Heat treatments of ginger root modify but not diminish its antioxidant activity as measured with multiple free radical scavenging (MULTIS) method.

Ginger ( Rosc.) root (or rhizome) has been reported to have antioxidant properties such as reactive oxygen species scavenging activities. Using multiple free-radical scavenging method, we have newly determined the scavenging abilities of ginger roots against five reactive oxygen species, i.

Multiple free-radical scavenging capacity in serum.

We have developed a method to determine serum scavenging-capacity profile against multiple free radical species, namely hydroxyl radical, superoxide radical, alkoxyl radical, alkylperoxyl radical, alkyl radical, and singlet oxygen. This method was applied to a cohort of chronic kidney disease patients. Each free radical species was produced with a common experimental procedure; i.

Oxygen radical absorbance capacity (ORAC) of cyclodextrin-solubilized flavonoids, resveratrol and astaxanthin as measured with the ORAC-EPR method.

Recently, we proposed an oxygen radical absorbance capacity method that directly quantifies the antioxidant's scavenging capacity against free radicals and evaluated the radical scavenging abilities for water soluble antioxidant compounds. In this study, we determined the radical scavenging abilities of lipophilic antioxidants which were solubilized by cyclodextrin in water. Commonly employed fluorescence-based method measures the antioxidant's protection capability for the fluorescent probe, while we directly quantify free-radical level using electron paramagnetic resonance spin trapping technique.

Nitric oxide (NO) scavenging capacity of natural antioxidants.

Nitric oxide (NO)-scavenging capacities of several hydrophilic antioxidants were determined by using the PTIO method, a competitive NO-scavenging method with 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO). Relative NO-scavenging rates of antioxidants were measured with respect to PTIO and the scavenging rate constants were calculated based on PTIO's rate constant. Results indicated that NO-scavenging rate constants of the antioxidants were: uric acid (2.

Identification of mitochondrial electron transport chain-mediated NADH radical formation by EPR spin-trapping techniques.

The mitochondrial electron transport chain (ETC) is a major source of free radical production. However, due to the highly reactive nature of radical species and their short lifetimes, accurate detection and identification of these molecules in biological systems is challenging. The aim of this investigation was to determine the free radical species produced from the mitochondrial ETC by utilizing EPR spin-trapping techniques and the recently commercialized spin-trap, 5-(2,2-dimethyl-1,3-propoxycyclophosphoryl)-5-methyl-1-pyrroline N-oxide (CYPMPO).

Serum hydroxyl radical scavenging capacity as quantified with iron-free hydroxyl radical source.

We have developed a simple ESR spin trapping based method for hydroxyl (OH) radical scavenging-capacity determination, using iron-free OH radical source. Instead of the widely used Fenton reaction, a short (typically 5 seconds) in situ UV-photolysis of a dilute hydrogen peroxide aqueous solution was employed to generate reproducible amounts of OH radicals. ESR spin trapping was applied to quantify OH radicals; the decrease in the OH radical level due to the specimen's scavenging activity was converted into the OH radical scavenging capacity (rate).

An oxygen radical absorbance capacity-like assay that directly quantifies the antioxidant's scavenging capacity against AAPH-derived free radicals.

A new method is proposed for the evaluation of oxygen radical absorbance capacity (ORAC). The current fluorescence-based ORAC assay (ORAC-FL) is an indirect method that monitors the antioxidant's ability to protect the fluorescent probe from free radical-mediated damage, and an azo-radical initiator, AAPH (2,2-azobis(2-amidinopropane) dihydrochloride), has been used as a thermal free radical source. The new ORAC assay employs a short in situ photolysis of AAPH to generate free radicals.

Visualization of the protective ability of a free radical trapping compound against rat C6 and F98 gliomas with diffusion tensor fiber tractography.

Purpose: To apply fiber tractography to assess the effect of a possible antiglioma drug, phenyl N-tert-butyl nitrone (PBN), on glioma-affected neuronal fibers. The fiber tractography method was able to differentiate between different tumor types, such as the C6 and F98 rat glioma models.

Materials And Methods: C6 or F98 cells were intracranially injected into the cortex of male Fischer 344 rats.

Chemical natures of 6-formylpterin nucleoside analogs.

Pterin is an electron transfer compound in biological systems. Among the analogs, 6-formylpterin (6FP) has been demonstrated to have many marked physiological activities. In the present study, we have developed the synthetic procedure for nucleoside analogs of 6FP and prepared 1-(beta-D-ribofuranosyl)-2-(N,N-diethylaminomethyleneamino)-6-formylpteridin-4-one (RDEF) and 1-(beta-D-ribofuranosyl)-2-(piperidine-1-ylmethyleneamino)-6-formylpteridin-4-one (RPIF) in which the 1-position is glycosylated.

