Effects of mulberry leaf extract on blood glucose and serum lipid profiles in patients with type 2 diabetes mellitus: A systematic review

Abstract

IntroductionMulberry, which belongs to the family Moraceae, has been widely used for decades in Korean traditional medicine as well as in other countries in East Asia. However, studies of mulberry leaf extract have not been systematically reviewed. Therefore, we assessed the safety and efficacy of mulberry leaf extract against hyperglycemia and hyperlipidemia in patients with type 2 diabetes. MethodsInternational and Korean databases were searched for randomized controlled trials published through July 2015. Studies reporting anti-hyperglycemic effects, lipid-lowering effects, and/or adverse effects of mulberry leaf extract were included. Assessments of the risk of bias and data extraction were carried out by two independent reviewers. ResultsThree randomized control trials met the criteria for inclusion, and the quality of included studies was poor. In three trials, mulberry leaf extract did not significantly decrease blood glucose levels, such as glycated hemoglobin, fasting glucose levels, or postprandial glucose levels. Two studies showed that mulberry leaf extract do not have beneficial effects with respect to controlling abnormal lipid profiles compared to placebo or glibenclamide treatments. ConclusionsThis review revealed that the number of high-quality studies is insufficient to determine whether mulberry leaf extract is helpful for the management of blood glucose and lipid levels in patients with type 2 diabetes. Additional well-designed, randomized controlled trials are required to elucidate the clinical effects of mulberry leaf extract in patients with type 2 diabetes.