Possible Interaction: Quercetin and Vitamin E

“Consumption of LDL alpha-tocopherol was partially inhibited by ascorbic acid and quercetin , whereas epicatechin and flavone were without effect.”

“ Quercetin inhibited the formation of … (CE-OOH) and endogenous alpha-tocopherol consumption effectively throughout the incubation period of 6 h. Ascorbic acid exhibited an effective inhibition only in the initial stage … preloaded with fivefold alpha-tocopherol did not affect the formation of CE-OOH compared with the native LDL.”

“While endogenous alpha-tocopherol was completely depleted after 2 h of LDL oxidation, quercetin , Q7G, and Q3G prevented the consumption of alpha-tocopherol.”

“When SSL were exposed to UV, the stilbenes and quercetin remarkably accelerated photo-oxidation of alpha-tocopherol , squalene, and cholesterol fractions, whilst verbascoside protected them.”

“Based on the above data, as possible mechanisms of the inhibition of photooxidation of alpha-TH in blood cell membranes by quercetin , competition of quercetin with alpha-TH for excited HP and for radicals generated during lipid peroxidation and reduction of oxidized alpha-TH by quercetin are proposed.”

“Half maximal inhibition for the photooxidation of alpha-TH was obtained at about 0.3 mM quercetin and that for the lipid photoperoxidation at about 1.5 microM quercetin.”

“In the presence of linoleic acid in PBS solution, quercetin inhibited the photooxidation of alpha-TH and alpha-TH stimulated the photooxidation of quercetin.”

“Photooxidation of alpha-tocopherol alpha-TH ) and photoperoxidation of lipids in blood cell membranes in the presence of hematoporphyrin (HP) as a photosensitizer were inhibited by quercetin.”

“The photooxidation of alpha-TH in PBS solution was inhibited by quercetin and vice versa.”

“Both in the presence and in the absence of linoleic acid, photooxidation of alpha-tocopherol which was suspended in the PBS solution was also inhibited by quercetin.”

“ Quercetin inhibited the photooxidation of alpha-tocopherol.”

“The photooxidation of quercetin , which was suspended in the PBS solution, was inhibited by alpha-tocopherol in the absence of linoleic acid, but stimulated in the presence of the fatty acid.”

“When quercetin inhibited the photooxidation of alpha-tocopherol contained in blood cells or suspended in PBS solution, quercetin was oxidized.”

“Our results suggest that α-tocopherol may promote quercetin transport across the BBB, leading to a significant increase of α-tocopherol and quercetin concentration in the brain.”

“ConclusionConclusively, dietary supplementation of quercetin along with α-tocopherol improves growth performance, antioxidant capacity, stability of lipids and fatty acid composition in breast meat of birds.”

“Fatty acid compositional analysis revealed that addition of quercetin with α-tocopherol in the bird’s diet decreased the fatty acid generation particularly saturated fatty acids.”

“Our study also showed that combined pretreatment quercetin and α‐tocopherol ) was highly effective than single pretreatment (quercetin or α‐tocopherol).”

“Our results indicate that the combined treatment with QE and AT has normalized all the previously mentioned biochemical parameters in Cd-intoxicated rats than the individual treatments.”

“3) Based on comparisons between experimental peroxidation curves and simulated curves assuming additivity, it can be concluded that combinations of alpha-tocopherol and quercetin are generally synergistic.”