The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform
Qiang Meng - One of the best experts on this subject based on the ideXlab platform.
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Yangonin inhibits ethanol induced hepatocyte senescence via mir 194 fxr axis
European Journal of Pharmacology, 2021Co-Authors: Renchao Dong, Changyuan Wang, Xiaohui Wang, Kexin Liu, Huijun Sun, Lu Wang, Kai Huang, Qiang MengAbstract:Abstract Chronic alcohol assumption has been recognized as a major cause of alcoholic liver disease (ALD), which ranges from alcoholic steatohepatitis to fibrosis and hepatocellular carcinoma. Alcoholic liver disease has become the leading cause of liver-related health problem in the world. Herewith, effective therapeutic strategy for alcoholic liver disease is necessary. Yangonin (Yan), a bioactive compound extract from Kava, has been reported to exert hepatoprotective effects via Farnesoid X receptor (FXR) activation. The present study aims to investigate whether Yan ameliorated the ethanol-stimulated liver injury and further to elucidate the mechanisms in vivo and in vitro. Yan improved cell viabilities via cell count kit-8 (CCK-8) methods and obviously reduced aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC) and total triglyceride (TG) levels. We detected miR-194 levels in ethanol-induced LO2 cells and male C57BL/6 mice by quantitative real-time PCR. Also, the effects of miR-194 on modulating cellular senescence via targeting FXR were further verified. The cellular senescence markers p16, p21, telomerase activity and senescence-related β-galactosidase (SA-β-gal) were evaluated by quantitative real-time PCR and Western blot. Also, LO2 cells or liver tissues were stained with special primary antibodies and 4′,6′-Diamidino-2-phenylindole (DAPI). The cell cycle was detected by flow cytometry. We observed that Yan significantly inhibited ethanol-induced cellular senescence via FXR activation (P
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Yangonin inhibits ethanol-induced hepatocyte senescence via miR-194/FXR axis
European journal of pharmacology, 2020Co-Authors: Renchao Dong, Changyuan Wang, Xiaohui Wang, Kexin Liu, Huijun Sun, Lu Wang, Kai Huang, Qiang MengAbstract:Abstract Chronic alcohol assumption has been recognized as a major cause of alcoholic liver disease (ALD), which ranges from alcoholic steatohepatitis to fibrosis and hepatocellular carcinoma. Alcoholic liver disease has become the leading cause of liver-related health problem in the world. Herewith, effective therapeutic strategy for alcoholic liver disease is necessary. Yangonin (Yan), a bioactive compound extract from Kava, has been reported to exert hepatoprotective effects via Farnesoid X receptor (FXR) activation. The present study aims to investigate whether Yan ameliorated the ethanol-stimulated liver injury and further to elucidate the mechanisms in vivo and in vitro. Yan improved cell viabilities via cell count kit-8 (CCK-8) methods and obviously reduced aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC) and total triglyceride (TG) levels. We detected miR-194 levels in ethanol-induced LO2 cells and male C57BL/6 mice by quantitative real-time PCR. Also, the effects of miR-194 on modulating cellular senescence via targeting FXR were further verified. The cellular senescence markers p16, p21, telomerase activity and senescence-related β-galactosidase (SA-β-gal) were evaluated by quantitative real-time PCR and Western blot. Also, LO2 cells or liver tissues were stained with special primary antibodies and 4′,6′-Diamidino-2-phenylindole (DAPI). The cell cycle was detected by flow cytometry. We observed that Yan significantly inhibited ethanol-induced cellular senescence via FXR activation (P
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Hepatoprotection of Yangonin against hepatic fibrosis in mice via farnesoid X receptor activation
International Immunopharmacology, 2019Co-Authors: Xiaohui Wang, Junqiao Wang, Changyuan Wang, Ting Fu, Jingjing Wu, Xiaodong Ma, Qiang MengAbstract:Abstract Hepatic fibrosis is a reversible would-healing response following chronic liver injury of different aetiologies and represents a major worldwide health problem. Up to date, there is no satisfactory drugs treated for liver fibrosis. The present study was to investigate hepatoprotection of Yangonin against liver fibrosis induced by thioacetamide (TAA) in mice and further to clarify the involvement of farnesoid X receptor (FXR) in vivo and in vitro. Yangonin treatment remarkably ameliorated TAA-induced liver injury by reducing relative liver weight, as well as serum ALT and AST activities. Moreover, Yangonin alleviated TAA-induced accumulation of bile acids through increasing the expression of bile acid efflux transporters such as Bsep and Mrp2, and reducing hepatic uptake transporter Ntcp expression, all of these are FXR-target genes. The liver sections stained by H&E indicated that the histopathological change induced by TAA was improved by Yangonin. Masson and Sirius red staining indicated the obvious anti-fibrotic effect of Yangonin. The mechanism of anti-fibrotic effect of Yangonin was that Yangonin reduced collagen content by regulating the genes involved in hepatic fibrosis including COL1-α1 and TIMP-1. Besides, Yangonin inhibited hepatic stellate cell activation by reducing TGF-β1 and α-SMA expression. In addition, Yangonin protected against TAA-induced hepatic inflammation via its inhibition of NF-κB and TNF-α. These hepatoprotective effects of Yangonin were abrogated by guggulsterone which is a FXR antagonist. In vitro experiment further demonstrated dose-dependent activation of FXR by Yangonin using dual-luciferase reporter assay. In summary, Yangonin produces hepatoprotection against TAA-induced liver fibrosis via FXR activation.
