Department of Nutritional Science, School of Nutritional Science and Food Technology, Kermanshah University of Medical Sciences, Kermanshah, Iran.
Research Center for Environmental Determinants of Health (RCEDH), Research Institute for Health, Kermanshah University of Medical Sciences, Kermanshah, Iran.
Pharmacol Res. 2020 Nov;161:105210. doi: 10.1016/j.phrs.2020.105210. Epub 2020 Sep 29.
Oxidative stress, defined as an imbalance between pro-oxidants and neutralizing antioxidants within the body, is a growing public health concern. Oxidative stress is involved in the progression of nearly all chronic diseases. Melatonin has been suggested to reduce oxidative stress by its potential radical scavenging properties.
To determine the efficacy and safety of melatonin as a therapy for the improvement of oxidative stress parameters in randomized controlled trials.
A systematic database search using Scopus, PubMed/Medline, EMBASE, Web of Science, the Cochrane Controlled Register of Trials and clinicaltrials.gov (https://clinicaltrials.gov) for studies published up to July 2020 was conducted. We included studies which investigated the effect of supplemental melatonin compared to placebo on oxidative stress parameters in unhealthy patients. Quantitative data synthesis was conducted using a random-effects model with standard mean difference (SMD) and 95 % confidence intervals (CI). Cochrane's Q and I values were used to evaluate heterogeneity.
A total of 12 randomized controlled trials (RCTs) were eligible. The meta-analysis indicated an association between melatonin intake and a significant increase in total antioxidant capacity (TAC) (SMD: 0.76; 95 % CI: 0.30, 1.21; I = 80.1 %), glutathione (GSH) levels (SMD: 0.57; 95 % CI: 0.32, 0.83; I = 15.1 %), superoxide dismutase (SOD) (SMD: 1.38; 95 % CI: 0.13, 2.62; I = 86.9 %), glutathione peroxidase (GPx) (SMD: 1.36; 95 % CI: 0.46, 2.30; I = 89.3 %), glutathione reductase (GR) (SMD: 1.21; 95 % CI: 0.65, 1.77; I = 00.0 %) activities, and a significant reduction in malondialdehyde (MDA) levels (SMD: -0.79; 95 % CI: -1.19, -0.39; I = 73.1 %). Melatonin intake was not shown to significantly affect nitric oxide (NO) levels (SMD: -0.24; 95 % CI: -0.61, 0.14; I = 00.0 %) or catalase (CAT) activity (SMD: -1.38; 95 % CI: -1.42, 4.18; I = 96.6 %).
Melatonin intake was shown to have a significant impact on improving Oxidative stress parameters. However, future research through large, well-designed randomized controlled trials are required to determine the effect of melatonin on oxidative stress parameters in different age groups and different disease types.
氧化应激是指体内促氧化剂和中和抗氧化剂之间的不平衡，它是一个日益受到关注的公共卫生问题。氧化应激与几乎所有慢性疾病的进展都有关。褪黑素具有潜在的自由基清除特性，被认为可以降低氧化应激。
确定褪黑素作为治疗药物，改善随机对照试验中氧化应激参数的疗效和安全性。
对 Scopus、PubMed/Medline、EMBASE、Web of Science、Cochrane 对照试验注册中心和 clinicaltrials.gov（https://clinicaltrials.gov）进行系统的数据库检索，检索截至 2020 年 7 月发表的研究。我们纳入了研究褪黑素补充剂与安慰剂相比对不健康患者氧化应激参数影响的研究。使用随机效应模型和标准均数差（SMD）和 95%置信区间（CI）进行定量数据合成。使用 Cochrane's Q 和 I 值评估异质性。
共有 12 项随机对照试验（RCT）符合纳入标准。荟萃分析表明，褪黑素摄入与总抗氧化能力（TAC）（SMD：0.76；95%CI：0.30，1.21；I = 80.1%）、谷胱甘肽（GSH）水平（SMD：0.57；95%CI：0.32，0.83；I = 15.1%）、超氧化物歧化酶（SOD）（SMD：1.38；95%CI：0.13，2.62；I = 86.9%）、谷胱甘肽过氧化物酶（GPx）（SMD：1.36；95%CI：0.46，2.30；I = 89.3%）和谷胱甘肽还原酶（GR）（SMD：1.21；95%CI：0.65，1.77；I = 00.0%）活性的显著增加相关，与丙二醛（MDA）水平（SMD：-0.79；95%CI：-1.19，-0.39；I = 73.1%）的显著降低相关。褪黑素摄入对一氧化氮（NO）水平（SMD：-0.24；95%CI：-0.61，0.14；I = 00.0%）或过氧化氢酶（CAT）活性（SMD：-1.38；95%CI：-1.42，4.18；I = 96.6%）无显著影响。
褪黑素摄入对改善氧化应激参数有显著影响。然而，需要通过大型、精心设计的随机对照试验来确定褪黑素对不同年龄组和不同疾病类型的氧化应激参数的影响。
