Disease relevance of Flavanol

• In addition, intake of flavanol-rich cocoa augmented the vasodilator response to ischemia [1].
• Since consumption of green tea has been reported to lower the risk of prostate cancer, we investigated the effects of the major flavanol of green tea, (-)epigallocatechin-3-gallate (EGCG), on expression and activity of PSA by prostate carcinoma cells [2].
• Long-term ingestion of high flavanol cocoa provides photoprotection against UV-induced erythema and improves skin condition in women [3].
• (-)-Epigallocatechin-3-gallate (EGCG), a main flavanol of green tea, potently suppressed the urokinase-type plasminogen activator (uPA) expression in human fibrosarcoma HT 1080 cells [4].
• If so, then flavanol-rich cocoa could be a potential candidate for the treatment, or possibly prevention, of the broad array of chronic diseases that are linked to dysfunctional inflammatory responses [5].

High impact information on Flavanol

• We show in healthy male adults that the ingestion of flavanol-rich cocoa was associated with acute elevations in levels of circulating NO species, an enhanced FMD response of conduit arteries, and an augmented microcirculation [6].
• In acute feeding studies, flavanol-rich cocoa and chocolate increased plasma antioxidant capacity and reduced platelet reactivity [7].
• We have previously shown that flavanol-rich cocoa induced peripheral vasodilation, improving endothelial function via a nitric oxide (NO)-dependent mechanism [8].
• (-)Epigallocatechin-3-gallate (EGCG), the main flavanol in green tea and known to inhibit inflammation and tumor invasion, exerts dose-dependent inhibition of degradation of gelatin (IC(50)<20 micro M) and casein, which is directly triggered by PR-3 [9].
• The ingestion of high flavanol cocoa led to increases in blood flow of cutaneous and subcutaneous tissues, and to increases in skin density and skin hydration [3].

Biological context of Flavanol

• The induction of an experimental hepatitis did not affect the overall ability of the rat to metabolize the flavanol 3-O-(+)-[14C]methylcatechin by methylation or glucuronidation [10].
• Potential beneficial effect of cocoa may be attributed to flavanol-mediated improvement of endothelial function, as well as to enhancement of bioavailability and bioactivity of nitric oxide in vivo [11].
• Polyploidy was induced by procyanidins consisting of 3 or 4 flavanol units and to a lesser extent by flavone, flavonol, and anthocyanidin aglycones [12].
• There is now an increasing body of research that suggests that consuming flavanol-rich foods can positively affect hemostasis, through mechanisms that either directly affect platelet function or increase certain endothelium-derived factors that maintain platelet acquiescence or increase fibrinolysis [13].
• CONCLUSIONS: Flavanol-rich cocoa inhibited epinephrine-stimulated platelet activation and function [14].

Anatomical context of Flavanol

• In the small intestine these modifications lead primarily to the formation of glucuronide conjugates that are more polar than the parent flavanol and are marked for renal excretion [15].
• This review will highlight the major sites of flavanol metabolism in the gastrointestinal tract and the processes that give rise to potential bioactive forms of flavan-3-ols in vivo [15].
• Acute and chronic effects of flavanol-rich cocoa on vascular function in subjects with coronary artery disease: a randomized double-blind placebo-controlled study [16].
• Here, we examined whether the major dietary flavanol, (-)-epicatechin, counteracts the action of oxidized LDL on endothelial cells, an action considered pivotal for endothelial dysfunction in the pathogenesis of atherosclerosis [17].
• Here, the octanol/buffer partition coefficient of (-)-epicatechin is observed to be 1.5, indicating that the flavanol is soluble in aqueous as well as lipophilic cellular phases, thus capable of permeating the cell membrane [18].

Associations of Flavanol with other chemical compounds

• Peroxynitrite acted through oxidative, but not nitrative chemistry, as ERK remained activated while nitration was prevented by the flavanol epicatechin [19].
• These flavonoids belong to 5 different groups: flavone, isoflavone, flavanone, flavanol and flavonol, and many individual members are natural products present in edible portions of a variety of food plants [20].
• Because wine is an alcoholic beverage naturally rich in flavanols, we decided to study the effect of chronic ingestion of Port wine (PW), which also contains 20% ethanol and approximately 200 mg/l of flavanol oligomers, upon lipofuscin accumulation in the hippocampal CA1 and CA3 pyramidal neurons and in the cerebellar Purkinje cells [21].
• The green tea fraction, with the highest flavanol/proanthocyanidin content, also exhibited the highest protective activity (99%) against hepatic microsomal lipid peroxidation, and completely inhibited skin tumour formation [22].
• Previous findings suggested that epigallocatechin gallate (EGCG), a main flavanol of green tea, caused decreased levels of MMP-2 and MMP-9 activities to be secreted into culture medium [23].

Gene context of Flavanol

• In the present study, we sought to determine the effect of flavanol-rich cocoa on vascular function in individuals with CAD (coronary artery disease) [16].
• New isoflavones and flavanol from Iris potaninii [24].
• The young roots of Onion cepa are totally devoid of flavanol structures [25].
• To further elucidate the potential immuno-modulatory functions of flavanol-rich cocoa, the present investigation examined whether isolated CFP fractions (monomers through decamers) influence the secretion of tumor necrosis factor-alpha (TNF-alpha) from resting and phytohemagluttinin (PHA)-stimulated human peripheral blood mononuclear cells (PBMC) [26].

Analytical, diagnostic and therapeutic context of Flavanol

• Oral administration of chemically pure (-)-epicatechin to humans closely emulated acute vascular effects of flavanol-rich cocoa [6].
• Flow-mediated vasodilation, measured by tonometry in the finger, was enhanced with flavanol-rich cocoa in both groups, but significantly more so among the old (P = 0.01) [8].
• We suggest that this is due to a large variation of the flavanol content in tea, which is not taken into consideration in most of the epidemiological studies [27].
• The effect of flavanol-rich cocoa on the fMRI response to a cognitive task in healthy young people [28].
• Analysis by HPLC of the aqueous tea extracts employed in the current study showed that the total flavanol content of the green variety was much higher than the black varieties, and confirmed the absence of caffeine in the decaffeinated black tea [29].

References