Potential Hypoglycemic Effect of Pomegranate Juice and Its Mechanism of Action: A Systematic Review

Pomegranate juice (PJ) has gained popularity attributed to its phenolic compounds and their medicinal properties. Its potential hypoglycemic effect has been related to enzymatic inhibition, insulin release, and the protection of pancreatic tissue. These effects depend on several aspects, such as the content and composition of phenols in pomegranate and characteristics of the organism that consumes the juice. The objective of this study was to systematically review scientific evidence investigating the hypoglycemic effect of PJ; the factors that affect bioactive compounds; and the mechanisms of action attributed to this effect. Human and rodent in vivo and in vitro studies were retrieved from PubMed, Scopus, and ScienceDirect databases. After reviewing the articles, it was identified that the methodologies and results among the scientific evidence were quite heterogeneous. Despite these limitations, many of the in vivo and in vitro studies found important hypoglycemic effects from PJ, as well as an increase in the function of β-cell, insulin secretion, a significantly lower activity of α-amylase enzyme, an inhibition of the enzyme α-glucosidase and dipeptidyl peptidase-4 (DPP-4), and the protection against DNA damage. Determining the potential health benefits of polyphenols contained in the pomegranate is limited for multiple factors that could affect the efficacy of PJ. Overall, the results of this review suggest the need for further experimentation, using controlled variable factors and testing the effect of PJ under similar experimental conditions.