Department of Biochemistry, University of Allahabad, Allahabad 211002, India.
Department of Biochemistry, University of Allahabad, Allahabad 211002, India.
Gen Comp Endocrinol. 2019 Sep 1;280:97-103. doi: 10.1016/j.ygcen.2019.04.016. Epub 2019 Apr 16.
Continuous light or dark photoperiods are the leading cause of disruption in the circadian rhythm of day-night cycle. The purpose of this study was to understand the cellular redox balance in a model of circadian disrupted rat model and determine the effect of melatonin supplementation. Young male Wistar rats were randomly divided into five groups (n = 4). Group (I): normal day-night (12 h:12 h) cycle, Group (II): normal rats treated with melatonin, Group (III): rats subjected to continuous light exposure (CLE), Group (IV): CLE rats treated with melatonin, and Group (V) Rats subjected to continuous dark. Melatonin (10 mg/kg) was administered orally at dusk to the Group (II) & (IV). Rats were sacrificed after 10 days of treatment and biomarkers of oxidative stress were evaluated. Results demonstrated significant (p < 0.05) increase of malondialdehyde (MDA), plasma membrane redox system (PMRS), protein carbonyl oxidation (PCO), advanced oxidation protein products (AOPPs), and advanced glycation end products (AGEs) during CLE. A significantly (p < 0.05) decreased level of reduced glutathione (GSH) and ferric reducing antioxidant potential in plasma (FRAP) was also observed during CLE. Treatment with melatonin in CLE rats showed reduced level of MDA, PMRS, PCO, AOPPs and AGEs while GSH and FRAP activity were increased. During continuous dark exposure (CDE) the biomarkers of oxidative stress were attenuated compared to control. Supplementation of melatonin could be a promising strategy to maintain redox homeostasis during prolonged condition of light exposure and other conditions of redox imbalance.
持续的光照或黑暗光照周期是昼夜节律中昼夜循环紊乱的主要原因。本研究旨在了解昼夜节律打乱的大鼠模型中的细胞氧化还原平衡，并确定褪黑素补充的效果。将年轻雄性 Wistar 大鼠随机分为五组（n=4）。组（I）：正常的昼夜（12 h：12 h）周期；组（II）：正常大鼠用褪黑素处理；组（III）：连续光照暴露（CLE）大鼠；组（IV）：CLE 大鼠用褪黑素处理；组（V）：连续黑暗大鼠。褪黑素（10 mg/kg）在黄昏时口服给予组（II）和（IV）。治疗 10 天后处死大鼠，评估氧化应激生物标志物。结果表明，在 CLE 期间，丙二醛（MDA）、质膜氧化还原系统（PMRS）、蛋白质羰基氧化（PCO）、高级氧化蛋白产物（AOPPs）和晚期糖基化终产物（AGEs）显著增加（p<0.05）。在 CLE 期间，还观察到血浆还原型谷胱甘肽（GSH）和铁还原抗氧化能力（FRAP）水平显著降低（p<0.05）。在 CLE 大鼠中用褪黑素治疗显示 MDA、PMRS、PCO、AOPPs 和 AGEs 水平降低，而 GSH 和 FRAP 活性增加。与对照组相比，在持续黑暗暴露（CDE）期间，氧化应激生物标志物减弱。补充褪黑素可能是维持长时间光照暴露和其他氧化还原失衡条件下氧化还原平衡的有前途的策略。
