Biological and Pharmaceutical Bulletin
Online ISSN : 1347-5215
Print ISSN : 0918-6158
ISSN-L : 0918-6158
Volume 38 , Issue 10
Showing 1-32 articles out of 32 articles from the selected issue
Regular Articles
  • Hong Liu, Xinhong Xue, Huijian Shi, Lifeng Qi, Dianrong Gong
    2015 Volume 38 Issue 10 Pages 1439-1449
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Adult hippocampal neurogenesis occurs in the dentate gyrus (DG) of the mouse hippocampus, and plays roles in learning and memory progresses. In amyloid precursor protein (APP)/presenilin 1 (PS1) transgenic mice, a rodent model of Alzheimer’s disease (AD), severe impairment of neurogenesis in the dentate subgranular zone (SGZ) of the DG has been reported. Osthole, an active constituent of Cnidium monnieri (L.) CUSSON, has been reported to exert neuroprotective effects and may promote neural stem cell proliferation. However, whether osthole ameliorates spatial memory deficits and improves hippocampal neurogenesis in APP/PS1 mice remains unknown. In this study we found that osthole (30 mg/kg intraperitoneally (i.p.) once daily) treatment dramatically ameliorated the cognitive impairments by Morris Water Maze test and passive avoidance test, and augmented neurogenesis in the DG of hippocampus in APP/PS1 mice. Furthermore, osthole treatment upregulated expression of brain-derived neurotrophic factor (BDNF) and enhanced activation of the BDNF receptor tyrosine receptor kinase B (TrkB) following increased phosphorylation of cyclic AMP response element-binding protein (CREB), indicating that osthole improves neurogenesis via stimulating BDNF/TrkB/CREB signaling in APP/PS1 transgenic mice.
  • Mulin Liu, Wei Wu, Qun Zhao, Qiupeng Feng, Wenbin Wang
    2015 Volume 38 Issue 10 Pages 1450-1457
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: August 05, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Triggering receptor expressed on myeloid cells (TREM)-1 expression on neutrophils is associated with inflammation and infection. However, the dynamic changes of the TREM-1 expression on neutrophils have not been clarified in inflammatory acute pancreatitis (AP). The aim of this study was to longitudinally investigate the TREM-1 expression on peripheral blood and peritoneal neutrophils and its relationship with the levels of plasma cytokines and disease severity in a mouse model of AP following injection with varying doses of L-arginine to induce mild AP (MAP) or severe AP (SAP). The results indicated that induction of MAP or SAP was associated with moderate and severe pancreatic tissue damage and varying levels of serum and peritoneal fluid amylase as well as survival rates in mice. In comparison with that in the healthy controls, significantly increased percentages of peripheral blood and peritoneal fluid CD14-TREM-1+ neutrophils and higher levels of TREM-1 mRNA transcripts in peripheral blood nuclear cells were detected in the MAP and SAP mice, particularly in the SAP mice. Higher levels of plasma tumor necrosis factor (TNF)-α and granulocyte-macrophage colony stimulating factor (GM-CSF), but lower levels of plasma interleukin (IL)-10, were detected in the MAP and SAP mice at varying time points post induction. The percentages of peripheral blood CD14-TREM-1+ neutrophils were correlated positively with the levels of TNF-α, GM-CSF, and amylase as well as the pathogenic scores, but negatively with the levels of IL-10 in the AP mice. Therefore, TREM-1+ neutrophils may participate in the pathogenesis of AP and serve as a biomarker for evaluating the severity of AP.
  • Junjun Jiang, Liyuan Li, Mingchao Xie, Ryosuke Fuji, Shangfeng Liu, Xi ...
    2015 Volume 38 Issue 10 Pages 1458-1463
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Spermatogenesis associated 4 (SPATA4) is a testis-specific gene first cloned by our laboratory, and plays an important role in maintaining the physiological function of germ cells. Accumulated evidence suggests that SPATA4 might be associated with apoptosis. Here we established HeLa cells that stably expressed SPATA4 to investigate the function of SPATA4 in apoptosis. SPATA4 protected HeLa cells from etoposide-induced apoptosis through the mitochondrial apoptotic pathway, in the way that SPATA4 suppressed decrease of the mitochondrial membrane potential, the release of cytochrome c, and subsequent activation of caspase-9 and -3. We further demonstrated that SPATA4 upregulated anti-apoptotic members of Bcl-2 family proteins, Bcl-2, and downregulated the pro-apoptotic member of Bcl-2 family proteins, Bax. Knockdown of SPATA4 in HeLa/SPATA4 cells could partially rescue expression levels of bcl-2 and bax. In conclusion, SPATA4 protects HeLa cells against etoposide-induced apoptosis through the mitochondrial apoptotic pathway. Our findings provide further evidence that SPATA4 plays a role in regulating apoptosis.
  • Xiangcheng Xie, Wenkai Xia, Xiao Fei, Qunhong Xu, Xiu Yang, Donghao Qi ...
    2015 Volume 38 Issue 10 Pages 1464-1469
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Diabetic nephropathy (DN) is the leading cause of end-stage renal disease (ESRD). DN is characterized by glomerular extracellular matrix accumulation, mesangial expansion, basement membrane thickening, and renal interstitial fibrosis. To date, mounting evidence has shown that H2 relaxin possesses powerful antifibrosis properties; however, the mechanisms of H2 relaxin on diabetic nephropathy remain unknown. Here, we aimed to explore whether H2 relaxin can reduce production of extracellular matrix (ECM) secreted by human mesangial cells (HMC). HMC were exposed to 5.5 mM glucose (NG) or 30 mM glucose (HG) with or without H2 relaxin. Fibronectin (FN) and collagen type IV levels in the culture supernatants were examined by solid-phase enzyme-linked immunoadsorbent assay (ELISA). Western blot was used to detect the expression of α-smooth muscle actin (α-SMA) protein. Quantitative polymerase chain reaction (qPCR) method was employed to analyze transforming growth factor (TGF)-β1 mRNA expression. Compared with the normal glucose group, the levels of fibronectin and collagen type were markedly increased after being cultured in high glucose medium. Compared with the high glucose group, remarkable decreases of fibronectin, collagen type IV, α-smooth muscle actin, and TGF-β1 mRNA expression were observed in the H2 relaxin-treated group. The mechanism by which H2 relaxin reduced high glucose-induced overproduction of ECM may be associated with inhibition of TGF-β1 mRNA expression and mesangial cells’ phenotypic transition. H2 relaxin is a potentially effective modality for the treatment of DN.
