Protective effects of green tea against hepatic injury induced by high-cholesterol diet in rats: histopathological analysis, oxidative DNA damage and COX-2 expression.

Purpose: The goal of this study was to investigate whether daily administration of green tea is able to protect the liver injury induced by cholesterol.

Methods: Male Wistar rats (n = 24) were distributed into four groups: group 1, negative control; group 2, cholesterol at 1% (w/w) in the diet treated for 5 weeks; group 3, cholesterol at 1% treated for 5 weeks and green tea at 1% (w/v) in drinking water in the last week only and group 4, cholesterol and green tea at 1% in drinking water for 5 weeks.

Results: The results pointed out that treatment with green tea in the last week (group 3) showed mild degenerative changes of liver tissue in cholesterol exposed group when compared to group 2.

Grape juice concentrate prevents oxidative DNA damage in peripheral blood cells of rats subjected to a high-cholesterol diet.

The goal of the present study was to investigate whether subchronic treatment with grape juice concentrate is able to protect liver and peripheral blood cells against cholesterol-induced injury in rats. The effects of the grape juice concentrate treatment on histopathological changes, immunohistochemistry for cyclo-oxygenase-2 (COX-2), and basal and oxidative DNA damage induced by H2O2 using a single-cell gel (comet) assay were evaluated. Male Wistar rats (n 18) were divided into three groups: group 1--negative control; group 2--cholesterol at 1 % (w/w) in their diet, treated for 5 weeks; group 3--cholesterol at 1 % in their chow, treated for 5 weeks, and grape juice concentrate at 222 mg/d in their drinking-water in the final week only.