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71.
Chen CY Yiin SJ Hsu JL Wang WC Lin SC Chern CL 《Journal of agricultural and food chemistry》2012,60(13):3533-3539
Hepatoma cells are relatively resistant to TRAIL. We have previously shown that isoobtusilactone A (IOA), a potent anticancer agent isolated from Cinnamomum kotoense, induced mitochondria-mediated apoptosis in hepatoma cells. Here, we report that IOA could potentiate TRAIL-induced apoptosis in Hep G2 cells. The combined treatment with IOA and TRAIL significantly induced caspase-dependent apoptosis. This correlated with the up-regulation of C/EBP homologous protein (CHOP) and death receptor 5 (DR5) protein levels. Gene silencing of the DR5 by small interfering RNA abrogated the apoptosis induced by the combined regimen of IOA and TRAIL, suggesting that the sensitization to TRAIL was mediated through DR5. By analyzing the DR5 promoter, we found that IOA induced a CHOP-dependent DR5 transactivation. DR5 expression after IOA treatment was accompanied by provoking intracellular reactive oxygen species (ROS) generation. Pretreatment with N-acetyl-L-cysteine (NAC) attenuated IOA-induced CHOP and DR5 expression and inhibited TRAIL-induced apoptosis. Taken together, our data suggested that ROS-dependent and CHOP-regulated DR5 expression played a pivotal role in the synergistic enhancement of TRAIL-induced apoptosis instigated by IOA in Hep G2 cells. 相似文献
72.
Five new nardosinane-type sesquiterpenoids, paralemnolins Q-U (1-5), along with three known compounds (6-8), were isolated from the Formosan soft coral Paralemnalia thyrsoides. The structures of new metabolites were elucidated on the basis of extensive spectroscopic methods, and the absolute configuration of 1 was determined by the application of Mosher's method on 1. Among these metabolites, 1 and 3 are rarely found nardosinane-type sesquiterpenoids, possessing novel polycyclic structures. Compounds 1, 3, 6 and 7 were found to possess neuroprotective activity. 相似文献
73.
Hsieh YC Rao YK Whang-Peng J Huang CY Shyue SK Hsu SL Tzeng YM 《Journal of agricultural and food chemistry》2011,59(20):10943-10954
The triterpenoids methylantcinate B (MAB) and antcin B (AB), isolated from the medicinal mushroom Antrodia camphorata , have been identified as strong cytotoxic agents against various type of cancer cells; however, the mechanisms of MAB- and AB-induced cytotoxicity have not been adequately explored. This study investigated the roles of caspase cascades, reactive oxygen species (ROS), DNA damage, mitochondrial disruption, and Bax and Bcl-2 proteins in MAB- and AB-induced apoptosis of hepatocellular carcinoma (HCC) HepG2 cells. Here, we showed that MAB and AB induced apoptosis in HepG2 cells, as characterized by increased DNA fragmentation, cleavage of PARP, sub-G1 population, chromatin condensation, loss of mitochondrial membrane potential, and release of cytochrome c. Increasing the levels of caspase-2, -3, -8, and -9 activities was involved in MAB- and AB-induced apoptosis, and they could be attenuated by inhibitors of specific caspases, indicating that MAB and AB triggered the caspase-dependent apoptotic pathway. Additionally, the enhanced apoptotic effect correlates with high expression of Fas, Fas ligand, as well as Bax and decreased protein levels of Bcl-(XL) and Bcl-2, suggesting that both the extrinsic and intrinsic apoptosis pathways were involved in the apoptotic processes. Incubation of HepG2 cells with antioxidant enzymes superoxide dismutase and catalase and antioxidants N-acetylcysteine and ascorbic acid attenuated the ROS generation and apoptosis induced by MAB and AB, which indicate that ROS plays a pivotal role in cell death. NADPH oxidase activation was observed in MAB- and AB-stimulated HepG2 cells; however, inhibition of such activation by diphenylamine significantly blocked MAB- and AB-induced ROS production and increased cell viability. Taken together, our results provide the first evidence that triterpenoids MAB and AB induced a NADPH oxidase-provoked oxidative stress and extrinsic and intrinsic apoptosis as a critical mechanism of cause cell death in HCC cells. 相似文献
74.
Sara T. Elazab Nahla S. Elshater Yousreya H. Hashem Seung-Chun Park Walter H. Hsu 《Journal of veterinary pharmacology and therapeutics》2020,43(1):57-66
The pharmacokinetics of tylosin were investigated in 3 groups of ducks (n = 6). They received a single dose of tylosin (50 mg/kg) by intravenous (IV), intramuscular (IM), and oral administrations, respectively. Plasma samples were collected at various time points to 24 hr post-administration to evaluate tylosin concentration over time. Additionally, tylosin residues in tissues and its withdrawal time were assessed using 30 ducks which received tylosin orally (50 mg/kg) once daily for 5 consecutive days. After IV administration, the volume of distribution, elimination half-life, area under the plasma concentration–time curve, and the total body clearance were 7.07 ± 1.98 L/kg, 2.04 hr, 19.47 µg hr/ml, and 2.82 L hr−1 kg−1, respectively. After IM and oral administrations, the maximum plasma concentrations were 3.70 and 2.75 µg/ml achieved at 1 and 2 hr, and the bioavailability was 93.95% and 75.77%, respectively. The calculated withdrawal periods of tylosin were 13, 8, and 5 days for kidney, liver, and muscle, respectively. For the pharmacodynamic profile, the minimum inhibitory concentration for tylosin against M. anatis strain 1,340 was 1 µg/ml. The calculated optimal oral dose of tylosin against M. anatis in ducks based on the ex vivo pharmacokinetic/pharmacodynamic modeling was 61 mg kg−1 day−1. 相似文献
75.
