The Experts below are selected from a list of 2904 Experts worldwide ranked by ideXlab platform
J. Chen - One of the best experts on this subject based on the ideXlab platform.
-
Ultra-performance liquid chromatography-tandem mass spectrometric assay for the simultaneous determination of Brucine, strychnine and Brucine N-oxide in rat plasma: application to a pharmacokinetic study.
Biomedical chromatography : BMC, 2016Co-Authors: Dongyue Wang, Bao-chang Cai, Zihao Pan, Xiao Liu, J. ChenAbstract:A rapid, simple and sensitive UHPLC-MS/MS method was developed and validated for the simultaneous determination of Brucine, strychnine and Brucine N-oxide in rat plasma using huperzine A as an internal standard (IS) after protein precipitation with methanol. The analytes were separated on a Purospher® STAR RP18 UHPLC column (2 µm, 2.1 × 100 mm) by gradient elution using a mobile phase composed of methanol and water (containing 0.1% formic acid) at a flow rate of 0.3 mL/min. Brucine, strychnine, Brucine N-oxide and IS were detected in positive ion multiple reaction monitoring mode by means of an electrospray ionization interface (m/z 395.2 → 324.1, m/z 335.2 → 184.1, m/z 411.2 → 394.2, m/z 243.1 → 226.1). The calibration curve was linear over the range of 1-500 ng/mL for Brucine and strychnine and 0.2-50 ng/mL for Brucine N-oxide. The intra- and inter-day precisions of these analytes were all within 15% and the accuracy ranged from 85 to 115%. The stability experiment indicated that the plasma samples at three concentration levels were stable under different conditions. The developed method was successfully applied for the first time to pharmacokinetic studies of Brucine, strychnine and Brucine N-oxide following a single oral and intravenous administration of modified total alkaloid fraction in rats. Copyright © 2016 John Wiley & Sons, Ltd.
-
Evaluation of the pharmacodynamics and pharmacokinetics of Brucine following transdermal administration
Fitoterapia, 2013Co-Authors: J. Chen, Yun Fang, Zhipeng Chen, Jie Dong, Ying Gao, Fang Fang, Bao-chang CaiAbstract:Abstract Before the design of Brucine-containing transdermal formulations, the pharmacodynamics and pharmacokinetics of Brucine following transdermal administration should be evaluated. In this study, the effect of addition of ethanol on solubility of bruicne was investigated and 20% ethanol was added into PBS to obtain 10 mg/mL Brucine solution. Then three transdermal doses (10, 20 and 40 mg/kg) were administered to mice to evaluate pharmacological activity. It had been demonstrated that Brucine possessed analgesic and anti-inflammatory activity in a dose-dependent manner. Cytotoxicities of Brucine against various tumor cells including skin tumor cell were also compared in vitro. Brucine was found to possess antitumor activity in a concentration and time-dependent manner and gastrointestinal tumor cells seemed to be more sensitive to Brucine. Then in vitro skin permeation behavior and in vivo pharmacokinetics following transdermal administration were further investigated. The cumulative amounts of Brucine across mouse skin in vitro were found to be higher than 90%. The absolute bioavailability of Brucine was determined to be 40.83%. And compared with intravenous administration, MRT and T1/2 values were increased about 8 ~ 12-fold by transdermal route. Moreover, fluctuations of drug levels were found to be significantly decreased in tissues, especially in brain. Finally, no dermal toxicity of Brucine was observed. The results of this study indicated that transdermal administration might be beneficial for the sustained efficacy and reduced toxicity of Brucine.
-
Optimization and application of method to determine plasma concentration of Brucine
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica, 2013Co-Authors: Dongyue Wang, J. Chen, Bao-chang CaiAbstract:The HPLC method for determining plasma concentration of Brucine was optimized during the study on the effect of the extraction reagent, the extraction frequency and the volume of extraction solvent on the extraction recovery of Brucine. The optimum sample treatment method was obtained in the study. Specifically, ammonia water was added, 4 mL extraction solvent (N-hexane-methylene chloride-isopropyl alcohol 65:30:5) were adopted to extract Brucine for twice. The method to determine plasma concentration of Brucine was applied in pharmacokinetic study to compare pharmacokinetic properties of intravenous injection (5 mg x kg(-1)) and transdermal administration (40 mg x kg(-1)) of Brucine aqueous alkali. The results showed that both pharmacokinetic parameters of Brucine after intravenous injection and transdermal administration were in conformity with the two-compartment model. After transdermal administration, the absolute bioavailability was calculated to be 18.72%. The optimized HPLC method can satisfy the demands of the pharmacokinetic study on Brucine.
