Disease relevance of phenol

• Malignant melanomas have been shown to contain high levels of monophenol monooxygenase (tyrosinase) enzyme activity; the enzyme is responsible for melanin synthesis [1].
• Melanogenesis is regulated in large part by tyrosinase (monophenol monooxygenase; monophenol, L-dopa:oxygen oxidoreductase, EC 1.14.18.1), and defective tyrosinase leads to albinism [2].
• Microarray-assisted pathway analysis identifies mitogen-activated protein kinase signaling as a mediator of resistance to the green tea polyphenol epigallocatechin 3-gallate in her-2/neu-overexpressing breast cancer cells [3].
• Furthermore, green tea polyphenol infusion resulted in marked inhibition of markers of angiogenesis and metastasis most notably vascular endothelial growth factor, urokinase plasminogen activator, and matrix metalloproteinases 2 and 9 [4].
• Stability, cellular uptake, biotransformation, and efflux of tea polyphenol (-)-epigallocatechin-3-gallate in HT-29 human colon adenocarcinoma cells [5].

Psychiatry related information on phenol

• Recently, we have shown that green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) exerts a beneficial role on reducing brain Abeta levels, resulting in mitigation of cerebral amyloidosis in a mouse model of Alzheimer disease [6].

High impact information on phenol

• Green tea polyphenol, epigallocatechin-3-gallate (EGCG) differentially regulates the cellular growth of cancer cells in a p53-dependent manner through apoptosis and/or cell cycle arrest [7].
• Pro-phenol oxidase [pro-PO; zymogen of phenol oxidase (monophenol, L-dopa:oxygen oxidoreductase, EC 1.14.18.1)] is present in the hemolymph plasma of the silkworm Bombyx mori [8].
• Clones encoding pro-phenol oxidase [pro-PO; zymogen of phenol oxidase (monophenol, L-dopa:oxygen oxidoreductase, EC 1.14.18.1)] A1 were isolated from a lambda gt10 library that originated from Drosophila melanogaster strain Oregon-R male adults [9].
• Tyrosinase (monophenol, L-dopa:oxygen oxidoreductase, EC 1.14.18.1) is regarded as the key enzyme in pigment synthesis in both these cell types [10].
• Previously, we showed that the green tea polyphenol epigallocatechin 3-gallate (EGCG) inhibits growth of NF639 Her-2/neu-driven breast cancer cells via reducing receptor autophosphorylation and downstream Akt and NF-kappaB activities [3].

Chemical compound and disease context of phenol

• In 10 separate experiments, mice with established chemically induced or UV light-induced skin papillomas were treated continuously with green tea in the drinking water or with i.p. injections of a green tea polyphenol fraction or (-)-epigallocatechin gallate three times a week for 4-10 weeks [11].
• The present study investigated the inhibitory effects of Polyphenon E [a standardized green tea polyphenol preparation containing 65% (-)-epigallocatechin-3-gallate] and caffeine on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK)-induced lung tumor progression from adenoma to adenocarcinoma [12].
• Green tea polyphenol stimulates cancer preventive effects of celecoxib in human lung cancer cells by upregulation of GADD153 gene [13].
• Green tea polyphenol epigallocatechin-3 gallate (EGCG) affects gene expression of breast cancer cells transformed by the carcinogen 7,12-dimethylbenz[a]anthracene [14].
• Black tea polyphenol theaflavins inhibit aromatase activity and attenuate tamoxifen resistance in HER2/neu-transfected human breast cancer cells through tyrosine kinase suppression [15].

Biological context of phenol

• Screening of a lambda gt11 human melanocyte cDNA library with antibodies against hamster tyrosinase (monophenol, L-dopa:oxygen oxidoreductase, EC 1.14.18.1) resulted in the isolation of 16 clones [16].
• Involvement of protein kinase C activation and cell survival/ cell cycle genes in green tea polyphenol (-)-epigallocatechin 3-gallate neuroprotective action [17].
• Suppression of UVB-induced phosphorylation of mitogen-activated protein kinases and nuclear factor kappa B by green tea polyphenol in SKH-1 hairless mice [18].
• The tea polyphenol, EGCG, inhibited LNCaP cell growth and the expression of androgen regulated PSA and hK2 genes [19].
• No significant changes were observed in the pharmacokinetics of EGCG after repeated green tea polyphenol treatment at a regimen of 400 mg twice daily [20].

