Department of Community Nutrition, School of Nutritional Sciences and Dietetics, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran.
Horm Mol Biol Clin Investig. 2020 Nov 13;41(4):/j/hmbci.ahead-of-print/hmbci-2020-0030/hmbci-2020-0030.xml. doi: 10.1515/hmbci-2020-0030.
Previous studies showed that melatonin supplementation may suppress oxidative stress, however, the results have not been consistent. So, we conducted this meta-analysis to assess the precise relationship between melatonin supplementation and oxidative stress.
PubMed and Scopus were searched for randomized controlled trials that investigated the effect of melatonin supplementation on oxidative stress up to March 2020. Heterogeneity was assessed by Cochran's Q test and I-square ( ) statistic. Data were pooled using the random effect model and standardized mean difference (SMD) was considered as the summary effect size. Also, standard methods were used for assessment of sensitivity analysis and publication bias.
We included 15 related articles and our findings indicated that melatonin supplementation significantly increased total antioxidant capacity (TAC) level (SMD: 1.03, 95% CI: 0.24, 1.81, p=0.011) and reduced protein carbonyl (PCO) (SMD: -1.78, 95% CI: -2.97, -0.58, p=0.004) and malondialdehyde (MDA) levels (SMD: -0.94, 95% CI: -1.48, -0.40, p=0.001). Additionally, there was considerable effect on TAC level by using ≥20 mg/d melatonin and in people under 35 years old. MDA level also decreased using dosage of below 20 mg/d and in people ≥35 years old.
The present study showed a promising effect of melatonin administration for reducing MDA, PCO, and increasing TAC levels. However, further studies especially with more attention to PCO level assessment are needed to confirm the findings of the present study in larger samples on different populations.
先前的研究表明，褪黑素补充剂可能抑制氧化应激，然而，结果并不一致。因此，我们进行了这项荟萃分析，以评估褪黑素补充与氧化应激之间的确切关系。
我们在 PubMed 和 Scopus 上搜索了截至 2020 年 3 月调查褪黑素补充对氧化应激影响的随机对照试验。使用 Cochran's Q 检验和 I 平方（ ）统计量评估异质性。使用随机效应模型汇总数据，并将标准化均数差（SMD）视为汇总效应大小。还使用标准方法评估敏感性分析和发表偏倚。
我们纳入了 15 项相关研究，我们的研究结果表明，褪黑素补充剂显著增加了总抗氧化能力（TAC）水平（SMD：1.03，95%CI：0.24，1.81，p=0.011），降低了蛋白羰基（PCO）（SMD：-1.78，95%CI：-2.97，-0.58，p=0.004）和丙二醛（MDA）水平（SMD：-0.94，95%CI：-1.48，-0.40，p=0.001）。此外，使用≥20mg/d 的褪黑素和年龄在 35 岁以下的人群，对 TAC 水平有显著影响。使用剂量低于 20mg/d 和年龄在 35 岁以上的人群，MDA 水平也降低。
本研究表明，褪黑素给药具有降低 MDA、PCO 和增加 TAC 水平的良好效果。然而，需要进一步的研究，特别是在更大的不同人群样本中更关注 PCO 水平评估，以证实本研究的发现。
