Antidiabetic potential of anthraquinones: A review.

The present study was designed to review the antidiabetic potential of anthraquinones (AQs) with emphasis on the extent of blood glucose reduction, the half maximal inhibitory concentration values (in vitro studies), the proposed mechanisms of action, and the structure activity relationship studies. We sourced relevant data from the major scientific databases (Pubmed, Science Direct, Medline, and Google Scholar). According to our search, 25 AQs have shown variable antidiabetic potential, whereas one AQ (morindone-6-O-β-D-primeveroside) showed no blood glucose-lowering ability. Emodin and rhein showed the most promising antidiabetic potential in various models. The proposed mechanisms of antidiabetic action include upregulation of insulin receptor substrates-1, phosphoinositide-3-kinase, and Akt-ser473 expression and elevation of glucagon-like peptide-1 level in diabetic animal models linked to the potent protein tyrosine phosphatase 1B and dipeptidyl peptidase-4 inhibitions. In addition, activation of peroxisome proliferator-activated receptors gamma and inhibition of α-glucosidase activity are other possible targets proposed as the mechanism of AQs antidiabetic action. The position and the number of hydroxyl group showed great influence on the overall antidiabetic potential of AQs. AQs hold promising antidiabetic activity despite scanty information. We hope that the present study will serve as a template to further explore the antidiabetic potential of AQs and subsequent antidiabetic drug development.