The Experts below are selected from a list of 2307 Experts worldwide ranked by ideXlab platform
J.c. Seegers - One of the best experts on this subject based on the ideXlab platform.
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Chemical analyses of Ukrain™, a semi-synthetic Chelidonium majus Alkaloid Derivative, fail to confirm its trimeric structure
2000Co-Authors: Annie Panzer, Annie M. Joubert, J.n Eloff, C.f Albrecht, E Erasmus, J.c. SeegersAbstract:Ukrain has been described as a semi-synthetic Chelidonium majus Alkaloid Derivative, consisting of three chelidonine Alkaloids combined to triaziridide. We found the actions of Ukrain to be similar to the Chelidonium Alkaloids it is prepared from, and therefore became concerned about its chemical integrity. Chemical analyses of Ukrain by thin layer chromatography, high-performance liquid chromatography and liquid chromatography-mass spectrometry was inconsistent with the proposed trimeric structure and demonstrated that at least some commercial preparations of Ukrain consist of a mixture of C. majus Alkaloids (including chelidonine).
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ukraintm a semisynthetic chelidonium majus Alkaloid Derivative acts by inhibition of tubulin polymerization in normal and malignant cell lines
2000Co-Authors: Annie Panzer, Annie M. Joubert, E Hamel, Pepita C Bianchi, J.c. SeegersAbstract:Ukrain(TM) has been described as a semisynthetic Chelidonium majus Alkaloid Derivative, which exhibits selective toxicity towards malignant cells only. Its mechanism of action has hitherto been uncertain. We found that Ukrain(TM) inhibits tubulin polymerization, leading to impaired microtubule dynamics. This results in activation of the spindle checkpoint and thus a metaphase block. The effects of Ukrain(TM) on the growth, cell cycle progression and morphology of two normal, two transformed and two malignant cell lines did not differ. We could thus find no evidence for the selective cytotoxicity previously reported for Ukrain(TM).
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the antimitotic effects of ukrain a chelidonium majus Alkaloid Derivative are reversible in vitro
2000Co-Authors: Annie Panzer, Pepita C Bianchi, Anna Margaretha Joubert, J.c. SeegersAbstract:Ukrain is alleged to be an effective chemotherapeutic drug which causes minimal side-effects as a result of selective toxicity towards malignant cells only. We previously failed to confirm this claim and found Ukrain to be equally toxic to normal, transformed and malignant cell lines by causing a metaphase arrest. In this study we have found the antimitotic actions of Ukrain to be reversible in low doses in vitro, as shown by flow cytometry and concurrent haematoxylin and eosin stains. We hypothesize that the lack of side-effects found in vivo may be due to the lack of therapeutically effective dosages being administered, therefore enabling cells to overcome the metaphase arrest and survive.
Ying Qin Zang - One of the best experts on this subject based on the ideXlab platform.
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berberine differentially modulates the activities of erk p38 mapk and jnk to suppress th17 and th1 t cell differentiation in type 1 diabetic mice
2009Co-Authors: Guoliang Cui, Xia Qin, Yuebo Zhang, Zhenwei Gong, Ying Qin ZangAbstract:Berberine, an Alkaloid Derivative from Berberis vulgaris L., has been used extensively in traditional Chinese medicine to treat diarrhea and diabetes, but the underlying mechanisms for treating diabetes are not fully understood. Recent studies suggested that berberine has many beneficial biological effects, including anti-inflammation. Because type 1 diabetes is caused by T cell-mediated destruction of β cells and severe islet inflammation, we hypothesized that berberine could ameliorate type 1 diabetes through its immune regulation properties. Here we reported that 2 weeks of oral administration of berberine prevented the progression of type 1 diabetes in half of the NOD mice and decreased Th17 and Th1 cytokine secretion. Berberine suppressed Th17 and Th1 differentiation by reducing the expression of lineage markers. We found that berberine inhibited Th17 differentiation by activating ERK1/2 and inhibited Th1 differentiation by inhibiting p38 MAPK and JNK activation. Berberine down-regulated the activity of STAT1 and STAT4 through the suppression of p38 MAPK and JNK activation, and it controlled the stability of STAT4 through the ubiquitin-proteasome pathway. Our findings indicate that berberine targets MAPK to suppress Th17 and Th1 differentiation in type 1 diabetic NOD mice. This study revealed a novel role of ERK in Th17 differentiation through down-regulation of STAT3 phosphorylation and RORγt expression.