-
analgesic and anti inflammatory activity and pharmacokinetics of alkaloids from seeds of strychnos nux vomica after transdermal administration effect of changes in alkaloid composition
Journal of Ethnopharmacology, 2012Co-Authors: J. Chen, Yange Qu, Fei Xu, Xuan Wang, Zhipeng Chen, Tulin LuAbstract:Abstract Ethnopharmacological relevance Strychnos nux-vomica L. (Loganiaceae) is grown extensively in southern Asian countries. The dried seed of this plant, nux vomica , has been clinically used in Chinese folk medicine for improving blood circulation, relieving rheumatic pain, reducing swelling and treating cancer. Aim of the study This study was carried out to investigate the effect of removing most strychnine from the total alkaloid fraction (TAF) extracted from nux vomica on analgesic and anti-inflammatory activity and pharmacokinetics after transdermal administration. Materials and methods Most strychnine was removed from TAF and the resulted modified total alkaloid fraction (MTAF) was obtained. The contents of strychnine and Brucine in TAF and MTAF were determined. Then the analgesic and anti-inflammatory activity of TAF, MTAF, Brucine and strychnine dissolved in hydrogel was compared after transdermal administration. Furthermore, in vitro and in vivo transdermal absorption profiles of Brucine after administration of TAF, MTAF and Brucine dissolved in hydrogel were also compared. Results In contrast to TAF, most strychnine was removed from MTAF and the ratio of Brucine to strychnine was adjusted from 1:1.8 to 2.7:1. MTAF showed significant analgesic activity in all the chemical-, thermal- and physical- induced nociception models, which indicated the presence of both centrally and peripherally mediated activities. MTAF also showed significant anti-inflammatory activity against xylene-induced ear edema. But TAF and strychnine demonstrated little activity in all those pharmacological tests. Brucine showed to be effective in acetic acid-induced writhing and xylene-induced ear edema test. Brucine in MTAF was absorbed more completely than it alone at the same dosage of Brucine after transdermal administration. Conclusions The results from the present study appeared to support the viewpoint that most strychnine should be removed from TAF to improve analgesic and anti-inflammatory activity. The relatively higher pharmacological activity of MTAF compared to Brucine alone is partly due to the enhanced transdermal absorption of Brucine.
-
Preparation and pharmacokinetics of Brucine hydrogel patch
Zhong yao cai = Zhongyaocai = Journal of Chinese medicinal materials, 2012Co-Authors: J. Chen, Zhipeng Chen, Bao-chang CaiAbstract:OBJECTIVE To investigate the effect of dose on pharmacokinetic properties of Brucine hydrogel patch. METHODS The plasma concentration of Brucine was determined by HPLC. Brucine hydrogel patch was prepared and its pharmaceutical characterization was investigated. After transdermal administration of different dose Brucine hydrogel patch; Plasma concentration versus time profiles were determined and pharmacokinetic parameters were calculated by DAS program. RESULTS The pharmaceutical properties of Brucine hydrogel patch were satisfactory. The AUC0-1 values were 7.24 +/- 0.61, 16.02 +/- 2.34 and 54.84 +/- 26.59 microg x h/mL after administration of 30, 60 and 180 mg/kg Brucine hydrogel patch, respectively. The corresponding C(max) values were 0.73 +/- 0.23, 1.45 +/- 0.28 and 4.59 +/- 1.85 microg/mL, respectively. And the corresponding T(max) values were 8.67 +/- 2.07, 11.67 +/- 2.66 and 8.33 +/- 2.65 h, respectively. CONCLUSION The pharmacokinetic properties of Brucine do not vary with the dose of Brucine hydrogel patch.
