Red wine alcohol promotes quercetin absorption and directs its metabolism towards isorhamnetin and tamarixetin in rat intestine in vitro

Abstract

1 Moderate consumption of red wine has been associated with beneficial effects on human health, and this has been attributed to the flavonoid content. Factors that influence the bioavailability of this group of polyphenolic compounds are therefore important. 2 Using the rat cannulated everted jejunal sac technique, we have investigated the effect of alcohol on the intestinal absorption of quercetin and its 3-O-glucoside from red wine. Tissue preparations were incubated in whole or dealcoholised red wine, diluted 1 : 1 with Krebs buffer for 20 min at 371C, after which the mucosa was removed and processed for HPLC analysis. Tissues exposed to red wine had significantly higher amounts of both quercetin ( Â 3; Po0.001) and quercetin-3-O-glucoside ( Â 1.5; Po0.01) associated with them, compared with sacs incubated in the dealcoholised equivalent. In addition, both tamarixetin (T) and isorhamnetin (I), in the mucosal tissue from sacs exposed to the whole wine, were significantly elevated approximately two fold (Po0.05; Po0.01, respectively). 3 Similar results were obtained when sacs were incubated in Krebs buffer containing a mixture of pure quercetin and quercetin-3-O-glucoside with or without alcohol, and, although effects on the apparent absorption of Q and Q-3-G were not so marked, concentrations of the metabolites quercetin-3-O-glucuronide and I were significantly increased by the presence of alcohol (Po0.01 and Po0.001, respectively). 4 It is therefore plausible that the moderate alcohol content of red wine contributes to its beneficial health effects in humans by both increasing the absorption of quercetin and quercetin-3-O-glucoside and by channelling their metabolism towards O-methylation to yield compounds (T and I), which have potential protective effects against cancer and cardiovascular diseases.

Review of anticancer mechanisms of isoquercitin

“…In 2005, Kern et al [80] reported a perspective on the antiproliferative effect and demonstrated the potent EGFRinhibitory properties of polyphenolrich apple juice extract in adenocarcinoma colon in vitro model (HT29) [80] . Another study suggested that the beneficial effects of red wine on human health were attributable to the flavonoid content, which channeled the body metabolism towards Omethylation to yield compounds with potential protective effects against cancer [81] .…”

Absorption and metabolism of red wine polyphenols and their potential health benefits in cardiovascular function

“…The authors suggested that resveratrol metabolite concentrations were statistically higher after the DRW compared with RW intervention (P ¼ 0.002). However, it seems clear from a great number of recent studies that the cardiovascular effects of polyphenols are dependent on their bioavailability, and alcohol in RW may improve polyphenol availability by increasing its intestinal absorption or by delaying its excretion (2,3), indicating that RW intake should produce higher concentrations of urinary resveratrol metabolites than DRW ingestion. It is, therefore, reasonable to assume that the consumption of RW and DRW also should, at least, lead to similar concentrations of urinary resveratrol metabolites, despite the fact that the resveratrol content of RW is slightly higher than that of DRW as depicted in Table 1 of their article.…”

Comparison of the Preventive Activity of Isorhamnetin Glycosides from Atsumi-kabu (Red Turnip,Brassica, campestrisL.) Leaves on Carbon Tetrachloride-Induced Liver Injury in Mice

“…[1][2][3] Consequently, many physiological functions of flavonoids, such as their preventive effects on cancer, cardiovascular disease, liver injury and oxidative stress, neuroprotective effects, and hypoglycemic effects, have been investigated and reported, [4][5][6][7][8][9][10][11] and the bioavailability, absorption from the gastro-intestinal tract, and metabolism of flavonoids have been examined in relation to their function. [12][13][14] However, few reports have been presented on the precise relationship between the chemical structure of dietary flavonoids and their bioavailability or functions. Therefore, it is very important to determine the relationship between the chemical structures and physiological functions in order to know which structures are more important for preventing disease.…”