Green tea polyphenols and their potential role in health and disease.

There is a growing body of evidence that plant polyphenols such as resveratrol, anthocyanins, catechins, and terpenes like taxol are effectively used in the treatment of chronic conditions including cancer, Alzheimer, Parkinsonism, diabetes, aging, etc. The link between oxidative stress and inflammation is well accepted. Thus, the mechanism of action of these natural products is partly believed to be through their significant antioxidant properties. The main constituent of green tea, with clinical significance, is epigallocatechin gallate (EGCG). It has been associated with antitumor, anti-Alzheimer, and anti-aging properties, improve redox status at the tissue level possibly preventing system level structural damage. This review focuses on EGCG and its potential therapeutic role in health and disease.

Cyto-protective and immunomodulating effect of Curcuma longa in Wistar rats subjected to carbon tetrachloride-induced oxidative stress.

A comparison of crude curcuminoid extract and purified curcumin was made to evaluate hepato- and immunoprotective effect of Curcuma longa (turmeric) Zingiberaceae. Carbon tetrachloride (CCl4) induced cellular hepatic damage was evaluated by transmission electron microscopy, hepatic enzymes and thiobarbituric acid reactive species (TBAR) values. A selective cytolytic effect of CCl4 was observed among immature (PNA+) thymocytes and peripheral helper (CD4+) T lymphocytes in spleen and was paralleled by a significant reduction in CD25, CD71 and Con A receptor expression. Treatment with curcuminoid crude extract at two different doses, showed a significant cellular recovery among hepatocytes, which was reflected in a reduction of hepatic enzymes and TBAR values. A significant restoration of lymphocyte viability and CD25, CD71 and Con A receptor expression in both immature (PNA+) thymocytes and splenic helper (CD4+) T lymphocytes was observed. Turmeric crude extract, at both low and high dose, was found to be more efficient as compared to purified curcumin.

Hepatotoxicity induced by the anti-oxidant food additive, butylated hydroxytoluene (BHT), in rats: an electron microscopical study.

The anti-oxidant food additive, butylated hydroxytoluene (BHT), was fed to Sprague-Dawley rats at three concentrations: 0.2%, 0.4% and 0.8% for periods of 6, 12, 18 and 24 weeks, and the results were compared with corresponding groups treated with a potent carcinogen, 7,12-dimethylbenz[a]anthracene (DMBA) groups, with olive oil, and with untreated control groups. BHT resulted in a significant increase in liver weight. The liver cells presented gradual vacuolization, cytoplasmic disintegration, "moth-eaten" appearance, ballooning degeneration, hepatocellular necrosis, aggregation of chromatin material around the periphery of the nuclear envelope, SER proliferation, RER clumping with broken cisternae, withered and autolyzed mitochondria, augmentation of lipid droplets and glycogen depletion. On the other hand, there was no sign of tumorigenicity. Whether or not BHT acts as a carcinogen in long-term administration may depend not only upon the organ system examined, but also on the strain of the animal used.

Cytotoxicity of Kuwait weathered lake crude oil on rat hepatocytes: a histological and ultrastructural study.

In the present study, the cytotoxic effects of Kuwaiti weathered crude oil and a potent carcinogen (DMBA) on rat liver cells were examined by light and electron microscopy at each of 4 sampling periods after the start of low dosing (0.5 and 0.2 mg/kg) of feed. Such effects were compared with those of olive oil and uncontaminated food-exposed controls. The results confirm a pronounced cell damage which statistically not significant (p < 0.05). In crude oil, the organelle changes were variable and highly comparable to that of DMBA. The nuclei were mostly disintegrated while the cell showed demarcation of cytoplasmic vacuolization, lipid augmentation, and mitochondrial aberrations. The latter showed a remarkable association with the rough endoplasmic reticulum and lipid droplets, and appeared as decayed and diffused structures within the cell matrix. There was no comparable changes in the hepatocytes of animals fed with uncontaminated food except for the formation of lipid droplets in the olive oil-fed groups. Although the animals food was contaminated with Kuwaiti weathered oil formed in 1991 were exposed to extreme seasonal temperatures, yet the residues of such oil led to severe histopathological alterations in the liver cells which were similar to those of DMBA-treated cells. There is the need to pay attention to potential hazardous effects of the crude oil on environments.