  • Fang He, Wen Zhang, Caiwen Zeng, Chunhua Xia, Yuqing Xiong, Hong Zhang ...
    2015 Volume 38 Issue 10 Pages 1470-1477
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    In our previous study, panaxytriol (PXT) was shown to enhance midazolam (MDZ) 1′-hydroxylation significantly but to inhibit MDZ 4-hydroxylation. To explore the underlying mechanism, we investigated the effects of PXT on cytochrome P450 3A (CYP3A)-mediated MDZ metabolic pathways using rat liver microsomes (RLM), human liver microsomes (HLM), and rat primary hepatocytes. In the presence of PXT, the Vmax of 4-OH MDZ decreased from 0.72 to 0.51 nmol/min·mg pro in RLM and from 0.32 to 0.12 nmol/min·mg pro in HLM, and the Km value increased from 5.12 to 7.26 µM in RLM and from 27.87 to 32.80 µM in HLM. But the presence of PXT reduced the Km and increased the Vmax values of MDZ 1′-hydroxylation in RLM and HLM. Interestingly, the differential effect of PXT on MDZ 4-hydroxylation and 1′-hydroxylation was also observed in primary rat hepatocytes after 45-min culture. PXT did not affect the expression levels of CYP3A1/2 mRNA in rat hepatocytes. With extension of the culture time to 6 h, however, PXT significantly inhibited both MDZ 4-hydroxylation and 1′-hydroxylation, and the expression level of CYP3A1/2 mRNA was decreased to 87% and 80% (CYP3A1) and to 89% and 85% (CYP3A2) of those in controls in the presence of PXT 4.0 and 8.0 µg/mL, respectively. These results suggest that PXT could activate MDZ 1′-hydroxylation but inhibit MDZ 4-hydroxylation by changing the CYP3A enzyme affinity and metabolic rate after a short-term intervention. However, long-term treatment with PXT could inhibit both the 4-hydroxylation and 1′-hydroxylation of MDZ by downregulating CYP3A1/2 mRNA expression.
  • Noppawan Phumala Morales, Srisuporn Sirijaroonwong, Paveena Yamanont, ...
    2015 Volume 38 Issue 10 Pages 1478-1483
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    The quantitative free radical scavenging capacity of curcumin and its demethoxy derivatives (demethoxycurcumin (Dmc) and bisdemethoxycurcumin (Bdmc)) and hydrogenated derivatives (tetrahydrocurcumin (THC), hexahydrocurcumin (HHC) and octahydrocurcumin (OHC)) towards 1,1-diphenyl-2-picryl hydrazyl (DPPH), nitric oxide radical (NO), hydroxyl radical (HO·) and superoxide anion radical (O2·) were investigated by electron paramagnetic resonance (EPR) spectroscopy. One mole of the hydrogenated derivatives scavenged about 4 mol of the DPPH radical, while curcumin and Dmc scavenged about 3 mol of the DPPH radical. Curcumin and THC showed moderate scavenging activity towards NO, yielding 200 mmol of NO scavenged per 1 mol of the scavenger. In contrast, curcumin and its derivatives showed very low scavenging activity towards HO· and O2·, yielding approximately only 3–12 mmol scavenged per 1 mol of the tested compounds. Our results suggest that curcumin and its derivatives principally act as chain breaking antioxidants rather than as direct free radical scavengers. Furthermore, we showed that the ortho-methoxyphenolic group and the heptadione linkage of these molecules greatly contributed to their DPPH and NO scavenging activity.
  • Saki Kakizuka, Tomoki Takeda, Yukiko Komiya, Akihiko Koba, Hiroshi Uch ...
    2015 Volume 38 Issue 10 Pages 1484-1495
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    This study investigated dioxin-induced changes in metabolomes in pubertal rat excrement. The administration of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or restricting dietary intake (pair-fed group) markedly altered the metabolomic profile including lipids, hormones, and vitamins in the urine and feces. TCDD caused an increase in the fecal chenodeoxycholic acid and taurocholic acid content and in urinary adrenaline and 17β-estradiol, while the urinary melatonin level was reduced by TCDD. These changes were not observed in the pair-fed group. In accordance with the elevated level of fecal bile acids, TCDD reduced the intestinal expression of the apical sodium-dependent bile salt transporter, which plays a role in resorbing bile acids from the bile duct. In addition, CYP7A1, a rate-limiting enzyme for bile acid biosynthesis, was attenuated by TCDD treatment, although TCDD induced hepatic CYP8B1, an enzyme essential for cholic acid synthesis. Supplying cholic acid or chenodeoxycholic acid to TCDD-exposed rats tended to restore the TCDD-produced reduction in serum triglycerides, whereas no similar trend was observed in wasting syndrome and lipid accumulation in the liver. These results suggest that: 1) TCDD alters the circulating levels of bile acids and hormones via a mechanism distinct from an attenuation in dietary intake, although the majority of TCDD-induced changes in nutrient contents in the excrement is due to a reduction in food intake; and 2) TCDD facilitates the excretion of bile acids and disrupts their biosynthesis, resulting in the disturbance of lipid homeostasis.
  • Takahiro Yamada, Yasuaki Mino, Tatsuya Yagi, Takafumi Naito, Junichi K ...
