Isolation and antioxidant activity of zeylaniin A, a new macrocyclic ellagitannin from Syzygium zeylanicum leaves.

Methanol extract obtained from Syzygium zeylanicum leaves exhibited potent antioxidant activity. The water extract obtained from this methanol extract by sequential extraction with hexane, chloroform, ethylacetate, and n-butanol also showed the strongest antioxidant activity among extracts. This water extract was further fractionated by column chromatography with various concentrations of methanol solutions. Among the 6 resultant fractions, the fraction developed with 20% methanol exhibited the most potent antioxidant activity. The one peak among the three major HPLC peaks in this fraction was isolated and purified using a preparative HPLC. The structure of a pure compound was elucidated as a novel macrocyclic ellagitannin using a (1)H/(13)C NMR and a high-resolution electrospray ionization mass spectrometer. This newly isolated compound, which was named zeylaniin A, exhibited potent antioxidant activities in the assays of DPPH, oxygen radical absorbance capacity, and malonadehyde/gas chromatography. S. zeylanicum leaves can be a possible source of natural antioxidants.

Dose of 3-methylcholanthrene enhances vitamin C accumulation and mRNA expression of its transporter in the liver of ODS rats and in HepG2 cells.

Polycyclic aromatic hydrocarbon (PAH) compounds including 3-methylcholanthrene induce harmful reactive intermediates and reactive oxygen species. This study reports the effect of 3-methylcholanthrene on the accumulation of vitamin C and the expression of vitamin C transporters. ODS rats were given l-ascorbic acid daily and intraperitoneal injections of 10 mg 3-methylcholanthrene in total. On day 10, vitamin C concentrations and the expression of vitamin C transporter in the tissues were measured. As a result, the levels of sodium-dependent vitamin C transporter (SVCTs) 1 and the l-ascorbic acid concentration in 3-methylcholanthrene-treated livers and hepatocytes have increased significantly. However, the content of vitamin C in the urine and TBARS in the liver have not changed. These results suggest that the administration of 3-methylcholanthrene elevates the requirement for vitamin C via (SVCTs) 1 due to xenobitics-metabolizing, such as the induction of cytochrome P450 family.

Antioxidant/anti-inflammatory activities and total phenolic content of extracts obtained from plants grown in Vietnam.

BACKGROUND: Medicinal plants have been used to treat various diseases since ancient times. Their specific activities, such as antioxidant, anti-inflammatory and anti-cancer, have been studied intensively. In particular, plants grown in Vietnam have attracted considerable attention among food chemists as ideal sources of natural medicinal chemicals. RESULTS: The methanol extracts from three edible Vietnamese-grown plants, Tram, Voi and Gac, tested with the DPPH assay showed antioxidant activities of 91.7 ± 0.4, 63.4 ± 0.7 and 3.7 ± 0.1% respectively. The malonaldehyde/gas chromatography assay also revealed strong antioxidant activity in Tram and Voi at a level of 25 µg mL(-1) (95.5 ± 0.3 and 78.5 ± 1.4% respectively). These results were confirmed by the thiobarbituric acid assay. The antioxidant activities correlated positively with the level of total phenolics in all plants. Tram exhibited dose response-related lipoxygenase-inhibitory activity, with values of 74.2 ± 3.1% at 5 µg mL(-1) , 62.0 ± 0% at 0.5 µg mL(-1) and 3.0 ± 1.5% at 0.05 µg mL(-1) . Conversely, Voi and Gac showed negative anti-lipoxygenase activity. CONCLUSION: The antioxidant/anti-inflammatory activities and total phenolic contents of the three edible plants grown in Vietnam revealed that they are good sources of supplements for human health.

Effects of oxygen concentration on the expression of an antioxidant gene in HepG2.

To clarify the effects of O(2) concentration (cO(2)) on antioxidant gene expression in human hepatocytes, mRNA expression of HepG2 cells cultured at 1, 3, and 5% cO(2) and atmospheric gas-phase, was measured. The expression of some genes fluctuated depending on the cO(2) in the incubator. This indicates that cO(2) is a critically important factor in the investigation of human biological mechanisms.

Association of lifestyle factors, polymorphisms in adiponectin, perilipin and hormone sensitive lipase, and clinical markers in Japanese males.

According to recent genome-wide association studies, a number of single nucleotide polymorphisms is reported to be associated with diseases or several clinical markers. Among them, adiponectin (ADIPOQ) and perilipin (PLIN) polymorphisms are major factors of obesity. However, the association between lifestyle factor, these polymorphisms and obesity-related clinical markers in Japanese is not well researched. Therefore, the aim of present study is to investigate the association between lifestyle factor, polymorphisms of lipid metabolic genes, and clinical markers in 148 middle-aged Japanese males. The study revealed that ADIPOQ 45 T>G and ADIPOQ 276 G>T genotypes were significantly associated with triglyceride, total cholesterol, hemoglobin A1c (HbA1c) in blood and body mass index (BMI). PLIN4 11482 G>A and hormone sensitive lipase (LIPE)-60 C>G genotypes were respectively associated with BMI and serum triglyceride. Not only genetic factors but also lifestyle factors influence several clinical markers. The BMI of subjects who like sweets and have the GG allele in ADIPOQ 276 G>T was higher than that of subjects who don't like sweets. The habit of eating fruits and fish affected low-density lipoprotein-cholesterol of the GT allele and HbA1c of the TT allele in ADIPOQ 276 G>T. Those findings indicate improvement and conservation of lifestyle depending on genetic predisposition in ADIPOQ, PLIN and LIPE should be encouraged.

