Effects of green tea catechins on the pro-inflammatory response after haemorrhage/resuscitation in rats

Abstract

Plant polyphenols, i.e. green tea extract (GTE), possess high antioxidative and anti-inflammatory capacity, thus being protective in various models of acute inflammation. However, their anti-inflammatory effect and a feasible mechanism in haemorrhage/resuscitation (H/R)-induced liver injury remain unknown. We investigated the effects of GTE and the role of NF-kB in the pathogenesis of liver injury induced by H/R, and their effects on intercellular adhesion molecule-1 (ICAM-1) expression and neutrophil infiltration. Female Lewis rats were fed a standard chow diet (control, ctrl) or a diet containing 0·1 % polyphenolic GTE for five consecutive days before H/R. Rats were haemorrhaged to a mean arterial pressure of 30 (SEM 2) mmHg for 60 min and resuscitated. Control groups (sham_ctrl and sham_GTE) underwent surgical procedures without H/R. At 2 h after resuscitation, tissues were harvested. Serum alanine aminotransferase (ALT) and IL-6 were measured. Hepatic necrosis, ICAM-1 expression and polymorphonuclear leucocyte (PMNL) infiltration were assessed. Hepatic expression of IkBa (phospho) was measured. H/R induced strong liver damage with increased necrosis and serum ALT levels. Compared with both sham groups, inflammatory markers (serum IL-6 and hepatic PMNL infiltration) were elevated after H/R (P, 0·05). Also, H/R increased IkBa phosphorylation. GTE administration markedly (P,0·05) decreased serum ALT and IL-6 levels, hepatic necrosis as well as PMNL infiltration and the expression of ICAM-1 and phosphorylated IkBa compared with H/R. In conclusion, we observed that NF-kB activation plays an important role in the pathogenesis of liver injury after H/R through the up-regulation of hepatic ICAM-1 expression and subsequent PMNL infiltration. GTE pre-treatment prevents liver damage in this model of acute inflammation through a NF-kB-dependent mechanism.

Green tea protects human osteoblasts from cigarette smoke-induced injury: possible clinical implication

“…This emphasizes the need for new treatment strategies to reduce oxidative stress in patients, e.g., smokers that are reported to have strongly elevated oxidative stress levels. GTE and its major components, catechins, have been attributed anti-oxidative properties in the past [27]. This is supported by the report of Wu et al describing GTE's potential to improve bone mineral density in habitual tea drinkers [30].…”

“…Besides their function to directly scavenge ROS like the superoxide anion, oxygen singlet, and lipidic peroxyradicals, they can stabilize free ROS by means of hydrogenation or formation of complexes with oxidating species [23][24][25]. Based on that, polyphenols have been shown to have numerous biochemical and physiological benefits, including antioxidant, anti-microbial, anti-inflammatory, and cytoprotective activities [23,[26][27][28]. Clinical observations suggest that consuming green tea increases bone density and therefore reduces the risk of osteoporotic fractures [29,30].…”

Ethanol, ethyl and sodium pyruvate decrease the inflammatory responses of human lung epithelial cells via Akt and NF-κB in vitro but have a low impact on hepatocellular cells

“…Moreover, reduced tissue infiltration by neutrophils was closely associated with decreased CD54 expression (47). Jonsson and Palmblad have demonstrated that increased CD54 expression in HUVECs after stimulation with LPS resulted in enhanced adhesion rates of neutrophils to endothelial monolayers (22).…”

Leukotriene B4 indicates lung injury and on-going inflammatory changes after severe trauma in a porcine long-term model

“…Sections were counterstained with hematoxylin. Polymorphonuclear leukocytes were determined by counting the number of CAE positive cells in a total of 25 high power (400x) fields per lung section per pig in a blinded manner as described before [36]. Both lung lobes are included in the evaluation.…”