    2015 Volume 38 Issue 10 Pages 1496-1503
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Metabolic saturation of voriconazole based on the trough plasma concentrations of voriconazole and its major metabolite N-oxide were evaluated according to CYP2C19 genotypes in 58 Japanese patients receiving voriconazole (median dose; 200 mg twice daily) for prophylaxis or treatment. Predose trough plasma concentrations of voriconazole and N-oxide were monitored on day 5 d or later after initiation of voriconazole treatment. Large interindividual variations in trough plasma concentrations of voriconazole and N-oxide were observed. Dose-normalized trough plasma concentrations of voriconazole were strongly correlated with its absolute trough concentrations, and the straight regression line between them intersected close to the origin of the coordinates. No significant correlation was observed between the trough plasma concentrations of voriconazole and N-oxide. The inverse value of the metabolic ratio of N-oxide to voriconazole was strongly correlated with the absolute trough voriconazole concentrations. No significant differences in the trough plasma concentrations of voriconazole and N-oxide or the metabolic ratio of N-oxide to voriconazole between the CYP2C19 genotypes were observed. Saturated metabolism of voriconazole N-oxidation rather than CYP2C19 genotypes contributed to the nonlinear pharmacokinetics. The metabolic process converting voriconazole to N-oxide was saturated at the clinical dose.
  • Hirotaka Matsuo, Yoshiyuki Kondo, Takashi Kawasaki, Shinji Tokuyama, N ...
    2015 Volume 38 Issue 10 Pages 1504-1511
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    An inhibitor of 3T3-L1 adipocyte differentiation was isolated from Streptomyces sp. TK08330 and identified by spectroscopy as the 18-membered macrolide borrelidin. Treatment with 1.0 μM borrelidin suppressed intracellular lipid accumulation by 80% and inhibited the expression of adipocyte-specific genes. Borrelidin suppressed the mRNA expression of two master regulators of adipocyte differentiation, peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT/enhancer binding protein (C/EBPα). Studies on well-known upstream regulators of PPARγ revealed that borrelidin down-regulated C/EBPδ mRNA expression but did not affect expression of C/EBPβ. Borrelidin increased mRNA expression of negative regulators of differentiation such as GATA-binding protein (GATA) 3, Krüppel-like factor (KLF) 3 and KLF7, as well as positive regulators, KLF4, KLF6 and KLF15, at early stages of differentiation. To elucidate a primary mediator of borrelidin differentiation inhibitory activity, small interfering RNA (siRNA) transfection experiments were performed. The mRNA expression of PPARγ, which was down-regulated by borrelidin, was not changed by KLF3 and KLF7 siRNA treatment. In contrast, expression of PPARγ in GATA-3 siRNA-treated cells was not significantly different from that of control siRNA-treated cells. Borrelidin significantly inhibited lipid accumulation in control siRNA-treated cells, and treatment with GATA-3 siRNA slightly reduced the inhibitory effect of borrelidin. These results indicate that borrelidin inhibited adipocyte differentiation partially via GATA-3.
  • Meng-Meng Liu, Yong-Mei Xing, Shun-Xing Guo
    2015 Volume 38 Issue 10 Pages 1512-1517
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: July 25, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Polyporus (P.) umbellatus, an endangered medicinal fungus in China, is distributed throughout most areas of the country. Thirty-seven natural P. umbellatus samples collected from 12 provinces in China were subjected to the inter-simple sequence repeat (ISSR) assay to investigate the genetic diversity within and among the 11 natural populations. Nine ISSR primers selected from 100 primers produced 88 discernible DNA bands, with 46 being polymorphic. The frequency of polymorphism varied from 19.57 to 93.48% with an average of 61.26% across all populations. At the population level, the within-population variance was much greater (92.04%) than the between-population variance (7.96%) as revealed by analysis of molecular variance. Eleven P. umbellatus populations were grouped into two major clusters, and the clustering pattern displayed four groups using the unweighted pair-group method with an arithmetic mean dendrogram. Principal coordinate analysis further indicated that the genetic diversity of P. umbellatus strains was unevenly distributed and displayed a clustered distribution pattern instead. Within these clusters, subgrouping (Henan and Hubei) and cluster II (Jilin and Heilongjiang) related to the geographic distribution were evident. The present study provides the first global overview of P. umbellatus diversity analysis in China, which may open up new opportunities in comparative genetic research on this medicinal fungus in other countries.
  • Jin Su, Qing Miao, Peipei Miao, Yuanyuan Zhao, Yuanyuan Zhang, Ning Ch ...
    2015 Volume 38 Issue 10 Pages 1518-1528
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: July 29, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Coptisine (COP), a protoberberine alkaloid (PBA) from Chinese medicinal plants (such as family Berberidaceae), may be useful for improving central nervous system disorders. However, its pharmacokinetics, disposition and metabolism are not well defined. In the present study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established for the analysis of COP in biological samples. To better understand its in vivo pharmacological activities, COP concentrations in rat plasma were determined after oral (50 mg/kg) and intravenous administration (10 mg/kg). For the brain distribution study, the concentration of COP in five different regions was examined after intravenous administration at 10 mg/kg. Pharmacokinetic parameters from the COP concentration–time profiles in plasma and brain, and the brain-to-plasma coefficient (Kp, brain) were calculated by non-compartmental analysis. The metabolites of COP in rats in vivo and in vitro (urine, bile, liver microsomes and intestinal bacteria incubation) were also identified. Seventeen metabolites, including 11 unconjugated metabolites formed by hydroxylation, hydrogenation, demethylation, dehydrogenation, demethylation, and 6 glucuronide and sulfate conjugates were identified for the first time. The results suggested that COP had low oral bioavailability of 8.9% and a short (plasma) half-life (T1/2=0.71 h) in rats. After intravenous administration, it quickly crossed the blood–brain barrier, accumulating at higher concentrations and then was slowly eliminated from different brain regions. Moreover, COP was transformed into metabolites through multiple metabolic pathways in vivo and in vitro. These results should help to promote further research on COP and contribute to clarifying the metabolic pathways of PBAs.
  • Yutaka Masuda, Jun Yazawa, Yuuka Makino, Kimihiko Takada
    2015 Volume 38 Issue 10 Pages 1529-1535
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Thrombin-activatable fibrinolysis inhibitor (TAFI) is a carboxypeptidase B-like proenzyme biosynthesized in the liver and released into the blood circulation. Activated TAFI (TAFIa) has been implicated as an important player in maintaining the balance between blood coagulation and fibrinolysis. In the present study, regulation of TAFI (CPB2) gene expression was investigated using cultured human hepatoma HepG2 cells. HepG2 cells were treated with the phosphoinositide 3-kinase (PI3K) inhibitor LY294002, and the levels of TAFI antigen and CPB2 mRNA were measured. HepG2 cells treated with LY29400 decreased their release of TAFI antigen into the conditioned medium (CM). In parallel, there were decreased levels of CPB2 mRNA and TAFI antigen in the cells. However, CPB2 gene promoter activity was not influenced by treatment of the cells with LY294002. The half-life of the CPB2 transcript was shortened by treatment with LY294002 compared with control. The present results suggest that the PI3K inhibitor LY294002 suppresses expression of TAFI, a prothrombotic factor, by decreasing the stability of CPB2 transcripts.