Bao-chang Cai - One of the best experts on this subject based on the ideXlab platform.
-
Involved Mitochondrial Pathway
2016Co-Authors: Xukun Deng, Bao-chang Cai, Fangzhou Yin, Wu YinAbstract:ow nloaded from 2 In an attempt to dissect the mechanism of Strychnos nux-vomica, a commonly used Chinese folk medicine in the therapy of liver cancer, the cytotoxic effects of four alkaloids in Strychnos nux-vomica, Brucine, Brucine N-oxide, strychnine and isostrychnine on human hepatoma cells (HepG2) were screened by MTT assay. Brucine, among the four alkaloids, exhibited the strongest toxic effect, the mechanism of which was found to cause HepG2 cells apoptosis, since Brucine caused HepG2 cells shrinkage, the formation of apoptotic bodies, DNA fragmentation, cell cycle arrest as well as phosphatidylserine externalization, all of which are typical characteristics of apoptotic programmed cell death. Brucine-induced HepG2 cells apoptosis was caspase-dependent, among which caspase-3 was activated by caspase-9. Brucine also caused the proteolytic processing of caspase-9. In addition, Brucine caused the HepG2 cells mitochondrial membrane depolarization, th
-
Ultra-performance liquid chromatography-tandem mass spectrometric assay for the simultaneous determination of Brucine, strychnine and Brucine N-oxide in rat plasma: application to a pharmacokinetic study.
Biomedical chromatography : BMC, 2016Co-Authors: Dongyue Wang, Bao-chang Cai, Zihao Pan, Xiao Liu, J. ChenAbstract:A rapid, simple and sensitive UHPLC-MS/MS method was developed and validated for the simultaneous determination of Brucine, strychnine and Brucine N-oxide in rat plasma using huperzine A as an internal standard (IS) after protein precipitation with methanol. The analytes were separated on a Purospher® STAR RP18 UHPLC column (2 µm, 2.1 × 100 mm) by gradient elution using a mobile phase composed of methanol and water (containing 0.1% formic acid) at a flow rate of 0.3 mL/min. Brucine, strychnine, Brucine N-oxide and IS were detected in positive ion multiple reaction monitoring mode by means of an electrospray ionization interface (m/z 395.2 → 324.1, m/z 335.2 → 184.1, m/z 411.2 → 394.2, m/z 243.1 → 226.1). The calibration curve was linear over the range of 1-500 ng/mL for Brucine and strychnine and 0.2-50 ng/mL for Brucine N-oxide. The intra- and inter-day precisions of these analytes were all within 15% and the accuracy ranged from 85 to 115%. The stability experiment indicated that the plasma samples at three concentration levels were stable under different conditions. The developed method was successfully applied for the first time to pharmacokinetic studies of Brucine, strychnine and Brucine N-oxide following a single oral and intravenous administration of modified total alkaloid fraction in rats. Copyright © 2016 John Wiley & Sons, Ltd.
-
Evaluation of the pharmacodynamics and pharmacokinetics of Brucine following transdermal administration
Fitoterapia, 2013Co-Authors: J. Chen, Yun Fang, Zhipeng Chen, Jie Dong, Ying Gao, Fang Fang, Bao-chang CaiAbstract:Abstract Before the design of Brucine-containing transdermal formulations, the pharmacodynamics and pharmacokinetics of Brucine following transdermal administration should be evaluated. In this study, the effect of addition of ethanol on solubility of bruicne was investigated and 20% ethanol was added into PBS to obtain 10 mg/mL Brucine solution. Then three transdermal doses (10, 20 and 40 mg/kg) were administered to mice to evaluate pharmacological activity. It had been demonstrated that Brucine possessed analgesic and anti-inflammatory activity in a dose-dependent manner. Cytotoxicities of Brucine against various tumor cells including skin tumor cell were also compared in vitro. Brucine was found to possess antitumor activity in a concentration and time-dependent manner and gastrointestinal tumor cells seemed to be more sensitive to Brucine. Then in vitro skin permeation behavior and in vivo pharmacokinetics following transdermal administration were further investigated. The cumulative amounts of Brucine across mouse skin in vitro were found to be higher than 90%. The absolute bioavailability of Brucine was determined to be 40.83%. And compared with intravenous administration, MRT and T1/2 values were increased about 8 ~ 12-fold by transdermal route. Moreover, fluctuations of drug levels were found to be significantly decreased in tissues, especially in brain. Finally, no dermal toxicity of Brucine was observed. The results of this study indicated that transdermal administration might be beneficial for the sustained efficacy and reduced toxicity of Brucine.
