The activity of catechol-O-methyltransferase (COMT) is not impaired by high doses of epigallocatechin-3-gallate (EGCG) in vivo

Lorenz, Mario; Paul, Friedemann; Moobed, M.; Baumann, Gert; Zimmermann, Benno F.; Stangl, Karl; Stangl, Verena

doi:10.1016/j.ejphar.2014.06.014

Cited by 47 publications

(28 citation statements)

References 37 publications

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“…When EGCG was incubated with rat liver microsomes at 1–100 μM for 30 min in vitro, EGCG selectively bound to COMT [81]. However, in vivo tests showed that supplementation with a high dose of EGCG does not impair the activity of COMT [82]. A bioavailability test using 3 H-EGCG in mice revealed a wide distribution of radioactivity in target organs, including digestive tract, liver, lung, pancreas, mammary gland, brain, kidney, uterus, and ovary.…”

Section: Inconsistent Results and Further Study Suggestionsmentioning

confidence: 99%

Suppressive Effects of Tea Catechins on Breast Cancer

Xiang

Wang²,

et al. 2016

Nutrients

110

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Tea leaf (Camellia sinensis) is rich in catechins, which endow tea with various health benefits. There are more than ten catechin compounds in tea, among which epigallocatechingallate (EGCG) is the most abundant. Epidemiological studies on the association between tea consumption and the risk of breast cancer were summarized, and the inhibitory effects of tea catechins on breast cancer, with EGCG as a representative compound, were reviewed in the present paper. The controversial results regarding the role of tea in breast cancer and areas for further study were discussed.

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Section: Inconsistent Results and Further Study Suggestionsmentioning

confidence: 99%

Suppressive Effects of Tea Catechins on Breast Cancer

Xiang

Wang²,

et al. 2016

Nutrients

110

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“…Hodgson et al (40), using targeted catecholamine profiling techniques, determined that GTE did not increase concentrations of norepinephrine, which suggests that GTE supplementation may not alter COMT activity. Furthermore, Lorenz et al (41) determined that the administration of 750 mg EGCG did not impair the in vivo activity of COMT. Epidemiologic studies have linked green tea consumption to higher bone density (14) and reduced risk of hip fractures (42).…”

Section: Discussionmentioning

confidence: 99%

Long-Term Supplementation of Green Tea Extract Does Not Modify Adiposity or Bone Mineral Density in a Randomized Trial of Overweight and Obese Postmenopausal Women

Dostal

Arikawa

Espejo

et al. 2016

The Journal of Nutrition

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“…Qualitative synthesis showed that findings were inconsistent, were not replicated, or lacked statistical evidence to substantiate reported genotype differences (Table S11 in Supplement 2). (20)(21)(22)(44)(45)(46)(47)(48)(49)(50)(51)(52)(53)(54)(55)(56)(57)(58)(59)(60)…”

Section: No Consistent Evidence For Functional Polymorphisms In Dopammentioning

confidence: 99%

Which Dopamine Polymorphisms Are Functional? Systematic Review and Meta-analysis of COMT, DAT, DBH, DDC, DRD1–5, MAOA, MAOB, TH, VMAT1, and VMAT2

Tunbridge

Narajos

Harrison

et al. 2019

Biological Psychiatry

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BACKGROUND: Many polymorphisms in dopamine genes are reported to affect cognitive, imaging, or clinical phenotypes. It is often inferred or assumed that such associations are causal, mediated by a direct effect of the polymorphism on the gene product itself. However, the supporting evidence is not always clear. METHODS: We conducted systematic reviews and meta-analyses to assess the empirical evidence for functional polymorphisms in genes encoding dopaminergic enzymes (COMT, DBH, DDC, MAOA, MAOB, and TH), dopamine receptors (DRD1, DRD2, DRD3, DRD4, and DRD5), the dopamine transporter (DAT), and vesicular transporters (VMAT1 and VMAT2). We defined functionality as an effect of the polymorphism on the expression, abundance, activity, or affinity of the gene product. RESULTS: We screened 22,728 articles and identified 255 eligible studies. We found robust and medium to large effects for polymorphisms in 4 genes. For catechol-O-methyltransferase (COMT), the Val 158 Met polymorphism (rs4680) markedly affected enzyme activity, protein abundance, and protein stability. Dopamine b-hydroxylase (DBH) activity was associated with rs1611115, rs2519152, and the DBH-STR polymorphism. Monoamine oxidase A (MAOA) activity was associated with a 5 0 VNTR polymorphism. Dopamine D 2 receptor (DRD2) binding was influenced by the Taq1A (rs1800497) polymorphism, and rs1076560 affected DRD2 splicing. CONCLUSIONS: Some widely studied dopaminergic polymorphisms clearly and substantially affect the abundance or activity of the encoded gene product. However, for other polymorphisms, evidence of such an association is negative, inconclusive, or lacking. These findings are relevant when selecting polymorphisms as "markers" of dopamine function, and for interpreting the biological plausibility of associations between these polymorphisms and aspects of brain function or dysfunction.

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The activity of catechol-O-methyltransferase (COMT) is not impaired by high doses of epigallocatechin-3-gallate (EGCG) in vivo

Cited by 47 publications

References 37 publications

Suppressive Effects of Tea Catechins on Breast Cancer

Suppressive Effects of Tea Catechins on Breast Cancer

Long-Term Supplementation of Green Tea Extract Does Not Modify Adiposity or Bone Mineral Density in a Randomized Trial of Overweight and Obese Postmenopausal Women

Which Dopamine Polymorphisms Are Functional? Systematic Review and Meta-analysis of COMT, DAT, DBH, DDC, DRD1–5, MAOA, MAOB, TH, VMAT1, and VMAT2

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