Catechins, polyphenols extracted from green tea leaves, have a broad range of biological activities although the specific molecular mechanisms responsible are not known. At the high experimental concentrations typically used polyphenols bind to membrane phospholipid and also are easily auto-oxidized to generate superoxide anion and semiquinones, and can adduct to protein thiols. We report that ...

A comprehensive study on the composition and antioxidant properties of black tea samples with a chemometric approach was performed via LC-ESI-Q-TOF-MS, DPPH radical scavenging assay, and Folin-Ciocalteu assay (TPC). Marked differences between the teas from seven different countries (China, India, Iran, Japan, Kenya, Nepal, Sri Lanka) were shown. The Indian samples demonstrated the highest total...

Aegle marmelos is a medicinal herb that has variety of biological constituents. “Catechins” are class phenolic compounds have therapeutic value. The present study employs batch extraction with methanol as solvent to extract the catechins from pulp fruit. Box–Behnken design response surface methodology (RSM-BBD) used optimize operational parameters impacting catechin extraction, such concentrati...

Vascular endothelial growth factor (VEGF) receptors (VEGFR) play a major role in tumor angiogenesis and, thus, represent attractive targets for the development of novel anticancer therapeutics. In this work, we report that green tea catechins are novel inhibitors of VEGFR-2 activity. Physiological concentrations (0.01-1 microM) of epigallocatechin-3 gallate, catechin-3 gallate, and, to a lesser...

Evaluating the binding energy of a catechin/caffeine complex in water is important in order to elucidate the ability for molecular recognition of tea catechins. The results of this study revealed that the stoichiometric ratio of the complexation between tea chatechins (EGCg, ECg, EGC, and EC) and caffeine was 1:1 at least up to a concentration of 5.0 mM. The free energy (-DeltaG) values for bin...

We compared anti-proliferative activities of (-)-epigallocatechin gallate (EGCG) and (-)-epigallocatechin (EGC) against HCT116 colorectal carcinoma cells. These catechins inhibited cell growth to nearly the same extent at low cell confluency in plates. However, their inhibitory effect grew weaker as cell confluence increased, and this tendency was more conspicuous for EGC than for EGCG. Both EG...

Nowadays it is accepted that natural flavonoids present in fruits and plant-derived-foods are relevant, not only for technological reasons and organoleptic properties, but also because of their potential health-promoting effects, as suggested by the available experimental and epidemiological evidence. The beneficial biological effects of these food bioactives may be driven by two of their chara...

The health benefits stemming from green tea are well known, but the exact mechanism of its biological activity is not elucidated. Epicatechin (EC) and epicatechin gallate (ECG) are two dietary catechins ubiquitously present in green tea. Serum albumins functionally carry these catechins through the circulatory system and eliminate reactive oxygen species (ROS) induced injury. In the present stu...