Background and purpose:
5α,8α‐Epidioxy‐22E‐ergosta‐6, 22‐dien‐3β‐ol (ergosterol peroxide) is a major antitumour sterol produced by edible or medicinal mushrooms. However, its molecular mechanism of ...action has yet to be determined. Here, we examine the anticancer and anti‐inflammatory effects of ergosterol peroxide.
Experimental approach:
After treating RAW264.7 macrophages with LPS and purified ergosterol peroxide or ergosterol, we determined LPS‐induced inflammatory cytokines, nuclear DNA binding activity of transcription factors and phosphorylation of MAP kinases (MAPKs). HT29 colorectal adenocarcinoma cells were treated with ergosterol peroxide for 5 days. To investigate the antitumour properties of ergosterol peroxide, we performed DNA microarray and RT‐PCR analyses and determined the reactive oxygen species (ROS) in HT29 cells.
Key results:
Ergosterol peroxide suppressed LPS‐induced TNF‐α secretion and IL‐1α/β expression in RAW264.7 cells. Ergosterol peroxide and ergosterol suppressed LPS‐induced DNA binding activity of NF‐κB and C/EBPβ, and inhibited the phosphorylation of p38, JNK and ERK MAPKs. Ergosterol peroxide down‐regulated the expression of low‐density lipoprotein receptor (LDLR) regulated by C/EBP, and HMG‐CoA reductase (HMGCR) in RAW264.7 cells. In addition, ergosterol peroxide showed cytostatic effects on HT29 cells and increased intracellular ROS. Furthermore, ergosterol peroxide induced the expression of oxidative stress‐inducible genes, and the cyclin‐dependent kinase inhibitor CDKN1A, and suppressed STAT1 and interferon‐inducible genes.
Conclusion and Implication:
Our results suggest that ergosterol peroxide and ergosterol suppress LPS‐induced inflammatory responses through inhibition of NF‐κB and C/EBPβ transcriptional activity, and phosphorylation of MAPKs. Moreover, ergosterol peroxide appears to suppress cell growth and STAT1 mediated inflammatory responses by altering the redox state in HT29 cells.
British Journal of Pharmacology (2007) 150, 209–219. doi:10.1038/sj.bjp.0706972
Nitrification, a key process in the global nitrogen cycle that generates nitrate through microbial activity, may enhance losses of fertilizer nitrogen by leaching and denitrification. Certain plants ...can suppress soil-nitrification by releasing inhibitors from roots, a phenomenon termed biological nitrification inhibition (BNI). Here, we report the discovery of an effective nitrification inhibitor in the root-exudates of the tropical forage grass Brachiaria humidicola (Rendle) Schweick. Named "brachialactone," this inhibitor is a recently discovered cyclic diterpene with a unique 5-8-5-membered ring system and a γ-lactone ring. It contributed 60-90% of the inhibitory activity released from the roots of this tropical grass. Unlike nitrapyrin (a synthetic nitrification inhibitor), which affects only the ammonia monooxygenase (AMO) pathway, brachialactone appears to block both AMO and hydroxylamine oxidoreductase enzymatic pathways in NITROSOMONAS: Release of this inhibitor is a regulated plant function, triggered and sustained by the availability of ammonium (NHFormula: see text) in the root environment. Brachialactone release is restricted to those roots that are directly exposed to NHFormula: see text. Within 3 years of establishment, Brachiaria pastures have suppressed soil nitrifier populations (determined as amoA genes; ammonia-oxidizing bacteria and ammonia-oxidizing archaea), along with nitrification and nitrous oxide emissions. These findings provide direct evidence for the existence and active regulation of a nitrification inhibitor (or inhibitors) release from tropical pasture root systems. Exploiting the BNI function could become a powerful strategy toward the development of low-nitrifying agronomic systems, benefiting both agriculture and the environment.
