Gilhwan An

Inhaled Fluorescent Magnetic Nanoparticles Induced Extramedullary Hematopoiesis in the Spleen of Mice

Inhaled Fluorescent Magnetic Nanoparticles Induced Extramedullary Hematopoiesis in the Spleen of Mice: Jung‐Taek Kwon, et al. Laboratory of Toxicology, College of Veterinary Medicine, Seoul National University, Korea

Metabolite profiles of glucosinolates in cabbage varieties (Brassica oleracea var. capitata) by season, color, and tissue position

Glucosinolates (GSLs) are sulfur-containing anionic secondary metabolites that are precursors of biologically active compounds, such as isothiocyanates, in Brassicaceae. The GSLs found in 10 cultivars of cabbage (Brassica oleracea var. capitata) popularly cultivated in Korea and China were identified and quantified. Three GSL classes (6 aliphatic, 1 aromatic, and 3 indolyl) were identified and quantified using high-performance liquid chromatography mass spectrometry (HPLC-MS) and HPLC. The concentration of these GSLs varied by season (spring- and fall-sown), leaf position (inside and outside), and cabbage color (green and red). The average total amounts of GSLs in the inner and outer sections of green and red cabbages ranged from 8.55–13.5 μmol∙g−1 dry weight. The spring-sown cabbages contained significantly higher GSL concentration (2.3–4.3 times higher) compared to their fall-sown counterparts. The inner sections of cabbages contained 1.1- to 1.8-fold greater GSL concentrations than the outer sections. These results indicate that an increase in temperature induces GSL accumulation in both green and red cabbages. The green cabbage cultivars contained significantly higher concentration of GSLs synthesized from homo-methionine, whereas the red cabbage cultivars had greater amounts of GSLs synthesized from dihomo-methionine, which suggests that the activities of enzymes involved in the elongation of homo-methionine are greater in red cabbages. The fall-sown red cabbages also contained 2- to 3-fold higher contents of GSLs synthesized from tryptophan compared to the spring-sown cabbages. In conclusion, the color of cabbage, tissue position of cabbage, temperature, and rainfall were all significantly correlated with the amount of GSL accumulation in cabbages.

Low dietary inorganic phosphate stimulates lung tumorigenesis through altering protein translation and cell cycle in K-ras(LA1) mice.

Recent surveys indicate that Pi intake has increased steadily as Pi-containing foods have increased. Our previous study demonstrated that high dietary Pi strongly stimulated lung tumorigeneis. In order to answer the issue whether low Pi may be chemopreventive, we examined the effects of low Pi on lung cancer. Eighteen 5-wk-old male K-ras LA1 lung cancer model mice were randomly allocated to 2 groups. One group was fed a normal diet (0.5% Pi) and other group was fed low Pi (0.1% Pi) diet for 4 wk. Lung cancer development was evaluated by histopathological examination, Western blot, kinase assay, and immunohistochemistry. Low Pi increased the expression of sodium-dependent phosphate co-transporter 2b, and activated Akt signal with decreased PTEN expression in the lungs of K-ras LA1 mice. Low Pi increased the Akt/mTOR-mediated protein translation through upregulating the phosphorylation of p70S6K and 4E-BP1. In addition, low Pi stimulated cell cycling as evidenced by altered cell cycle regulators such as cyclin D1 and D3. Finally, low Pi increased lung tumorigenesis in K-ras LA1 mice compared to the normal diet group. Our results clearly demonstrated that low Pi also promoted lung tumorigenesis, thus suggesting that an appropriate intake of dietary Pi may be critical for lung cancer prevention as well as treatment.

