Possible Interaction: Quercetin and Vitamin C

“There is evidence that vitamin C and quercetin co-administration exerts a synergistic antiviral action due to overlapping antiviral and immunomodulatory properties and the capacity of ascorbate to recycle quercetin, increasing its efficacy.”

“ Quercetin inhibition was prevented in the presence of ascorbic acid , but not by thiol reagents that modify the extracellular Cys-loop of these receptors.”

“ Quercetin similarly antagonized GABA-evoked responses mediated by mutant (H141D)GABA(Aρ₁) and wild-type receptors, but prevention exerted by ascorbic acid on quercetin effects was impaired in mutant receptors.”

“Flavonoids that have been found to be antiproliferative, quercetin and genistein, inhibited the accumulation of ascorbic acid.”

“Potential interactions with vitamin C and quercetin with some ARVs should be noted and efficacy and tolerance of the treatment should be monitored.”

“Finally, supplementing the media with ascorbic acid increases quercetin's ability to induce cell death probably by reduction oxidative dimerization.”

“We report that Qu blocks mammalian target of rapamycin signaling and inhibits c-Fos protein expression directly through this mechanism because cotreatment with Qu and AA resulted in the complete suppression of UVB-induced c-Fos protein expression even in the presence of significantly increased mRNA levels.”

“In the present study, it was investigated whether the water-soluble antioxidants ascorbic acid ASA ), N-acetyl-cysteine (NAC) and reduced glutathione (GSH) can enhance both the antioxidant and anticancer activity of quercetin in human myeloid leukemia cells (HL-60 cells).”

“The initial oxidation of quercetin was inhibited by AA , and quercetin enhanced the oxidation of AA, suggesting AA-dependent reduction of quercetin radicals, which might be formed during the oxidation of quercetin by nitrous acid.”

“The presence of ascorbic acid enhanced the protective effect of quercetin and rutin against oxidative stress in sickle Hb and lipid peroxidation.”

“Exposure of cells to ascorbic acid (2 µg/ml) and 2 µg/ml of either fisetin or quercetin resulted in 61 and 45% inhibition of cell growth, respectively, in 72 h, while treatment with ascorbic acid alone had no effect on cellular proliferation.”

“Fisetin and quercetin significantly impaired cell growth in the presence of ascorbic acid.”