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Zhihua Liao – One of the best experts on this subject based on the ideXlab platform.
comparison of two hyoscyamine 6β hydroxylases in engineering Scopolamine biosynthesis in root cultures of scopolia luridaBiochemical and Biophysical Research Communications, 2018Co-Authors: Junlan Zeng, Zhihua Liao, Min Chen, Fangyuan Zhang, Luqi HuangAbstract:
Scopolia lurida, a medicinal plant native to the Tibetan Plateau, is among the most effective producers of pharmaceutical tropane alkaloids (TAs). The hyoscyamine 6β-hydroxylase genes of Hyoscyamus niger (HnH6H) and S. lurida (SlH6H) were cloned and respectively overexpressed in hairy root cultures of S. lurida, to compare their effects on promoting the production of TAs, especially the high-value Scopolamine. Root cultures with SlH6H/HnH6H overexpression were confirmed by PCR and real-time quantitative PCR, suggesting that the enzymatic steps defined by H6H were strongly elevated at the transcriptional level. Tropane alkaloids, including hyoscyamine, anisodamine and Scopolamine, were analyzed by HPLC. Scopolamine and anisodamine contents were remarkably elevated in the root cultures overexpressing SlH6H/HnH6H, whereas that of hyoscyamine was more or less reduced, when compared with those of the control. These results also indicated that SlH6H and HnH6H promoted anisodamine production at similar levels in S. lurida root cultures. More importantly, HnH6H-overexpressing root cultures had more Scopolamine in them that did SlH6H-overexpressing root cultures. This study not only provides a feasible way of overexpressing H6H to produce high-value Scopolamine in engineered root cultures of S. lurida but also found that HnH6H was better than SlH6H for engineering Scopolamine production.
enhanced biosynthesis of Scopolamine in transgenic atropa belladonna by overexpression of h6h geneChina journal of Chinese materia medica, 2013Co-Authors: Baifu Qin, Xiaozhong Lan, Chunxian Yang, Zhihua LiaoAbstract:
Transgenic Atropa belladonna with high levels of Scopolamine was developed by metabolic engineering. A functional gene involved in the rate limiting enzyme of h6h involved in the biosynthetic pathway of Scopolamine was over expressed in A. belladonna via Agrobacterium-mediation. The transgenic plants were culturing till fruiting through micropropogating and acclimating. The integration of the h6h genes into the genomic DNA of transgenic plants were confirmed by genomic polymerase chain reaction (PCR) analysis. Analysis of the difference of plant height, crown width, stem diameter, leaf length, leaf width, branch number and fresh weight was carried out using SPSS software. The content of hyoscyamine and Scopolamine in roots, stems, leaves and fruits was determined by HPLC. The investigation of the expression levels of Hnh6h by qPCR. Both Kan(r) and Hnh6h genes were detected in five transgenic lines of A. belladonna plants (A8, A11, A12, C8 and C19), but were not detected in the controls. The plant height, crown width, stem diameter, leaf length, leaf width, branch number and fresh weight of transgenic plants did not decrease by comparison with the non-transgenic ones, and furthermore some agronomic characters of transgenic plants were better than those of the controls. The highest level of Scopolamine was found in leaves of transgenic A. belladonna, and the content of Scopolamine was also higher than that of hyoscyamine in leaves. The contents of Scopolamine of leaves in different transgenic lines were listed in order: C8 > A12 > C19 > A11 > A8, especially, the content of Scopolamine in transgenic line C8 was 2.17 mg x g(-1) DW that was 4.2 folds of the non-transgenic ones (0.42 mg x g(-1) DW). The expression of transgenic Hnh6h was detected in all the transgenic plants but not in the control. The highest level of Hnh6h expression was found in transgenic leaves. Overexpression of Hnh6h is able to break the rate limiting steps involved in the downstream pathway of Scopolamine biosynthesis, and thus promotes the metabolic flux flowing toward biosynthesis of Scopolamine to improve the capacity of Scopolamine biosynthesis in transgenic plants. As a result, transgenic plants of A. belladonna with higher level of Scopolamine were developed.