-
Optimization and application of method to determine plasma concentration of Brucine
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica, 2013Co-Authors: Dongyue Wang, J. Chen, Bao-chang CaiAbstract:The HPLC method for determining plasma concentration of Brucine was optimized during the study on the effect of the extraction reagent, the extraction frequency and the volume of extraction solvent on the extraction recovery of Brucine. The optimum sample treatment method was obtained in the study. Specifically, ammonia water was added, 4 mL extraction solvent (N-hexane-methylene chloride-isopropyl alcohol 65:30:5) were adopted to extract Brucine for twice. The method to determine plasma concentration of Brucine was applied in pharmacokinetic study to compare pharmacokinetic properties of intravenous injection (5 mg x kg(-1)) and transdermal administration (40 mg x kg(-1)) of Brucine aqueous alkali. The results showed that both pharmacokinetic parameters of Brucine after intravenous injection and transdermal administration were in conformity with the two-compartment model. After transdermal administration, the absolute bioavailability was calculated to be 18.72%. The optimized HPLC method can satisfy the demands of the pharmacokinetic study on Brucine.
-
Preparation and pharmacokinetics of Brucine hydrogel patch
Zhong yao cai = Zhongyaocai = Journal of Chinese medicinal materials, 2012Co-Authors: J. Chen, Zhipeng Chen, Bao-chang CaiAbstract:OBJECTIVE To investigate the effect of dose on pharmacokinetic properties of Brucine hydrogel patch. METHODS The plasma concentration of Brucine was determined by HPLC. Brucine hydrogel patch was prepared and its pharmaceutical characterization was investigated. After transdermal administration of different dose Brucine hydrogel patch; Plasma concentration versus time profiles were determined and pharmacokinetic parameters were calculated by DAS program. RESULTS The pharmaceutical properties of Brucine hydrogel patch were satisfactory. The AUC0-1 values were 7.24 +/- 0.61, 16.02 +/- 2.34 and 54.84 +/- 26.59 microg x h/mL after administration of 30, 60 and 180 mg/kg Brucine hydrogel patch, respectively. The corresponding C(max) values were 0.73 +/- 0.23, 1.45 +/- 0.28 and 4.59 +/- 1.85 microg/mL, respectively. And the corresponding T(max) values were 8.67 +/- 2.07, 11.67 +/- 2.66 and 8.33 +/- 2.65 h, respectively. CONCLUSION The pharmacokinetic properties of Brucine do not vary with the dose of Brucine hydrogel patch.
Yan-wen Liu - One of the best experts on this subject based on the ideXlab platform.
-
influence of p glycoprotein on Brucine transport at the in vitro blood brain barrier
European Journal of Pharmacology, 2012Co-Authors: Miao Yan, Ping-fei Fang, Yan-wen LiuAbstract:Abstract Brucine is a central agonist that can pass through the blood–brain barrier (BBB). The goal of this study is to examine whether Brucine is one of the substrates of the drug transporter P-glycoprotein (P-gp) and to examine the effects of P-gp on the Brucine transport at the in vitro BBB model. The P-gp ATPase assay was utilized to investigate the in vitro affinity of P-gp to Brucine. Results suggested that K m of Brucine (11.4 μmol/l) was smaller than the positive control, verapamil (16.4 μmol/l). In this study, we developed an in vitro BBB model, comprising a co-culture of primary rat brain microvessel endothelial cells and astrocytes for the transport study. The validated model was correct and available. Transendothelial electrical resistance reached (283.78±18.85) Ω cm 2 . The model displayed limited permeability to fluorescein sodium and [ 125 I]albumin, with the apparent permeability coefficient P app of (10.36±0.86)×10 −6 cm/s and (6.00±0.78)×10 −6 cm/s, respectively. The quantity of the bidirectional transport of Brucine was determined by ultra-performance liquid chromatography-tandem mass spectrometry. In the absence of verapamil, the transport of Brucine from basolateral compartment to apical compartment (BL–AP) was higher than from AP to BL at low, middle, and high concentrations ( P P in vitro BBB model.