Synthesis of 6-formylpterin nucleoside analogs and their ROS generation activities in the presence of NADH in the dark.

We demonstrated previously that 3-position-modified 6-formylpterin (6FP) derivatives produce reactive oxygen species (ROS) such as hydrogen peroxide (H(2)O(2)) from oxygen in the presence of NADH in the dark. It has been shown that 6FP derivatives markedly generate ROS, which gives rise to their particular physiological activities, such as induction of apoptosis in cellular and living systems, suggesting that such compounds provide a hint for the design of a ROS controlling agent in vivo. However, it is not well understood why such unique activities appear on chemical modification.

Toll-like receptor (TLR) 2 induced through TLR4 signaling initiated by Helicobacter pylori cooperatively amplifies iNOS induction in gastric epithelial cells.

Cell-surface Toll-like receptors (TLRs) initiate innate immune responses, such as inducible nitric oxide synthase (iNOS) induction, to microorganisms' surface pathogens. TLR2 and TLR4 play important roles in gastric mucosa infected with Helicobacter pylori (H. pylori), which contains lipopolysaccharide (LPS) as a pathogen.

Modulation of Fas-FasL related apoptosis by PBN in the early phases of choline deficient diet-mediated hepatocarcinogenesis in rats.

This study focused on the detection of apoptosis related events in very early phases of choline-deficient (CD)-induced hepatocarcinogenesis (at 2-5 weeks). Flow cytometry of isolated intact primary hepatocytes from CD diet fed rats indicated increased expression of the apoptosis-associated protein Fas. Increased apoptosis in CD-treated livers was confirmed by Western blot analyses of caspases and cytochrome c.

Synthesis and characterization of a practically better DEPMPO-type spin trap, 5-(2,2-dimethyl-1,3-propoxy cyclophosphoryl)-5-methyl-1-pyrroline N-oxide (CYPMPO).

5-(2,2-dimethyl-1,3-propoxy cyclophosphoryl)-5-methyl-1-pyrroline N-oxide (CYPMPO), a new cyclic DEPMPO-type nitrone was evaluated for spin-trapping capabilities toward hydroxyl and superoxide radicals. CYPMPO is colorless crystalline and freely soluble in water. Both the solid and diluted aqueous solution did not develop electron spin resonance (ESR) signal for at least 1 month at ambient conditions.

LINE-1 hypomethylation in a choline-deficiency-induced liver cancer in rats: dependence on feeding period.

Chronic feeding of methyl-donor (methionine, choline, folic acid, and vitamin B12) deficient diet induces hepatocellular carcinoma formation in rats. Previous studies have shown that promoter CpG islands in various cancer-related genes are aberrantly methylated in this model. Moreover, the global genome in methyl-donor-deficient diet fed rats contains a lesser amount of 5-methylcytosine than control livers.

DNA cytosine methylation profile in various cancer-related genes is altered in cultured rat hepatocyte cell lines as compared with primary hepatocytes.

We determined the DNA cytosine methylation status in the promoter CpG islands of eight cancer-related genes (p16, Socs-1, Rassf1A, Hic-1, Dlc-1, Timp-1, Timp-2, and Timp-3) in five rat hepatocyte cell lines, including normal cell lines (Clone 9 and CWSV-1) and tumor cell lines (H4-II-E-C3, MH1C1, and McA-RH7777). The experimental methods used to assess the methylation profile were methylation-specific PCR (MSP) and methylation-sensitive digestion combined with PCR. The results were compared with the methylation status of rat primary hepatocytes.

High static pressure alters spin trapping rates in solution. Dependence on the structure of nitrone spin traps.

Using a competitive spin trapping method, relative spin trapping rates were quantified for various short-lived radicals (methyl, ethyl, and phenyl radicals). High static pressure was applied to the competitive spin-trapping system by employing high-pressure electron spin resonance (ESR) equipment. Under high pressure (490 bar), spin trapping rate constants for alkyl and phenyl radicals increased by 10 to 40%, and the increase was dependent on the structure of nitrone spin traps.

Nitric oxide production by primary liver cells isolated from amino acid diet-fed rats.

Primary mixed liver cells were isolated from rats that had been fed an amino acid (AA) diet in which natural protein was replaced with a defined mixture of pure AAs. Nitric oxide (NO) production from these cells in vitro was monitored using a nitric oxide (NO)-selective fluorescent probe, diaminofluorescein, followed by flow cytometric analysis. High levels of NO fluorescence were seen in approximately half of liver cells isolated from rats fed an AA diet for 1-7 days, whereas there was baseline fluorescence in cells obtained from regular diet-fed rats.

