Soluble dietary fibers are widely used in functional foods as their adsorption of sugars and fats inhibits absorption of these substances from the gastrointestinal tract. However, they also adsorb drugs and may thus decrease the absorption volume and efficacy of pharmacological products. The present study investigated the effects of soluble dietary fiber on acetaminophen absorption. The acetaminophen absorbability of the following three types of soluble dietary fiber with different molecular weights was investigated using ultrafiltration. 1) Xanthan gum: molecular weight, 3,000,000 - 7,500,000; 2) Pectin: molecular weight, 10,000 - 400,000; and, 3) Indigestible dextrin: molecular weight, 1600. All of the soluble dietary fibers adsorbed acetaminophen in a concentration-dependent manner, and adsorption rates increased with greater fiber molecular weight. The effect of soluble dietary fiber on acetaminophen absorption from the gastrointestinal tract in rats was then investigated using portal vein catheterization. The area under the blood concentration time curve for each fiber was significantly lower than for the control group at 0.1%, 2.0% and 60.0%, respectively, for xanthan gum, pectin and indigestible dextrin; this clarified that the greater the fiber molecular weight, the greater the inhibition of low-concentration drug absorption.

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We compared the inhibitory effect of green tea, oolong tea, black tea, and pu-erh tea on lipid absorption using rats in which catheters were placed in the gastric and subclavian veins. The results showed that among rats that received continuous infusion of lipid emulsion and hot water extract of green tea, oolong tea, black tea, or pu-erh tea, increases in blood concentrations of triglycerides (TG) and nonesterified fatty acids (NEFA) were strongly inhibited in rats given green tea, an unfermented tea, compared to oolong tea, black tea, and pu-erh tea, which are fermented teas. Similarly, lipase activity was also strongly inhibited in rats given green tea compared to oolong tea, black tea, and pu-erh tea. These findings indicate that teas inhibit lipid absorption by inhibiting lipase activity, and that this effect is the most prominent for green tea, an unfermented tea.

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Much attention has been paid to the metabolism of isoflavones daidzein and genistein with regard to the prevention of several hormone-dependent diseases. It was recently reported that several glucuronic and/or sulfuric acid conjugated metabolites of daidzein and genistein are also biologically active. In order to evaluate the beneficial effects of isoflavones on health, it is important to grasp the pharmacokinetics of isoflavone metabolites in humans. In this study, we investigated individual differences in the metabolism and disposition of biologically active metabolites after soy ingestion among 10 healthy Japanese volunteers: five men and five women aged 33-55 and 21-31 years, respectively. The principal metabolite of daidzein in plasma was the estrogenic active daidzein-7-glucuronide-4'-sulfate. Whereas the area under the curve (AUC) value of this metabolite varied 1.7-fold among subjects (4.52-7.76μmol・h/l), those of monoglucuronides of daidzein (daidzein-7-glucuronide and daidzein-4'-glucuronide) varied widely among subjects (0.90-9.40μmol・h/l). These variations would contribute to individual differences in the total AUC of daidzein. For genistein, individual differences in the total AUC were highly influenced by the estrogenic active major metabolite genistein-7-glucuronide-4'-sulfate. Because the isoflavone profiles in plasma differed greatly, it may be possible to make a difference of in the prevention of several diseases according to individual differences in the enzymatic activity that participates in the metabolism of isoflavones and the gastrointestinal permeability of isoflavones and their metabolites.

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The degree of DNA fragmentation in commercially processed potato products was investigated using qualitative polymerase chain reaction (PCR) with primers designed to amplify amplicons of different lengths. The PCR amplified the amplicons up to 301 bp using 25 ng of the DNA purified from snack foods, frozen potatoes, dried potatoes and pre-cooked potatoes. In contrast, the DNA from potato starch and processed potato products, such as vermicelli, were amplifiable up to 51-101 bp. The amplicons with 63 bp using the real-time PCR from the DNA extracted from all processed potato products were detected. The study suggests that the primers that are designed to produce amplicons less than 51-101 bp are required for detecting genetically modified potatoes in processed potato products.

