Involvement of Putrescine,Nitric Oxide,and Hydrogen Peroxide in Methyl Jasmonate-Induced Ginsenoside Synthesis in Adventitious Root Cultures of Panax ginseng C.A. Meyer

Journal of Plant Growth Regulation - The adventitious root (AR) culture of Panax ginseng C.A. Meyer is an alternative route for mass production of ginsenosides. During the AR culture of P. ginseng,...     

Iodine Excess Induces Hepatic Steatosis Through Disturbance of Thyroid Hormone Metabolism Involving Oxidative Stress in BaLB/c Mice

Iodine excess is emerging as a new focus. A better understanding of its hazardous effects on the liver will be of great benefit to health. The aim of this study is to illustrate the effects of iodine excess on hepatic lipid homeostasis and explore its possible mechanisms. One hundred twenty BaLB/c mice were given iodine at different levels (0, 0.3, 0.6, 1.2, 2.4, and 4.8 mg I/L) in drinking water for 1 or 3 months. Lipid parameters and serum thyroid hormones were measured. Hepatic type 1 deiodinase activity and oxidative stress parameters were evaluated. The mRNA expression of sterol regulatory element-binding protein-1c (SREBP-1c) and fatty acid synthase (FAS) was detected by real-time polymerase chain reaction. Dose-dependent increase of hepatic triglyceride content was detected (r?=?0.680, P?<?0.01) in iodine-loaded groups. Evident hepatic steatosis was observed in 2.4 and 4.8 mg I/L iodine-loaded groups. The activities of antioxidant enzymes (glutathione peroxidase and superoxide dismutase) were decreased, and the malondialdehyde level was increased by excessive iodine in both serum and liver in a dose-dependent manner, accompanying the decrease of hepatic D1 activity. That resulted in the increase of serum total thyroxine and the decrease of serum total triiodothyronine in iodine-loaded groups. The mRNA expression of SREBP-1c and FAS was increased in iodine-loaded groups in response to the change of serum triiodothyronine. Present findings demonstrated that iodine excess could dose dependently induce hepatic steatosis. Furthermore, our data suggested that the disturbance of thyroid hormone metabolism involving oxidative stress may play a critical role in iodine excess-induced hepatic steatosis.     

High-Efficiency Rescue of Equine Infectious Anemia Virus from a CMV-Driven Infectious Clone

<正>Dear Editor,Equine infectious anemia virus (EIAV) belongs to the macrophage-tropic lentiviruses family and infects mainly equines, including horses, donkeys and mules. EIAV shares many similar characteristics in its viral biology and hostvirus immune regulation with other lentiviruses, such as human immunodeficiency virus type 1 (HIV-1) and simian immunodeficiency virus (SIV), and has been accepted as a     

Homoepiboxidines: further potent agonists for nicotinic receptors

Homoepiboxidine (3) and the corresponding N-methyl (4) and N-benzyl (5) derivatives were prepared from a 6beta-carbomethoxynortropane (8). Affinities and functional activities at neuromuscular, central neuronal and ganglionic-type nicotinic receptors were compared to those of epibatidine 1, and epiboxidine 2. Homoepiboxidine had equivalent affinity/activity to epiboxidine at neuromuscular, neuronal alpha4beta2, and most alpha3-containing ganglionic-type nicotinic receptors. The N-substituted derivatives showed reduced affinity/activity at most receptor subtypes. Replacement of the methylisoxazole moiety of 3 and 4 with a methyloxadiazole moiety provided analogues 6 and 7, which had greatly reduced affinity/activity in virtually all assays at nicotinic receptors. Marked analgetic activity in mice occurred at the following ip doses: epibatidine 10 microg/kg; epiboxidine 25 microg/kg; homoepiboxidine 100 microg/kg; N-methylhomoepiboxidine 100 microg/kg; the methyloxadiazole (6) 100 microg/kg. The time course at such ip doses was significantly longer for homoepiboxidine 3 with marked analgesia still manifest at 30 min post-injection. Epiboxidine and the homoepiboxidines were less toxic than epibatidine.     

铜胁迫对穿心莲幼苗生长及生理特性的影响

通过对盆栽穿心莲(Andrographis paniculata)幼苗浇灌Cu SO4溶液实验,研究外施Cu2+对穿心莲幼苗的生理特性和药效成分含量的影响。结果显示,外施Cu2+对穿心莲幼苗的生长、生理生化指标和穿心莲内酯、脱水穿心莲内酯的含量均有显著影响。当Cu SO4溶液浓度超过6.25 mmol/L时,Cu2+能显著抑制穿心莲幼苗株高、叶长、叶宽的增长,且随胁迫时间的延长和Cu2+浓度的增大抑制作用增强;穿心莲叶片中超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量均随Cu2+浓度增大和胁迫时间的延长而升高,当Cu SO4溶液浓度达到12.5 mmol/L且胁迫20 d和30 d时,叶片中SOD活性达到对照组的168.3%和171.18%;过氧化物酶(POD)、过氧化氢酶(CAT)活性则随Cu2+浓度的增大呈先升高后下降的趋势;当外施Cu SO4溶液浓度大于1.25 mmol/L时,与对照相比,穿心莲药效成分穿心莲内酯和脱水穿心莲内酯的含量均显著降低(P0.05)。研究结果表明,外施Cu SO4溶液浓度高于6.25 mmol/L时,能显著影响穿心莲幼苗的生理特性和有效成分含量,从而降低穿心莲药材的产量和质量。     