  • Asami Mori, Hironori Suzawa, Kenji Sakamoto, Tsutomu Nakahara, Kunio I ...
    2015 Volume 38 Issue 10 Pages 1536-1541
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    The aim of this study was to examine the effects of elcatonin, a synthetic derivative of eel calcitonin, on rat retinal blood vessels, and to determine how diabetes affects the retinal vascular responses. Ocular fundus images were captured with an original high-resolution digital fundus camera in vivo. The retinal vascular responses were evaluated by measuring the diameter of retinal blood vessels contained in the digital images. Both systemic blood pressure and heart rate were continuously recorded. Elcatonin increased the diameter of retinal blood vessels but decreased mean blood pressure in a dose-dependent manner, whereas it had no significant effect on heart rate. A diminished retinal vasodilator response and significant pressor response to elcatonin were observed in rats injected intravenously with NG-nitro-L-arginine methyl ester, a nitric oxide (NO) synthase inhibitor. Intravitreal injection of indomethacin, a non-selective cyclooxygenase (COX) inhibitor, and SQ22536, an adenylyl cyclase inhibitor, markedly attenuated the vasodilator effects of elcatonin on retinal blood vessels. The retinal vasodilator responses to elcatonin were unaffected 2 weeks after the induction of diabetes by a combination of streptozotocin treatment and D-glucose feeding. These results suggest that elcatonin dilates rat retinal blood vessels via NO- and COX-dependent mechanisms and that the adenylyl cyclase-adenosine 3′,5′-cyclic monophosphate system plays a major role in the vasodilator mechanisms. The retinal vasodilatory effects of elcatonin seem to be preserved at early stages of diabetes.
  • JaeHo Lee, SeungJun Lee, ByungMan Lee, KyungBaeg Roh, DeokHoon Park, E ...
    2015 Volume 38 Issue 10 Pages 1542-1547
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: July 15, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    For screening of skin-whitening ingredients that modulate inhibition of melanogenesis, tyrosinase promoter-based assay using a three-dimensional (3D) spheroid culture technique is a beneficial tool to improve the accuracy of raw material screening in cosmetics through mimicking of the in vivo microenvironment. Although the advantages of high-throughput screening (HTS) are widely known, there has been little focus on specific cell-based promoter assays for HTS in identifying skin-whitening ingredients that inhibit accumulation of melanin. The aim of this study was therefore to develop a large-scale compatible assay through pTyr-EGFP, an enhanced green fluorescent protein (EGFP)-based tyrosinase-specific promoter, to seek potential melanogenesis inhibitors for cosmetic use. Herein, a stably transfected human melanoma cell line expressing EGFP under the control of a 2.2-kb fragment derived from the tyrosinase gene was generated. Spontaneous induction of the tyrosinase promoter by 3D spheroid culture resulted in increased expression of EGFP, providing a significant correlation with the tyrosinase mRNA level, and subsequent inhibition of tyrosinase activity. Importantly, the pTyr-EGFP system provided successful tracking of the changes in the live image and real-time monitoring. Thus tyrosinase promoter-based fluorescent assay using a 3D spheroid culture can be useful as a screening system for exploring the efficiency of anti-melanogenesis ingredients.
  • Xiu-Kun Wang, Yong Zhao, Ting Liu, Yan Yi, Chun-Ying Li, Hong-Jie Wang ...
    2015 Volume 38 Issue 10 Pages 1548-1556
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: July 18, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    The present study assessed the safety/toxicity of Senecio scandens, a well-known Chinese herb that is used as an anti-inflammatory, antibiosis, and antipyretic drug. A 90-d subchronic oral toxicity study of S. scandens was performed in Wistar rats. The extract of S. scandens was administered orally to male and female rats at a single dose of 225, 450, and 900 mg/kg/d. There was no obvious toxicity. Certain changes in hematology and coagulation parameters (red cell distribution width (RDW), platelet count (PLT), monocyte percentage (Mo%), activated partial thromboplastin time (APTT), prothrombin time (PT)) were observed in some administration groups. In regards to the blood biochemical parameters, the levels of creatinine (CRN), potassium, and chloride were increased in a number of the treated rats. There were no significant changes in other hematology, coagulation, or biochemical parameters in rats orally administered S. scandens. S. scandens has a slight effect on rat coagulation and metabolism systems. The herb was safe at all doses tested, but caution should be taken when administering S. scandens at higher doses.
  • Kyong-Son Min, Erika Sano, Hidenori Ueda, Fumitoshi Sakazaki, Keita Ya ...
    2015 Volume 38 Issue 10 Pages 1557-1563
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: July 29, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    The major route of cadmium (Cd) intake by non-smokers is through food ingestion. Cd is a non-essential metal absorbed through one or more transporters of essential metal ions. Expression of these transporters is affected by nutritional status. To investigate the risk factors for Cd toxicity, the effects of deficiency of essential metals on hepatic and renal accumulation of Cd were studied in mice of different ages. Mice were administered a control diet or one of the essential metal-deficient diets, administered Cd by gavage for 6 weeks, and killed; then, Cd accumulation was evaluated. Iron deficiency (FeDF) or calcium deficiency (CaDF) resulted in remarkable increases in hepatic and renal Cd accumulation compared with control-diet mice and other essential metal-deficient mice. Cd accumulation in hepatic and renal tissue was increased significantly at all ages tested in FeDF and CaDF mice. Renal Cd concentrations were higher in 4-week-old mice than in 8- and 25-week-old mice. Increase in intestinal mRNA expression of calcium transporter (CaT)1, divalent metal ion transporter-1, and metallothionein (MT)1 was also higher in 4-week-old mice than in other mice. Renal accumulation of Cd showed strong correlation with intestinal mRNA expression of CaT1 and MT1. These data suggest that CaDF and FeDF at younger ages can be a risk factor for Cd toxicity.
