In Vitro Inhibitory Effects of Organic Acids Identified in Commercial Vinegars on α-Amylase and α-Glucosidase.

The aim of this work was to evaluate the inhibitory activities of organic acids identified from commercial vinegars on α-amylase and α-glucosidase. Six organic acids (acetic, citric, lactic, malic, succinic, and tartaric) were identified in nine commercial vinegars, whose contents varied considerably depending on the raw materials. Most of the fruit vinegars, comprised of various organic acids, were found to be more effective inhibitors against digestive enzymes than grain vinegars containing mainly acetic acid. Citric acid had the lowest IC50 values for α-amylase and α-glucosidase activities 0.64±0.04 µM/mL and 8.95±0.05 µM/mL, respectively, and thus exhibited the strongest antidiabetic effect. Mulberry fruit vinegar containing the highest content of total organic acid (111.02±1.50 mg/mL) showed the strongest digestive enzyme inhibitory impact. The results indicate that vinegars with higher contents of various organic acids hold strong potential against digestive enzymes.

Carotenoid Biosynthesis in Oriental Melon (Cucumis melo L. var. makuwa).

Full-length cDNAs encoding ξ-carotene desaturase (CmZDS), lycopene ε-cyclase (CmLCYE), ß-ring carotene hydroxylase (CmCHXB), and zeaxanthin epoxidase (CmZEP), and partial-length cDNA encoding ε-ring carotene hydroxylase (CmCHXE) were isolated in Chamoe (Cucumis melo L. var. makuwa), an important commercial fruit. Sequence analyses revealed that these proteins share high identity and common features with other orthologous genes. Expression levels of entire genes involved in the carotenoid biosynthetic pathway were investigated in the peel, pulp, and stalk of chamoe cultivars Ohbokggul and Gotgam. Most of the carotenoid biosynthetic genes were expressed at their highest levels in the stalk, whereas carotenoids were highly distributed in the peel. The expression levels of all carotenoid biosynthetic genes in fruits of the native cultivar Gotgam chamoe were higher than those in the cultivar Ohbokggul chamoe, consistent with the abundant carotenoid accumulation in Gotgam chamoe fruits and trace carotenoid content of Ohbokggul chamoe fruit. Lutein and ß-carotene were the dominant carotenoids; high levels (278.05 µg g-1 and 112.02 µg g-1 dry weight, respectively) were found in the peel of Gotgam chamoe. Our findings may provide a foundation for elucidating the carotenoid biosynthetic mechanism in C. melo and inform strategies for developing new chamoe cultivars with improved characteristics.

Profiling of the Major Phenolic Compounds and Their Biosynthesis Genes in Sophora flavescens Aiton.

Sophorae Radix (Sophora flavescens Aiton) has long been used in traditional medicine in East Asia due to the various biological activities of its secondary metabolites. Endogenous contents of phenolic compounds (phenolic acid, flavonol, and isoflavone) and the main bioactive compounds of Sophorae Radix were analyzed based on the qualitative HPLC analysis and evaluated in different organs and at different developmental stages. In total, 11 compounds were detected, and the composition of the roots and aerial parts (leaves, stems, and flowers) was significantly different. trans-Cinnamic acid and p-coumaric acid were observed only in the aerial parts. Large amounts of rutin and maackiain were detected in the roots. Four phenolic acid compounds (benzoic acid, caffeic acid, ferulic acid, and chlorogenic acid) and four flavonol compounds (kaempferol, catechin hydrate, epicatechin, and rutin) were higher in aerial parts than in roots. To identify putative genes involved in phenolic compounds biosynthesis, a total of 41 transcripts were investigated. Expression patterns of these selected genes, as well as the multiple isoforms for the genes, varied by organ and developmental stage, implying that they are involved in the biosynthesis of various phenolic compounds both spatially and temporally.

Xanthomonas euvesicatoria Causes Bacterial Spot Disease on Pepper Plant in Korea.

