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The aim of this review is to summarize current studies on the relationship between melatonin and aging. Nowadays, age-related diseases come into prominence, and identifying age-related changes and developing proper therapeutic approaches are counted as some of the major issues regarding community health. Melatonin is the main hormone of the pineal gland. Melatonin is known to influence many biological processes in the body, including circadian rhythms, the immune system, and neuroendocrine and cardiovascular functions.Melatoninrhythms also reflect the biological process of aging. Aging is an extremely complex and multifactorial process. Melatonin levels decline considerably with aging and its decline is associated with several age-related diseases. Aging is closely associated with oxidative damage and mitochondrial dysfunction. Free radical reactions initiated by the mitochondria constitute the inherent aging process. Melatonin plays a pivotal role in preventing age-related oxidative stress. Coronavirus disease 2019 (COVID-19) fatality rates increase with chronic diseases and age, where melatonin levels decrease. For this reason, melatonin supplementation in elderly could be beneficial in COVID-19 treatment. Therefore, studies on the usage of melatonin in COVID-19 treatment are needed., (This work is licensed under a Creative Commons Attribution 4.0 International License.)

Diabetic patients suffer from persistent and non-healing wounds. Salvia species are traditionally used for the treatment of wounds and colds. The aims of the present study were to evaluate the in vivo wound healing potential, in vitro antimicrobial and antioxidant activities, and total phenolic and flavonoid contents of the aerial parts of two endemic taxa, Salvia kronenburgii Rech. f. (SK) and Salvia euphratica Montbret, Aucher & Rech. f. var. euphratica (SE). Two different concentrations (0.5% and 1% (w/w)) of ethanol extracts were investigated in incision and excision wound models on Streptozotocin-induced diabetic rats using biomechanical, biochemical, histopathological, macroscopic, and genotoxic methods for 7 and 14 days. Antimicrobial activity was evaluated against Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Acinetobacter baumannii, Aeromonas hydrophila, Mycobacterium tuberculosis, Candida glabrata, Candida parapsilosis, and Candida tropicalis using the broth microdilution and the resazurin microtiter assay plate methods. Fito ® , Ampicillin, Ethambutol, Isoniazid, and Fluconazole were used as reference drugs. Antioxidant capacities and total phenolic and flavonoid contents of both extracts were detected using DPPH free radical scavenging assay, Folin-Ciocalteu, and Al(NO 3 ) 3 methods, respectively. SK ointment at 0.5% and 1% (w/w) concentrations and SE ointment at 1% (w/w) concentration showed 99.9%, 99.5%, and 99.7% contraction, respectively for excision wounds, and SK and SE ointments at 1% (w/w) concentration showed 99.4% and 99.2% contraction for incision wounds while Fito ® showed 98.9% and 98.5% contraction, respectively. Increased re-epithelialization (P < 0.01 and P < 0.001), angiogenesis, and decreased dermal inflammation (P < 0.001) were determined for SK and SE ointments at both 7 and 14 days. SE ointment on day 7 and SK ointment on day 14 reduced oxidative damage to DNA when compared to control (P < 0.01 and P < 0.001). Both tested plants had greater antibacterial activity against A. baumannii (62.5 μg/mL MIC value) and SE had greater antimycobacterial activity against M. tuberculosis (0.24 μg/mL MIC value) when compared to reference drugs Ampicillin, Isoniazid, and Ethambutol (125, 0.97, and 1.95 μg/mL MIC values, respectively). Antioxidant capacities, total phenolic and flavonoid contents of SE and SK were 87.08%, 76.21 μg GAE/mg, 43.43 μg QE/mg and 72.17%, 41.81 μg GAE/mg, 33.62 μg QE/mg, respectively. SK and SE had strong wound healing effects while SK found to be more effective than SE at both 7 and 14 days., (Copyright © 2019 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Objective: The aim of this study is to show the possible positive effect of coenzyme Q10 (Co Q10) on regenerating in facial palsy., Materials and Methods: Sixteen female Sprague-Dawley albino rats were randomly divided into 2 groups as Co Q10 and control groups. Group Q10 (n = 8) received Co Q10 of 10 mg/kg/d intraperitoneally for 30 days, and group C (n = 8) received saline solution of 1 mL/d intraperitoneally once daily for 30 days. The right facial nerve stimulation thresholds were determined before crush, immediately after crush, and after 1 month.After determination of the thresholds, the crushed part of the facial nerve was then excised. All specimens were examined by a pathologist using a light microscope., Results: No statistically significant difference in stimulation threshold was found between the Co Q10 and saline groups after crushing (P = 0.645). After 1 month of treatment, stimulation thresholds were significantly lower in both the Co Q10 and saline groups (Ps = 0.028 and 0.016). However, the Co Q10 group showed greater improvement than the saline group (P = 0.050).After 1 month of treatment, neither the Co Q10 group nor the saline group had reached the precrushing amplitude levels (Ps = 0.027 and 0.011).Significant differences were found in vascular congestion, macrovacuolization, and myelin thickness between the Co Q10 and control groups by light microscopy (P < 0.05)., Conclusions: Although many treatment methods have been tried to accelerate facial nerve regeneration after trauma, a definitive method has not been found yet. Co Q for the treatment of acute facial paralysis is promising on both physiologic assessments and pathologic evaluation.