Effects of salt concentration on the reaction rate of Glc with amino acids, peptides, and proteins.

The reaction between the amino group and the carbonyl group is important in food quality control. Furthermore, advanced glycation end products from foods are considered to relate to aging and diabetes. Thus, it is important to control this reaction. In this study, we investigated the effects of salt concentration on the rates of browning reaction of amino acid, peptides, and proteins. A high concentration of sodium chloride retarded the reaction rate of Glc with amino acids as measured with the absorbance at 470 nm, but did not change the browning rate of Glc with peptides. On the other hand, sodium chloride retarded the browning reaction rate of proteins as measured with polymerization degree or by the loss of Lys. It is hoped that the results of this study will be applied in the control of amino-carbonyl reaction rates in the food industry.

Altered signaling pathway in the dysmorphogenesis of telencephalon in the Gli3 depressed mouse embryo, Pdn/Pdn.

The responsible gene of genetic polydactyly/arhinencephaly mouse (Pdn/Pdn) is Gli3. Pdn/Pdn exhibits absence of the olfactory bulb, suggesting telencephalic dysmorphogenesis. It has been cleared that a transposon was inserted into intron 3 of the Gli3 gene in the Pdn mouse. Adequate PCR primers in the intron 3 and transposon allowed us to discriminate +/+, Pdn/+ and Pdn/Pdn embryos. After genotyping of the Pdn embryos using genomic DNA from the yolk sac membrane, gene expressions in the embryo proper were analyzed by DNA microarray, real-time PCR and whole-mount in situ hybridization (WISH) methods. DNA microarray detected 368 depressed and 425 over-expressed genes in the Pdn/Pdn mouse embryos on day 9 of gestation. In these genes, six signaling pathway and 20 transcription factor genes were included. From these genes, we further investigated Gli3, Emx2, Wnt8b and Wnt7b gene expressions using real-time PCR and WISH, and depression of these gene expression amounts and altered expression patterns were confirmed. Although alterations of Shh and Fgf8 gene expressions were not detected in the DNA microarray, as these genes have been closed up in the telencephalic morphogenesis, we investigated these gene expressions by real-time PCR and WISH. Shh gene expression amount and pattern were not changed. Alteration of Fgf8 gene expression amount was not detected also in the real-time PCR, but altered expression pattern was detected in the Pdn/Pdn embryos by WISH. From the present data, we suggested that Emx2, Wnt8b, Wnt7b and Fgf8 are the important Gli3 signaling pathway in the morphogenesis of telencephalon.

Expression, purification and characterization of yeast protein disulfide isomerase produced by a recombinant baculovirus-mediated silkworm, Bombyx mori, pupae expression system.

Protein disulfide isomerase (PDI) is a multifunctional polypeptide presents in the endoplasmic reticulum of the cell. Silkworm (Bombyx mori) pupae were used as hosts to produce recombinant PDI (rPDI). The concentration-dependent chaperone activity of rPDI was evidenced by the inhibition of the aggregation of rhodanese. Approximately 297 microg rPDI was purified from a single silkworm pupa. Results of rPDI treated with endoglycosidase H and N-glycanase, PNGase F, indicate that non-N-glycosylated rPDI (occupying 90%) and N-glycosylated rPDI are expressed in the silkworm expression system. The difference in glycosylation between silkworm pupae and yeast is discussed.

The effect of cigarette smoke exposure and ascorbic acid intake on gene expression of antioxidant enzymes and other related enzymes in the livers and lungs of Shionogi rats with osteogenic disorders.

Cigarette smoking causes many chronic diseases but is a preventable risk factor in developing countries. However, it may be possible to relieve the smoke-induced damage by increasing the protective defense system. As vitamin C intake reduces smoking risk, it is recommended that smokers should take more vitamin C. However, the molecular mechanism of vitamin C intake on smokers has not been thoroughly investigated. We have found there to be suppression of smoke-induced cytochrome P-450 1A1 (CYP1A1) mRNA expression by high-dose ascorbic acid administration. Therefore, we surveyed other genes, the expressions of which were altered by the administration of high-dose ascorbic acid. As cigarette smoking increases oxidative stress, we investigated the effect on antioxidative enzyme expression. The osteogenic disorder Shionogi (ODS) rat, which lacks ascorbic acid synthesis enzyme, was administered either minimal amounts (4 mg/day, S4) or high-dose amounts (40 mg/day, S40) of ascorbic acid, and were exposed to cigarette smoke daily for 25 days. The effect on antioxidative enzymes mRNA expression in the liver was measured by competitive reverse transcription-polymerase chain reaction method (competitive RT-PCR). CuZn-superoxide dismutase (SOD), MnSOD, catalase and protein disulfide isomerase (PDI) were significantly decreased by high-dose ascorbic acid administration, and plasma glutathione peroxidase was also decreased, but not significantly. Cigarette smoke exposure slightly increased gene expression of PDI and catalase, but not significantly. The differently expressed 27 genes in the liver were found by differential display methods. From 27 genes, altered expression of plasma proteinase inhibitor, alpha-1-inhibitor III and CYP1A2 were confirmed by competitive RT-PCR. These results show that ascorbic acid intake influences gene expression of antioxidative enzymes, an ascorbic acid recycle enzyme, and xenobiotic metabolizing enzymes.