Inhibition of Advanced Glycation End Product Formation in Rat Tail Tendons by Polydatin and p-Coumaric acid: an In Vitro Study.

Advanced glycation end products (AGEs) formed through non-enzymatic glycosylation between a protein and sugar molecule are highly harmful to the human body. In hyperglycemic patients, AGE formation is more due to high glucose circulating in the blood, causing inter and intra molecular cross-linking of collagen leading to reduction of collagen elasticity. This cross-linked collagen develops resistance to matrix metalloproteinases leading to impaired collagen turnover. The aim of this work is to determine the anti-glycation effects of polydatin and p-coumaric acid in preventing collagen cross-linking by incubating rat tail tendons (RTTs) as collagen source in high glucose concentration (50 mM) for a week. The RTTs were then characterized for tensile strength, cross-linking efficiency, circular dichroism spectrometry, collagen, glucose, and aldehyde contents. Electrophoresis was carried out to evaluate the level of cross-linking in collagen and the results confirmed the ability of the drugs in preventing complex intermolecular cross-link formation induced by non-enzymatic glycosylation. CD data showed alteration in the secondary structure of collagen where AGE formation had occurred. More collagen was extracted by pepsin from RTTs treated with glucose alone (6.88 mg/10 mg tendon) when compared with drug-treated groups (4.25, 2.56 mg/10 mg tendon for polydatin and p-coumaric acid, respectively). Tensile strength (20.66% and 18.95%), cross-linking percentage (32.5% and 29.84%), and glucose content (2.3 and 1.8 mg/100 mg) of drug-treated groups were similar to the positive control (19.07%, 30.13%, and 2.61 mg/100 mg) thus proving the anti-glycation potential of the drugs. Hence, both polydatin and p-coumaric acid could play a pivotal role in preventing AGE formation.