Phenolic acid concentrations in plasma and urine from men consuming green or black tea and potential chemopreventive properties for colon cancer

Abstract

Scope Tea polyphenols are metabolized by the colonic microflora yielding phenolic metabolites, which may contribute to the health benefits of tea. We determined the serum and urine concentrations of phenolic acids, hippuric acid and polyhydroxyphenyl-γ-valerolactones during green tea (GT) and black tea (BT) administration. The effects of (−)-epigallocatechin gallate (EGCG) and 3,4-dihydroxyphenylacetic acid (3,4-DHPAA) alone and in combination on bioavailability, intracellular metabolism, and antiproliferative activity was determined in HCT-116 colon cancer cells. Methods and Results The concentration of phenolic metabolites was quantified by HPLC with electrochemical detection and MS. Urine concentrations of 4-hydroxyphenylacetic acid (4-HPAA), 3-hydroxyphenylacetic acid (3-HPAA) and polyhydroxy-γ-valerolactones were increased significantly in men drinking GT compared to control. Urine concentration of 3-O-methylgallic acid (3OMGA) was significantly increased in men drinking BT compared to control. Serum 3,4-DHPAA was significantly increased after consumption of GT and BT and 4-HPAA after GT consumption. In vitro treatment of HCT-116 colon cancer cells with 3,4-DHPAA and EGCG exhibited an additive antiproliferative effect, while methylation of 3,4-DHPAA was significantly decreased. 3OMGA exhibited the strongest antiproliferative activity among the phenolic acids. Conclusions The consumption of both, GT and BT, was associated with a significant increase in urinary and serum phenolic acids.

The urinary phenolic acid profile varies between younger and older adults after a polyphenol-rich meal despite limited differences in in vitro colonic catabolism

“…As the concentration in the colon is much higher than in the circulation with concentration ranging from 46 to 479 µmol/L in human faecal water [59,66], some effects exerted at high doses may still be physiological [67]. Moreover, while phenolic acid intake is usually in the range of 50-900 mg per day, phenolic acids in urines can reach levels close to 1 mmol/day-as urinary phenolic acid largely come from the colonic metabolism of (poly) phenolics, but also other compounds such as benzoic acid and precursors (quinic acid, aromatic amino acid tryptophan, tyrosine, and phenylalanine).…”

“…The bioactivity of specific phenolic acids is less well defined, with examples including 3,4diOHPAA an inhibitor of enzymes involved in detoxification (GSTT2), inflammation (COX-2) and anti-proliferative activity in HCT-116 colon cancer cells [67,70]; 3,4-diOHPPA (3 µM) and 3,4-diOHPAA (3 µM), inhibitors of the pro-inflammatory cytokines such as TNF-a, IL-1b and IL-6 in lipopolysaccharide-stimulated peripheral blood mononuclear cells [70,71]; and gallic acid (882 µM) inhibitor of Clostridium histolyticum in in vitro faecal fermentation [65,72].…”

Anticancer Properties of Phenolic Acids in Colon Cancer – A Review

“…The interaction between the diet and the microbiome is complex. Bacteria can influence cancer risk by metabolizing dietary components and dietary components can influence the composition and activity of the microbiome [10].…”

Pharmacological and dietary agents for colorectal cancer chemoprevention: Effects on polyamine metabolism (Review)

“…Most of the polyphenols are flavanols, and EGCG is the most abundant and representative for its putative antineoplastic effect. Green tea plays an important role in reducing cancer risk and in delaying cancer outbreak and recurrence (102) and epidemiological studies have revealed that the incidence of stomach and prostate cancers are low among populations that introduce regularly green tea in their diet. Various experimental studies performed in vivo and in vitro have confirmed the anticancer effects by green tea and/or EGCG (103).…”