Based on genome mining, a new antibacterial peptide named actinokineosin was isolated from a rare actinomycete Actinokineospora spheciospongiae. The amino acid sequence of the C‐terminus of ...actinokineosin was established by TOF‐MS/MS experiments. The amino acid sequence in the macrolactam ring was determined by TOF‐MS/MS analyses after cleavage with BNPS‐skatole and successive trypsin treatment. As a result of an antibacterial assay using a paper disk, actinokineosin showed antibacterial activity against Micrococcus luteus at a dosage of 50 μg per disk. From the genome sequence data of A. spheciospongiae, the biosynthetic gene cluster of actinokineosin was found and was indicated to consist of 10 genes. Among the genes, the gene aknA encoded the precursor of actinokineosin and the genes including aknC, aknB1 and aknB2 were proposed as modification enzymes to give mature actinokineosin.
Significance and Impact of the Study
Genome mining is a powerful tool to find new bioactive compounds from the genome database. In this report, we succeeded in isolation and structure determination of a new antibacterial peptide named actinokineosin based on genome mining.
Significance and Impact of the Study: Genome mining is a powerful tool to find new bioactive compounds from the genome database. In this report, we succeeded in isolation and structure determination of a new antibacterial peptide named actinokineosin based on genome mining.
Acrylamide concentrations in processed foods (63 samples covering 31 product types) from Japan were analysed by LC-MS/MS and GC-MS methods. The limit of detection and limit of quantification of ...acrylamide were 0.2 ng ml
-1
(6 fmol) and 0.8 ng ml
-1
(22 fmol), respectively, by LC-MS/MS, and those of 2,3-dibromopropionamide derived from acrylamide were 12 ng ml
-1
(52 fmol) and 40 ng ml
-1
(170 fmol), respectively, by GC-MS. Repeatability given as RSD was <5 and <15% for the LC-MS/MS and GC-MS methods, respectively. High correlation (r
2
= 0.946) was observed between values obtained by the two methods. Most potato crisps and whole potato-based fried snacks showed acrylamide concentrations >1000 μg kg
-1
. The concentrations in non-whole potato-based snacks, rice crackers processed by grilling or frying, and candied sweet potatoes were lower compared with those in the potato crisps and the whole potato-based fried snacks. One of the whole potato-based fried snacks, however, showed low acrylamide concentration (<50 μg kg
-1
) suggesting the formation of acrylamide is strongly influenced by processing conditions. Acrylamide concentrations in instant precooked noodles and won-tons were <100 μg kg
-1
with only one exception. Roasted barley grains for 'Mugi-cha' tea contained 200-600 μg kg
-1
acrylamide.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
The receptor for advanced glycation end products (RAGE) is a multi-ligand receptor involved in the development of diabetic complications. Although the soluble form of the extracellular domain ...maintains the ability to bind multi-ligands, it is unstable and degrades into several peptide species during storage. Proteolysis with thrombin or factor Xa revealed several protease sensitive sites. Most sensitive site is located between Arg228 and Val229, and peptide bond next to Arg216, Arg116, Arg114 and Trp271 are also cleaved. Seven truncated extracellular domains of RAGE were engineered in order to obtain a stable soluble fragment. RAGE 143 (Ala23-Thr143) is not only protease resistant but also shows the same ligand-binding ability as that of the full-length extracellular domain. The resultant minimum RAGE 143 works as a stable recognition devise to detect advanced glycation end products (AGEs).
