Protective effect of green tea against lipid peroxidation in the rat liver, blood serum and the brain

Skrzydlewska, Elżbieta; Ostrowska, Justyna; Farbiszewski, R; Michalak, Kamil

doi:10.1078/0944-7113-00119

Cited by 175 publications

(115 citation statements)

References 34 publications

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“…Administration of tea and tea polyphenols was previously reported to prevent or attenuate decreases in levels of tissue GSH in a number of animal models. [39][40][41] In addition, it bears notice that EGCG was used at 50 mM in our experiments, which was much lower than that of NAC (5 mM) used (Figures 7-10). However, the phyto-chemical showed a similar ability, if not higher, to increase the level of cellular GSH and to interrupt TGF-b signaling.…”

Section: Discussionmentioning

confidence: 99%

The antifibrogenic effect of (−)-epigallocatechin gallate results from the induction of de novo synthesis of glutathione in passaged rat hepatic stellate cells

Zhou

Zheng

et al. 2006

Laboratory Investigation

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Hepatic stellate cells (HSC) are the major players during hepatic fibrogenesis. Overproduction of extracellular matrix (ECM) is a characteristic of activated HSC. Transforming growth factor-beta (TGF-b) is the most potent fibrogenic cytokine while connective tissue growth factor (CTGF) mediates the production of TGF-b-induced ECM in activated HSC. HSC activation and hepatic fibrogenesis are stimulated by oxidative stress. Glutathione (GSH) is the most important intracellular antioxidant. The aim of this study is to explore the mechanisms of (À)-epigallocatechin-3-gallate (EGCG), the major and most active component in green tea extracts, in the inhibition of ECM gene expression in activated HSC. It is hypothesized that EGCG inhibits ECM gene expression in activated HSC by interrupting TGF-b signaling through attenuating oxidative stress. It is found that EGCG interrupts TGF-b signaling in activated HSC by suppressing gene expression of type I and II TGF-b receptors. EGCG inhibits CTGF gene expression, leading to the reduction in the abundance of ECM, including aI(I) procollagen. Exogenous CTGF dose dependently eliminates the antifibrogenic effect. EGCG attenuates oxidative stress in passaged HSC by scavenging reactive oxygen species and reducing lipid peroxidation. De novo synthesis of GSH is a prerequisite for EGCG to interrupt TGF-b signaling and to reduce the abundance of aI(I) procollagen in activated HSC in vitro. Taken together, our results demonstrate that the interruption of TGF-b signaling by EGCG results in the suppression of gene expression of CTGF and ECM in activated HSC in vitro. In addition, our results, for the first time, demonstrate that the antioxidant property of EGCG derived from de novo synthesis of intracellular GSH plays a critical role in its antifibrogenic effect. These results provide novel insights into the mechanisms of EGCG as an antifibrogenic candidate in the prevention and treatment of liver fibrosis.

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Section: Discussionmentioning

confidence: 99%

The antifibrogenic effect of (−)-epigallocatechin gallate results from the induction of de novo synthesis of glutathione in passaged rat hepatic stellate cells

Zhou

Zheng

et al. 2006

Laboratory Investigation

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“…These data confirmed by [42] they said that SOD plays an important role in attenuating oxidative damage in vivo, thereby delaying not only the onset of age-related degenerative disease, but also aging itself. In vivo study made by [43] intake of green tea extracts also increase the activity of superoxide dismutase in serum and the expression of catalase, these enzymes play a role in cellular protection against reactive oxygen species.…”

Section: Discussionmentioning

confidence: 99%

Protictive effects of green tea and garlic on the morphological and oxidative stress changes of hippocampus in aged male and female albino rats

El‐Sokkary¹,

Alghriany²,

Atia³

2018

J Histol Histopathol

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Objective: Green tea is an extremely popular drink and particularly rich in strong antioxidants, flavonoids. Also, garlic is important dietary and has medicinal role for centuries and possess both antioxidant and antiinflammatory action in several oxidative stress conditions. Materials and methods: Four groups of both male and female rats [young (3 months-old), aged (26 months-old), aged+green tea (200 mg/kg) and aged+garlic (100 mg/kg)] were used. Histological changes in the pyramidal cells of the hippocampus were examined. Levels of oxidized lipids (LPO), superoxide dismutase (SOD) activity and glutathione concentration (GSH) were measured in the serum. Results: Irregular, shrinked and deeply stained large and small pyramidal cells with fragmented nuclei and basophilic cytoplasm observed in the hippocampus of aged male and female rats. Green tea and garlic administration preserve these changes in the pyramidal cells in both genders. Aging increased the level of LPO, decreased the activity of SOD and the concentration of GSH of both male and female rats versus those of young ones. Again, green tea and garlic ameliorated these changes. Conclusion: our results showed that the protective role of green tea and garlic against oxidative stress parameters was more effective in males than females. Morphologically, garlic exerted preservation to the pyramidal cells of hippocampus more than green tea in both genders. This study suggests that the use of both green tea and garlic may inhibit the bodily changes related to aging.

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“…Animal studies have shown that green tea administration can reduce lipid peroxidation in diabetic animals (Yamaguchi et al, 1991;Tijburg et al, 1997;Vinson et al, 1998;Miura et al, 2001;Guleria et al, 2002;Kasaoka et al, 2002;Liuji et al, 2002;Sabu et al, 2002;Skrzydlewska et al, 2002;. Black tea has been reported to be an efficient reducer of peroxidation of lipoproteins as well Vinson et al, 1998;Sur-Altiner et al, 2000;Yokozawa et al, 2002;Vinson et al, 2005;Alipoor et al, 2008).…”

Section: Evidence From Animal Studiesmentioning

confidence: 99%

“…Actually some enzymes showed greater activity after the very supplementation in one study but not the other which seems to be due to different doses of supplementation, design and duration of the study (Khan et al, 1992;Lin et al, 1998;Durate et al, 2001;Sabu et al, 2002;Skrzydlewska et al, 2002;Chander et al, 2003;Kuo et al, 2005;Alipoor et al, 2009). …”

Section: Evidence From Animal Studiesmentioning

confidence: 99%

See 1 more Smart Citation

Diabetes, Oxidative Stress and Tea

Alipoor¹,

Rad²,

Mehrabany³

2012

Oxidative Stress - Environmental Induction and Dietary Antioxidants

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Protective effect of green tea against lipid peroxidation in the rat liver, blood serum and the brain

Cited by 175 publications

References 34 publications

The antifibrogenic effect of (−)-epigallocatechin gallate results from the induction of de novo synthesis of glutathione in passaged rat hepatic stellate cells

The antifibrogenic effect of (−)-epigallocatechin gallate results from the induction of de novo synthesis of glutathione in passaged rat hepatic stellate cells

Protictive effects of green tea and garlic on the morphological and oxidative stress changes of hippocampus in aged male and female albino rats

Diabetes, Oxidative Stress and Tea

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