-
Influence of P-glycoprotein on Brucine transport at the in vitro blood-brain barrier.
European journal of pharmacology, 2012Co-Authors: Miao Yan, Ping-fei Fang, Yan-wen LiuAbstract:Brucine is a central agonist that can pass through the blood-brain barrier (BBB). The goal of this study is to examine whether Brucine is one of the substrates of the drug transporter P-glycoprotein (P-gp) and to examine the effects of P-gp on the Brucine transport at the in vitro BBB model. The P-gp ATPase assay was utilized to investigate the in vitro affinity of P-gp to Brucine. Results suggested that K(m) of Brucine (11.4 μmol/l) was smaller than the positive control, verapamil (16.4 μmol/l). In this study, we developed an in vitro BBB model, comprising a co-culture of primary rat brain microvessel endothelial cells and astrocytes for the transport study. The validated model was correct and available. Transendothelial electrical resistance reached (283.78 ± 18.85) Ω cm(2). The model displayed limited permeability to fluorescein sodium and [(125)I]albumin, with the apparent permeability coefficient Papp of (10.36 ± 0.86) × 10(-6) cm/s and (6.00 ± 0.78) × 10(-6)cm/s, respectively. The quantity of the bidirectional transport of Brucine was determined by ultra-performance liquid chromatography-tandem mass spectrometry. In the absence of verapamil, the transport of Brucine from basolateral compartment to apical compartment (BL-AP) was higher than from AP to BL at low, middle, and high concentrations (P
-
Influence of P-glycoprotein on Brucine transport at the in vitro blood–brain barrier
European Journal of Pharmacology, 2012Co-Authors: Miao Yan, Ping-fei Fang, Yan-wen LiuAbstract:Abstract Brucine is a central agonist that can pass through the blood–brain barrier (BBB). The goal of this study is to examine whether Brucine is one of the substrates of the drug transporter P-glycoprotein (P-gp) and to examine the effects of P-gp on the Brucine transport at the in vitro BBB model. The P-gp ATPase assay was utilized to investigate the in vitro affinity of P-gp to Brucine. Results suggested that K m of Brucine (11.4 μmol/l) was smaller than the positive control, verapamil (16.4 μmol/l). In this study, we developed an in vitro BBB model, comprising a co-culture of primary rat brain microvessel endothelial cells and astrocytes for the transport study. The validated model was correct and available. Transendothelial electrical resistance reached (283.78±18.85) Ω cm 2 . The model displayed limited permeability to fluorescein sodium and [ 125 I]albumin, with the apparent permeability coefficient P app of (10.36±0.86)×10 −6 cm/s and (6.00±0.78)×10 −6 cm/s, respectively. The quantity of the bidirectional transport of Brucine was determined by ultra-performance liquid chromatography-tandem mass spectrometry. In the absence of verapamil, the transport of Brucine from basolateral compartment to apical compartment (BL–AP) was higher than from AP to BL at low, middle, and high concentrations ( P P in vitro BBB model.
Xukun Deng - One of the best experts on this subject based on the ideXlab platform.