Ischemia-reperfusion (I/R) injury induces the generation of reactive oxygen species (ROS) which affect many organs. This study was designed to investigate the roles of melatonin and 1,25-dihydroxyvitamin D3 (VD3) on renal I/R injury. Thirty male Wistar albino rats were divided into five groups: group 1, control; group 2, right nephrectomy (RN) +  I/R in the contralateral kidney; group 3, melatonin + RN + I/R; group 4, VD3 + RN + I/R; and group 5, melatonin + VD3 + RN + I/R. Melatonin (10 mg/kg), VD3 (0.5 μg/kg), and melatonin plus VD3 were injected intraperitoneally for 7 days before renal I/R. After 7 days, right nephrectomy was initially performed and left renal artery was clamped for 45 min. After 45-min reperfusion, the serum and kidney tissue samples were obtained for assays. Melatonin and VD3 had an ameliorative effect on biochemical parameters such as serum creatinine (SCr) and blood urea nitrogen (BUN). Renal tissue malondialdehyde (MDA), glutathione (GSH), nitric oxide (NO) levels, and superoxide dismutase (SOD) activity were determined. Renal I/R decreased the kidney tissue GSH levels and SOD activity and increased the NO levels as compared with control group. However, melatonin and VD3 and melatonin plus VD3 treatment significantly increased the tissue GSH levels and SOD activity and decreased the NO levels compared with those of I/R group. Meanwhile, MDA levels were not different between the control and I/R groups. But, MDA levels decreased in all treated groups compared to I/R and control groups. These data support that melatonin and VD3 have beneficial effects on renal injury.

Objective: To compare the efficacy of ozone with melatonin, shown as the most powerful antioxidant in attenuation of testicular ischemia/reperfusion injury, in an experimental rat model of testicular torsion/detorsion., Methods: Twenty-four male Wistar rats were divided into 4 groups: sham-operated, torsion/detorsion, torsion/detorsion plus melatonin, and torsion/detorsion plus ozone. Melatonin (10 mg/kg) and ozone (4 mg/kg) were intraperitoneally injected daily beginning 15 minutes before detorsion for the following 7 days. At the seventh day, blood and tissue samples were obtained. Johnsen score, malondialdehyde, inhibin B, glutathione plasma total sulfhydryl group (RSH) levels, and total nitric oxide were studied., Results: Torsion/detorsion caused increase in tissue malondialdehyde and total nitric oxide along with a decrease in Johnsen score, tissue and plasma inhibin B, RSH, and glutathione levels. Melatonin prevented the rise in malondialdehyde and total nitric oxide levels and improved Johnsen score, tissue and plasma inhibin B, and tissue glutathione levels, along with a decrease in plasma RSH level. Ozone showed similar results except for the total nitric oxide level. Concomitantly, in contralateral testis, melatonin and ozone induced similar changes for Johnsen score, malondialdehyde, and inhibin B (not significant) and in glutathione (significant). Melatonin decreased the total nitric oxide level in both testes and ozone increased the same parameter., Conclusion: On different pathways, ozone was comparable with melatonin in the amelioration of ischemia/reperfusion injury. Protective effects of ozone were associated with nitrous oxide. The potential for ozone as a treatment for torsion/detorsion therefore deserves to be further elucidated., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Oxidative stress is an important factor for aging. The antioxidative enzymes glutathione peroxidase (GPx), glutathione reductase (GRd) and superoxide dismutase (SOD) play a crucial role protecting the organism against the age-dependent oxidative stress. Glutathione (GSH) is present in nearly all living cells. GSH is one of the main antioxidants in the cell and it serves several physiological functions. Our purpose was to evaluate the age-related changes in mitochondrial GPx, GRd and SOD activities, and mitochondrial GSH pool in the brains of young (3 months) and aged rats (24 months). We also investigated whether melatonin administration influences these brain mitochondrial enzyme activities and GSH levels in young and aged rats. The results showed that GPx activity increased with age, whereas melatonin treatment decreased GPx activity in the aged rats at levels similar to those in young and young+melatonin groups. The activities of GRd and SOD, however, did not change with age. But, melatonin treatment increased SOD activity in the aged rats. GSH levels, which also increased with age, were not modified by melatonin treatment. The reduction in the SOD/GPx and GR/GPx ratios with age was prevented by melatonin administration. Together, our results suggest that the age-related oxidative stress in rat brain mitochondria is more apparent when the antioxidant enzyme ratios are analyzed instead of their absolute values. The antioxidative effects of melatonin were also supported by the recovery of the enzyme ratios during aging., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Purpose: To investigate oxidative damage and antioxidant enzyme status in the liver of guinea pigs exposed to mobile phone-like radiofrequency radiation (RFR) and the potential protective effects of N-acetyl cysteine (NAC) and epigallocatechin-gallate (EGCG) on the oxidative damage., Materials and Methods: Nine groups of guinea pigs were used to study the effects of exposure to an 1800-MHz Global System for Mobile Communications (GSM)-modulated signal (average whole body Specific Absorption Rate (SAR) of 0.38 W/kg, 10 or 20 min per day for seven days) and treatment with antioxidants., Results: Significant increases in malondialdehyde (MDA) and total nitric oxide (NO(x)) levels and decreases in activities of superoxide dismutase (SOD), myeloperoxidase (MPO) and glutathione peroxidase (GSH-Px) were observed in the liver of guinea pigs after RFR exposure. Only NAC treatment induces increase in hepatic GSH-Px activities, whereas EGCG treatment alone attenuated MDA level. Extent of oxidative damage was found to be proportional to the duration of exposure (P < 0.05)., Conclusion: Mobile phone-like radiation induces oxidative damage and changes the activities of antioxidant enzymes in the liver. The adverse effect of RFR may be related to the duration of mobile phone use. NAC and EGCG protect the liver tissue against the RFR-induced oxidative damage and enhance antioxidant enzyme activities.