The objective of this study was to investigate the differences in the muscle proteome of grass-fed and grain-fed cattle. Eight Japanese Black Cattle 10 mo of age were separated randomly into 2 ...groups: 1) grazing (grass-fed) and 2) concentrate (grain-fed) groups. All cattle were first housed individually in a stall barn and fed a combination of concentrate ad libitum and Italian ryegrass hay until 21 mo of age. After this control period, the 4 grass-fed cattle were placed on outdoor pasture, whereas the other 4 grain-fed cattle continued on the concentrate diet. The cattle were slaughtered at 27 mo of age, and tissues from the semitendinosus muscle were obtained for use in proteome analysis. Differential expression of muscle proteins in the 2 groups was carried out using 2-dimensional gel electrophoresis (2DE) and Western blot analyses, with subsequent mass spectrometry. Approximately 200 individual protein spots were detected and compared in each group using 2DE, of which 20 and 9 spots, respectively, showed differences in the spot intensity for the sarcoplasmic fraction and myofibrillar fraction. In the grazing group, the relative intensity of spots was significantly greater for adenylate kinase 1 and myoglobin in the sarcoplasmic fraction, and for slow-twitch myosin light chain 2 in the myofibrillar fraction (P < 0.05), than the concentrate group. The relative spot intensity of several glycolytic enzymes was significantly greater in the grazing group, such as β-enolase 3, fructose-1,6-bisphosphate aldolase A, triosephosphate isomerase, and heat shock 27 kDa protein (P < 0.05). Moreover, significantly greater slow twitch of troponin T, troponin I, and myosin heavy chain of semitendinosus muscle was detected in the grazing group than in the concentrate group using Western blot analysis (P < 0.05). Several previous reports have described that the slow-twitch muscle contents affect elements of nutrition, flavor, and food texture of meat. This study revealed muscle fiber type conversion to slow-twitch tissues from fast-twitch tissues occurring with change in the energy metabolic enzyme when cattle were grazed in the latter fattening period. Although analyses of the influence on elements of nutrition, flavor, and food texture were not done for this study, these results show that slow-twitch converted muscle resulting from the grazing of cattle might modify several meat characteristics.
The objective of this study was to investigate the differences in the muscle proteome of grass-fed and grain-fed cattle. Eight Japanese Black Cattle 10 mo of age were separated randomly into 2 ...groups: 1) grazing (grass-fed) and 2) concentrate (grain-fed) groups. All cattle were first housed individually in a stall barn and fed a combination of concentrate ad libiturn and Italian ryegrass hay until 21 mo of age. After this control period, the 4 grass-fed cattle were placed on outdoor pasture, whereas the other 4 grain-fed cattle continued on the concentrate diet. The cattle were slaughtered at 27 mo of age, and tissues from the semi-tendinosus muscle were obtained for use in proteome analysis. Differential expression of muscle proteins in the 2 groups was carried out using 2-dimensional gel electroplioresis (2DE) and Western blot analyses, with subsequent mass spectrometry. Approximately 200 individual protein spots were detected and compared in each group using 2DE, of which 20 and 9 spots, respectively, showed differences in the spot intensity for the sarcoplasmic fraction and myofibrillar fraction. In the grazing group, the relative intensity of spots was significantly greater for adenylate kinase 1 and myoglobin in the sarcoplasmic fraction, and for slow-twitch myosin light chain 2 in the myofibrillar fraction (P < 0.05), than the concentrate group. The relative spot intensity of several glycolytic enzymes was significantly greater in the grazing group, such as ß-enolase 3, fructose-1,6-bis-phosphate aldolase A, triosephosphate isomerase, and heat shock 27 kDa protein (P < 0.05). Moreover, significantly greater slow twitch of troponin T, troponin I, and myosin heavy chain of semitendinosus muscle was detected in the grazing group than in the concentrate group using Western blot analysis (P < 0.05). Several previous reports have described that the slow-twitch muscle contents affect elements of nutrition, flavor, and food texture of meat. This study revealed muscle fiber type conversion to slow-twitch tissues from fast-twitch tissues occurring with change in the energy metabolic enzyme when cattle were grazed in the latter fattening period. Although analyses of the influence on elements of nutrition, flavor, and food texture were not done for this study, these results show that slow-twitch converted muscle resulting from the grazing of cattle might modify several meat characteristics. PUBLICATION ABSTRACT
Among the lipophilic extracts of seven traditional edible mushrooms, the acetone extract of Sarcodon aspratus markedly inhibited the growth of HL60 human leukemia cells and induced apoptosis after 24 ...h incubation. The major active component was identified as ergosterol peroxide by NMR and ESI-MS analysis. Ergosterol peroxide completely inhibited growth and induced apoptosis of HL60 cells at a concentration of 25 MicroM.
Novel diterpenoids, erinacines H (1) and I (3), were isolated from the cultured mycelia of Hericium erinaceum. The structures of the compounds were determined by interpretation of the spectral data. ...Erinacine H showed stimulating activity of nerve growth factor (NGF)-synthesis.
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