-
Involved Mitochondrial Pathway
2016Co-Authors: Xukun Deng, Bao-chang Cai, Fangzhou Yin, Wu YinAbstract:ow nloaded from 2 In an attempt to dissect the mechanism of Strychnos nux-vomica, a commonly used Chinese folk medicine in the therapy of liver cancer, the cytotoxic effects of four alkaloids in Strychnos nux-vomica, Brucine, Brucine N-oxide, strychnine and isostrychnine on human hepatoma cells (HepG2) were screened by MTT assay. Brucine, among the four alkaloids, exhibited the strongest toxic effect, the mechanism of which was found to cause HepG2 cells apoptosis, since Brucine caused HepG2 cells shrinkage, the formation of apoptotic bodies, DNA fragmentation, cell cycle arrest as well as phosphatidylserine externalization, all of which are typical characteristics of apoptotic programmed cell death. Brucine-induced HepG2 cells apoptosis was caspase-dependent, among which caspase-3 was activated by caspase-9. Brucine also caused the proteolytic processing of caspase-9. In addition, Brucine caused the HepG2 cells mitochondrial membrane depolarization, th
-
Brucine an alkaloid from seeds of strychnos nux vomica linn represses hepatocellular carcinoma cell migration and metastasis the role of hypoxia inducible factor 1 pathway
Toxicology Letters, 2013Co-Authors: Xue Mi, Xinlin Zhang, Lvyi Chen, You Li, Xinzhou Yang, Xukun DengAbstract:Brucine is an alkaloid derived from the seeds of Strychnos nux-vomica Linn. which have long been used as a traditional medicine for the treatment of hepatocellular carcinoma (HCC) in China. HCC prognosis can be greatly influenced by metastasis. There has thus far been little research into Brucine as a source of anti-metastasis activity against HCC. In this study, we revealed that Brucine dramatically repressed HepG2 and SMMC-7721 HCC cell migration with few cytotoxic effects. Hypoxia inducible factor 1 (HIF-1) is a key transcription factor mediating cell migration and invasion. Brucine suppressed HIF-1-dependent luciferase activity in HepG2 cells. The transcriptions of four known HIF-1 target genes involved in HCC metastasis, i.e., fibronectin, matrix metallopeptidase 2, lysyl oxidase, and cathepsin D, were also attenuated after Brucine treatment. Experiments in vivo showed that an intraperitoneal injection of 5 and 15 mg/kg of Brucine resulted in dose-dependent decreases in the lung metastasis of H22 ascitic hepatoma cells. Moreover, a dosage of Brucine at 15 mg/kg exhibited very low toxic effects to tumor-bearing mice. Consistently, Brucine downregulated expression levels of HIF-1 responsive genes in vivo. Our current study demonstrated the capacity of Brucine in suppressing HCC cell migration in vitro and lung metastasis in vivo. The inhibition of the HIF-1 pathway is implicated in the anti-metastasis activity of Brucine.
-
the cytotoxicity induced by Brucine from the seed of strychnos nux vomica proceeds via apoptosis and is mediated by cyclooxygenase 2 and caspase 3 in smmc 7221 cells
Food and Chemical Toxicology, 2007Co-Authors: Xukun Deng, Xiaochun ZhangAbstract:Abstract To study the cytotoxicity of four alkaloids: Brucine, strychnine, Brucine N-oxide and isostrychnine from nux vomica on SMMC 7721 cells and their possible mechanisms, MET assay was used to examine the growth inhibitory effects of these alkaloids. Brucine revealed the strongest growth inhibitory effect on SMMC-7721 cells. Furthermore, as directly observed under an inverted microscope, fluorescent microscope and transmission electronic microscope, Brucine caused SMMC-7721 cell shrinkage, membrane blobbing, formation of apoptotic body as well as nucleus condensation, all of which are typical characteristics of apoptotic programmed cell death. In addition, Brucine dose-dependently caused SMMC-7721 cells apoptosis via formation of subdipolid DNA and phosphatidylserine externalization, as evidenced by flow cytometry analysis. The Brucine-induced apoptosis was partially attributed to the activation of caspase 3 as well as cyclooxygenase 2 inhibition, since neither caspase 3 specific inhibitor, z-DEVD-fmk nor was exogenous addition of prostaglandin E 2 able to completely abrogate the Brucine-induced SMMC 7721 cell apoptosis. In sum, this paper indicate that the major alkaloids present in the seed of Strychnos nux-vomica are effective against SMMC-7721 cells proliferation, among which Brucine proceeds SMMC-7721 cells death via apoptosis, probably through the participation of caspase 3 and cyclooxygenase 2.