  • Jie Yu, Zhuyun Jiang, Ling Ning, Zhilong Zhao, Na Yang, Lu Chen, Hui M ...
    2015 Volume 38 Issue 10 Pages 1564-1572
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: July 22, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Heat-shock protein 70 (HSP70) is known to function as a protective molecular chaperone that is massively induced in response to misfolded proteins following cerebral ischemia. The objective of this study was to characterize HSP70 induction by Z-ligustilide and explore its potential role in protection against cerebral ischemia–reperfusion injury. Our results demonstrated that the intranasal administration of Z-ligustilide reduced infarct volume and improved neurological function in a rat stroke model. Meanwhile, Z-ligustilide enhanced the cell viability of PC12 cells insulted by oxygen–glucose deprivation-reoxygenation (OGD-Reoxy) and decreased apoptotic and necrotic cell death. Importantly, Z-ligustilide induced HSP70 expression both in vitro and in vivo. Although heat-shock factor 1 (HSF1) nuclear translocation was promoted by Z-ligustilide, HSP70-based heat-shock element (HSE)-binding luciferase activity was not activated, and HSP70 expression responsive to Z-ligustilide was not attenuated by HSE decoy oligonucleotides. However, Z-ligustilide significantly activated the phosphorylation of mitogen-activated protein kinases (MAPKs). Further inhibition of MAPK activity by specific inhibitors attenuated HSP70 induction by Z-ligustilide. Meanwhile, downregulation of HSP70 using KNK437, an HSP70 synthesis inhibitor, or small hairpin RNA (shRNA) significantly attenuated the protection of Z-ligustilide against OGD-Reoxy-induced injury. Moreover, the application of specific inhibitors of MAPKs also achieved similar results. Finally, Z-ligustilide alleviated the accumulation of ubiquitinated proteins induced by OGD-Reoxy, which was inhibited by HSP70-shRNA. Taken together, our results demonstrated that Z-ligustilide may induce protective HSP70 expression via the activation of the MAPK pathway, but not canonical HSF1 transcription. HSP70 plays a key role in the protection of Z-ligustilide against OGD-Reoxy-induced injury.
  • Dong Wook Lim, Jae Goo Kim, Taewon Han, Sung Keun Jung, Eun Yeong Lim, ...
    2015 Volume 38 Issue 10 Pages 1573-1579
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: July 31, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Ilex paraguariensis, known as “Yerba Mate,” is an herb used in a beverage that is widely consumed in southern Latin American countries. Furthermore, it has been traditionally used to treat depression, and as an analgesic to manage both nerve pain and headache. The pain-related experimental evidence regarding the analgesic effects of Mate is unclear. Therefore, this study was designed to investigate whether Mate extract exhibits analgesic effects in both the plantar incision and spared nerve injury (SNI) models in rats. We tested the mechanical withdrawal threshold (MWT) using von Frey filaments. We also tested pain-related behavior using ultrasonic vocalization (USV). Neuropeptide Y (NPY) and pain-related cytokines were also determined in the dorsal root ganglia in a rat model of SNI. Our results showed that oral administration of Mate extract significantly increased MWT values, and reduced the number of 22–27 kHz USVs 24 h after the plantar incision operation. Moreover, after 15 d of continuous treatment with Mate extract, the SNI-induced hypersensitivity, cytokine levels, and NPY expression were significantly reduced compared to the corresponding findings in the control group. These results suggest that the intake of Mate extract has potential as a treatment for both postoperative pain and neuropathic pain.
  • Noriaki Nagai, Tadatoshi Tanino, Yoshimasa Ito
    2015 Volume 38 Issue 10 Pages 1580-1590
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    It is well known that rheumatoid arthritis patients taking nonsteroidal anti-inflammatory drugs (NSAIDs) are more susceptible to NSAIDs-induced gastroenteropathy in comparison with other patients. In this study we demonstrate that expression levels of interleukin (IL)-18 are related to aggravation of intestinal ulcerogenic lesions in adjuvant-induced arthritis (AA) rats following oral administration of indomethacin. AA rats were administered oral indomethacin (40 mg/kg) and killed under deep isoflurane anesthesia after 24 h. The small intestinal mucosa was then examined. Oral administration of indomethacin caused hemorrhagic lesions in the small intestinal mucosa of AA rats, and the lesion score of AA rats 24 h after indomethacin treatment was approximately 5.6-fold higher than for normal rats administered indomethacin. IL-18 expression in the small intestinal mucosa of AA rats administered indomethacin was also higher in comparison with normal rats receiving indomethacin. In addition, interferon-γ and nitric oxide levels in the small intestinal mucosa of AA rats were increased following oral administration of indomethacin. It is possible that IL-18 expression in AA rats renders the small intestinal mucosa more sensitive to indomethacin, and that IL-18 may play a role in aggravating intestinal ulcerogenic lesions in AA rats treated with this drug.
  • Hua Yang, Lihui Gao, Yanfen Niu, Yuanfang Zhou, Hua Lin, Jing Jiang, X ...
    2015 Volume 38 Issue 10 Pages 1591-1598
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: July 29, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Mangiferin, a natural glucosyl xanthone from the leaves of Mangifera indica L., was previously shown to exert potent hypouricemic effects associated with inhibition of the activity of xanthine dehydrogenase/oxidase. The present study aimed to evaluate its uricosuric effect and possible molecular mechanisms underlying the renal urate transporters responsible for urate reabsorption in vivo. Mangiferin (1.5–24.0 mg/kg) was administered intragastrically to hyperuricemic mice and rats induced by the intraperitoneal injection of uric acid and potassium oxonate, respectively. The uricosuric effect was evaluated by determining the serum and urinary urate levels as well as fractional excretion of uric acid (FEUA). The mRNA and protein levels of renal urate-anion transporter 1 (URAT1), organic anion transporter 10 (OAT10), glucose transporter 9 (GLUT9), and PDZ domain-containing protein (PDZK1) were analyzed. The administration of mangiferin significantly decreased the serum urate levels in hyperuricemic mice in a dose- and time-dependent manner. In hyperuricemic rats, mangiferin also reduced the serum urate levels and increased the urinary urate levels and FEUA. These results indicate that mangiferin has uricosuric effects. Further examination showed that mangiferin markedly inhibited the mRNA and protein expression of renal URAT1, OAT10, and GLUT9 in hyperuricemic rats, but did not interfere with PDZK1 expression. Taken together, these findings suggest that mangiferin promotes urate excretion by the kidney, which may be related to the inhibition of urate reabsorption via downregulation of renal urate transporters.