76.
Shang-Tse Ho Ying-Ning Ho Chih Lin Wei-Chen Hsu Han-Jung Lee Chia-Chi Peng Han-Tan Cheng Yu-Liang Yang 《Marine drugs》2021,19(4)
Empedopeptins—eight amino acid cyclic lipopeptides—are calcium-dependent antibiotics that act against Gram-positive bacteria such as Staphylococcus aureus by inhibiting cell wall biosynthesis. However, to date, the biosynthetic mechanism of the empedopeptins has not been well identified. Through comparative genomics and metabolomics analysis, we identified empedopeptin and its new analogs from a marine bacterium, Massilia sp. YMA4. We then unveiled the empedopeptin biosynthetic gene cluster. The core nonribosomal peptide gene null-mutant strains (ΔempC, ΔempD, and ΔempE) could not produce empedopeptin, while dioxygenase gene null-mutant strains (ΔempA and ΔempB) produced several unique empedopeptin analogs. However, the antibiotic activity of ΔempA and ΔempB was significantly reduced compared with the wild-type, demonstrating that the hydroxylated amino acid residues of empedopeptin and its analogs are important to their antibiotic activity. Furthermore, we found seven bacterial strains that could produce empedopeptin-like cyclic lipopeptides using a genome mining approach. In summary, this study demonstrated that an integrated omics strategy can facilitate the discovery of potential bioactive metabolites from microbial sources without further isolation and purification. 相似文献
77.
The effects of calcium (Ca2+), cadmium (Cd2+), and copper (Cu2+) cations on NADH‐linked electron transfer in com root plasma membrane vesicles were investigated. The reduction of both cytochrome c and ferricyanide were slightly stimulated by Ca2+ but not significantly affected by Cd2+. However, Cd2+ induced a redox‐linked increase in light scattering suggesting an increase in the size/volume of the vesicles. The presence of micromolar levels of Cu2+ decreased the reduction rates of both cytochrome c and ferricyanide. However, in contrast to ferricyanide reduction, Cu inhibition to the cytochrome c reduction was more effective, and was less sensitive to ionic strength. Copper inhibition changed the Michaelis‐Menten dependence of the ferricyanide reduction but not that of cytochrome c. These results suggest that the reduction of cytochrome c. and ferricyanide must occur at different membrane sites. 相似文献
78.
Eight new cembranoids, crassarines A-H (1-8) were isolated from the Formosan soft coral Sinularia crassa. Compounds 1-3 represent the rare cembranoids with a 1,12-oxa-bridged tetrahydrofuran ring, while 4 and 5 are the firstly discovered 1,11-oxa-bridged tetrahydropyranocembranoids. The absolute configuration of 6 was determined using the Mosher's method. Compounds 6 and 8 were found to significantly inhibit the expression of both pro-inflammatory iNOS and COX-2 proteins at 10 μM, respectively, while compounds 4-8 were found to be non-cytotoxic toward the selected human liver cancer cells. 相似文献
79.
Chia-Chang Lin Chao-Chiung Huang You-Liang Chen Ching-Wen Lou Chin-Mei Lin Chan-Hung Hsu Jia-Horng Lin 《Fibers and Polymers》2008,9(6):761-767
The energy of impact must decay and be transmitted after a bullet is shot through a ballistic-resistant cloth with a laminate
structure. A rigid net structure transmits the impact stress to reduce the breakage of the material in the direction perpendicular
to the fabric after the impacting of a projectile. This work combines the rigid net structure of stainless steel mesh with
two layers a needle-punched polyamide nonwoven fabric to create a sandwich-like laminate structure. A compound fabric that
is composed of a stainless steel mesh and polyamide nonwoven fabrics is placed in multi-layer Kevlar fabrics, and the buffer
effect is measured by performing a dropping weight impact test and a bullet-shooting test. The specifications of the stainless
steel mesh and the order of placement of the compound fabrics are varied to show the effect of these parameters on the energy
of fracture propagation and the buffer effect of the multi-layered Kevlar compound fabric that includes a layer of compound
fabric that is made of stainless steel mesh and polyamide nonwoven fabrics. In this study, the compound fabric replaces several
layers of Kevlar unidirectional fabric, to be used to reduce the cost of bulletproof vests without reducing ballistic resistance. 相似文献
80.
Multiplex PCR genotyping for five bacterial blight resistance genes applied to marker‐assisted selection in rice (Oryza sativa) 下载免费PDF全文
Bacterial blight (BB) is the most economically damaging disease of rice in Asia and other parts of the world. In this study, a multiplex PCR genotyping method was developed to simultaneously identify genotypes of five BB resistance genes, Xa4, xa5, Xa7, xa13 and Xa21. The resistance R alleles were amplified using five functional markers (FMs) to generate amplicons of 217, 103, 179, 381 and 595 bp in IRBB66. Amplicons of 198, 107, 87, 391 and 467 bp corresponded to susceptible alleles in Taiwanese japonica rice cultivars. In backcross breeding programmes, the multiplex PCR assay was integrated into selection from a population using BB resistance donor IRBB66 crossed to rice cultivar ‘Tainung82’. Two plants with homozygosity for Xa4, xa5, Xa7, xa13 and Xa21 were selected from 1100 BC2F2 plants. In addition, the five BB resistance genes were also accurately identified in F2 populations. This multiplex PCR method provides a rapid and efficient method for detecting various BB resistance genes, which will assist in pyramiding genes to improve durability of BB resistance in Taiwanese elite rice cultivars. 相似文献