Because of the possible application of tea in the prevention of oral and esophageal cancers, the salivary levels of tea catechins were determined in six human volunteers after drinking tea. Saliva samples were collected after thoroughly rinsing the mouth with water. After drinking green tea preparations equivalent to two to three cups of tea, peak saliva levels of (-)-epigallocatechin (EGC; 11....

The effects of tea catechins, including (–)-epicatechin (EC), (–)-epigallocatechin (EGC), (–)-epicatechingallate (ECg) or (–)-epigallocatechingallate (EGCg) on the lipid peroxidation induced by either ferrous (Fe), copper (Cu) or vanadium (V ) ions were examined in normal and α-linolenic acid-loaded (LNA-loaded) cultured rat hepatocytes. The order of antioxidative activity was almost similar an...

The main aims of this study were to elucidate the effect of green tea catechins on Nudix-type motif 6 (NUDT6) suppression and to characterize NUDT6's biological activity. Our microarray data showed that the green tea component epicatechin-3-gallate suppressed NUDT6 expression, and this was confirmed by RT-PCR. Subsequently, the use of different catechins showed that the effect of epigallocatech...

Carbonylation is an irreversible modification in oxidized proteins that has been directly related to a number of health disorders including Type 2 diabetes. Dietary antioxidants have been proposed to counteract the oxidative stress occurring under hyperglycemic conditions. An understanding of the nature and consequences of the molecular interactions between phytochemicals and human plasma prote...

Our previous research showed that tea catechins could significantly increase the viability of lead-exposed PC12 cells. Whereas the cellular thiol status is known to be responsible for protecting against lead-induced toxicity, whether the role of tea catechins on lead-induced PC12 cell toxicity is related to the metabolism of intracellular thiol compounds remained vague. In the present study, it...

Tea is the most widely consumed beverage in the world. Tea leaves are a source of polyphenols, especially catechins, a decisive group for their antioxidative activity. This paper reviews what is known of green tea species, its leaves processing and changes occurring in tea components. The main green tea polyphenols are catechins: (±)-catechin C, (-)-epicatechin EC, (+)-gallocatechin GC, (-)-epi...

diabetes is one of the most common metabolic disorders and is interrelated to oxidative stress-induced diseases. according to the role of dietary antioxidants in control and prevention of diabetes, this study was aimed to evaluate the effect of green tea extract on serum glucose levels and serum and hepatic total antioxidant capacity (tac) and lipid (mda) in diabetic rats. experimental diabetes...

cent studies have shown that green tea and its component polyphenol have a chemopreventing effect on models of cancer in vitro and in vivo. ( )-Epigallocatechin-3-gallate (EGCG) is a major component of polyphenols in green tea and is reported to inhibit the proliferation and to induce apoptosis in cancer cells. A typical cup of green tea contains 100—150 mg of catechins, including 8% ( )-epicat...

Tea catechins, an important class of polyphenols, have been shown to have wide spectrum of antitumor activity believed to be due mainly to their antioxidative effect. In this study, the radical scavenging behavior of catechins on 2,2-diphenyl-1-picrylhydrazyl (DPPH) was studied. Two reaction products of (+)-catechin, and two reaction products of (-)-epicatechin were purified and identified. The...

Numerous laboratory and clinical studies have reported that the green tea catechin extract Polyphenon E exert anticancer activity, but the underlying mechanism of action was elusive. We have recently shown that Polyphenon E exerts antineoplastic effects by antagonizing tumor-induced myeloid derived suppressor cells (MDSCs).