Structure - Activity Relationship and Therapeutic Benefits of Flavonoids in the Management of Diabetes and Associated Disorders

Commonly flavonoids are the natural components found in vegetables, spices and colored fruits. Flavonoids include a large group of polyphenolic compounds, namely flavones, flavanols, flavonols, flavanones, isoflavones and anthocyanidins, which have been proposed as effective supplements for the management of diabetes and associated disorders. The aim of present review was to highlight various classes of flavonoids, their structure - activity relationships, bioavailability, and mechanisms involved in the management of diabetes and associated complications. The relevant research and review articles were collected from online (Pubmed, Sciencedirect, Scopus, Google, andWeb of science) and offline sources (books and journals from library). A total of 245 articles published between 1996 to 2018 were reviewed, and 232 articles were included in present review. Article being related with flavonoids and diabetes is the major criterion for inclusion in this compilation. Flavonoids regulate the redox status and prevent damage caused by oxidative stress and possess anti-oxidant activity. Flavonoids are a wide group of compounds including quercetin, kaempferol, luteolin, apigenin, genistein, glycitein, eriodictyol, hesperidin, catechin, gallocatechin, pelargonidin, and cyanidin. Type 2 diabetes mellitus is associated with insulin resistance, beta-cell dysfunction, inflammation, altered lipid metabolism and increased oxidative stress. It can affect many metabolic processes may cause serious complications such as retinopathy, cardiovascular disease and nephropathy. Flavonoids produce antidiabetic effect through suppressing alpha-amylase activities, attenuating insulin resistance and promoting pancreatic beta-cells proliferation. Several reports including in-vitro and in-vivo studies on flavonoids confirmed their major role in maintaining metabolic pathways during type 2 diabetes mellitus treatment.