Wednesday, February 22, 2012
Food and Chemical Toxicology, Available online 4 February 2012
The aim of the present work was to analyze the phenolic extracts from two monofloral Cuban honeys for their in vitro total antioxidant capacity, phenolic compounds content and free radical scavenging activity.
The phenolic extracts, rich in lipophilic compounds, were tested further for their ability to inhibit AAPH-induced oxidative damage (hemolysis, lipid peroxidation and cytosolic depletion of reduced glutathione and decrease of superoxide dismutase activity) in erythrocytes. Results indicate an important total antioxidant capacity measured by TEAC and ORAC assays, as well as a relevant radical scavenging activity performed by EPR. Moreover, 13 phenolic compounds were identified using HPLC–LC/MS with quercetin as the most abundant flavonoid.
The results also show that both extracts were able to inhibit erythrocytes oxidative damage, and that this may likely be due to their incorporation into cell membranes and their ability to cross it and reach the cytosol. In fact, flavonoid uptake by erythrocytes was further confirmed by testing quercetin, which efficiently incorporated into erythrocytes.
Overall, this study indicates that honey contains relevant antioxidant compounds responsible, at least in part, for its biological activity and that uptake of its flavonoids may provide defense and promote cell functions in erythrocytes.
► Monofloral honey extracts have high content of polyphenols and antioxidant capacity (ORAC). ► Honey phenolic extracts have radical scavenging activity (DPPH, ABTS+ and HO). ► Honey phenolic extracts protect RBC against AAPH-induced lysis and lipid peroxidation. ► Honey phenolic extracts protect RBC from cytosolic depletion of enzymes GSH and SOD. ► Quercetin is able to incorporate into RBC structures providing defence and promoting cell function.