The efficacy of exogenous melatonin supplement in ameliorating irritable bowel syndrome severity: A meta-analysis of randomized controlled trials.

BACKGROUND: Irritable bowel syndrome (IBS) was found in 11% of the general population worldwide. The current pharmacologic management of IBS was unsatisfactory, and it was accompanied by a number of adverse events. Melatonin was found to play an important role in gastrointestinal smooth muscle motility. Dysregulation of endogenous melatonin secretion has been found in IBS patients. Exogenous melatonin supplement has become one alternative treatment for IBS, but the evidence is inconclusive. The current meta-analysis sought to determine the efficacy of exogenous melatonin supplement in improving IBS severity in IBS patients. METHODS: We included randomized controlled trials (RCTs) that investigated the efficacy of exogenous melatonin supplement in ameliorating IBS severity in IBS patients. This meta-analysis was conducted using a random effects model. The primary target outcomes were changes in IBS severity associated with melatonin or placebo. RESULTS: This meta-analysis of 4 RCTs and 115 participants revealed that exogenous melatonin supplement was associated with significantly better improvement in overall IBS severity than placebo (k = 4, Hedges' g = 0.746, 95% confidence intervals = 0.401-1.091, p < 0.001). The subgroup without concurrent medication had the same result (p < 0.001). In addition, exogenous melatonin supplement was also associated with significantly better improvement in IBS pain severity (p < 0.001) and quality of life (p = 0.007) than placebo, but not in abdominal distension (p = 0.111) or sleep quality (p = 0.142). Finally, melatonin was associated with similar safety profiles with placebo. CONCLUSION: This meta-analysis provides evidence for the use of exogenous melatonin in IBS patients to ameliorate overall IBS severity, IBS pain severity, and quality of life. TRIAL REGISTRATION: PROSPERO CRD42021269451.

Black cohosh extracts in women with menopausal symptoms: an updated pairwise meta-analysis.

OBJECTIVE: Menopausal symptoms are common in midlife women and have broad impacts on their daily functioning and quality of life. Black cohosh extracts have been widely used to relieve menopausal symptoms. However, the comparative benefits of different combined black cohosh regimens remain inconclusive. The aim of the current updated meta-analysis is to address the comparative efficacies of different black cohosh regimens in improving menopausal symptoms. METHODS: Random-effect model pairwise meta-analysis of randomized controlled trials was conducted to investigate the treatment effect on menopausal symptoms by the black cohosh extract both alone or combined with other related active ingredients. The outcomes studied were changes in menopausal symptoms after treatment with black cohosh extracts in menopausal women. RESULTS: Twenty-two articles including information on 2,310 menopausal women were included in the analyses. Black cohosh extracts were associated with significant improvements in overall menopausal symptoms (Hedges' g = 0.575, 95% CI = 0.283 to 0.867, P < 0.001), as well as in hot flashes (Hedges' g = 0.315, 95% CIs = 0.107 to 0.524, P = 0.003), and somatic symptoms (Hedges' g = 0.418, 95% CI = 0.165 to 0.670, P = 0.001), compared with placebo. However, black cohosh did not significantly improve anxiety (Hedges' g = 0.194, 95% CI = -0.296 to 0.684, P = 0.438) or depressive symptoms (Hedges' g = 0.406, 95% CI = -0.121 to 0.932, P = 0.131). The dropout rate for black cohosh products was similar to that for placebo (odds ratio = 0.911, 95% CI = 0.660 to 1.256, P = 0.568). CONCLUSIONS: This study provides updated evidence regarding the potentially beneficial effects of black cohosh extracts for relieving menopausal symptoms in menopausal women.