In 2004, bacterial spot-causing xanthomonads (BSX) were reclassified into 4 species-Xanthomonas euvesicatoria, X. vesicatoria, X. perforans, and X. gardneri. Bacterial spot disease on pepper plant in Korea is known to be caused by both X. axonopodis pv. vesicatoria and X. vesicatoria. Here, we reidentified the pathogen causing bacterial spots on pepper plant based on the new classification. Accordingly, 72 pathogenic isolates were obtained from the lesions on pepper plants at 42 different locations. All isolates were negative for pectolytic activity. Five isolates were positive for amylolytic activity. All of the Korean pepper isolates had a 32 kDa-protein unique to X. euvesicatoria and had the same band pattern of the rpoB gene as that of X. euvesicatoria and X. perforans as indicated by PCR-restriction fragment length polymorphism analysis. A phylogenetic tree of 16S rDNA sequences showed that all of the Korean pepper plant isolates fit into the same group as did all the reference strains of X. euvesicatoria and X. perforans. A phylogenetic tree of the nucleotide sequences of 3 housekeeping genes-gapA, gyrB, and lepA showed that all of the Korean pepper plant isolates fit into the same group as did all of the references strains of X. euvesicatoria. Based on the phenotypic and genotypic characteristics, we identified the pathogen as X. euvesicatoria. Neither X. vesicatoria, the known pathogen of pepper bacterial spot, nor X. perforans, the known pathogen of tomato plant, was isolated. Thus, we suggest that the pathogen causing bacterial spot disease of pepper plants in Korea is X. euvesicatoria.

Development of PCR and TaqMan PCR Assays to Detect Pseudomonas coronafaciens, a Causal Agent of Halo Blight of Oats.

Pseudomonas coronafaciens causes halo blight on oats and is a plant quarantine bacterium in many countries, including the Republic of Korea. Using of the certificated seed is important for control of the disease. Since effective detection method of P. coronafaciens is not available yet, PCR and TaqMan PCR assays for specific detection of P. coronafaciens were developed in this study. PCR primers were designed from the draft genome sequence of P. coronafaciens LMG 5060 which was obtained by the next-generation sequencing in this study. The PCR primer set Pc-12-F/Pc-12-R specifically amplified 498 bp from the 13 strains of P. coronafaciens isolated in the seven different countries (Canada, Japan, United Kingdom, Zimbabwe, Kenya, Germany, and New Zealand) and the nested primer set Pc-12-ne-F/Pc-12-ne-R specifically amplified 298 bp from those strains. The target-size PCR product was not amplified from the non-target bacteria with the PCR and nested primer sets. TaqMan PCR with Pc-12-ne-F/Pc-12-ne-R and a TaqMan probe, Pc-taqman, which were designed inside of the nested PCR amplicon, generated Ct values which in a dose-dependent manner to the amount of the target DNA and the Ct values of all the P. coronafaciens strains were above the threshold Ct value for positive detection. The TaqMan PCR generated positive Ct values from the seed extracts of the artificially inoculated oat seeds above 10 cfu/ml inoculation level. PCR and TaqMan PCR assays developed in this study will be useful tools to detect and identify the plant quarantine pathogen, P. coronafaciens.

Effects of high hydrostatic pressure treatment on the enhancement of functional components of germinated rough rice (Oryza sativa L.).

This study was performed to evaluate the enhancement of functional components of germinated rough rice. Rough rice was germinated at 37 °C for 6 days, and subjected to a high hydrostatic pressure treatment (HPT) at 30 MPa for 24 h (HP24) and 48 h (HP48). Germinated rough rice without HPT (HP0), HP24, and HP48 were analysed for their functional components. The highest γ-aminobutyric acid, total arabinoxylan, and tricin 4'-O-(threo-ß-guaiacylglyceryl) ether contents were 121.21 mg/100g, 10.6%, and 85.82 µg/g, respectively, after HP48 for 2 days. γ-Oryzanol contents increased from 23.19-36.20 mg/100g (at HP0) to 31.80-40.32 mg/100g (at HP48). The highest vitamin B (60.99 mg/100g) and E (4.07 mg/100g) contents were observed after HP24 for 5 and 2 days, respectively. These results suggest that a combination of HPT and germination efficiently enhances the functional characteristics of rough rice.

Expression of colSR Genes Increased in the rpf Mutants of Xanthomonas oryzae pv. oryzae KACC10859.

The rpf genes and colS XOO1207/colR XOO1208 were known to require for virulence of Xanthomonas oryzae pv. oryzae (Xoo). In Xoo KACC10331 genome, two more colS/colR genes, colS XOO3534 (raxH)/colR XOO3535 (raxR) and colS XOO3762/colR XOO3763 were annotated. The colS XOO3534/colR XOO3535 were known to control AvrXa21 activity and functions of colS XOO3762/colR XOO3763 were unknown in Xoo. To characterize the relationship between rpf and colS/colR genes, expression of colS/colR genes in Rpf mutants of Xoo were analyzed with quantitative reverse transcription PCR (qRT-PCR). Expressions of all three colS/colR genes increased in the rpfF mutant in which DSF synthesis is defective. Expression of colS XOO1207/colR XOO1208, colS XOO3534/colR XOO3535 and colS XOO3762/colR XOO3763 increased 2, 2-7, 3-13 folds respectively. Expression of colS XOO3534 and colS XOO3762 also increased 2-4 folds in the rpfG mutant in which the signal from DSF is no longer transferred to down-stream. Expression of the other colS/colR genes was not significantly changed in the rpfG mutant compared to the wild type. Since RpfF and RpfG are responsible for DSF synthesis and signal transfer from DSF to down-stream to regulate virulence gene expression, these results suggest that the DSF and DSF-mediated signal regulate negatively three colS/colR genes in Xoo.

