Chemical composition of green tea (Camellia sinensis) infusions commercialized in Portugal.

To evaluate the potential benefits and risks associated with tea consumption it is important to identify the constituents of this beverage. Levels of some minerals, caffeine and catechins in green tea samples commercialized in Portugal were evaluated. Potassium is the metal present in larger amount (92-151 mg/l). The content of sodium, calcium, fluoride, aluminium, manganese and iron were 35-69, 1.9-3.5, 0.80-2.0, 1.0-2.2, 0.52-1.9, 0.020-0.128 mg/l, respectively. Chromium and selenium were not detected. The resulting data showed considerable variability in catechins content. The levels of epigallocatechin gallate (EGCG) ranged from 117 to 442 mg/l, epicatechin 3-gallate (EGC) from 203 to 471 mg/l, epigallocatechin (ECG) from 16.9 to 150 mg/l, epicatechin (EC) from 25 to 81 mg/l and catechin (C) from 9.03 to 115 mg/l. Caffeine contents in the green tea infusions studied were between 141-338 mg/l. Green tea infusions provide significant amounts of catechins and could be an important source of some minerals.

Noncleavable poly(ADP-ribose) polymerase-1 regulates the inflammation response in mice.

Poly(ADP-ribosyl)ation is rapidly formed in cells following DNA damage and is regulated by poly(ADP-ribose) polymerase-1 (PARP-1). PARP-1 is known to be involved in various cellular processes, such as DNA repair, genomic stability, transcription, and cell death. During apoptosis, PARP-1 is cleaved by caspases to generate 89-kDa and 24-kDa fragments, a hallmark of apoptosis. This cleavage is thought to be a regulatory event for cellular death. In order to understand the biological significance of PARP-1 cleavage, we generated a PARP-1 knockin (PARP-1(KI/KI)) mouse model, in which the caspase cleavage site of PARP-1, DEVD(214), was mutated to render the protein resistant to caspases during apoptosis. While PARP-1(KI/KI) mice developed normally, they were highly resistant to endotoxic shock and to intestinal and renal ischemia-reperfusions, which were associated with reduced inflammatory responses in the target tissues and cells due to the compromised production of specific inflammatory mediators. Despite normal binding of NF-kappaB to DNA, NF-kappaB-mediated transcription activity was impaired in the presence of caspase-resistant PARP-1. This study provides a novel insight into the function of PARP-1 in inflammation and ischemia-related pathophysiologies.