-
the anti tumor effects of alkaloids from the seeds of strychnos nux vomica on hepg2 cells and its possible mechanism
Journal of Ethnopharmacology, 2006Co-Authors: Xukun Deng, Xiaoyu Lu, Weidong Li, Xiaochun ZhangAbstract:Abstract To screen the anti-tumor effects of the four alkaloids: Brucine, strychnine, Brucine N-oxide and isostrychnine from the seed of Strychnos nux-vomica, MTT assay was used to examine the growth inhibitory effects of these alkaloids on human hepatoma cell line (HepG2). Brucine, strychnine and isostrychnine revealed significant inhibitory effects against HepG2 cell proliferation, whereas Brucine N-oxide didn’t have such an effect. In addition, Brucine caused HepG2 cell shrinkage, membrane blebbing, apoptotic body formation, all of which are typical characteristics of apoptotic programmed cell death. The results of flow cytometric analysis demonstrated that Brucine caused dose-dependent apoptosis of HepG2 cells through cell cycle arrest at G0/G1 phase, thus preventing cells entering S or G2/M phase. Immunoblot results revealed that Brucine significantly decreased the protein expression level of cyclooxygenase-2, whereas increased the expression caspase-3 as well as the caspase-3-like protease activity in HepG2 cells, suggesting the involvement of cyclooxygenase-2 and caspase-3 in the pro-apoptotic effects exerted by Brucine. Therefore, this paper indicate that the major alkaloids present in the seed of Strychnos nux-vomica are effective against HepG2 cells proliferation, among which Brucine proceed HepG2 cells death via apoptosis, probably through the participation of caspase-3 and cyclooxygenase-2.
-
the apoptotic effect of Brucine from the seed of strychnos nux vomica on human hepatoma cells is mediated via bcl 2 and ca2 involved mitochondrial pathway
Toxicological Sciences, 2006Co-Authors: Xukun Deng, Xiaoyu LuAbstract:In an attempt to dissect the mechanism of Strychnos nuxvomica, a commonly used Chinese folk medicine in the therapy of liver cancer, the cytotoxic effects of four alkaloids in Strychnos nux-vomica, Brucine, Brucine N-oxide, strychnine, and isostrychnine, on human hepatoma cells (HepG2) were screened by 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyl-tetrasolium bromide (MTT) assay. Brucine, among the four alkaloids, exhibited the strongest toxic effect, the mechanism of which was found to cause HepG2 cell apoptosis, since Brucine caused HepG2 cell shrinkage, the formation of apoptotic bodies, DNA fragmentation, cell cycle arrest, as well as phosphatidylserine externalization, all of which are typical characteristics of apoptotic programmed cell death. Brucine-induced HepG2 cell apoptosis was caspase dependent, with caspase-3 activated by caspase-9. Brucine also caused the proteolytic processing of caspase-9. In addition, Brucine caused depolarization of the mitochondrial membrane of HepG2 cells, the inhibition of which by cyclosporine A completely abrogated the activation of casapses and release of cytochrome c in Brucinetreated HepG2 cells. These findings suggested a pivotal role of mitochondrial membrane depolarization in HepG2 cell apoptosis elicited by Brucine. Furthermore, Brucine induced a rapid and sustained elevation of intracellular [Ca 2+ ], which compromised the mitochondrial membrane potential and triggered the process of HepG2 cell apoptosis. Finally, Bcl-2 was found to predominately control the whole event of cell apoptosis induced by Brucine. The elevation of [Ca 2+ ]i caused by Brucine was also suppressed by overexpression of Bcl-2 protein in HepG2 cells. From the facts given above, Ca 2+ and Bcl-2 mediated mitochondrial pathway
Miao Yan - One of the best experts on this subject based on the ideXlab platform.