Background/purpose: The hormone melatonin affects cellular immunity in particular and the immune system in general both directly and indirectly. We report our evaluation of the effects of decreasing and increasing serum melatonin levels on hepatocyte damage in rats with experimental acute pancreatitis., Methods: Wistar Albino rats with experimentally induced acute pancreatitis were divided into three groups of ten rats each: (1) control (induced acute pancreatitis only); (2) rats with induced acute pancreatitis plus surgical pinealectomy (no melatonin injections); (3) rats with induced acute pancreatitis plus injections of exogenous melatonin. The effects of melatonin levels were evaluated using biochemical and histopathological parameters., Results: Rats undergoing the pinealectomy had increased amylase and lactate dehydrogenase (LDH) levels, while those receiving injections of exogenous melatonin had decreased amylase, aspartate transaminase, LDH, and bilirubin levels but increased levels of alanine transferase levels., Conclusion: Melatonin may have a therapeutic or protective effect on acute pancreatitis and obstructive jaundice.

In order to test whether antioxidants have beneficiary effects on electric field induced damage, we determined the pulmonary levels of heme oxygenase-1 (HO-1), protein carbonyl content (PCO), malondialdehyde (MDA), nitric oxide (NO) and hydroxyproline (HP) under extremely low frequency (ELF) electric (E) field exposure (50 Hz, 12 kV/m, 7 days/for 8 h/day). While PCO levels significantly increased (p<0.05), insignificant changes (p>0.05) were observed in HO-1, MDA, NO and HP levels for electric field exposure groups compared to the control group. We have not observed any significant change in these parameters on the electric field group compared to the group where NAC and EGCG were separately applied along with electric field. However, during our previous studies, we have concluded that NAC and EGCG are potent antioxidants and we believe that new studies should be established by way of setting up different experimental conditions.

Melatonin (MEL) is synthesized mainly in the pineal gland and derived from 5-hydroxytryptophan (5-HTP). Zinc (Zn) is one of the most important trace elements in the body. Zn and MEL levels are changed with aging. The aim of this study was to investigate the age-related changes of tissue and plasma Zn levels and effect of MEL administration on these parameters. Male wistar rats received for 3 weeks subcutaneous injection of MEL (10 mg/kg). Kidney and pancreas Zn levels in old rats were significantly lower than middle-aged group. Spleen, small intestine, and plasma Zn levels were not different in middle-aged and old rats. On the other hand, MEL treatment increased Zn levels of small intestine and plasma in middle-aged rats. However, kidney, spleen, and pancreas Zn levels were unaffected by MEL treatment.

Purpose: The aim of this study was to evaluate the possible effects of varied exposure to 50 Hz extremely low frequency (ELF) electric field (EF) on the lipid peroxidation levels and antioxidant enzyme activities in the brain homogenates of guinea pigs. Subjects were exposed to 2 kV/m, 2.5 kV/m, 3 kV/m, 3.5 kV/m, 4 kV/m, 4.5 kV/m and 5 kV/m electric fields for three days, 8 h a day in both vertical and horizontal directions., Materials and Methods: Malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-Px) activities were measured in order to identify possible alterations in lipid peroxidation levels and antioxidant status due to electric field exposure. Xanthine oxidase (XO), myeloperoxidase (MPO) and adenosine deaminase (ADA) activities were also evaluated in the same samples., Results: Although the study showed several positive but non-significant findings (p > 0.05), we did not find significant differences among all of the exposed groups and sham groups in lipid peroxidation levels and enzyme activities (p > 0.05) at all strengths and in both directions. Furthermore, the result was the same when the comparison was made between the groups in vertical directions and horizontal directions (p > 0.05)., Conclusion: The present study observed effects of 50 Hz EF exposure on lipid peroxidation levels and antioxidant defense mechanisms but these were not statistically significant at the 95% confidence level. Further research on the effects ELF-EF exposure on lipid peroxidation levels and antioxidant defence mechanisms are warranted.