Poplar-type propolis components as trapping agents to prevent the formation of advanced glycation end-products (AGEs)

Propolis is a complex mixture used by bees to seal off hives, or use as a chemical weapon against intruders. Propolis is mainly composed of plant resins and beeswax so that its chemical composition, and consequently biological activity, varies with collection sites. Therefore propolis is generally classified as "poplar-type" in temperate zones vs "green Brazilian", "Clusia", "Macaranga" or Mediterranean-type in tropical zones [1]. The antiglycation potential of an organic poplar-type propolis sample had been already evaluated by our team. This study revealed that a DCM extract exhibited a strong anti-AGEs activity (IC₅₀ 28 µg/mL vs 90 µg/mL for the reference i.e. an EtOH extract of Styphnolobium japonicum) [2]. A bioassay-guided fractionation highlighted the major anti-AGEs components of this extract as pinobanksine derivatives and prenyl cafeate. The present workaims to show that the associated inhibition mechanism is directly related to their trapping ability of reactive dicarbonyl species such as methylglyoxal, an intermediate component in AGEs formation (Figure 1). Rapid identification of chemical markers is an important issue in propolis studies. A fast dereplication analysis of the propolis DCM extract, using a Laser Desorption Ionization (LDI) MS technique [3], allowed us to instantly identify 25 polyphenol derivatives previously identified by classical methods [2,4]. The results clearly show that LDI-MS represents a fast and powerful method to characterize propolis extracts and identify their origin.

Fig. 1: The Maillard reaction – Schematic formation of AGEs.

Keywords: Propolis, Advanced Glycation End-products, reactive dicarbonyl species, laser desorption ionization (LDI).

References:

[1] Salatino A, Fernandes-Silva CC, Righi AA, Salatino MLF. Propolis research and the chemistry of plant products. Nat Prod Rep 2011; 28: 925 – 936

[2] Boisard S, Le Ray AM, Gatto J, Aumond MC, 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

[3] Le Pogam P, Schinkovitz A, Legouin B, Le Lamer AC, Boustie J, Richomme P. Matrix-Free UV-Laser Desorption Ionization Mass Spectrometry as a Versatile Approach for Accelerating Dereplication Studies on Lichens. Anal Chem 2015; 87: 10421 – 10428

[4] Boisard S, Le Ray AM, Landreau A, Kempf M, Cassisa V, Flurin C, Richomme P. Antifungal and antibacterial metabolites from a French poplar type propolis. Evid Based Complement Alternat Med 2015; e319240.

No conflict of interest has been declared by the author(s).