Oxidative stress has been proposed to be a unifying cause for diabetic nephropathy and a target for novel therapies. Here we apply a new endogenous reduction-oxidation (redox) sensor, hyperpolarized (HP) (13)C dehydroascorbate (DHA), in conjunction with MRI to noninvasively interrogate the renal redox capacity in a mouse diabetes model. The diabetic mice demonstrate an early decrease in renal r...

Marigold plants (Calendula officinalis Linn) var. ‘Plamen Plus’ were grown under field conditions during the 2009 season in Trebišov, Slovakia and in Sofia, Bulgaria. The antioxidant potential in Slovak marigold flowers was due to the content of glutathione and ascorbate, two peroxidases (glutathione peroxidase and guaiacol peroxidase) and monodehydroascorbate reductase. The antioxidant capacit...

The rate of scavenging by Ehrlich ascites cells of anionic ascorbyl and 2,6-dimethoxy-p-semiquinone free radicals has been investigated by electron spin resonance spectroscopy both for viable cells and for subcellular fractions obtained by differential centrifugation. The scavenging activity is concluded to be associated with an NAD(P)H enzyme containing an active sulfhydryl group. Attempts to ...

The present study evaluates the genotoxic potential of different soil samples collected from rice fields employing Allium cepa root chromosomal aberration assay using in situ and root dip modes of treatment. The study also involves assessment of oxidative stress by analyzing responses of certain antioxidative enzymes viz. catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), g...

Evidence exists to suggest that melatonin (MT) is important to abiotic stress tolerance in plants. Here, we investigated whether exogenous MT reduces heat damage on biological parameters and gene expression in kiwifruit (Actinidia deliciosa) seedlings. Pretreatment with MT alleviates heat-induced oxidative harm through reducing H₂O₂ content and increasing proline content. Moreover, MT applicati...

One approach to understanding the Reactive Oxygen Species (ROS)-scavenging systems in plant stress tolerance is to manipulate the levels of antioxidant enzyme activities. In this study, we expressed in the chloroplast three such enzymes: dehydroascorbate reductase (DHAR), glutathione-S-transferase (GST) and glutathione reductase (GR). Homoplasmic chloroplast transformants containing either DHAR...

Iron and probably also copper are absorbed by the intestine in their reduced form. A b-type cytochrome, Dcytb, has recently been cloned from mouse and has been proposed to be the corresponding reductase. However, the nature of the cytochrome and the reduction reaction remain unknown. Here we describe the isolation and functional characterization of a novel b-type cytochrome from rabbit enterocy...

Vitamin C plays an important role in neutralizing toxic free radicals formed during oxidative metabolism or UV exposure of human skin. This study was performed to investigate the mechanisms that regulate the homoeostasis of vitamin C in HaCaT cells by identifying the events involved in the transport and in the reduction of dehydroascorbic acid. Dehydroascorbic acid accumulated to a greater exte...