Enhancement of tropane alkaloids production in transgenic hair roots of Atropa belladonna by overexpressing endogenous genes AbPMT and AbH6HActa pharmaceutica Sinica, 2013Co-Authors: Shi-ping Long, Xiaozhong Lan, Chunxian Yang, Ya-xiong Wang, Zhihua LiaoAbstract:
Atropa belladonna L. is the officially medicinal plant species and the main commercial source of Scopolamine and hyoscyamine in China. In this study, we reported the simultaneous overexpression of two functional genes involved in biosynthesis of Scopolamine, which respectively encoded the upstream key enzyme putrescine N-methyltransferase (PMT; EC 220.127.116.11) and the downstream key enzyme hyoscyamine 6beta-hydroxylase (H6H; EC 18.104.22.168) in transgenic hair root cultures of Atropa belladonna L. HPLC results suggested that four transgenic hair root lines produced higher content of Scopolamine at different levels compared with nontransgenic hair root cultures. And Scopolamine content increased to 8.2 fold in transgenic line PH2 compared with that of control line; and the other four transgenic lines showed an increase of Scopolamine compared with the control. Two of the transgenic hair root lines produced higher levels of tropane alkaloids, and the content increased to 2.7 fold in transgenic line PH2 compared with the control. The gene expression profile indicated that both PMT and H6H expressed at a different levels in different transgenic hair root lines, which would be helpful for biosynthesis of Scopolamine. Our studies suggested that overexpression of A. belladonna endogenous genes PMT and H6H could enhance tropane alkaloid biosynthesis.
Motohisa Suzuki – One of the best experts on this subject based on the ideXlab platform.
TAK-071, a muscarinic M1 receptor positive allosteric modulator, attenuates Scopolamine-induced quantitative electroencephalogram power spectral changes in cynomolgus monkeys.PLOS ONE, 2019Co-Authors: Emi Kurimoto, Masato Nakashima, Haruhide Kimura, Motohisa SuzukiAbstract:
Activation of the muscarinic M1 receptor is a promising approach to improve cognitive deficits associated with cholinergic dysfunction in Alzheimer’s disease, dementia with Lewy bodies, and schizophrenia. TAK-071 is an M1-selective positive allosteric modulator that improves cognitive deficits induced by Scopolamine, a non-selective muscarinic recereceptor antagonist, with reduced side effects on gastrointestinal function in rats. In this study, we explored changes in quantitative electroencephalography (qEEG) power bands, with or without Scopolamine challenge, as a non-invasive translational biomarker for the effect of TAK-071 in cynomolgus monkeys. Scopolamine has been reported to increase theta and delta power bands and decrease alpha power band in healthy volunteers. In line with the clinical observations, Scopolamine (25-100 μg/kg, subcutaneous administration [s.c.]) increased theta and delta power bands in cynomolgus monkeys in a dose-dependent manner, whereas it had the opposite effect on alpha power band. The effects of TAK-071 on Scopolamine (25 μg/kg, s.c.)-induced qEEG spectral changes were examined using an acetylcholinesterase inhiinhibitor donepezil and a muscarinic M1/M4 receptor agonist xanomeline as comparative cholinomimetics. TAK-071 (0.3-3 mg/kg, oral administration [p.o.]), donepezil (3 mg/kg, p.o.), and xanomeline (1 mg/kg, s.c.) suppressed the Scopolamine-induced increases in alpha, theta, and delta power bands. These results suggest that changes in specific qEEG power bands, in particular theta and delta power bands in the context of Scopolamine challenge, could be used as translational biomarkers for the evaluation of TAK-071 in clinical studies.
Min Whan Jung – One of the best experts on this subject based on the ideXlab platform.
Scopolamine induced learning impairment reversed by physostigmine in zebrafishNeuroscience Research, 2010Co-Authors: Min Whan JungAbstract:
Abstract In this study, the effects of Scopolamine, an acetylcholine muscarinic recereceptor antagonist, and physostigmine, an acetylcholinesterase inhiinhibitor, on the learning ability and memory of zebrafish were evaluated using a passive avoiavoidance response test. The zebrafish were trained to stay in a dark compartment to avoid a weight dropping into an acryl shuttle chamber with a central sliding door. The crossing time was increased significantly, from 30.7 ± 40.8 s to 179.3 ± 27.3 s in the training session and 179.9 ± 28.0 s in the test session carried out 2 h later in the controls. When treatment with 200 μM Scopolamine was administered for 1 h prior to the training session, the crossing time did not increase. The Scopolamine-induced learning deficit was ameliorated by pretreatment with 20 μM physostigmine for 1 h prior to Scopolamine treatment; the crossing time was similarly increased, as shown with the controls (60.9 ± 11.5 s, 130.9 ± 27.5 s, and 183.4 ± 26.6 s in the training session and 108.1 ± 23.9 s in the test session). When Scopolamine treatment was administered after the training session, the crossing time in the test session was reduced significantly as compared to that noted in the third trial of the training session, which was also ameliorated by physostigmine pretreatment. These results show that Scopolamine impairs both the acquisition of passive avoiavoidance response and retention of the learned response, and that physostigmine rescues the amnesic effects of Scopolamine in zebrafish.