Antiradical, chelating and antioxidant activities of hydroxamic acids and hydroxyureas. (73/170)

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Fast and direct determination of butylated hydroxyanisole in biodiesel by batch injection analysis with amperometric detection. (74/170)

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Induction of NAD(P)H-quinone oxidoreductase 1 by antioxidants in female ACI rats is associated with decrease in oxidative DNA damage and inhibition of estrogen-induced breast cancer. (75/170)

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Activator protein-1 regulation of murine aldehyde dehydrogenase 1a1. (76/170)

Previously we demonstrated that aldehyde dehydrogenase (ALDH) 1a1 is the major ALDH expressed in mouse liver and is an effective catalyst in metabolism of lipid aldehydes. Quantitative real-time polymerase chain reaction analysis revealed a approximately 2.5- to 3-fold induction of the hepatic ALDH1A1 mRNA in mice administered either acrolein (5 mg/kg acrolein p.o.) or butylated hydroxylanisole (BHA) (0.45% in the diet) and of cytosolic NAD(+)-dependent ALDH activity. We observed approximately 2-fold increases in ALDH1A1 mRNA levels in both Nrf2(+)/(+) and Nrf2(-)/(-) mice treated with BHA compared with controls, suggesting that BHA-induced expression is independent of nuclear factor E2-related factor 2 (Nrf2). The levels of activator protein-1 (AP-1) mRNA and protein, as well as the amount of phosphorylated c-Jun were significantly increased in mouse liver or Hepa1c1c7 cells treated with either BHA or acrolein. With use of luciferase reporters containing the 5'-flanking sequence of Aldh1a1 (-1963/+27), overexpression of c-Jun resulted in an approximately 4-fold induction in luciferase activity, suggesting that c-Jun transactivates the Aldh1a1 promoter as a homodimer and not as a c-Jun/c-Fos heterodimer. Promoter deletion and mutagenesis analyses demonstrated that the AP-1 site at position -758 and possibly -1069 relative to the transcription start site was responsible for c-Jun-mediated transactivation. Electrophoretic mobility shift assay analysis with antibodies against c-Jun and c-Fos showed that c-Jun binds to the proximal AP-1 site at position -758 but not at -1069. Recruitment of c-Jun to this proximal AP-1 site by BHA was confirmed by chromatin immunoprecipitation analysis, indicating that recruitment of c-Jun to the mouse Aldh1a1 gene promoter results in increased transcription. This mode of regulation of an ALDH has not been described before.  (+info)

Analysis of the role of Nrf2 in the expression of liver proteins in mice using two-dimensional gel-based proteomics. (77/170)

BACKGROUND: The transcription factor Nrf2 regulates expression of multiple cellular defence proteins through the antioxidant response element (ARE). Nrf2-deficient mice (Nrf2(-/-)) are highly susceptible to xenobiotic-mediated toxicity, but it is not known whether this reflects low basal expression or reduced inducibility of Nrf2-regulated genes in response to chemical insults. METHODS: Wild type and Nrf2(-/-) mice were fed diet supplemented with the established Nrf2 inducer butylated hydroxyanisole (BHA) [0.5% (w/w)] for 14 days. To define the range of Nrf2-regulated proteins, both basally and following exposure to BHA, a comparison of the liver proteomes of Nrf2(-/-) and wild type mice was conducted. The two-dimensional gel electrophoresis (2-DE) technique and MALDI mass spectrometry were utilized in the attempt to define Nrf2-regulated proteins. RESULTS: Overall, 24 proteins were identified, which were regulated either basally (3 proteins), inducibly (16 proteins), or both (5 proteins). These included several well-established Nrf2-driven gene products e.g., aldo-keto reductase and glutathione transferases. Multiple consensus ARE/ARE-like sequences were found in the Nrf2-regulated genes. CONCLUSIONS: This study confirms the central role of Nrf2 in the induction of multiple defense proteins as well as its control in the constitutive expression of certain proteins.  (+info)

Antioxidant, antihemolytic and nephroprotective activity of aqueous extract of Diospyros lotus seeds. (78/170)

This study was conducted to quantitatively evaluate the antioxidant, antihemolytic and nephroprotective effects of Diospyros lotus seeds extract in experimental in vitro and in vivo models. Antioxidant potential of Diospvyos lotus seeds extract was examined by employing seven in vito models i.e., DPPH, nitric oxide and hydrogen peroxide radicals scavenging activity, iron ion chelating, reducing power and lipid peroxidation through linoleic acid. Antihemolytic activity of extract was examined against hydrogen peroxide-induced erythrocytes hemolysis. Also, nephroprotective effect of extract against gentamicin (GM)-induced renal injury was evaluated. Renal injury was achieved by injecting 100 mg/kg, intraperitoneally (i.p.) of GM in normal saline. Extracts were administrated i.p. in doses 200 and 400 mg/kg. Blood samples were examined for serum creatinine and blood urea nitrogen after 10 consecutive days of treatment. Results show that extract showed different level of antioxidant and antihemolytic activity in the studied models. Also, results show that GM-induced nephrotoxic animal model was successfully constructed. Extract attenuated the gentamicin-induced increase in level of serum creatinine and blood urea nitrogen. The present study shows that the extract offered significant biological action compared with standard compound.  (+info)

Superoxide dismutase 3 is induced by antioxidants, inhibits oxidative DNA damage and is associated with inhibition of estrogen-induced breast cancer. (79/170)

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Stability and antioxidant activity of semi-synthetic derivatives of 4-nerolidylcatechol. (80/170)

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