-
influence of p glycoprotein on Brucine transport at the in vitro blood brain barrier
European Journal of Pharmacology, 2012Co-Authors: Miao Yan, Ping-fei Fang, Yan-wen LiuAbstract:Abstract Brucine is a central agonist that can pass through the blood–brain barrier (BBB). The goal of this study is to examine whether Brucine is one of the substrates of the drug transporter P-glycoprotein (P-gp) and to examine the effects of P-gp on the Brucine transport at the in vitro BBB model. The P-gp ATPase assay was utilized to investigate the in vitro affinity of P-gp to Brucine. Results suggested that K m of Brucine (11.4 μmol/l) was smaller than the positive control, verapamil (16.4 μmol/l). In this study, we developed an in vitro BBB model, comprising a co-culture of primary rat brain microvessel endothelial cells and astrocytes for the transport study. The validated model was correct and available. Transendothelial electrical resistance reached (283.78±18.85) Ω cm 2 . The model displayed limited permeability to fluorescein sodium and [ 125 I]albumin, with the apparent permeability coefficient P app of (10.36±0.86)×10 −6 cm/s and (6.00±0.78)×10 −6 cm/s, respectively. The quantity of the bidirectional transport of Brucine was determined by ultra-performance liquid chromatography-tandem mass spectrometry. In the absence of verapamil, the transport of Brucine from basolateral compartment to apical compartment (BL–AP) was higher than from AP to BL at low, middle, and high concentrations ( P P in vitro BBB model.
-
Influence of P-glycoprotein on Brucine transport at the in vitro blood-brain barrier.
European journal of pharmacology, 2012Co-Authors: Miao Yan, Ping-fei Fang, Yan-wen LiuAbstract:Brucine is a central agonist that can pass through the blood-brain barrier (BBB). The goal of this study is to examine whether Brucine is one of the substrates of the drug transporter P-glycoprotein (P-gp) and to examine the effects of P-gp on the Brucine transport at the in vitro BBB model. The P-gp ATPase assay was utilized to investigate the in vitro affinity of P-gp to Brucine. Results suggested that K(m) of Brucine (11.4 μmol/l) was smaller than the positive control, verapamil (16.4 μmol/l). In this study, we developed an in vitro BBB model, comprising a co-culture of primary rat brain microvessel endothelial cells and astrocytes for the transport study. The validated model was correct and available. Transendothelial electrical resistance reached (283.78 ± 18.85) Ω cm(2). The model displayed limited permeability to fluorescein sodium and [(125)I]albumin, with the apparent permeability coefficient Papp of (10.36 ± 0.86) × 10(-6) cm/s and (6.00 ± 0.78) × 10(-6)cm/s, respectively. The quantity of the bidirectional transport of Brucine was determined by ultra-performance liquid chromatography-tandem mass spectrometry. In the absence of verapamil, the transport of Brucine from basolateral compartment to apical compartment (BL-AP) was higher than from AP to BL at low, middle, and high concentrations (P
-
Influence of P-glycoprotein on Brucine transport at the in vitro blood–brain barrier
European Journal of Pharmacology, 2012Co-Authors: Miao Yan, Ping-fei Fang, Yan-wen LiuAbstract:Abstract Brucine is a central agonist that can pass through the blood–brain barrier (BBB). The goal of this study is to examine whether Brucine is one of the substrates of the drug transporter P-glycoprotein (P-gp) and to examine the effects of P-gp on the Brucine transport at the in vitro BBB model. The P-gp ATPase assay was utilized to investigate the in vitro affinity of P-gp to Brucine. Results suggested that K m of Brucine (11.4 μmol/l) was smaller than the positive control, verapamil (16.4 μmol/l). In this study, we developed an in vitro BBB model, comprising a co-culture of primary rat brain microvessel endothelial cells and astrocytes for the transport study. The validated model was correct and available. Transendothelial electrical resistance reached (283.78±18.85) Ω cm 2 . The model displayed limited permeability to fluorescein sodium and [ 125 I]albumin, with the apparent permeability coefficient P app of (10.36±0.86)×10 −6 cm/s and (6.00±0.78)×10 −6 cm/s, respectively. The quantity of the bidirectional transport of Brucine was determined by ultra-performance liquid chromatography-tandem mass spectrometry. In the absence of verapamil, the transport of Brucine from basolateral compartment to apical compartment (BL–AP) was higher than from AP to BL at low, middle, and high concentrations ( P P in vitro BBB model.