Anatomical context of phenol

• Tea polyphenol (-)-epigallocatechin-3-gallate inhibits DNA methyltransferase and reactivates methylation-silenced genes in cancer cell lines [21].
• Activation of hINV promoter activity by the green tea polyphenol, (-)-epigellocathecin-3-gallate, is also inhibited by apigenin, suggesting that the two chemopreventive agents can produce opposing actions in keratinocytes [22].
• Green tea polyphenol EGCG suppresses cigarette smoke condensate-induced NF-kappaB activation in normal human bronchial epithelial cells [23].
• BACKGROUND: We previously demonstrated the successful 1-month storage of peripheral nerve segments in a green tea polyphenol extract [24].
• Green tea polyphenol (-)-epigallocatechin-3-gallate induces neurorescue of long-term serum-deprived PC12 cells and promotes neurite outgrowth [25].

Associations of phenol with other chemical compounds

• Green tea polyphenol and curcumin inversely regulate human involucrin promoter activity via opposing effects on CCAAT/enhancer-binding protein function [26].
• Tyrosinase activity (Monophenol, dihydroxyphenylalanine: oxygen oxidoreductase EC 1.14.18.1) in vitiligo and normal epidermal homogenates of skin from human beings was measured by estimating beta 3,4-dihydroxyphenylalanine (dopa) by a highly sensitive fluorometric method described in this paper [27].
• The naturally occurring resveratrol analog piceatannol (100 microM) also diminished ODC activity, protein and mRNA levels, whereas the green tea polyphenol (-)-epigallocatechin gallate (EGCG; 100 microM) exerted only weak effects on ODC [28].
• Green tea polyphenol (-)-epigallocatechin gallate blocks epithelial barrier dysfunction provoked by IFN-gamma but not by IL-4 [29].
• Although this Michaelis constant is much lower than the Michaelis constant for diphenol in the absence of monophenol, the binding site is the same [30].
• The calculations further indicate that the bond strength between the copper atom and the oxygen atom of the phenoxy radical is weakened by the presence of neutral phenol from 2.6 eV in bare [Cu(PhO)](+) to 2.1 eV in [Cu(PhOH)(PhO)](+) [31].
• Structural analysis showed that CYP80G2 had high amino acid sequence similarity to Berberis stolonifera CYP80A1, an intermolecular C-O phenol-coupling P450 involved in berbamunine biosynthesis [32].
• Toluene dioxygenase-catalysed cis-dihydroxylation of phenols has led to the discovery of new enantiopure cyclohexenone cis-diol, o-quinol dimer and phenol hydrate metabolites having synthetic potential [33].

Gene context of phenol

• Melanin synthesis in mammals is catalysed by at least three enzymic proteins, tyrosinase (monophenol dihydroxyphenylalanine:oxygen oxidoreductase, EC 1.14.18.1) and tyrosinase-related proteins (tyrps) 1 and 2, whose genes map to the albino, brown and slaty loci in mice, respectively [34].
• Matrix metalloproteinase (MMP)-7 (matrilysin-1) plays significant roles in the growth, invasion, and metastasis of colorectal tumors, while (-)-epigallocatechin-3-gallate (EGCG), a green tea polyphenol with chemopreventive properties, has been shown to be an inhibitor of MMP-2 and MMP-9 [35].
• Green tea polyphenol-induced epidermal keratinocyte differentiation is associated with coordinated expression of p57/KIP2 and caspase 14 [36].
• Therefore, the green tea polyphenol EGCG is a potent inhibitor of IL-1 beta signal transduction in vitro [37].
• Inhibition of UVB-induced oxidative stress-mediated phosphorylation of mitogen-activated protein kinase signaling pathways in cultured human epidermal keratinocytes by green tea polyphenol (-)-epigallocatechin-3-gallate [38].

Analytical, diagnostic and therapeutic context of phenol

• These observations indicate that oral administration of green tea, i.p. administration of a green tea polyphenol fraction, or i.p. administration of (-)-epigallocatechin gallate inhibited the growth and/or caused the regression of established experimentally induced skin papillomas [11].
• Peripheral nerve allografts stored in green tea polyphenol solution [24].
• In the present study, a nested case-control study design was used to investigate the association between prediagnostic urinary tea polyphenol markers and subsequent risk of gastric and esophageal cancers [39].
• Administration of the green tea polyphenol (-)-epigallocatechin-3-gallate (EGCG) in the drinking water significantly decreased both tumor number and total tumor burden compared with untreated ODC/Ras mice without decreasing the elevated polyamine levels present in the ODC/Ras mice [40].
• Epigallocatechin, a green tea polyphenol, attenuates myocardial ischemia reperfusion injury in rats [41].

References