The Health Effects of Tea Polyphenols and Their Antioxidant Mechanism

Zhao, Baolu

doi:10.3164/jcbn.38.59

Cited by 16 publications

(13 citation statements)

References 62 publications

(55 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Green tea, which has polyphenols as a principal constituent, has been drunk widely in Japan and China for more than 5000 years [ 24 ]. It has been reported that the polyphenols in green tea have anti-tumor effects [ 16 , 17 ], and epidemiologically those who drink green tea regularly have a lower risk of cancer. Those who drink 10 cups or more of green tea every day have a lower risk of gastric cancer compared with those having a lesser intake[ 25 ].…”

Section: Discussionmentioning

confidence: 99%

“…Green tea polyphenols (GTP), which are compounds in Japanese green tea, are reported to have bactericidal properties against pathogenic bacteria in food and also have anti-tumor effects; attention has been given to their application as a new treatment for infectious diseases and malignant neoplasm [ 16 , 17 ]. In this study, we examined the effects of GTP on gastric proliferation and apoptosis in an H. pylori -infected mouse model.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Green Tea Polyphenols Reduce Gastric Epithelial Cell Proliferation and Apoptosis Stimulated by Helicobacter pylori Infection

Akai¹,

Nakajima²,

Itō³

et al. 2007

J. Clin. Biochem. Nutr.

View full text Add to dashboard Cite

Summary Recently the finding of gastric cancer in Helicobacter pylori (H. pylori)-infected mouse models was reported. Studies of humans and animal models have shown that H. pylori infection stimulates gastric epithelial cell proliferation and apoptosis. Polyphenols contained in green tea and related compounds were reported to have a variety anti-tumor effects and bactericidal properties. We studied the effect of green tea polyphenols on gastric cell proliferation and apoptosis in an H. pylori-infected mouse model. This model was prepared by inoculating Balb/c mice with 10 8 cfu of H. pylori (NCTC 11637 strain) by gavage. Beginning 18 weeks after inoculation, 0.5% polyphenols were given in drinking water every day for 2 weeks. Mice were sacrificed 1 h after bromodeoxyuridine (BrdU) was given i.p. for preparation of paraffin-embedded specimens. Cell proliferation and apoptosis were examined by the avidin-biotin complex method using anti-BrdU antibody and the TUNEL method, respectively. H. pylori infection resulted in increased BrdU-labeled cells in both the antrum and the bodies. Administration of polyphenols suppressed this increased proliferation. H. pylori infection increased apoptotic cells in both the antrum and the corpus in comparison with controls. This increase was not seen in H. pylori-infected mice given polyphenols. We conclude the administration with polyphenols might suppress gastric carcinogenesis that is in part related to H. pylori infection.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Green Tea Polyphenols Reduce Gastric Epithelial Cell Proliferation and Apoptosis Stimulated by Helicobacter pylori Infection

Akai¹,

Nakajima²,

Itō³

et al. 2007

J. Clin. Biochem. Nutr.

View full text Add to dashboard Cite

show abstract

“…The growing evidence towards the health benefits of tea has resulted in extensive studies to unravel the scientific basis of the healing and curing power of tea 3,4. A well accepted scientific consensus that is emanating from several scientific investigations is that tea contains high levels of antioxidant polyphenols, including flavonoids, and catechins, and all of which scavenge the dangerous free radicals in the body and thus, prevent the progress of various diseases 25-34. Polyphenolic flavonoids in tea (Fig 1), of which epigallocatechin gallate (EGCG) is the second major constituent, has anticarcinogenic activity in vitro which may support the results of the epidemiologic research on the correlation between drinking tea and the risk of morbidity from cancer.…”

Section: Introductionmentioning

confidence: 99%

Green nanotechnology from tea: phytochemicals in tea as building blocks for production of biocompatible gold nanoparticles

et al. 2009

View full text Add to dashboard Cite

Phytochemicals occluded in tea have been extensively used as dietary supplements and as natural pharmaceuticals in the treatment of various diseases including human cancer. Results on the reduction capabilities of phytochemicals present in tea to reduce gold salts to the corresponding gold nanoparticles are presented in this paper. The phytochemicals present in tea serve the dual roles as effective reducing agents to reduce gold and also as stabilizers to provide robust coating on the gold nanoparticles in a single step. The Tea-generated gold nanoparticles (T-AuNPs), have demonstrated remarkable in vitro stability in various buffers including saline, histidine, HSA, and cysteine solutions. T-AuNPs with phytochemical coatings have shown significant affinity toward prostate (PC-3) and breast (MCF-7) cancer cells. Results on the cellular internalization of T-AuNPs through endocytosis into the PC-3 and MCF-7 cells are presented. The generation of T-AuNPs follows all principles of green chemistry and have been found to be non toxic as assessed through MTT assays. No 'man made' chemicals, other than gold salts, are used in this true biogenic green nanotechnological process thus paving excellent opportunities for their applications in molecular imaging and therapy.

show abstract

“…Green tea is widely consumed in the eastern world. Studies have shown that green tea possess diverse pharmacological properties that include anti-oxidative, anti-inflammatory, anti-carcinogenic, anti-arteriosclerotic and anti-bacterial effects [ 8 – 11 ]. Several previous studies demonstrated the inhibitory effects of green tea on NV in the vascular changes of the eye.…”

Section: Introductionmentioning

confidence: 99%

Effects of Green Tea Fractions on Oxygen-Induced Retinal Neovascularization in the Neonatal Rat

Saito

Hasebe-Takenaka

Ueda

et al. 2007

J. Clin. Biochem. Nutr.

View full text Add to dashboard Cite

Summary This study aimed to investigate the preventive effects of green tea fractions (GTFs) on rat model of oxygen-induced retinopathy (OIR). Neonatal Sprague-Dawley rats were exposed to daily cycles of 80% oxygen (20.5 h), ambient air (0.5 h), and progressive return to 80% oxygen (3 h) until postnatal day 12 (P12), then the rats were placed in ambient air until P18. The green tea was fractionated by DM-A50, DM-W, M-B, and M-W. The rats were treated once daily from P6 to P17 by gastric gavage of GTFs (0.05 or 0.01 g/ml) or distilled water (DW) at 50 µl/10 g body weight. On P18, the rats were sacrificed and the retinal samples were collected. The retinal neovascularization (NV) was scored and avascular areas (AVAs) were measured as a % of total retinal area (%AVAs) in ADPase stained retinas. The NV scores in 0.01 g/ml M-W were significantly lower than those in DW. The %AVAs in 0.05 g/ml DM-A50 and in 0.05 g/ml and 0.01 g/ml M-W were significantly lower than those in DW. There were less catechins, and less caffeine in M-W fraction compared with other GTFs, suggesting components of green tea except for catechins and caffeine might suppress the neovascularization in rat model of OIR.

show abstract

The Health Effects of Tea Polyphenols and Their Antioxidant Mechanism

Cited by 16 publications

References 62 publications

Green Tea Polyphenols Reduce Gastric Epithelial Cell Proliferation and Apoptosis Stimulated by Helicobacter pylori Infection

Green Tea Polyphenols Reduce Gastric Epithelial Cell Proliferation and Apoptosis Stimulated by Helicobacter pylori Infection

Green nanotechnology from tea: phytochemicals in tea as building blocks for production of biocompatible gold nanoparticles

Effects of Green Tea Fractions on Oxygen-Induced Retinal Neovascularization in the Neonatal Rat

Contact Info

Product

Resources

About