Possible Interaction: Quercetin and Caffeic Acid

“The concomitant oral administration of melatonin along with 15 mg/kg of caffeic acid or quercetin or caffeic acid plus quercetin significantly (p < 0.05) increased the AUC0–t of melatonin by 30.0, 66.7 and 114.0%, respectively.”

“Concerning the effects on LDL protein oxidation, the results from carbonyl … the tryptophan fluorescence measurements showed that the combination of uercetin … affeic acid revealed the strongest inhibitory effect (p < 0.001 carbonyl content; p ≤ 0.002 tryptohan …) on protein oxidation which was higher than the effect of the single compounds.”

“A comparable antioxidant effect of rutin under these experimental conditions was observed at higher concentrations of 1–10 mM. The antioxidant activity of quercetin in the concentration range of 10–500 μM during the first minutes of incubation was higher than that of caffeic acid.”

“Changes in bioactivity after purification suggest synergistic interactions between quercetin and caffeic acid.”

“Combined caffeic acid and quercetin pretreatments significantly reduced the levels of lipid peroxidation markers, that is thiobarbituric acid reactive substance (TBARS), protein carbonyls (PCO) and decreased DNA damage in LTC portion.”

“Further, combined caffeic acid and quercetin pretreatment maintain antioxidant enzyme activities and glutathione content near to normal values.”

“Paracetamol at the oral dose of 1 g/kg produced 100% mortality in mice while pretreatment of separate groups of animals with caffeic acid (6 mg/kg) and quercetin (10 mg/kg) reduced the death rate to 20% and 30%, respectively.”