  • Taiji Sato, Yukiko K. Kaneko, Toshiaki Sawatani, Akiko Noguchi, Tomohi ...
    2015 Volume 38 Issue 10 Pages 1599-1605
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Our previous study using apoptosis analysis suggested that Ca2+ release through inositol 1,4,5-trisphosphate (IP3) receptors and the subsequent Ca2+ influx through store-operated channels (SOCs) constitute a triggering signal for H2O2-induced β-cell apoptosis. In the present study, we further examined the obligatory role of early Ca2+ responses in β-cell apoptosis induction. H2O2 induced elevation of the cytosolic Ca2+ concentration ([Ca2+]c) consisting of two phases: an initial transient [Ca2+]c elevation within 30 min and a slowly developing one thereafter. The first phase was almost abolished by 2-aminoethoxydiphenylborate (2-APB), which blocks IP3 receptors and cation channels including SOCs, while the second phase was only partially inhibited by 2-APB. The inhibition by 2-APB of the second phase was not observed when 2-APB was added 30 min after the treatment with H2O2. 2-APB also largely inhibited elevation of the mitochondrial Ca2+ concentration ([Ca2+]m) induced by H2O2 when 2-APB was applied simultaneously with H2O2, but not when applied 30 min after H2O2 application. In addition, 2-APB inhibited the release of mitochondrial cytochrome c to the cytosol induced by H2O2 when 2-APB was applied simultaneously with H2O2 but not 30 min post-treatment. H2O2-induced [Ca2+]m elevation and cell death were not inhibited by Ru360, an inhibitor of the mitochondrial calcium uniporter (MCU). These results suggest that the H2O2-induced initial [Ca2+]c elevation, occurring within 30 min and mediated by Ca2+ release through IP3 receptors and subsequent Ca2+ influx through SOCs, leads to [Ca2+]m elevation, possibly through a mechanism independent of MCU, thereby inducing cytochrome c release and consequent apoptosis.
  • Kazuaki Taguchi, Saori Nagao, Keishi Yamasaki, Hiromi Sakai, Hakaru Se ...
    2015 Volume 38 Issue 10 Pages 1606-1616
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    The hemoglobin-vesicle (HbV), a vesicle in which a concentrated human hemoglobin solution is encapsulated, was developed as an artificial oxygen carrier. Although HbV has a favorable safety, metabolic, and excretion performance in healthy animals, the effect of a massive amount of HbV, which also contains a large amount of a lipid component including cholesterol, on physiological response and metabolic performance under hyperlipidemic conditions is unclear. The aim of this study was to evaluate whether administration of HbV causes toxicity in apolipoprotein E-deficient mice (hyperlipidemic model mice). Apolipoprotein E-deficient mice were given a single injection of HbV (2000 mg hemoglobin/kg), and physiological responses and metabolic profiles were monitored for 14 d thereafter. All the mice tolerated the massive amount of HbV and survived, and adequate biocompatibility was observed. Serum biochemical parameters indicate that liver and kidney function were not remarkably affected, and morphological changes in the liver and spleen were negligible. Lipid parameters in serum were significantly increased until 3 d after HbV administration, but recovered within 7 d after the administration. In a pharmacokinetic study, HbV was mainly found distributed in the liver and spleen, and disappeared from the body within 14 d. In conclusion, even under conditions of hyperlipidemia, a massive dose of HbV and its components resulted in favorable biological compatibility, metabolic, and excretion profiles. These findings provide further support for the safety of HbV for clinical use.
  • Hatem Abdel-Kader Abdel-Aziz, Wagdy Mohamed Eldehna, Mohamed Fares, Ti ...
    2015 Volume 38 Issue 10 Pages 1617-1630
    Published: October 01, 2015
    Released: October 01, 2015
    [Advance publication] Released: July 08, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    In this study, we synthesized two series of novel 5-nitrofuran-2-carbohydrazides 21ah and 22ae in addition to a third series of thiophene-2-carbohydrazides 23ag to develop potent antimicrobial and/or antitubercular agents. The newly synthesized compounds were evaluated in vitro for their antimicrobial and antimycobacterial activities. Most of the 5-nitrofuran-2-carbohydrazides 21ah and 22ae displayed variable activity against Aspergillus fumigates, Staphylococcus aureus, Streptococcus pneumonia, Bacillis subtilis, Salmonella typhimurium, Klebsiella pneumonia, Escherichia coli and Mycobacterium tuberculosis. The sulfonamide derivative 21f exhibited superior potency and broad-spectrum antimicrobial activity with minimum inhibitory concentration (MIC)=0.06–0.98 µg/mL and antimycobacterial activity with MIC=3.9 µg/mL. The 5-nitrofuran-2-carbohydrazides 21a, b, g, h and 22ac exhibited significant antibacterial activity with MIC values in the range of 0.12–7.81 µg/mL. The significances of the 5-nitrofuran moiety and sulfonamide function were explored via the structure–activity relationship (SAR) study. In addition, docking studies revealed that the p-amino benzoic acid (PABA) and binding pockets of the dihydropteroate synthase (DHPS) were successfully occupied by compound 21f. Furthermore, two quantitative structure–activity relationship (QSAR) models were built to explore the structural requirements which controlled the activity.
Notes
  • Byung-Hwan Lee, Sun-Hye Choi, Hyeon-Joong Kim, Seok-Won Jung, Hyunsook ...
