Epigallocatechin-3-gallate enhances key enzymatic activities of hepatic thioredoxin and glutathione systems in selenium-optimal mice but activates hepatic Nrf2 responses in selenium-deficient mice

Dong, Ruixia; Wang, Dongxu; Wang, Xiaoxiao; Zhang, Ke; Chen, Pingping; Yang, Chung S.; Zhang, Jinsong

doi:10.1016/j.redox.2016.10.009

Cited by 40 publications

(38 citation statements)

References 72 publications

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“…Thus, the effects of Se can also result from its effect on the expression of Nrf2, a master transcription factor that regulates the expression of antioxidant proteins. A previous study showed that the influence of epigallocatechin-3-gallate on the intracellular Nrf2 levels was removed in Se-optimal mice [37]. Upon oxidative stress, the ubiquitination of Nrf2 stops.…”

Section: Discussionmentioning

confidence: 99%

Protective Effects of Inorganic and Organic Selenium on Heat Stress in Bovine Mammary Epithelial Cells

Zou

Shao

et al. 2019

Oxidative Medicine and Cellular Longevity

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When dairy cows are exposed to high-temperature environment, their antioxidant capacity and productive performance decrease, leading to economic losses. Emerging evidence has shown that selenium (Se) can effectively alleviate heat stress in dairy cows; however, the cellular mechanism underlying this protection is not clear. The purpose of this study was to investigate and compare the protective effects of inorganic Se (sodium selenite, SS) and organic Se (selenite methionine, SM) in MAC-T (mammary alveolar cells-large T antigen, a bovine mammary epithelial cell (BMEC) line) cells during heat stress. MAC-T cells were treated in 4 ways unless otherwise described: (i) cells in the heat treatment (HT) group were cultured at 42.5°C for 1 h and then recovered in 37°C for another 12 h; (ii) the SM group was pretreated with organic Se for 2 h, cultured at 42.5°C for 1 h, and then recovered in 37°C for 12 h; (iii) the SS group was treated similarly to the SM group except that the cells were pretreated with inorganic Se instead of organic Se; and (iv) the control group was continuously cultured in 37°C and received no Se treatment. The results showed that heat shock at 42.5°C for 1 h triggered heat shock response, sabotaged the redox balance, and reduced cell viability in MAC-T cells; and pretreatment of cells with SM or SS effectively alleviated the negative effects of heat shock on the cells. However, the cells were much more sensitive to SS treatment but more tolerant to SM. In addition, two forms of Se appeared to affect the expression of different genes, including nuclear factor erythroid 2-related factor 2 (Nrf2) and inducible nitric oxide synthase (iNOS) in the SM group and thioredoxin reductase 1 (TXNRD1) in the SS group in Nrf2-ARE (antioxidant response element) antioxidant pathway and inflammation response. In summary, results showed the mechanistic differences in the protective effects of organic and inorganic Se on heat stress in BMECs.

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Section: Discussionmentioning

confidence: 99%

Protective Effects of Inorganic and Organic Selenium on Heat Stress in Bovine Mammary Epithelial Cells

Zou

Shao

et al. 2019

Oxidative Medicine and Cellular Longevity

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“…In at least 13 animal models for human carcinogenesis of the lung, oral cavity, esophagus, stomach, small intestine, colorectal, colon, skin, liver, pancreas, bladder, prostate, or mammary glands, EGCG has shown cancer preventive activities [27,28]. Like melatonin, EGCG is also an antioxidant via its direct quenching of ROS or indirect induction of basal and/or Nrf2-dependent antioxidant defense systems [27,29]. On the other hand, at high doses and in certain environments, EGCG can act as a prooxidant owing to its auto-oxidation, resulting in the formation of the superoxide anion and hydrogen peroxide [30].…”