Protein modifications by 4-hydroxynonenal and 4-hydroxyhexenal in light-exposed rat retina.

Purpose: 4-Hydroxynonenal (4-HNE) and 4-hydroxyhexenal (4-HHE) are reactive aldehydes derived from the nonenzymatic oxidation of n-6 and n-3 polyunsaturated fatty acids, respectively. Increasing evidence suggests that protein modifications by reactive aldehydes are involved in various diseases. The present study was undertaken to test whether protein modifications by 4-HNE and 4-HHE increase in retinal tissues after exposure of rats to damaging levels of light.

Mitochondrial dysfunction in choline deficiency-induced apoptosis in cultured rat hepatocytes.

Our recent studies have demonstrated that generation of ROS is associated with choline deficiency (CD)-induced apoptosis in CWSV-1 cells, an immortalized rat hepatocyte that becomes tumorigenic by stepwise culturing in decreasing levels of choline. In the present study, we investigated the effect of CD on loss of mitochondrial membrane potential (MMP), using the JC-1 probe by FASCAN assay. Our data demonstrate that MMP in CD-cultured cells was decreased in a time- and dose-dependent manner and that significant disruption occurred at 24 h, relative to high choline (HC, 70 microM) cultured cells.

Mechanism of protection from light-induced retinal degeneration by the synthetic antioxidant phenyl-N-tert-butylnitrone.

Purpose: A prior study demonstrated that pretreatment with phenyl-N-tert-butylnitrone (PBN), a synthetic antioxidant and free radical trapping agent, protects rats from light-induced photoreceptor cell death. The objective of the present study was to elucidate the molecular mechanism of PBN neuroprotection.

Methods: Sprague-Dawley rats (5-6 weeks old) raised in dim (5 lux) cyclic light (12 hours ON/OFF) from birth were injected intraperitoneally with PBN or water 30 minutes before exposure to three columns of fluorescent light (approximately 2700 lux intensity) for 0, 3, 6, 12, or 24 hours.

Effects of iron and phytic acid on production of extracellular radicals by Enterococcus faecalis.

Enterococcus faecalis is a human intestinal commensal that produces extracellular superoxide, hydrogen peroxide, and hydroxyl radical while colonizing the intestinal tract. To determine whether dietary factors implicated in colorectal cancer affect oxidant production by E. faecalis, radicals were measured in rats colonized with this microorganism while on diets supplemented with iron or phytic acid.

Reactive oxygen species in choline deficiency-induced apoptosis in rat hepatocytes.

Choline deficiency (CD) is involved in hepatocellular carcinoma and CD-induced apoptosis may be implicated in cellular malignant transformation. In this report, we studied the effects of choline deficiency on generation of reactive oxygen species (ROS) using the fluorescent probe dichlorodihydrofluorescein diacetate and the possible role of ROS on CD-induced apoptosis in cultured CWSV-1 cells, an immortalized rat hepatocyte. This cell line is reported to become tumorigenic by step-wise culturing in lower levels of choline.

Spin trapping of nitric oxide with the iron-dithiocarbamate complex: chemistry and biology.

This brief review describes chemical and biological aspects concerning spin trapping of nitric oxide (NO) with the iron-dithiocarbamate (Fe-DTC) complex as a spin trap. Knowledge on basic properties of the Fe-DTC complex would help in understanding the applicability and limitation of the Fe-DTC-based NO spin-trapping method when it is employed in viable biological systems.

Inhibition of the development of hepatocellular carcinomas by phenyl N-tert-butyl nitrone in rats fed with a choline-deficient, L-amino acid-defined diet.

Effects of phenyl N-tert-butyl nitrone (PBN), a spin-trapping agent, on the development of frank cancers were examined in male Wistar rats fed with a choline-deficient, l-amino acid-defined (CDAA) diet for 70 weeks. PBN (0.065% in the drinking water) reduced incidences, multiplicities and possibly sizes of both hepatocellular adenomas and carcinomas when administered for all 70 weeks or only for the first 26 weeks, and those of carcinomas but not adenomas, when administered only for the last 44 weeks.

Free radicals and the pathogenesis of type 1 diabetes: beta-cell cytokine-mediated free radical generation via cyclooxygenase-2.

Free radical formation evoked by proinflammatory cytokines has been suggested to be involved in the destruction of beta-cells in the course of type 1 diabetes development. However, there is no direct evidence to support this hypothesis. In this study, we used electron paramagnetic resonance spectroscopy in conjunction with spin-trapping methodology to directly determine whether cytokines give rise to free radical formation in the islets.