In vitro investigation on the antiglycative and carbonyl trapping activities of hydroxytyrosol

Abstract

Advanced glycation end products (AGEs) are involved in the aging and the development of common chronic diseases. Hydroxytyrosol (HT) and its acetate derivative (HTA) exert a significant inhibitory activity on the formation of fluorescent AGEs in bovine serum albumin glycation model systems induced by methylglyoxal (IC50 value of 0.48 and 0.58 μmol/mL, respectively) and glucose (IC50 2.30 and 2.92 μmol/mL, respectively). Furthermore, HT and HTA showed a relevant carbonyl scavenging capacity toward methylglyoxal and glyoxal, which are the most potent promoters of the glycation in vivo, at molar reaction rates from 0.2 to 10 (carbonyl:phenol). However, carbonyl trapping capacity was significantly more effective against methylglyoxal (IC50 0.19 μmol/mL) than glyoxal (IC50 0.26 μmol/mL). At equimolar concentrations, the ester linkage did not significantly affect the antiglycative activity and carbonyl trapping capacity of the orthodiphenolic ring structure. Results were confirmed with the specific inhibition of the formation of the principal AGEs. Formation of carboxymethyl-lysine, argpyrimidine and carboxyethyl-lysine was significantly reduced by 61.9, 71.4 and 20.9 %, respectively. HT and its esters could be considered for upscaling studies as promising natural strategy against adverse consequences of protein glycation.

Caffeic Acid Modulates Processes Associated with Intestinal Inflammation

“…Caffeic acid was the most effective molecule exerting a dose-dependent antiglycative effect in both models. An explanation for this effect is related to the MGO-trapping capacity of caffeic acid [ 46 ], which might be exerted via the protection of lysine, arginine, and/or histidine groups [ 47 ]. This mechanism of protection is rather common to ortho-diphenolic compounds with a similar structure to that of caffeic acid and is linked to the antioxidant and chelating activity [ 19 , 47 ].…”

Olive leaf extract concentrated in hydroxytyrosol attenuates protein carbonylation and the formation of advanced glycation end products in a hepatic cell line (HepG2)

“…However, few studies have established a relationship between health beneficial properties and both antioxidant and antiglycative abilities through the reduction of the reactive dicarbonyl formed by the oxidative stress 27 . In a previous study, Navarro & Morales 24 have been chronically stressed and also stimulated the wound healing of pressure ulcers 40-4137-38 . In the OLEA project, the olive leaf extract has been the target of several investigations where it has been reported that olive leaf extract exerted cytoprotective and anti-inflammatory effects.…”

“…Previous studies have proved that several phenolic compounds present in olive leaves could exert a strong in vitro antiglycative capacity 24,[28][29] MGO-trapping capacity of OLE-B was significantly higher than OLE-A. Further, the αdicarbonyl-trapping capacity of the major phenolic compounds in OLE-A and OLE-B was also evaluated with standards.…”

Effect of hydroxytyrosol and olive leaf extract on 1,2-dicarbonyl compounds, hydroxymethylfurfural and advanced glycation endproducts in a biscuit model

“…Determination of CML and CEL by LC-MS/MS. CML and CEL were determined as described by Navarro and Morales (2016). LC-MS/MS was coupled to a triple quadrupole and the samples (10 lL) were injected on Hypercarb column (100 mm 2.1 lm, 5 lm, ThermoFisher Scientific).…”