Moscatilin from Dendrobium nobile, a naturally occurring bibenzyl compound with potential antimutagenic activity.

A bibenzyl compound that possesses antimutagenic activity was isolated from the storage stem of Dendrobium nobile. The isolated compound suppressed the expression of the umu gene following the induction of SOS response in Salmonella typhimurium TA1535/pSK1002 that have been treated with various mutagens. The suppressive compound was mainly localized in the n-hexane extract fraction of the processed D. nobile. This n-hexane fraction was further fractionated by silica gel column chromatography, which resulted in the purification and subsequent identification of the suppressive compound. EI-MS and (1)H and (13)C NMR spectroscopy were then used to delineate the structure of the compound that confers the observed antimutagenic activity. Comparison of the obtained spectrum with that found in the literature indicated that moscatilin is the secondary suppressive compound. When using 2-(2-furyl)-3-(5-nitro-2-furyl)acrylamide (furylfuramide) as the mutagen, moscatilin suppressed 85% of the umu gene expression compared to the controls at <0.73 micromol/mL, with an ID(50) value of 0.41 micromol/mL. Additionally, moscatilin was tested for its ability to suppress the mutagenic activity of other well-known mutagens such as 4-nitroquinoline-1-oxide (4NQO), N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), UV irradiation, 3-amino-1,4-dimethyl-5H-pyrido[4,3b]indole (Trp-P-1), benzo[a]pyrene (B[a]P), and aflatoxin B(1) (AFB(1)). With all of the aforementioned chemicals or treatments, moscatilin showed a dramatic reduction in their mutagenic potential. Interestingly, moscatilin almost completely suppressed (97%) the AFB(1)-induced SOS response at concentrations <0.73 micromol/mL, with an ID(50) of 0.08 micromol/mL. Finally, the antimutagenic activities of moscatilin against furylfuramide and Trp-P-1 were assayed by the Ames test using the S. typhimurium TA100 strain. The results those experiments indicated that moscatilin demonstrated a dramatic suppression of the mutagenicity of only Trp-P-1 but not furylfuramide.     

Quantification of relative flying fish paste content in the processed seafood ago-noyaki using real-time PCR

Real-time polymerase chain reaction (PCR) analysis of the 3′-portion of the mitochondrial 16S RNA gene (rDNA) coding sequence was used to determine flying fish paste in ago-noyaki. We quantified the amount of flying fish paste in ago-noyaki samples using flying fish-specific primers (Tobi16SF3/Tobi16SR) and universal primers (Univ16SF2/Univ16SR2). Using real-time PCR of standard ago-noyaki, a standard equation was obtained (y = 1.08x − 3.20; R ² = 0.977). This equation was then used to estimate the relative flying fish paste contents of eight commercially available ago-noyaki and two similar products. These results verified that the ago-noyaki products that had already been labeled with the E-mark deserved this status.     

Effects of Chilled Storage,Freezing Rates,and Frozen Storage Temperature on Lipid Oxidation in Meat Blocks from Cultured Bluefin Tuna Thunnus thynnus

ABSTRACT

The effects of a short chilled storage period before freezing, frozen storage temperature, and freezing rate on lipid oxidation of bluefin tuna (Thunnus thynnus) meat during frozen storage were investigated. After 12-months storage, all samples had increased in peroxide value though they were less at the lower temperatures (?45 and ?60°C). Peroxide values in all samples stored at ?20°C increased after 3 months storage, particularly those processed and stored 51 h after harvest. The lowest increase in peroxide value occurred in the samples frozen rapidly 3 h after harvest. Vitamin E levels decreased faster during frozen storage at ?20°C. There were no apparent differences in levels of triacylglycerides nor in n-3 fatty acid levels between treatments, storage periods, and storage temperatures. After 12-months storage, headspace oxidative volatiles were highest in samples stored at ?20°C and lowest in those stored at ?60°C. Lipid oxidation in tuna meat stored at ?45°C is similar to that at ?60°C, and rapid freezing rather than slow freezing should be used.     

Risk of introduction of BSE into Japan by the historical importation of cattle from the United Kingdom and Germany

All cattle of UK and German origin imported to Japan since 1980 and slaughtered before 2002 were traced (n = 33 and 15 respectively) and the probability that none, one, two or three of these imported cattle had developed BSE (reached the end or last stage of incubation period) at the year of slaughter/death was calculated. The predicted risk that BSE was introduced into Japan by imported cattle was 0.18. Among cattle imported from these countries in various years, cattle imported from the UK in 1987 and 1988 presented the highest risk, while the risk that BSE entered Japan by live cattle imported from the UK in 1982 and from Germany in 1993 was negligible. Because there was no effective system to avoid the recycling of the BSE agent, those infected cattle imported from the UK in 1987 and 1988 most probably entered the feed chain in Japan in 1992 and 1993.     

The pathology of phosphorus deficiency in fish--a review

Phosphorus (P) is an essential component of fish diets. Its deficiency affects not only hard tissues, where it is responsible for rickets, leading to skeletal malformation, but also influences various aspects of intermediary metabolism, and thus growth and feed conversion. Therefore, optimizing the dietary inclusion level is critical at all times. As the aquaculture industry has expanded, so the effects of P in farm effluents, derived from metabolic and uneaten food sources, have also become recognized. Diets are increasingly formulated on a basis that will not only provide adequate P for fish needs, but also endeavour to ensure minimal acceptable P levels in effluents at the same time. Many variables influence P requirements and P availability in fish diets, so it is inadvisable to feed diets formulated to an assumed minimum dietary requirement level, irrespective of the advantages that such a formulation may provide to environmental impact.