Chemical composition, antioxidant and anti-AGEs activities of a French propolis

Accumulation in tissues and serum of advanced glycation end-products (AGEs) plays an important role in pathologies such as Alzheimer\u27s disease or, in the event of complications of diabetes, atherosclerosis or renal failure. Therefore there is a potential therapeutic interest in natural antioxidants with true anti-AGEs capabilities for the prevention of this kind of pathologies. The aim of this study was to evaluate the antioxidant and anti-AGEs potential of a French propolis batch (natural resinous substance collected by honeybees from differents plants and trees), then to identify the main compounds responsible for this anti-AGEs effect. For this purpose, the phytochemical composition of a 70% ethanolic extract of propolis (EEP70) was determined, using HPLC/DAD/MS and/or 1H and 13C NMR (1D and 2D) analysis. This study showed the presence of phenolic acids and their esters as well as flavonoids. Then, the evaluation of the antioxidant, using DPPH and ORAC assays, and the anti-AGEs potential, using an automated test recently developed in our laboratory, showed that EEP70 exhibited both high antioxidant (1650 ± 149 µmol TE/g) and anti-AGEs (IC50=0.03 mg/ml) activities. A bio-guided fractionation allowed us to identify the most active anti-AGEs compounds: pinobanksin-3-acetate (IC50=0.06 mM) which is the major compound of EEP70. Thus, EEP70 represents a good candidate as food additive to prevent glycoxidation. Boisard S, Le Ray A-M, Gatto J, Aumond M-C, Blanchard P, Derbré S, Flurin C, Richomme P: Chemical Composition, Antioxidant and Anti-AGEs Activities of a French Poplar Type Propolis. J Agric Food Chem 2014, 62:1344–1351