    2015 Volume 38 Issue 10 Pages 1631-1637
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Gintonin is a novel ginseng-derived G protein-coupled lysophosphatidic acid (LPA) receptor ligand. Gintonin elicits an [Ca2+]i transient in animal cells via activation of LPA receptors. In vitro studies have shown that gintonin regulates various calcium-dependent ion channels and receptors. In in vivo studies, gintonin elicits anti-Alzheimer’s disease activity through the activation of the non-amyloidogenic pathway and anti-metastatic effects through the inhibition of autotaxin. However, a method for gintonin quantitation in ginseng has not been developed. In the present study, we developed an enzyme immunoassay (EIA) to measure gintonin. A monoclonal antibody was raised in a mouse using gintonin as the immunogen, and an indirect competitive EIA was used to measure gintonin. The working range was 0.01–10 µg per assay. The anti-gintonin monoclonal antibody did not cross-react with the ginsenosides Ra, Rb1, Rb2, Rc, Rd, Re, Rf, Rg1, and Rg3 or with LPAs such as LPA C16:0, LPA C18:0, LPA C18:1, and LPA C18:2. Using a standard curve, we measured the amount of gintonin in various ginseng extract fractions. Interestingly, we only detected a little amount of gintonin in conventional hot water extracts of Korean red ginseng. However, we can measure gintonin after ethanol extraction of Korean red ginseng marc. Thus, gintonin can be extracted from ginseng with ethanol but not water, and the remaining Korean red ginseng marc can be used to obtain gintonin. These results indicate that the EIA with the anti-gintonin monoclonal antibody can be used to quantify gintonin in various ginseng preparations, including commercial ginseng products.
  • Natsumi Ueda, Ryogo Umetsu, Junko Abe, Yamato Kato, Yoko Nakayama, Zen ...
    2015 Volume 38 Issue 10 Pages 1638-1644
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    There have been concerns that oseltamivir causes neuropsychiatric adverse events (NPAEs). We analyzed the association of age and gender with NPAEs in patients treated with oseltamivir using a logistic regression model. NPAE data were obtained from the U.S. Food and Drug Administration Adverse Event Reporting System (2004 to 2013). The lower limit of the reporting odds ratio (ROR) 95% confidence interval (CI) of “abnormal behavior” in Japan, Singapore, and Taiwan was ≥1. The effects of the interaction terms for oseltamivir in male patients aged 10–19 years were statistically significant. The adjusted ROR of “abnormal behavior” was 96.4 (95% CI, 77.5–119.9) in male patients aged 10–19 years treated with osletamivir. In female patients, the results of the likelihood ratio test for “abnormal behavior” were not statistically significant. The adjusted NPAE RORs were increased in male and female patients under the age of 20 years. Oseltamivir use could be associated with “abnormal behavior” in males aged 10–19 years. After considering the causality restraints of the current analysis, further epidemiological studies are recommended.
  • Hayato Iino, Makiko Fujii, Manami Fujino, Naoya Koizumi, Yoshiteru Wat ...
    2015 Volume 38 Issue 10 Pages 1645-1648
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    The purpose of this study was to clarify the effect of skin condition on skin penetration of the very high lipophilic drug, ufenamate (UF). UF was applied to stripped or delipidized skin using liquid paraffin (LP) or purified water containing polysorbate 80 at a dose of 2 µL/cm2. We found that UF penetration into intact and stripped skin using a water vehicle was respectively 5 and 10 times higher than that using LP. UF is freely soluble in oil and insoluble in water; thus, activity in water is higher than that in LP. Therefore, it is useful to use a water-based vehicle for both intact sites and those with defective stratum corneum (SC). Conversely, we found that delipidization of SC decreased the penetration of UF significantly with both LP and water, and the amount measured in the epidermis was 1 µg/cm2 with both vehicles. This indicates that UF is not suitable for so-called “dry skin.” This study revealed clinically relevant differences in the penetration of UF into intact, stripped, or delipidized skin conditions.
  • Tatsuaki Tagami, Hiroshi Yanai, Yuka Terada, Tetsuya Ozeki
    2015 Volume 38 Issue 10 Pages 1649-1651
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Malaria is one of the most prevalent parasitic diseases and is most widespread in tropical regions. The malarial parasite grows and reproduces in erythrocytes during its life cycle, resulting in programmed erythrocyte death, termed eryptosis. Lipid scrambling, which occurs following the exposure of anionic lipids such as phosphatidylserine (PS) on the outer surface of erythrocytes, is a characteristic physical change that occurs early during eryptosis. Here, we prepared “PS specific peptide (PSP)”-conjugated liposomes (PSP-liposomes) and investigated whether PSP-liposomes hold promise as a novel strategy for actively targeting eryptosis. Eryptosis was induced by exposing red blood cells (RBCs) to ionomycin, a known calcium ionophore. When PSP liposomes were mixed with either RBCs or RBCs undergoing eryptosis (E-RBCs), the amount of PSP-liposome bound to E-RBCs was much higher than the amount bound to RBCs. However, the amount of PSP-liposome bound to E-RBCs was significantly inhibited by the presence of annexin V protein, which binds specifically to PS. These results suggest that PSP-liposomes could be an effective drug nanocarrier for treating E-RBCs and malaria-infected erythrocytes.
  • Tetsuya Saita, Yuta Yamamoto, Masashi Shin, Yukitaka Nakano
    2015 Volume 38 Issue 10 Pages 1652-1657
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    In this paper, we describe the production of the first specific antibodies against the tyrosine kinase inhibitors lapatinib and nilotinib. Anti-lapatinib antibody was obtained by immunizing rabbits with an antigen conjugated with bovine serum albumin using 3-chloro-4-((3-fluorobenzyl)oxy)aniline. Anti-nilotinib antibody was produced by immunizing mice with an antigen conjugated with bovine serum albumin using 2-(5-amino-2-methylanilino)-4-(3-pyridyl)pyrimidine. The generated antibodies were used to develop highly sensitive and specific enzyme-linked immunosorbent assays (ELISAs) for lapatinib and nilotinib in human serum. The assays were capable of detecting lapatinib and nilotinib at serum concentrations as low as 40 and 8 ng/mL, respectively. Using the two ELISAs, drugs levels were easily measured in the serum of rats after a single dose oral administration of lapatinib or nilotinib. The assays are therefore expected be valuable tools for therapeutic drug monitoring in the clinical setting and pharmacokinetic studies of lapatinib and nilotinib.
