Role of apigenin in targeting metabolic syndrome: A systematic review

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities that has a high prevalence worldwide. Apigenin is a flavonoid present in several vegetables and fruits and has anti-inflammatory, anti-oxidant, and anti-MetS properties. This study aims to systematically review the effects of apigenin against MetS and the relevant molecular and cellular mechanisms of action, pharmacokinetics features, and potential structure-activity relationship. Electronic databases including Scopus, PubMed, Science Direct and Cochrane Library were searched for in vivo, and in vitro, and human studies with the following keywords: "apigenin" and "metabolic syndrome or insulin resistance syndrome", "fatty liver", "hypertension or blood pressure", "diabetes or blood glucose", "dyslipidemia", "heart or cardiovascular " and "obesity" in title/abstract. Data were collected from 2000 until 2021 (up to April). Only papers published in the English language were included. Forty-six full-text articles out of 1016 retrieved papers were reviewed and underwent quality assessment by investigators. Anti-obesity activity of apigenin is mainly through attenuating adipocyte differentiation by suppressing the mitotic clonal expansion and the adipogenesis-related factors. Its anti-diabetic effects can be exerted through inhibition of protein tyrosine phosphatase1B expression, maintaining the activity of anti-oxidant enzymes, reducing intracellular ROS production, cellular DNA damage, protein carbonylation, and attenuating β-cell apoptosis. Moreover, apigenin could attenuate dyslipidemia and subsequent atherosclerotic conditions through down-regulating sterol regulatory element-binding proteins (SREBP)-1c, SREBP-2, stearyl-CoA desaturase-1, and 3-hydroxy-3-methyl-glutaryl-CoA reductase. Apigenin as a dietary bioactive compound would be a promising candidate for improving MetS and its components.