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berberine differentially modulates the activities of erk p38 mapk and jnk to suppress th17 and th1 t cell differentiation in type 1 diabetic mice
2009Co-Authors: Guoliang Cui, Xia Qin, Yuebo Zhang, Zhenwei Gong, Ying Qin ZangAbstract:Berberine, an Alkaloid Derivative from Berberis vulgaris L., has been used extensively in traditional Chinese medicine to treat diarrhea and diabetes, but the underlying mechanisms for treating diabetes are not fully understood. Recent studies suggested that berberine has many beneficial biological effects, including anti-inflammation. Because type 1 diabetes is caused by T cell-mediated destruction of beta cells and severe islet inflammation, we hypothesized that berberine could ameliorate type 1 diabetes through its immune regulation properties. Here we reported that 2 weeks of oral administration of berberine prevented the progression of type 1 diabetes in half of the NOD mice and decreased Th17 and Th1 cytokine secretion. Berberine suppressed Th17 and Th1 differentiation by reducing the expression of lineage markers. We found that berberine inhibited Th17 differentiation by activating ERK1/2 and inhibited Th1 differentiation by inhibiting p38 MAPK and JNK activation. Berberine down-regulated the activity of STAT1 and STAT4 through the suppression of p38 MAPK and JNK activation, and it controlled the stability of STAT4 through the ubiquitin-proteasome pathway. Our findings indicate that berberine targets MAPK to suppress Th17 and Th1 differentiation in type 1 diabetic NOD mice. This study revealed a novel role of ERK in Th17 differentiation through down-regulation of STAT3 phosphorylation and RORgamma t expression.
Annie Panzer - One of the best experts on this subject based on the ideXlab platform.
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Chemical analyses of Ukrain™, a semi-synthetic Chelidonium majus Alkaloid Derivative, fail to confirm its trimeric structure
2000Co-Authors: Annie Panzer, Annie M. Joubert, J.n Eloff, C.f Albrecht, E Erasmus, J.c. SeegersAbstract:Ukrain has been described as a semi-synthetic Chelidonium majus Alkaloid Derivative, consisting of three chelidonine Alkaloids combined to triaziridide. We found the actions of Ukrain to be similar to the Chelidonium Alkaloids it is prepared from, and therefore became concerned about its chemical integrity. Chemical analyses of Ukrain by thin layer chromatography, high-performance liquid chromatography and liquid chromatography-mass spectrometry was inconsistent with the proposed trimeric structure and demonstrated that at least some commercial preparations of Ukrain consist of a mixture of C. majus Alkaloids (including chelidonine).
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ukraintm a semisynthetic chelidonium majus Alkaloid Derivative acts by inhibition of tubulin polymerization in normal and malignant cell lines
2000Co-Authors: Annie Panzer, Annie M. Joubert, E Hamel, Pepita C Bianchi, J.c. SeegersAbstract:Ukrain(TM) has been described as a semisynthetic Chelidonium majus Alkaloid Derivative, which exhibits selective toxicity towards malignant cells only. Its mechanism of action has hitherto been uncertain. We found that Ukrain(TM) inhibits tubulin polymerization, leading to impaired microtubule dynamics. This results in activation of the spindle checkpoint and thus a metaphase block. The effects of Ukrain(TM) on the growth, cell cycle progression and morphology of two normal, two transformed and two malignant cell lines did not differ. We could thus find no evidence for the selective cytotoxicity previously reported for Ukrain(TM).
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the antimitotic effects of ukrain a chelidonium majus Alkaloid Derivative are reversible in vitro
2000Co-Authors: Annie Panzer, Pepita C Bianchi, Anna Margaretha Joubert, J.c. SeegersAbstract:Ukrain is alleged to be an effective chemotherapeutic drug which causes minimal side-effects as a result of selective toxicity towards malignant cells only. We previously failed to confirm this claim and found Ukrain to be equally toxic to normal, transformed and malignant cell lines by causing a metaphase arrest. In this study we have found the antimitotic actions of Ukrain to be reversible in low doses in vitro, as shown by flow cytometry and concurrent haematoxylin and eosin stains. We hypothesize that the lack of side-effects found in vivo may be due to the lack of therapeutically effective dosages being administered, therefore enabling cells to overcome the metaphase arrest and survive.
Guoliang Cui - One of the best experts on this subject based on the ideXlab platform.