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A sample cleanup method that employs immunoaffinity chromatography (IAC) was investigated for potential use in the analysis of residual gentamicins (GMs) in meat samples. A column switching system was constructed to automate IAC operation online. GMs were measured by liquid chromatography with fluorescence detection after derivatization with 9-fluorenylmethylchloroformate. Most of the impurities in the meat samples were eliminated by IAC compared with conventional solid-phase extraction. The average recoveries of GMs from chicken meat and pork meat samples ranged from 77.5% to 89.0% (RSD:<7.0%) and from 75.6% to 87.7% (RSD:<6.4%), respectively. Method detection limit (MDL, S/N=3) and method quantification limit (MQL, S/N>10) were 30 ng/mL and 100 ng/mL, respectively, when calculations were conducted using MDL and MQL of pork meat thigh as total GM concentration. The results suggest that IAC is a useful cleanup method for the determination of residual GMs in meat samples.

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Black cohosh is one of the most popular herbal medicines which is produced from the roots and rhizomes of Cimicifuga racemosa (Ranunculaceae). Investigations so far have found that some of the black cohosh products were adulterated with other related Cimicifuga species, thus the accurate and convenient technique for the identification of the botanical sources is required. In the present study, we have developed a DNA analytical method to discriminate C. racemosa from six related species by an Amplification Refractory Mutation System (ARMS) analysis. Two kinds of species-specific sense primers were designed on the basis of the nucleotide substitution at position 61 on the trnL gene among the seven species, and the presence of 284 bp fragments was detected upon PCR amplification. The resultant fragments were species-specific when this method was applied for the referential plant samples. Commercial black cohosh products were then tested in the same way and the result indicated that three of the eight products were not derived from C. racemosa. Moreover, TLC and HPLC analyses were performed for marker compounds in sixteen commercial products to determine the reliability of the ARMS analysis. These metabolic analyses completely followed the results of the ARMS analysis and strongly suggested its usefulness.

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Caramel III, a food-coloring additive, is tested in Japan for the presence of the impurity, 2-acetyl-4-tetrahydroxybutylimidazole (THI), using an official HPLC method. In this HPLC method, THI is derivatized with 2,4-dinitrophenylhydrazine and then separated using octyl column. Improvement of the analytical conditions was attempted because contaminants can often compromise this test. Isolation of the analyte was improved when 0.1 mol/L phosphoric acid/methanol mixed solution (70:30) was used as the mobile phase. The revised method gave higher analyte concentrations compared to the standard method. The quantitative values obtained by LC/MS were equivalent to those obtained using the revised method, demonstrating the superiority of the revised method to the standard method.

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Lycopene existing in tomato is a nonprovitamin carotenoid with potent antioxidant properties. In addition to the antioxidant activities, lycopene is know to show anti-inflammatory effects through the inhibition of secretion of proinflammatory agents such as nitric oxide (NO) and cytokines from stimulated immune competent cells. In this study, we investigated the effects of lycopene on the secretion of NO and tumor necrosis factor-α (TNF-α) from mouse macrophage cell line RAW264.7 cells stimulated with CEL-I, a GalNAc-specific C-type lectin isolated from marine invertebrate Holothuroidea (Cucumaria echinata). Lycopene at 10μM showed significant inhibitory effect on the secretion of NO from CEL-I-stimulated RAW264.7 cells, and more potent inhibitory effects on NO and TNF-α secretions were observed at 100μM. Fluorescence microscopic observation using reactive oxygen species (ROS)-specific fluorescence probe suggested that lycopene effectively reduced intracellular ROS level in LPS-stimulated RAW264.7 cells, but it was less-effective on ROS level in RAW264.7 cells stimulated with CEL-I. These results suggest that the pathways leading to increase in intracellular ROS level and subsequent NO and TNF-α secretion may be somewhat different between LPS- and CEL-I-treated RAW264.7 cells. This is the first report indicating that lycopene can inhibit the secretion of NO and TNF-α from RAW264.7 cells stimulated with CEL-I.

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The quality and yield of DNA extracted from soybean and maize samples were compared using two commercial DNA extraction kits, the DNeasy Plant Mini kit (Mini kit) and the GM quicker kit. Subsequent quantification of the extracted DNA samples by UV spectrophotometry and fluorometry revealed that the yields of soybean DNA extracted using the Mini kit were approximately three times higher when determined by UV spectrophotometry than when they were determined by fluorometry. Conversely, the yields of soybean DNA extracted using the GM quicker kit were only slightly higher when determined by UV spectrophotometry than when they were determined by fluorometry. However, the relative DNA yields of maize DNA samples estimated by UV spectrophotometry and fluorometry were 1.77 with the Mini kit and 1.52 with the GM quicker kit. To validate the soybean DNA yields obtained using both extraction kits, DNA samples were analyzed by agarose gel electrophoresis and real-time PCR of a reference gene. These analyses indicated that the Mini kit yields estimated by UV spectrometry were overestimated, due to more low-intensity bands and fewer gene copies being observed, compared to DNA extracted with the GM quicker kit. Conversely, the maize DNA yields obtained using the Mini and GM quicker kits showed only slight differences between the real-time PCR and agarose gel electrophoresis analyses. The extracted DNA samples were then analyzed by size-exclusion chromatography. The results showed that the soybean DNA extracted using the Mini kit contained more low-molecular weight impurities than the DNA extracted using the GM quicker kit and maize extracts obtained with both extraction kits. Therefore, it appears that the presence of low molecular weight impurities in soybean DNA extracted with the Mini kit interferes with the UV quantification of DNA.

