Disease relevance of CATECHIN

• Concentrations of chitin, protein, and catechol increased substantially as dehydration and sclerotization progressed [1].
• The absolute levels and relative ratios of 16 alpha-hydroxylated estrogens and 2-hydroxylated estrogens (catechol estrogens) in the body may have a role in the etiology of breast cancer, but studies so far have provided only conflicting results [2].
• Papilloma multiplicity increased from subgroup A to subgroup C in the MNAN plus B. pilosa group but not in the MNAN plus catechol group [3].
• Chemical cocarcinogenesis with the use of a subclone derived from Balb/3T3 cells with catechol as cocarcinogen [4].
• These results support the view that catechol in cigarette smoke and B. pilosa as eaten in South Africa contribute to the etiology of human esophageal cancer [3].

Psychiatry related information on CATECHIN

• Following the optimization of the paste composition, PPO-based carbon paste biosensors were prepared and presented excellent analytical properties toward catechol detection with a sensitivity of 4.7 A M(-1) cm(-2) and a response time lower than 20 s [5].
• No association between functional catechol O-methyl transferase 1947A>G polymorphism and smoking initiation, persistent smoking or smoking cessation [6].
• These observations help to explain individual differences in response to treatment with catechol drugs and may explain some variations in the function of human catecholamine neurotransmitters [7].
• Quercetin and catechin are among the major flavonoids in plant foods and their intake has been associated to a risk reduction in several degenerative diseases [8].
• We have examined the ability of a novel catechol monoester of L-DOPA, NB-355 [L-3-(3-hydroxy-4-pivaloxyloyphenyl)alanine], to stimulate locomotor activity and induce dyskinesias in MPTP-treated primates [9].

High impact information on CATECHIN

• Using a new biochemical method, we detected catechol-modified parkin in the substantia nigra but not other regions of normal human brain [10].
• COMT also inactivates catechol-type compounds such as L-DOPA [11].
• The concentration of catechol estrogens in the hypothalamus and pituitary are at least ten times higher than reported previously for the parent estrogens [12].
• Catechol estrogens have potent endocrine effects and, because of their normal occurrence in the hypothalamic-pituitary axis, they have an important role in neuroendocrine regulation [12].
• IMPLICATIONS: I3C may have chemopreventive activity against breast cancer in humans, although the long-term effects of higher catechol estrogen levels in women require further investigation [13].

Chemical compound and disease context of CATECHIN

• Tobacco smoke tumor promoters, catechol and hydroquinone, induce oxidative regulation of protein kinase C and influence invasion and metastasis of lung carcinoma cells [14].
• Because catechol-O-methyltransferase (COMT) catalyzes the addition of methyl groups to stabilize catechol estrogens that may induce DNA damage, genetic variants could influence breast cancer risk [15].
• Hydroquinone also enhanced the development of esophageal squamous cell carcinomas but was less active than catechol or resorcinol [16].
• The reaction of oxygen with catechol 1,2-dioxygenase from Pseudomonas arvilla ATCC 23974 in complex with catechol, 4-methylcatechol, and 4-fluorocatechol has been studied using single turnover stopped flow spectrophotometry [17].
• Pyrocatechase (catechol 1,2-oxidoreductase (decyclizing), EC 1.13.11.1), a ferric ion-containing dioxygenase from Pseudomonas arvilla C-1, catalyzes the intradiol cleavage of catechol with insertion of 2 atoms of molecular oxygen to form cis,cis-muconic acid [18].

Biological context of CATECHIN

• The indirect formation of the catechol (dopa) from the phenol (tyrosine) leads to unusual enzyme kinetics [19].
• CYP3A metabolism generates epipodophyllotoxin catechol and quinone metabolites, which could damage DNA [20].
• The pKT530 plasmid also carries xylS (a gene whose product has been postulated to regulate expression of the lower pathway genes) and the control sequences of the pathway that interact with this product, because catechol 2,3-oxygenase synthesis is specifically induced by m-toluate in both P. putida and E. coli [21].
• Moreover, the active site of catechol oxidase has been found to be structurally conserved with the oxygen-binding site of a molluscan hemocyanin [22].
• Hydroquinone (50 microM), catechol (500 microM), or CSC (50 micrograms/ml) induced an initial cytosol-to-membrane translocation of PKC in LL/2 lung carcinoma cells, followed by a later down-regulation of the enzyme [14].

