Anti-AGE activity of poplar-type propolis: mechanism of action of main phenolic compounds

This study aimed to compare the protective effect of two geographically distinct propolis against the formation of advanced glycation end products (AGEs). The polyphenol content of propolis extracts (EEPs) was analysed using HPLC-DAD-MS profiling and evaluated for their protective effects against pentosidine-like AGEs. Dicarbonyl trapping capacities of major EEP compounds were determined using a methylglyoxal scavenging in vitro assay. Both propolis samples were characterised with high levels of pinobanksin derivatives exhibiting strong anti-AGE properties. EEPs reduced AGE formation more effectively than well-known natural AGE inhibitors such as quercetin or chlorogenic acid. Individual evaluations of the five major compounds in EEPs showed that flavonoids strongly inhibit the formation of AGEs by trapping dicarbonyl intermediates, whereas compounds such as caffeic acid derivatives only act as antioxidant agents. Propolis is thus a promising candidate for the prevention and control of AGE-related chronic diseases.