排序方式: 共有31条查询结果,搜索用时 93 毫秒
1.
Kamal Rashidi Asl Bahman Hosseini Ali Sharafi Javier Palazon 《Engineering in Life Science》2019,19(1):73-89
The use of nanotechnology and biotechnology to improve the production of plant bioactive compounds is growing. Hyoscyamus reticulatus L. is a major source of tropane alkaloids with a wide therapeutic use, including treatment of Parkinson's disease and to calm schizoid patients. In the present study, hairy roots were obtained from two‐week‐old cotyledon explants of H. reticulatus L. using the A7 strain of Agrobacterium rhizogenes. The effects of different concentrations of the signaling molecule nano‐zinc oxide (ZnO) (0, 50, 100 and 200 mg/L), with three exposure times (24, 48 and 72 h), on the growth rate, antioxidant enzyme activity, total phenol contents (TPC), tropane alkaloid contents and hyoscyamine‐6‐beta‐hydroxylase (h6h) gene expression levels were investigated. Growth curve analysis revealed a decrease in fresh and dry weight of ZnO‐treated hairy roots compared to the control. ANOVA results showed that the antioxidant activity of the enzymes catalase, guaiacol peroxidase and ascorbate peroxidase was significantly higher in the ZnO‐treated hairy roots than in the control, as was the TPC. The highest levels of hyoscyamine (37%) and scopolamine (37.63%) were obtained in hairy roots treated with 100 mg/L of ZnO after 48 and 72 h, respectively. Semi‐quantitative RT‐PCR analysis revealed the highest h6h gene expression was in hairy roots treated with 100 mg/L of ZnO after 24 h. It can be concluded that ZnO is as an effective elicitor of tropane alkaloids such as hyoscyamine and scopolamine due to its enhancing effect on expression levels of the biosynthetic h6h gene. 相似文献
2.
Moyano E Palazón J Bonfill M Osuna L Cusidó RM Oksman-Caldentey KM Piñol MT 《Journal of plant physiology》2007,164(4):521-524
Hyoscyamine-6beta-hydroxylase (H6H) catalyses the conversion of hyoscyamine into its epoxide scopolamine, a compound with a higher added value in the pharmaceutical market than hyoscyamine. We report the establishment of tobacco cell cultures carrying the Hyoscyamus muticus h6h gene under the control of the promoter CAMV 35S. The cell cultures were derived from hairy roots obtained via genetically modified Agrobacterium rhizogenes carrying the pRi and pLAL21 plasmids. The cultures were fed with hyoscyamine, and 4 weeks later the amount of scopolamine produced was quantified by HPLC. The transgenic cell suspension cultures showed a considerable capacity for the bioconversion of hyoscyamine into scopolamine, and released it to the culture medium. Although the scale-up from shake-flask to bioreactor culture usually results in reduced productivities, our transgenic cells grown in a 5-L turbine stirred tank reactor in a batch mode significantly increased the scopolamine accumulation. 相似文献
3.
Craig MC Fletcher PC Daly EM Rymer J Brammer M Giampietro V Stahl D Maki PM Murphy DG 《Hormones and behavior》2009,55(1):41-49
Recent evidence suggests that loss of ovarian function following ovariectomy is a risk factor for Alzheimer's disease (AD); however, the biological basis of this risk remains poorly understood. We carried out an fMRI study into the interaction between loss of ovarian function (after Gonadotropin Hormone Releasing Hormone agonist (GnRHa) treatment) and scopolamine (a cholinergic antagonist used to model the memory decline associated with aging and AD). Behaviorally, cholinergic depletion produced a deficit in verbal recognition performance in both GnRHa-treated women and wait list controls, but only GnRHa-treated women made more false positive errors with cholinergic depletion. Similarly, cholinergic depletion produced a decrease in activation in the left inferior frontal gyrus (LIFG; Brodmann area 45) - a brain region implicated in retrieving word meaning - in both groups, and activation in this area was further reduced following GnRHa treatment. These findings suggest biological mechanisms through which ovarian hormone suppression may interact with the cholinergic system and the LIFG. Furthermore, this interaction may provide a useful model to help explain reports of increased risk for cognitive decline and AD in women following ovariectomy. 相似文献
4.
