The efficacy and safety of Laminaria japonica for metabolic syndrome: A protocol for systematic review

BACKGROUND: Metabolic syndrome is a pathological condition characterized by abdominal obesity, insulin resistance, hypertension, and hyperlipidemia. Conventional treatments for metabolic syndrome have limitations due to their nonselectivity, drug resistance, and low bioavailability. The brown seaweed Laminaria japonica (LJP) is a traditional medicine and food in Asia that has shown pharmacological and biochemical properties favorable to the prevention and treatment of lifestyle-related diseases. We will systematically review randomized controlled trials and in vivo preclinical studies evaluating the efficacy and safety of LJP as a useful treatment for metabolic syndrome. METHODS: The following databases will be searched from inception to September 2021: MEDLINE (via PubMed), EMBASE, Cochrane Central Register of Controlled Trials, and Web of Science. Randomized controlled trials and in vivo preclinical studies that analyzed LJP for the prevention and treatment of metabolic syndromes will be included. The outcome measures will include body composition, dietary habit scores, serum lipid profiles, daily nutrient intake, quality of life, number of microbiomes, gastrointestinal symptoms, and bowel function. Studies comparing LJP with any type of control intervention will be included. Data extraction using Review Manager version 5.3 and risk of bias assessment using the Cochrane Collaboration's tool for assessing risk of bias will be performed by 2 independent assessors. RESULTS AND CONCLUSION: This systematic review will provide evidence confirming the efficacy and safety of LJP in the treatment of metabolic syndrome. ETHICS AND DISSEMINATION: Ethical approval was not required, as this study protocol does not include any personal information of the participants. TRIAL REGISTRATION NUMBER: DOI 10.17605/OSF.IO/G2BQK (https://osf.io/g2bqk).