Diet selection in overwinter caches of plateau zokor (Eospalax baileyi)

Subterranean herbivores affect the plant community by plant consumption and burrowing activities. However, diet selection of subterranean herbivores has not been studied in detail in complex natural fields, mainly for lack of an accurate method to determine diet species, frequency, and biomass. Plateau zokors' (Eospalax baileyi) caching habit for the long inclement winter makes it possible to solve this problem. We studied the diet composition and biomass in caches and vicinity of plateau zokors' burrow systems. We found that plateau zokors are dietary generalist but show a significant selection among the available food items, plant parts, functional groups, organ types, and habitats. These results suggested that plateau zokors strictly selected their diet and were able to adjust their foraging strategy according to the different conditions of food abundance and quality. Plateau zokors' selective foraging can directly reduce the proportion of toxicity forbs; plateau zokors can be recognized as an important element to influence the alpine meadow plant community and cattle husbandry.     

吉富罗非鱼IGF2基因分离及其单核苷酸多态性与体型、增重相关性

胰岛素样生长因子2(insulin-like growth factor2,IGF2)是控制动物生长和脂肪沉积的重要基因之一。本文采用PCR方法分离了吉富罗非鱼(GIFT strain Nile tilapia Oreochromis niloticus)IGF2基因5475bp,包含由4个外显子组成的整个阅读框669bp以及3个内含子。通过比对吉富罗非鱼10个个体IGF2序列,共发现11处单核苷酸多态性(single nucleotide polymorphism,SNP)位点,本文检测了内含子1的621nt(C/T)和外显子3的161nt(A/G)两位点在192尾吉富罗非鱼中的基因型分布,并分析不同基因型与体型、增重的相关性。使用四引物扩增受阻体系PCR检测内含子1的621nt基因型,结果显示,CC、CT、TT基因型频率在雄鱼中分别为0.32、0.32、0.36,在雌鱼中分别为0.38、0.38、0.24;与体型、增重的相关性分析表明,此位点不同基因型只与雄鱼体型(体高/体长)显著相关(P0.05),CC型个体显著高于CT和TT型个体。外显子3的A/G转换导致了MSPⅠ酶切位点改变,使用PCR-RFLP法检测该位点基因型,结果显示整个群体中不存在AA基因型,在雄鱼中,GG、AG基因型频率分别为0.71、0.29,而雌鱼中则为0.75和0.25;与体型、增重的相关性分析表明,此位点不同基因型只与雄鱼增重极显著相关(P0.01),GG型的雄鱼明显较AG型增重快。     

Therapeutic effect of anthracene-based anticancer agent ethonafide in an animal model of multiple sclerosis

The side effects of cancer chemotherapeutic agents such as mitoxantrone (MIT) in multiple sclerosis (MS) patients justify the search for less toxic drugs. Ethonafide is an anthracene-based antineoplastic drug similar to MIT. With reference to MIT, we examined the effect of ethonafide on experimental autoimmune encephalomyelitis (EAE) in C57BL/6 mice, an animal model of human MS. We demonstrated that ethonafide is effective in preventing development of EAE as well as in ameliorating the severity of EAE when disease is ongoing. In relatively higher dosages, the effects of ethonafide and MIT on EAE were identical, whereas in lower dosages, MIT seemed more effective. Therapeutic effects of ethonafide were associated with the initial reduction in cellular counts of CD3(+), CD4(+), CD8(+), B220(+), CD11b(+), NK cells, and NKT cells, followed by recovery of these cells from the bone marrow. Interestingly, the recovered autoreactive T cells in ethonafide-treated animals have reduced capacity to expand and produce cytokines in response to myelin Ag stimulation. Furthermore, CD4(+)CD25(+) regulatory T cells were relatively resistant to depletion and/or recovered faster than T effector cells. The ability of regulatory T cells to resist depletion and replenish quickly during cell ablation therapy may provide an opportunity to reprogram the immune system. Moreover, we provided evidences that ethonafide has less cardiac toxicity compared with MIT. The effectiveness and the low cardiotoxicity of ethonafide might make it a promising immunosuppressive agent for clinical use in treating MS patients.