Section: Introductionmentioning

confidence: 99%

Melatonin and (−)-Epigallocatechin-3-Gallate: Partners in Fighting Cancer

Zhang

et al. 2019

Cells

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We have demonstrated previously that melatonin attenuates hepatotoxicity triggered by high doses of (−)-epigallocatechin-3-gallate (EGCG) in mice. The current work investigated the influence of melatonin on the oncostatic activity of EGCG in two cancer cell lines, wherein melatonin induced an opposite response of p21. In human tongue cancer TCA8113 cells, melatonin-induced p21 and EGCG-mediated formation of quinoproteins were positively associated with the oncostatic effects of melatonin and EGCG. Melatonin-stimulated an increase in p21 which was correlated with a pronounced nuclear translocation of thioredoxin 1 and thioredoxin reductase 1, both of which are known to induce p21 via promoting p53 trans-activation. Melatonin did not influence the EGCG-mediated increase of quinoprotein formation nor did EGCG impair melatonin-induced p21 up-regulation. Co-treatment with both agents enhanced the cell-killing effect as well as the inhibitory activities against cell migration and colony formation. It is known that p21 also plays a powerful anti-apoptotic role in some cancer cells and confers these cells with a survival advantage, making it a target for therapeutic suppression. In human hepatocellular carcinoma HepG2 cells, melatonin suppressed p21 along with the induction of pro-survival proteins, PI3K and COX-2. However, EGCG prevented against melatonin-induced PI3K and COX-2, and melatonin probably sensitized HepG2 cells to EGCG cytotoxicity via down-regulating p21, Moreover, COX-2 and HO-1 were significantly reduced only by the co-treatment, and melatonin aided EGCG to achieve an increased inhibition on Bcl2 and NFκB. These events occurring in the co-treatment collectively resulted in an enhanced cytotoxicity. In addition, the co-treatment also enhanced the inhibitory activities against cell migration and colony formation. Overall, the results gathered from these two cancer cell lines with a divergent p21 response to melatonin show that the various oncostatic activities of melatonin and EGCG together are more robust than each agent alone, suggesting that they may be useful partners in fighting cancer.

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“…As the antioxidant and pro-oxidant activity of EGCG is not well established yet due to variation related to genetic background [99], doses, and pathological conditions [100], its use as a long-term treatment or supplement must be treated with caution.…”

Section: Discussionmentioning

confidence: 99%

Epigallocatechin Gallate Slows Retinal Degeneration, Reduces Oxidative Damage, and Modifies Circadian Rhythms in P23H Rats

et al. 2020

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Retinitis pigmentosa (RP) includes a group of genetic disorders that involve the loss of visual function due to mutations mainly in photoreceptors but also in other retinal cells. Apoptosis, retinal disorganization, and inflammation are common in the progression of the disease. Epigallocatechin gallate (EGCG) has been proved as beneficial in different eye diseases. Pigmented heterozygous P23H rat was used as an animal model of RP. Visual function was assessed by optomotor and electroretinogram (ERG) and circadian rhythms were evaluated by telemetry. Hepatic oxidative damage and antioxidant defenses were assessed using biochemical tests. The visual function of the EGCG P23H group was preserved, with a deterioration in the activity period and lower values in the interdaily stability parameter. Control rats treated with EGCG were less active than the sham group. EGCG increased antioxidant levels in P23H rats but reduced total hepatic antioxidant capacity by almost 42% in control rats compared to the sham group. We conclude that treatment with EGCG improves visual function and antioxidant status in P23H rats but diminishes antioxidant defenses in wild-type control animals, and slightly worsens activity circadian rhythms. Further studies are necessary to clarify the beneficial effects in disease conditions and in healthy organisms.

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Epigallocatechin-3-gallate enhances key enzymatic activities of hepatic thioredoxin and glutathione systems in selenium-optimal mice but activates hepatic Nrf2 responses in selenium-deficient mice

Cited by 40 publications

References 72 publications

Protective Effects of Inorganic and Organic Selenium on Heat Stress in Bovine Mammary Epithelial Cells

Protective Effects of Inorganic and Organic Selenium on Heat Stress in Bovine Mammary Epithelial Cells

Melatonin and (−)-Epigallocatechin-3-Gallate: Partners in Fighting Cancer

Epigallocatechin Gallate Slows Retinal Degeneration, Reduces Oxidative Damage, and Modifies Circadian Rhythms in P23H Rats

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