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berberine differentially modulates the activities of erk p38 mapk and jnk to suppress th17 and th1 t cell differentiation in type 1 diabetic mice
2009Co-Authors: Guoliang Cui, Xia Qin, Yuebo Zhang, Zhenwei Gong, Ying Qin ZangAbstract:Berberine, an Alkaloid Derivative from Berberis vulgaris L., has been used extensively in traditional Chinese medicine to treat diarrhea and diabetes, but the underlying mechanisms for treating diabetes are not fully understood. Recent studies suggested that berberine has many beneficial biological effects, including anti-inflammation. Because type 1 diabetes is caused by T cell-mediated destruction of β cells and severe islet inflammation, we hypothesized that berberine could ameliorate type 1 diabetes through its immune regulation properties. Here we reported that 2 weeks of oral administration of berberine prevented the progression of type 1 diabetes in half of the NOD mice and decreased Th17 and Th1 cytokine secretion. Berberine suppressed Th17 and Th1 differentiation by reducing the expression of lineage markers. We found that berberine inhibited Th17 differentiation by activating ERK1/2 and inhibited Th1 differentiation by inhibiting p38 MAPK and JNK activation. Berberine down-regulated the activity of STAT1 and STAT4 through the suppression of p38 MAPK and JNK activation, and it controlled the stability of STAT4 through the ubiquitin-proteasome pathway. Our findings indicate that berberine targets MAPK to suppress Th17 and Th1 differentiation in type 1 diabetic NOD mice. This study revealed a novel role of ERK in Th17 differentiation through down-regulation of STAT3 phosphorylation and RORγt expression.
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berberine differentially modulates the activities of erk p38 mapk and jnk to suppress th17 and th1 t cell differentiation in type 1 diabetic mice
2009Co-Authors: Guoliang Cui, Xia Qin, Yuebo Zhang, Zhenwei Gong, Ying Qin ZangAbstract:Berberine, an Alkaloid Derivative from Berberis vulgaris L., has been used extensively in traditional Chinese medicine to treat diarrhea and diabetes, but the underlying mechanisms for treating diabetes are not fully understood. Recent studies suggested that berberine has many beneficial biological effects, including anti-inflammation. Because type 1 diabetes is caused by T cell-mediated destruction of beta cells and severe islet inflammation, we hypothesized that berberine could ameliorate type 1 diabetes through its immune regulation properties. Here we reported that 2 weeks of oral administration of berberine prevented the progression of type 1 diabetes in half of the NOD mice and decreased Th17 and Th1 cytokine secretion. Berberine suppressed Th17 and Th1 differentiation by reducing the expression of lineage markers. We found that berberine inhibited Th17 differentiation by activating ERK1/2 and inhibited Th1 differentiation by inhibiting p38 MAPK and JNK activation. Berberine down-regulated the activity of STAT1 and STAT4 through the suppression of p38 MAPK and JNK activation, and it controlled the stability of STAT4 through the ubiquitin-proteasome pathway. Our findings indicate that berberine targets MAPK to suppress Th17 and Th1 differentiation in type 1 diabetic NOD mice. This study revealed a novel role of ERK in Th17 differentiation through down-regulation of STAT3 phosphorylation and RORgamma t expression.
Alison J. Frontier - One of the best experts on this subject based on the ideXlab platform.
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Enantioselective Nazarov Cyclization Catalyzed by a Cinchona Alkaloid Derivative.
2015Co-Authors: Yu-wen Huang, Alison J. FrontierAbstract:Diene-diones of type (I) undergo an 1,6-addition/Nazarov cyclization/elimination reaction in the presence of Hatkeyama′s chiral cinchona Alkaloid catalyst to give functionalized cyclopentenones in good yields and enantioselectivities.
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Enantioselective Nazarov Cyclization Catalyzed by a Cinchona Alkaloid Derivative.
2015Co-Authors: Yu-wen Huang, Alison J. FrontierAbstract:Nucleophilic catalysts for a 1,6 addition/Nazarov cyclization/elimination sequence were evaluated for their ability to induce enantioselectivity in the electrocyclization step. Of the tertiary amines examined, it was found that a cinchona Alkaloid Derivative was able to generate substituted 5-hydroxy γ-methylene cyclopentenones with excellent enantioselectivity. The study results suggest that successful cyclization depends upon the ability of the dienyl diketone substrate to readily adopt an s-cis conformation.