Cholinergic Control of Nerve Growth Factor in Adult Rats: Evidence from Cortical Cholinergic Deafferentation and Chronic Drug Treatment 总被引:2,自引:0,他引:2
Steffen Roßner Gitta Wörtwein †Zezong Gu †Juan Yu Reinhard Schliebs Volker Bigl † J. Regino Perez-Polo 《Journal of neurochemistry》1997,69(3):947-953
Abstract: It is well documented that nerve growth factor (NGF) plays an important role in maintaining functions of cholinergic basal forebrain neurons. In the present study, we tested the hypothesis that cholinergic activity controls NGF levels in cholinoceptive neurons of the cerebral cortex and hippocampus. To address that question, we used both cholinergic deafferentation of cerebral cortex and hippocampus by cholinergic immunolesion with 192IgG-saporin and chronic pharmacological treatment of sham-treated and immunolesioned rats with the cholinergic agonist pilocarpine and the cholinergic antagonist scopolamine. We observed an increase in NGF protein levels in the cortex and hippocampus after cholinergic immunolesions and also after muscarinic receptor blockade by chronic intracerebroventricular scopolamine infusion in sham-treated rats after 2 weeks. There was no further increase in the accumulation of NGF after scopolamine treatment of immunolesioned rats. Chronic infusion of pilocarpine had no effect on cortical and hippocampal NGF protein levels in sham-treated rats. In rats with cholinergic immunolesions, however, pilocarpine did prevent the lesion-induced accumulation of NGF. There was no effect of cholinergic lesion and drug treatment on cortical or hippocampal NGF mRNA levels, consistent with the importance of NGF retrograde transport as opposed to its de novo synthesis. This study provides strong evidence for the hypothesis that there is cholinergic control of cortical and hippocampal NGF protein but not mRNA levels in adult rats. 相似文献
5.
Samir Cherkaoui Lidia Mateus Philippe Christen Jean-Luc Veuthey 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》1997,696(2):204
A capillary zone electrophoresis method is described for the simultaneous determination of atropine, homatropine and scopolamine. Successful results were obtained after optimization of the electrophoretic parameters such as buffer composition and pH. The best separation was achieved using a 100 mM Tris-phosphate running buffer at pH 7. The validation data proved that the method had the requisite selectively, reproducibility and linearity to be used for the assay of these compounds in pharmaceutical formulations. Dosage of the separate drugs in ophthalmic preparations is also presented. 相似文献
6.
Richard J. Robins Adrian J. Parr John Payne Nicholas J. Walton Michael J. C. Rhodes 《Planta》1990,181(3):414-422
Using in combination an analysis of (i) the levels of enzyme activities present, (ii) the pool sizes of metabolic intermediates and end products and (iii) the effects of feeding metabolic intermediates, the limitations ? flux into tropane alkaloids in a Datura root culture have been examined. This culture, produced by transforming a Datura candida × D. aurea hybrid with Agrobacterium rhizogenes, is found to be highly competent in the biosynthesis of both hyoscyamine and scopolamine as well as a wide range of other hygrine-derived alkaloids. It has been found that, of six enzymes which are involved in this pathway, the two initial activities, ornithine decarboxylase (EC 4.1.1.17) and arginine decarboxylase (EC 4.1.1.19), are present at potentially flux-limiting levels, in contrast to those other enzymes assayed which act further down the pathway. An additional limitation to flux, involving the supply of activated acids for condensation with tropine to form the identified tropoyl and tigloyl derivatives, is also indicated from the observed effect of feeding free acids. The relative contribution to flux limitation caused by these two interacting phenomena is inferred from an analysis of the changing relative levels of metabolic intermediates and end products as cultures mature. 相似文献
7.
Abstract: Scopolamine (0.15 mg/kg), a muscarinic antagonist, when administered during training or at a discrete 6-h posttraining time point, is demonstrated to inhibit the recall of a step-down passive avoidance response when tested at 24 and 48 h after task acquisition. Nefiracetam (3 mg/ kg), a piracetam-related nootropic, when given with scopolamine during training tended to improve task recall, and this effect was more pronounced when given at the 6-h posttraining time. Co-administration of nefiracetam with scopolamine was not necessary to achieve the antiamnesic action, as nefiracetam given during training significantly improved the memory deficits produced by scopolamine at the 6-h posttraining time. The paradigm-specific increase in hippocampal neural cell adhesion molecule sialylation, which is observed during consolidation of a passive avoidance response, was attenuated by the presence of scopolamine during training and at the 6-h posttraining time, and this effect was reversed by co-administration of nefiracetam, albeit in a paradigm-independent manner. These results suggest nefiracetam exerts a neurotrophic action that protects memory consolidation from drug inter- ventive insults. 相似文献
8.
