The vitamin E analog tocopherol succinate strongly inhibits gap junctional intercellular communication in rat liver epithelial cells (IAR203)

Chaumontet, Catherine; Bex, Valérie; Véran, Frédéric; Martel, Paule Latino

doi:10.1016/j.jnutbio.2007.03.005

Cited by 15 publications

(6 citation statements)

References 45 publications

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“…The presence of tocopherols in soybean oil is very important, as they have nutritional value, as a source of vitamin E, besides acting as natural antioxidants, retarding the oxidation process (Chaumontet et al , 2008). In Table V, it is observed that the levels of tocopherols in treatments decreased during thermal oxidation, with significant difference among the times studied.…”

Section: Resultsmentioning

confidence: 99%

Effect of grape seed extract (Vitis labruscaL.) on soybean oil under thermal oxidation

Freitas

Cattelan

Rodrigues

et al. 2017

NFS

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Purpose This study aims to evaluate the effect of grape seed extract on the thermal oxidation of soybean oil. Design/methodology/approach Four treatments were used: soybean oil (SO), butylhydroxytoluene (BHT), antioxidant at concentration of 100 mg/kg in soybean oil (BHTSO), grape seed extract at a concentration of 100 mg/kg in soybean oil (Extract), and mixture at a concentration of 50 mg/kg of grape seed extract (Mixture) and 50 mg/kg of BHT in soybean oil subjected to 180°C for 20 h. The total phenolic compounds were quantified by spectrophotometry using the Folin-Ciocalteu reagent. The antioxidant activity was evaluated by the ABTS•+, DPPH• and FRAP acid systems. The fatty acid composition and phytosterols were determined by gas chromatography (GC) and tocopherols were determined by high-performance liquid chromatography. Findings Among the treatments studied, the Extract and the Mixture presented lower losses of total phenolic compounds, DPPH• and FRAP, while BHTSO had an opposite effect. After 10 h of heating, the Mixture and the Extract were more effective in reducing the formation decomposition products, measured by the amount of total polar compounds. The Mixture resulted in higher retention of essential fatty acids at the end of heating. The Extract and Mixture showed higher retention rates of total tocopherols and the Mixture resulted in 338.71 mg/100 g (P ≤ 0.05) of total phytosterol after 20 h of heating. Originality/value Oils undergoing the heating process suffer major changes, requiring the addition of antioxidant compounds. As a result of the questioning on the use of chemical additives, research on natural antioxidants, as substitute to the synthetic ones, is increasing. Among the natural compounds with high antioxidant potential, the grape wastes such as its seeds are highlighted. Studies using grape seed extract are scarce.

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Section: Resultsmentioning

confidence: 99%

Effect of grape seed extract (Vitis labruscaL.) on soybean oil under thermal oxidation

Freitas

Cattelan

Rodrigues

et al. 2017

NFS

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“…In cultured rat hepatocytes, aTP protects against ethyl methanesulfonate-induced cell death and lipid peroxidation, and protects against lethal doses of gamma irradiation, possibly by increasing the tissue aT levels (reviewed in [31]). aTP inhibited gap junctional intercellular communication in rat liver epithelial cells (IAR203) with no effect on connexin 43 phosphorylation, toxicity, and cell proliferation [100].…”

Section: Biological Activities Of Atpmentioning

confidence: 99%

α‐Tocopheryl phosphate – An active lipid mediator?

Zingg

Meydani

Azzi

2010

Molecular Nutrition Food Res

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The vitamin E (alpha-tocopherol, alphaT) derivative, alpha-tocopheryl phosphate (alphaTP), is detectable in small amounts in plasma, tissues, and cultured cells. Studies done in vitro and in vivo suggest that alphaT can become phosphorylated and alphaTP dephosphorylated, suggesting the existence of enzyme(s) with alphaT kinase or alphaTP phosphatase activity, respectively. As a supplement in animal studies, alphaTP can reach plasma concentrations similar to alphaT and only a part is dephosphorylated; thus, alphaTP may act both as pro-vitamin E, but also as phosphorylated form of vitamin E with possibly novel regulatory activities. Many effects of alphaTP have been described: in the test tube alphaTP modulates the activity of several enzymes; in cell culture alphaTP affects proliferation, apoptosis, signal transduction, and gene expression; in animal studies alphaTP prevents atherosclerosis, ischemia/reperfusion injury, and induces hippocampal long-term potentiation. At the molecular level, alphaTP may act as a cofactor for enzymes, as an active lipid mediator similar to other phosphorylated lipids, or indirectly by altering membrane characteristics such as lipid rafts, fluidity, and curvature. In this review, the molecular and cellular activities of alphaTP are examined and the possible functions of alphaTP as a natural compound, cofactor and active lipid mediator involved in signal transduction and gene expression discussed.

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“…Immunofluorescence staining was performed as previously described. 26,27) After the treatment of cells with the Tiglium seed extract for 1 h, WB-F344 cells were washed with D-PBS and fixed with 4% paraformaldehyde for 20 min at room temperature. The cells were further washed and blocked with 3% bovine serum albumin (Amresco, Solon, OH, USA) in D-PBS containing 0.05% Tween 20 for 1 h. The cells were incubated with rabbit polyclonal anti-Cx43 antibody (Sigma-Aldrich) at 4°C for overnight and then incubated with an Alexa fluor 488 goat anti-rabbit IgG (Molecular Probes, Eugene, OR, USA) for 1 h at room temperature.…”

Section: Methodsmentioning

confidence: 99%

Mutagenicity and tumor-promoting effects of Tiglium seed extract via PKC and MAPK signaling pathways

Kim

Yun

Kim

et al. 2015

Bioscience, Biotechnology, and Biochemistry

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Tiglium seed is a seed of mature Croton Tiglium Linne containing croton oils, which have been traditionally used as laxative or purgative. As it contains phorbol derivatives, we investigated the mutagenicity and tumor-promoting activity of Tiglium seed. Tiglium seed extract produced the mutagenic responses in five Salmonella typhimurium strains in Ames assay, whereas it did not alter the frequencies of chromosomal aberrations or micronuclei, indicating that it exerted the mutagenic potential, not clastogenicity. Accompanied with phosphorylation of connexin43 (Cx43) and extracellular signal-regulated kinases 1/2 (ERK1/2), Tiglium seed extract inhibited gap junctional intercellular communication (GJIC) associated with tumor-promoting potential. Importantly, these effects were blocked by a protein kinase C (PKC) inhibitor or mitogen-activated protein kinase (MAPKs) inhibitors, suggesting that Tiglium seed-induced GJIC inhibition was regulated by phosphorylation of Cx43 via PKC and MAPKs signaling. In conclusion, Tiglium seed has mutagenicity, possibly linking to tumor-promoting potential through the dysfunction of GJIC.

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The vitamin E analog tocopherol succinate strongly inhibits gap junctional intercellular communication in rat liver epithelial cells (IAR203)

Cited by 15 publications

References 45 publications

Effect of grape seed extract (Vitis labruscaL.) on soybean oil under thermal oxidation

Effect of grape seed extract (Vitis labruscaL.) on soybean oil under thermal oxidation

α‐Tocopheryl phosphate – An active lipid mediator?

Mutagenicity and tumor-promoting effects of Tiglium seed extract via PKC and MAPK signaling pathways

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