Xanthomonas oryzae pv. oryzae RpfE Regulates Virulence and Carbon Source Utilization without Change of the DSF Production.

It has been known that most regulation of pathogenicity factor (rpf) genes in xanthomonads regulates virulence in response to the diffusible signal factor, DSF. Although many rpf genes have been functionally characterized, the function of rpfE is still unknown. We cloned the rpfE gene from a Xanthomonas oryzae pv. oryzae (Xoo) Korean race KACC10859 and generated mutant strains to elucidate the role of RpfE with respect to the rpf system. Through experiments using the rpfE-deficient mutant strain, we found that mutation in rpfE gene in Xoo reduced virulence, swarm motility, and production of virulence factors such as cellulase and extracellular polysaccharide. Disease progress by the rpfE-deficient mutant strain was significantly slowed compared to disease progress by the wild type and the number of the rpfE-deficient mutant strain was lower than that of the wild type in the early phase of infection in the inoculated rice leaf. The rpfE mutant strain was unable to utilize sucrose or xylose as carbon sources efficiently in culture. The mutation in rpfE, however, did not affect DSF synthesis. Our results suggest that the rpfE gene regulates the virulence of Xoo under different nutrient conditions without change of DSF production.

The effects of ketorolac tromethamine and baicalein on the levels of inflammatory factors in human synoviocytes.

This study examined the effects of ketorolac tromethamine (KT) and baicalein (BE) on the levels of inflammatory factors in human synoviocytes. The fibroblast-like synoviocytes (FLS) cells were used to determine the possible regulatory effects of KT and BE (KTBE) on the levels of inflammatory factors in FLS cells. In addition, the levels of TNF-alpha, IL-6, and IL-1beta mRNA expression in FLS cells induced by a TNF-alpha and IL-1beta co-treatment were largely inhibited by a KTBE treatment. The level of FLS cells proliferation was increased by IL-1beta and TNF-alpha, and strongly inhibited by KTBE treatment. The production of oxygen species (ROS) was inhibited by KTBE in FLS cells. KTBE appears to regulate the levels of mRNA that are important for regulating RA progression.

Inhibitory effect of citral on NO production by suppression of iNOS expression and NF-kappa B activation in RAW264.7 cells.

Citral is a major compound of lemongrass (Cymbopogon citratus L.) that has many pharmacological activities such as anti-fungal and anti-bacterial effects. In this study, we investigated the anti-inflammatory effect of citral and defined its mechanism of action in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Citral (3-12 microg/mL) significantly inhibited LPS-induced nitric oxide (NO) production in a concentration-dependent manner (IC50: 6.5 microg/mL). Furthermore, it was found that citral effectively inhibited the transcriptional activity and expression of iNOS, and potently suppressed the DNA binding activity and nuclear translocation of NF-kappa B as well as I kappa B phosphorylation in a concentration dependent manner. These results suggest that citral is anti-inflammatory, and its effects may be due to the inhibition of NO production through the suppression of NF-kappa B activation.

Inhibitory effect of inflexinol on nitric oxide generation and iNOS expression via inhibition of NF-kappaB activation.

Inflexinol, an ent-kaurane diterpenoid, was isolated from the leaves of Isodon excisus. Many diterpenoids isolated from the genus Isodon (Labiatae) have antitumor and antiinflammatory activities. We investigated the antiinflammatory effect of inflexinol in RAW 264.7 cells and astrocytes. As a result, we found that inflexinol (1, 5, 10 microM) suppressed the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) as well as the production of nitric oxide (NO) in LPS-stimulated RAW 264.7 cells and astrocytes. Consistent with the inhibitory effect on iNOS and COX-2 expression, inflexinol also inhibited transcriptional and DNA binding activity of NF-kappaB via inhibition of IkappaB degradation as well as p50 and p65 translocation into nucleus. These results suggest that inflexinol inhibits iNOS and COX-2 expression through inhibition of NF-kappaB activation, thereby inhibits generation of inflammatory mediators in RAW 264.7 cells and astrocytes, and may be useful for treatment of inflammatory diseases.