Anatomical context of CATECHIN

• Metabolism of catechol estrogens by erythrocyte catechol-O methyltransferase [23].
• The carcinogenic and strong promoting activities of catechol and its structurally related compounds on rat glandular stomach epithelium are of greater concern because this tissue is directly analogous to human gastric epithelium.(ABSTRACT TRUNCATED AT 400 WORDS)[24]
• The vesicular amine transporter (VAT) catalyzes transport and storage of catechol and indolamines into subcellular organelles in a wide variety of cells [25].
• The total amount of EE2 catechol metabolites formed in untreated hamster liver microsomes was 65.5% [26].
• The tumor incidence in vivo did not correlate with the rates of catechol formation by hamster kidney microsomes in vitro [27].

Associations of CATECHIN with other chemical compounds

• From the time of the first MNAN injection, each group also received catechol, tannic acid (CAS: 1401-55-4), dried leaves of Bidens pilosa L., or croton oil (CAS: 8001-28-3) (respectively, 2, 10, 50, and 2 g/kg semipurified diet), or were given 20 ip injections of 6 mg phorbol (CAS: 17673-25-5)/rat [3].
• These studies have revealed that caffeic acid and sesamol are also tumorigenic for rat forestomach epithelium, whereas catechol and p-methylcatechol induce neoplasia in rat glandular stomach epithelium [24].
• Estradiol is converted to catechol estrogens via 2- and 4-hydroxylation by cytochrome P450 enzymes [28].
• Cleavage of DNA substrates containing the normal homologues of the MLL and AF-4 translocation breakpoints was examined in vitro upon incubation with human DNA topoisomerase IIalpha and etoposide, etoposide catechol, etoposide quinone, or dactinomycin [29].
• Modification by catechol and resorcinol of upper digestive tract carcinogenesis in rats treated with methyl-N-amylnitrosamine [16].

Gene context of CATECHIN

• The UGT1A1 6/6 genotype predicted lower catechol AUC [30].
• O-Methylation, catalyzed by catechol-O-methyltransferase (COMT), inactivates catechol estrogens [31].
• Because the P450-mediated oxidation of E2 and the O-demethylation of methoxyestrogens both yielded identical catechol estrogens as products, we used deuterated E2 (E2-d4), unlabeled methoxyestrogens, and gas chromatography/mass spectrometry to examine both reactions simultaneously [32].
• Using purified recombinant enzymes, we demonstrated that CYP1A1 and CYP1B1 O-demethylated the methoxyestrogens to catechol estrogens according to Michaelis-Menten kinetics [32].
• Metapyrocatechase which catalyzes the oxygenative ring cleavage of catechol to form alpha-hydroxymuconic epsilon-semialdehyde is encoded by the xylE gene on the TOL plasmid of Pseudomonas putida mt-2 [33].

Analytical, diagnostic and therapeutic context of CATECHIN

• Using a combination of enzyme oximetry, pulse radiolysis, and chemical oxidation, the study of structurally modified dopaquinones provides firm evidence of nonenzymatic catechol formation during tyrosinase oxidation of phenols and reveals significant differences in their modes of reaction [19].
• It is concluded from these experiments that in cell culture catechol formation and morphological transformation are directly related [27].
• Benzene, phenol, catechol, 1,2,4-benzenetriol, hydroquinone, and 1,4-benzoquinone induced significant concentration-related increases in the SCE frequency, decreases in mitotic indices, and inhibition of cell cycle kinetics [34].
• When sulfation of C4 was partially inhibited by addition of catechol to culture medium, three different forms of the peptide were resolved by high-performance liquid chromatography, consistent with peptides containing 1, 2, or 3 sulfates [35].
• Therefore we have investigated the effects of the catechin epicatechin gallate (ECG), on scar formation in a full thickness incisional model of wound healing in rats [36].

References