  • Lu-yang Lu, Yuan Liu, Zhi-feng Zhang, Xiao-jun Gou, Jun-hao Jiang, Ji- ...
    2015 Volume 38 Issue 10 Pages 1658-1662
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Pomegranate seed oil (PSO) has diverse bioactivities. It was hyphothesized that if PSO were employed to construct a trans-resveratrol-loaded self-nanoemulsifying drug delivery system (RES SNEDDS-PSO), not only could PSO serve as an oil phase but also exert synergistic effects with resveratrol to yield better therapeutic outcomes. In this study, we prepared RES SNEDDS-PSO for the first time to validate that hypothesis. The anti-inflammatory and anticancer activities of RES SNEDDS-PSO were compared with another SNEDDS composed of oil phase isopropyl palmitate (RES SNEDDS-IP). The results showed that upon exposure to a 10-fold amount of water, RES SNEDDS-PSO was converted into nanoemulsions with a mean size of 44 nm. Nanoemulsions enhanced the water solubility of resveratrol by 20-fold, significantly improved resveratrol stability in intestinal fluid, and slowed the decomposition of resveratrol in water by 1-fold. An in vivo anti-infection test showed that the degree of inflammatory swelling in mice given RES SNEDDS-PSO was only 60 and 76% that of the group fed with RES SNEDDS-IP at doses of 10 and 20 mg/kg, respectively. An in vitro anticancer study showed that the inhibitory rate of RES SNEDDS-PSO against MCF-7 breast cancer cells was 2.03- and 1.24-fold that of RES SNEDDS-IP at a concentration of 12.5 and 25 µg/mL, respectively. This study demonstrated that the newly developed SNEDDS may be a prospective formulation in the functional food and clinical fields.
  • Dae-Young Lee, Sang Chul Jeong, Yong Tae Jeong, Mi-Kyoung Lee, Kyeong- ...
    2015 Volume 38 Issue 10 Pages 1663-1667
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    This study was initiated to isolate active metabolites from the leaves of Panax ginseng. Among them, picrionoside A, a megastigmane glucoside, was isolated from the leaves of P. ginseng C. A. MAYER and its chemical structure was determined based on spectroscopic methods, including FAB-MS, one-dimensional (1D)-NMR, 2D-NMR, and IR spectroscopy. Picrionoside A from P. ginseng has not been investigated previously, and its biological or pharmaceutical activities have not been reported elsewhere. The IC50 value of mushroom tyrosinase-inhibitory activity of picrionoside A was 9.8 µM, and the rate of inhibition of synthesized melanin content in melan-a cells was 17.1% at a concentration of 80 µM without cytotoxicity. Furthermore, picrionoside A dramatically reduced body pigmentation in the zebrafish model. Taken together, the results suggest that picrionoside A isolated from the leaves of P. ginseng may be an effective skin-whitening agent that could be a potent candidate material in the cosmetic industry.
  • Maho Yagi-Utsumi, Christopher M. Dobson
    2015 Volume 38 Issue 10 Pages 1668-1672
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Among the various hereditary mutants of amyloid β (Aβ) in familial Alzheimer’s disease (AD), the A21G Flemish-type mutant has unique properties showing a low aggregation propensity but progressive deposition in vascular walls. Moreover, in contrast to other familial AD cases that show extensive Aβ1–42 deposition in the brain, patients with Flemish AD predominantly exhibit the deposition of the Aβ1–40 isoform. Here we report the structural characterization of the Flemish-type mutant (A21G) in comparison with the wild-type Aβ1–40 peptide to examine the possible effects of the A21G mutation on the conformation of the Aβ1–40 isoform. The kinetic analysis of the aggregation of the peptides monitored by thioflavin T fluorescence measurement indicates that the mutation precludes the initial nucleation process of amyloid fibril formation by Aβ1–40. Spectroscopic data indicate that the Flemish-type mutant bound to aqueous micelles composed of lyso-GM1, in which the mobile N-terminal segment is tethered through the C-terminal helical segment, has reduced α-helical structure compared to the wild-type peptide. Our findings suggest that the mutational perturbation to the membrane binding properties is coupled with the changes in nucleation behavior of Aβ during its fibril formation.
  • Yuji Mukai, Takaki Toda, Satoya Takeuchi, Asuna Senda, Miki Yamashita, ...
    2015 Volume 38 Issue 10 Pages 1673-1679
    Published: October 01, 2015
    Released: October 01, 2015
    JOURNALS FREE ACCESS FULL-TEXT HTML
    Epoxyeicosatrienoic acids (EETs) are produced primarily by CYPs from arachidonic acid (AA) and then further metabolized to the corresponding dihydroxyeicosatrienoic acids (DHETs). EETs play important roles in physiological processes such as regulating vasodilation and inflammation. Thus, the drug inhibition of CYP-mediated AA metabolism could reduce production of EETs, potentially resulting in adverse cardiovascular events. The aim of this study was to develop a simple method to simultaneously determine the concentrations of both EETs and DHETs using a conventional LC-MS/MS system to evaluate drug-endogenous substance interactions, including eicosanoids. Eight eicosanoids (5,6-EET, 8,9-EET, 11,12-EET, 14,15-EET, 5,6-DHET, 8,9-DHET, 11,12-DHET, and 14,15-DHET) were detected with their corresponding deuterium-labeled eicosanoids as internal standards. The samples were purified by solid-phase extraction columns. Liquid chromatographic separation was achieved on a C18 column. DHETs and EETs were eluted at 4–7 and 18–26 min, respectively. The weighted (1/y2) calibration curves were linear over a range of 5–2000 nmol/L for EETs and 2–2000 nmol/L for DHETs. In quality control (QC) samples, the recoveries of eicosanoids were 95.2–118%. The intra-day precisions were within 6% in all three QC samples, and the inter-day precisions were <16.7% at 50 nmol/L, <8.6% at 200 nmol/L, and <9.8% at 1000 nmol/L. We have applied this method for the determination of the eicosanoid levels in samples from incubation studies of AA by using human recombinant CYP enzyme (rCYP), and confirmed that the method has sensitivity sufficient for assessment of rCYP incubation study.
feedback
Top