Photo-oxidative stress was imposed under natural solar radiation on exposed and shaded sections of detached fruit of immature green tomato (Lycopersicon esculentum Miller = Solanum lycopersicum L.) mutants (anthocyanin absent, beta-carotene, Delta, and high pigment-1) and their nearly isogenic parents ('Ailsa Craig' and 'Rutgers'). After 5 h exposure to high solar irradiance, either with or wit...

Proanthocyanidins (PAs), also called condensed tannins, can protect plants against herbivores and are important quality components of many fruits. Two enzymes, leucoanthocyanidin reductase (LAR) and anthocyanidin reductase (ANR), can produce the flavan-3-ol monomers required for formation of PA polymers. We isolated and functionally characterized genes encoding both enzymes from grapevine (Viti...

Altered peripheral glucocorticoid metabolism may be important in the pathogenesis of obesity in humans and animal models. Genetically obese Zucker rats, Lep/ob mice, and obese humans exhibit increased regeneration of active glucocorticoids selectively in adipose tissue by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD-1) and increased glucocorticoid clearance by hepatic A-ring reductase...

Photosynthetic bacteria offer excellent experimental opportunities to explore both the structure and function of the ubiquinol-cytochrome c oxidoreductase (bcl complex). In both Rhodobacter sphaeroides and Rhodobaeter capsulatus, the bCl complex functions in both the aerobic respiratory chain and as an essential component of the photosynthetic electron transport chain. Because the bc~ complex i...

The effect of thermal stress on the antioxidant system was investigated in two invasive plants, Eupatorium adenophorum Spreng. and E. odoratum L. The former is sensitive to high temperature, whereas the latter is sensitive to low temperature. Our aim was to explore the relationship between the response of antioxidant enzymes and temperature in the two invasive weeds with different distribution ...

The incidence of hepatocellular carcinoma (HCC) is more prevalent in males than in females. 5alpha-Dihydrotestosterone is the most potent form of androgen and is converted from testosterone by 5alpha-reductase. The antitumor effect of a 5alpha-reductase inhibitor (FK143) was evaluated in a rat chemical hepatocarcinogenesis model (Solt-Farber). Male Fischer 344 rats were used in three groups: (a...

PURPOSE High ribonucleotide reductase M1 (RRM1) expression in resected lung cancers has been associated with better clinical outcomes. However, gemcitabine-treated patients with high tumoral RRM1 expression generally evidence poor prognoses due to the decreased efficacy of gemcitabine therapy. This study was designed in accordance with the hypothesis that polymorphisms (-37 and -524) of the RRM...

Cadmium (Cd) brings a devastating health hazard to human being as a serious consequence of agricultural and environmental contamination. We demonstrated the protective effect of silicon (Si) on cadmium (Cd)-stressed rapeseed (Brassica napus L. cv. BINA Sharisha 3) plants through regulation of antioxidant defense and glyoxalase systems. Twelve-day-old seedlings were exposed to Cd stress (0.5 and...

Thioredoxin reductase (TrxR) is an essential enzyme required for the efficient maintenance of the cellular redox homeostasis, particularly in cancer cells that are sensitive to reactive oxygen species. In mammals, distinct isozymes function in the cytosol and mitochondria. Through an intricate mechanism, these enzymes transfer reducing equivalents from NADPH to bound FAD and subsequently to an ...

Purified preparations of the reduced nicotinamide adenine dinucleotide dehydrogenase of the respiratory chain, extracted with the aid of phospholipase at moderate temperature, do not catalyze the reduction of long chain coenzyme Q derivatives (Q6 and QIO) at significant rates and are not inhibited by amytal or rotenone. On exposure of the enzyme to conditions which have been used for the extrac...