfere with one of the chain of events in the onset of atherosclerosis, that is, the formation of adhesion molecules. To test the role of melatonin in amelioration of atherogenesis, this work was designed to study the atherosclerosis-.related microscopic changes in the aorta of melatonin treated, high cholesterol fed rabbits. Thirty adult male rabbits were used throughout this work. The animals were fed a standard rabbit food free from cholesterol and antioxidants. The rabbits were divided into three groups each of 10 animals: Control (A) group, was raised on the ordinary diet alone for 6 weeks. Atherosclerotic induced, non treated (B) group was raised on the ordinary diet mixed with 1% cholesterol powder for a period of 6 weeks. Atherosclerotic induced, melatonin treated (C) group was raised on the ordinary diet mixed with 1% cholesterol powder and drenched 4.2 mg melatonin dissolved in saline solution daily at night for 6 weeks. The drug was given through naso-gastric tube under light ether anesthesia Paraffin sections of both control and experimental groups were prepared on the same slide. The sections were stained by haematoxylin and eosin, Masson trichrome, orcein; or periodic acid Schiff (PAS). The endothelial thickness, relative collagen, elastic fibers, smooth muscle fibers and glycosaminoglycan content in control and experimental groups were evaluated by computerized image analyzer. Statistical analysis of the results was carried out using Microsoft Excel 2000. The results revealed that the melatonin has antiatherosclerotic effects in experimental atherosclerosis in the rabbit aorta. Melatonin significantly reduced specific atherosclerotic lesions like fibrosis , smooth muscle atrophy, and decreased elastic fiber content in thoracic aortic wall. In conclusion, melatonin may be of value in the management of atherosclerosis by reducing its complications.