Low dietary inorganic phosphate affects the lung growth of developing mice

Inorganic phosphate (Pi) plays a critical role in diverse cellular functions, and regulating the Pi balance is accomplished by sodium-dependent Pi co-transporter (NPT). Pulmonary NPT has recently been identified in mammalian lungs. However, to date, many of the studies that have involved Pi have mainly focused on its effect on bone and kidney. Therefore, current study was performed to discover the potential effects of low Pi on the lung of developing transgenic mice expressing the renilla/firefly luciferase dual reporter gene. Two-weeks old male mice divided into 2 groups and these groups were fed either a low PI diet or a normal control diet (normal: 0.5% Pi, low: 0.1% Pi) for 4 weeks. After 4 weeks of the diet, all the mice were sacrificed. Their lungs were harvested and analyzed by performing luciferase assay, Western blotting, kinase assay and immunohistochemistry. Our results demonstrate that low Pi affects the lungs of developing mice by disturbing protein translation, the cell cycle and the expression of fibroblast growth factor-2. These results suggest that optimally regulating Pi consumption may be important to maintain health.

Increase of phenolic compounds in new Chinese cabbage cultivar with red phenotype

A newly developed red Chinese cabbage (Brassica rapa ssp. campestris; CC) was analyzed to determine the changes in functional compounds, especially in phenolic compounds. In the red CC, cyanidin was the major anthocyanidin, with 4.11 mg·g−1 dry weight (dw), while pelargonidin and peonidin were minor components. The control CC, however, contained no anthocyanidins. In both CCs, four hydroxycinnamic acids were detected, and sinapic acid was the principal compound found. Hydroxycinnamic acids in the red CC were significantly more abundant than were those in the control, by a factor of 1.4–13.3. Quercetin was the principal flavonol in the red CC, with 2.7 mg·g−1 dw, whereas it was the flavonol with the lowest concentration in the control CC (0.5 mg·g−1 dw). Kaempferol and isorhamnetin concentrations were also increased in the red CC by 1.41- and 3.10-times, respectively. The results imply that, due to the common synthetic pathways of the phenolic compounds, the creation of a red phenotype from the presence of anthocyanidin increased the levels of flavonols and phenolic acids. Pectin, reducing sugar, and cellulose levels in the red CC indicate that the red CC could be preferred by consumers because of its better taste. Consequently, the new red CC, by accumulating significant amounts of the bioactive anthocyanidin, has significant value for human nutrition.

Quality and safety of a new rapeseed ‘Kangyu’ cultivated at different regions in Korea

The quality and safety of rapeseed are greatly affected by glucosinolate and erucic acid. To determine the quality of a new variety, ‘Kangyu’ was cultivated at 3 different regions and analyzed to evaluate oil quality and glucosinolates contents. The new cultivar accumulated 38–43%(w/w) of oil and 5–14 μmol/g of glucosinolates, whereas the local race contained 43% and 52 μmol/g, respectively. The total glucosinolates in ‘Sunmang’ was above the permissible limit. All ‘Kangyu’ samples had safe fatty acid compositions but the local race contained 43% of erucic acid (C22:1) that is far from the International Standard. The contents of oleic (C18:1), linoleic (C18:2), and linolenic acid (C18:3) in ‘Kangyu’ were 61–65, 21–23, and 9–10%, respectively. Consequently, ‘Kangyu’ was good oil source in Korea in terms of erucic acid (C22:1) and total glucosinolates for human health.

Multivariate classification of the geographic origin of Chinese cabbage using an electronic nose-mass spectrometry

AbstractAn electronic nose-mass spectrometry (EN-MS) that profiles volatile compounds is a candidate device for identifying the geographic origin of cultivation of agricultural products when an adequate algorithm is derived. The objectives of this study were to apply two types of multivariate analysis, discriminant function analysis (DFA) and principal component analysis (PCA), to the volatile compounds detected by an EN-MS for the geographic classification of Chinese cabbage cultivated in Korea (42 samples) or in China (29 samples). DFA showed that Chinese cabbage from Korea were completely separable from those originating in China with 12 volatile compounds among the 151 detected. PCA revealed that Chinese cabbage data fell into two completely separable origins of Korea and China. This is the first study involving EN-MS data of volatile compounds with multivariate statistics to discriminate the geographical origin of Chinese cabbage, with further applications for other agricultural products.