Zhang L Yang B Lu B Kai G Wang Z Xia Y Ding R Zhang H Sun X Chen W Tang K 《Planta》2007,225(4):887-896
The cDNA from Nicotiana tabacum encoding Putrescine N-methyltransferase (PMT), which catalyzes the first committed step in the biosynthesis of tropane alkaloids, has been introduced
into the genome of a scopolamine-producing Hyoscyamus niger mediated by the disarmed Agrobacterium tumefaciens strain C58C1, which also carries Agrobacterium rhizogenes Ri plasmid pRiA4, and expressed under the control of the CaMV 35S promoter. Hairy root lines transformed with pmt presented fivefold higher PMT activity than the control, and the methylputrescine (MPUT) levels of the resulting engineered
hairy roots increased four to fivefold compared to the control and wild-type roots, but there was no significant increase
in tropane alkaloids. However, after methyl jasmonate (MeJA) treatment, a considerable increase of PMTase and endogenous H6Hase
as well as an increase in scopolamine content was found either in the transgenic hairy roots or the control. The results indicate
that hairy root lines over-expressing pmt have a high capacity to synthesize MPUT, whereas their ability to convert hyoscyamine into scopolamine is very limited. Exposure
to MeJA strongly stimulated both polyamine and tropane biosynthesis pathways and elicitation led to more or less enhanced
production simultaneously. 相似文献
9.
Wang ZF Yan J Fu Y Tang XC Feng S He XC Bai DL 《Cellular and molecular neurobiology》2008,28(2):245-261
(1) This study was to evaluate the anti-cholinesterase (ChE), cognition enhancing and neuroprotective effects of FS-0311,
a bis-huperzine B derivative. (2) ChE activity was evaluated using a spectrophotometric method. Cognitive deficits in mice
were induced by scopolamine or transient brain ischemia and reperfusion. Water maze was used to detect the cognitive performance.
PC12 cell injury was induced by β-amyloid 25–35 (Aβ25–35), oxygen-glucose deprivation (OGD), or staurosporine treatment. (3) FS-0311 was a potent, highly specific inhibitor of acetylcholinesterase
(AChE). FS-0311 bound to AChE in a reversible manner, causing linear mixed-type inhibition. FS-0311 had a high oral bioavailability
and a long duration of AChE inhibitory action in vivo. FS-0311 was found to antagonize cognitive deficits induced by scopolamine
or transient brain ischemia and reperfusion in a water maze task. FS-0311 possessed the ability to protect PC12 cells against
Aβ25–35 peptide toxicity, OGD insult and staurosporine-induced apoptosis. The neuroprotective effects of FS-0311 appeared to reflect
an attenuation of oxidative stress. (4) With the profile of anti-ChE and neuroprotective activities, FS-0311 might be a promising
candidate in neurodegenerative diseases, such as Alzheimer’s disease and Vascular dementia. 相似文献
10.
A transformed root clone of Datura candida×D. aurea was established following infection with Agrobacterium rhizogenes strain A4. This clone was examined for its growth and hyoscyamine and scopolamine content under various culture conditions.
Among the three basal culture media tested, half-strength Gamborg's B5 medium supplemented with 5% sucrose was the best for
root growth (288 mg dry weight/flask) and full-strength B5 medium for hyoscyamine and scopolamine content (0.36 and 0.17%
dry weight, respectively). Experiments with exogenous nitrate added to the medium revealed that the biomass increased (353
mg dry weight/flask) and the hyoscyamine content improved remarkably (0.54% dry weight), but that the scopolamine content
was significantly reduced. The addition of various precursors at two different concentrations did not significantly modify
root growth. Feeding (R,S)-phenyllactic acid stimulated the biosynthesis of both alkaloids, whereas the addition of ornithine specifically reduced
the scopolamine content.
Received: 12 March 1997 / Revision received: 22 April 1997 / Accepted: 5 May 1997 相似文献