a1 Biochemistry Division, National Institute of Nutrition, Jamai-Osmania, Tarnaka, Hyderabad 500 604, India
Formation of advanced glycation end products (AGE) plays a key role in the several pathophysiologies associated with ageing and diabetes, such as arthritis, atherosclerosis, chronic renal insufficiency, Alzheimer's disease, nephropathy, neuropathy and cataract. This raises the possibility of inhibition of AGE formation as one of the approaches to prevent or arrest the progression of diabetic complications. Previously, we have reported that some common dietary sources such as fruits, vegetables, herbs and spices have the potential to inhibit AGE formation. Flavonoids are abundantly found in fruits, vegetables, herbs and spices, and rutin is one of the commonly found dietary flavonols. In the present study, we have demonstrated the antiglycating potential and mechanism of action of rutin using goat eye lens proteins as model proteins. Under in vitro conditions, rutin inhibited glycation as assessed by SDS-PAGE, AGE-fluorescence, boronate affinity chromatography and immunodetection of specific AGE. Further, we provided insight into the mechanism of inhibition of protein glycation that rutin not only scavenges free-radicals directly but also chelates the metal ions by forming complexes with them and thereby partly inhibiting post-Amadori formation. These findings indicate the potential of rutin to prevent and/or inhibit protein glycation and the prospects for controlling AGE-mediated diabetic pathological conditions in vivo.
(Received March 09 2011)
(Revised June 07 2011)
(Accepted June 27 2011)
(Online publication August 25 2011)
Abbreviations: AGE, advanced glycation end products; ALR2, aldose reductase; BSA, bovine serum albumin; CML, carboxymethyllysine; HMW, high molecular weight; KLH, keyhole limpet haemocyanin; MGO, methylglyoxal; RNase, ribonuclease; TSP, total soluble protein