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A simple, rapid, and precise method was developed for the determination of colistin [CL: mixture of colistin-A (CLA) and colistin-B (CLB)] in chicken tissues by LC/FL using an on-column fluorescence derivatization and column-switching technique. CL in chicken tissues was extracted with 10% trichloroacetic acid aqueous solution and the crude extract was purified on an Oasis® HLB cartridge. CLA and CLB were derivatized into their respective o-phthalaldehyde fluorophores by an on-column reaction and then subjected to column-switching and subsequent chromatographic separation on a reversed-phase C₁₈ column. The on-column fluorescence derivatization LC method was superior to conventional pre-column fluorescence derivatization in term of the stability of the reaction products. The limits of detection (S/N=3) of CLA and CLB were 0.01μg/mL and 0.003μg/mL, respectively. The limits of quantification (S/N>10) of CLA and CLB were 0.04μg/mL and 0.01μg/mL, respectively. The average recoveries of CLA and CLB from chicken meat ranged from 67.9% to 78.9% and from 65.9% to 78.1%, respectively. The results suggest that the oncolumn fluorescence derivatization LC method is useful for the determination of CL in chicken tissues.

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The pungent phenolics were isolated from the rhizome of tetraploid ginger (Zingiber officinale Roscoe), and their structures were established as [6]-gingerol and [6]-dehydroparadol by chemical and spectroscopic evidence. And extracts and constituents in the rhizomes of diploid and tetraploid gingers were screened for their antibacterial activity against 6 Gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Salmonella enteritidis, Vibrio parahaemolyticus, and Yersinia enterocolitica) and 3 Gram-positive bacteria (Staphylococcus aureus, Listeria monocytogenes, and Bacillus cereus). The minimum inhibitory concentrations (MICs) of extracts and constituents in the rhizomes were determined by the microdilution method ranged from 0.49 to 16,000μg/ml, and 0.03 to 1,000μg/ml, respectively. Extracts and constituents in the rhizomes exhibited a fairly high antibacterial activity against the spectrum of most Gram-positive bacteria tested.

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An LC-MS/MS multiresidue method for the determination of pesticides in tea infusion was developed. An aliquot of tea infusion was cleaned up by macroporous diatomaceous earth column prior to LC-MS/MS determination. The recoveries for the tested pesticides (43 compounds) from infusion of green tea, oolong tea, and black tea after spiking at 0.05 ppm (0.1 ppm for lufenuron and triflumizole) were within the range 71-108%, with the relative standard deviations <15%, except for acrinathrin in oolong tea and black tea. No interfering peak was observed in the chromatograms of the blank extracts, indicating high selectivity of the method. The developed method is an efficient and reliable tool for the determination of pesticide residues in tea infusion.

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Thirty strains of Amylomyces, Fusarium, and Rhizopus were screened for the production of plant cell wall-degrading (PCWD) enzymes when they were cultured on medium containing wheat bran only. A. rouxii MIBA360 produced the highest quantities of PCWD enzyme, which was closely correlated with the quantity of pectinase produced. On the other hand, F. solani f. sp. asparagi MIB366 produced the highest amount of cellulase, although all the Fusarium species tested did not produce PCWD enzyme. The PCWD enzyme was most active at 55℃ and pH 5.0. The enzyme was stable after heating it for 1h at pH 6.0 and at 37℃. Full enzyme activity was maintained after heating for 16h between pH 6.0 and 7.5. After incubating with plant tissues such as bean curd lees, Japanese radish, Chinese cabbage, Japanese green (Mibuna) and potato, at 37℃ for 4 days, the PCWD enzyme preparation degraded 60-80% of the plant tissues.

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