Inhibition of AGEs formation, antioxidative, and cytoprotective activity of Sumac (Rhus typhina L.) tannin under hyperglycemia: molecular and cellular study

It is well known that accumulation of advanced glycation ends products (AGEs) lead to various diseases such as diabetes and diabetic complications. In this study we showed that hydrolysable tannin from Sumac ( Rhus typhina L.)—3,6-bis- O -di- O -galloyl-1,2,4-tri- O -galloyl-β- d -glucose (C 55 H 40 O 34 ) inhibited generation of glycation markers in bovine serum albumin such as AGEs, dityrosine, N ′-formylkynurenine and kynurenine under high glucose treatment. This effect was accompanied by stabilization of the protein structure, as was shown using ATR-FT-IR spectroscopy and fluorescence methods. C 55 H 40 O 34 exhibited also a neuroprotective effect in high glucose-exposed Neuro2A cells suppressing ROS formation and expression of phospho NF-κβ and iNOS. At the same time C 55 H 40 O 34 increased expression of heme oxygenase-1 and NAD(P)H: quinone oxidoreductase and mitochondrial complex I and V activities. Results from this study demonstrates a potent antiglycation activity of C 55 H 40 O 34 in vitro and indicates its possible therapeutic application in glycation related diseases. Graphical abstract