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Yangonin protects against estrogen-induced cholestasis in a farnesoid X receptor-dependent manner.
European journal of pharmacology, 2019Co-Authors: Renchao Dong, Junqiao Wang, Changyuan Wang, Xiaoguang Gao, Kexin Liu, Zhihao Liu, Huijun Sun, Qiang MengAbstract:Estrogen-induced cholestasis is a common etiology of hepatic diseases in women with contraceptives administration, pregnancy or hormone replacement therapy. Farnesoid X receptor (FXR) is a member of nuclear receptor super family of ligand-activated transcription factors that is highly expressed in liver. FXR is acknowledged to contribute to the bile acid homeostasis, as well as the pathogenesis and progression of cholestasis. Specific targeting of FXR is an innovative approach for the treatment of cholestasis. The current study aimed to verify the anti-cholestasis effect of Yangonin that is a natural product isolated from Kava via FXR signaling pathway in vivo and in vitro. The analyses of FXR gain- or loss-of-function were performed. Yangonin treatment ameliorates estrogen-induced cholestasis through increasing bile flow and biliary bile acid output. The mechanisms were an induction in the hepatic efflux transporters (Bsep and Mrp2) and an inhibition in hepatic uptake transporter (Ntcp) by Yangonin. Likewise, Yangonin through repressing Cyp7a1, Cyp8b1 and inducing Sult2a1 expression suppressed bile acid synthesis and promoted bile acid metabolism. Furthermore, Yangonin improved estrogen-induced inflammatory cell infiltration and the inflammation gene expression. In vitro experiments further consolidated that Yangonin alleviated estrogen-caused cholestasis via FXR activation. Noteworthily, the effects of Yangonin were enhanced by FXR expression plasmids but abrogated by FXR siRNA. In conclusion, Yangonin alleviates estrogen-induced cholestasis, due to FXR-mediated gene regulation.
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Yangonin protects against non-alcoholic fatty liver disease through farnesoid X receptor.
Phytomedicine : international journal of phytotherapy and phytopharmacology, 2018Co-Authors: Renchao Dong, Changyuan Wang, Kexin Liu, Zhihao Liu, Huijun Sun, Xiaokui Huo, Xiaobo Yang, Qiang MengAbstract:Abstract Backgroud Non-alcoholic fatty liver disease (NAFLD) is currently evolving as the most common liver disease worldwide. Dyslipidemia, pathoglycemia and insulin resistance are the major risk factors for the development of NAFLD. To date, no effective drug therapies for this condition have been approved. Purpose The present study was to investigate the protective effects of Yangonin, a kavalactone isolated from Kava, against NAFLD and further elucidate the mechanisms in vivo and in vitro. Study design A high-fat diet (HFD) induced mouse NAFLD model was used with or without Yangonin treatment. Methods The body weight, relative liver weight and serum biochemical indicators were measured. H&E and Oil Red O staining were used to identify the amelioration of the liver histopathological changes. Serum and hepatic triglyceride, free fatty acids and total cholesterol were analyzed. siRNA, quantitative real-time PCR and Western blot assay were used to clarify the mechanisms underlying Yangonin protection. Results Yangonin had obvious protective effects against NAFLD via farnesoid X receptor (FXR) activation. Through FXR activation, Yangonin attenuated lipid accumulation in the liver via inhibition of hepatic lipogenesis-related protein including sterol regulatory element-binding protein 1c (SREBP-1c), fatty acid synthetase (FAS), acetyl-CoA carboxylase 1 (ACC1) and stearoyl-CoA desaturase 1 (SCD1). Besides, Yangonin promoted lipid metabolism through an induction in genes required for lipoprotein lipolysis and fatty acid β-oxidation. Furthermore, Yangonin modulated blood glucose homeostasis through regulation of gluconeogenesis-related gene phosphoenol pyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), and glycogen synthesis-related gene glycogen synthase kinase 3β (GSK3β) and pyruvate dehydrogenase (PDase). Also, Yangonin increased insulin sensitivity through upregulating phosphorylation of insulin responsive substrate 1, 2 (IRS-1 and IRS-2). Then, in vivo and in vitro evidence further demonstrated the involvement of FXR activation in Yangonin hepatoprotection. Conclusions Yangonin protects against NAFLD due to its activation of FXR signalling to inhibit hepatic lipogenesis and gluconeogenesis, and to promote lipid metabolism and glycogen synthesis, as well as insulin sensitivity.
Markus Ganzera - One of the best experts on this subject based on the ideXlab platform.
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Quantitative Determination of Lactones in Piper methysticum (Kava-Kava) by Supercritical Fluid Chromatography
Planta Medica, 2017Co-Authors: Adele Murauer, Markus GanzeraAbstract:A fast and validated supercritical fluid chromatography method for the quantitative determination of major lactones in Piper methysticum, a plant used against nervous anxiety, stress, and restlessness, was developed. The baseline separation of dihydrokavain, demethoxyYangonin, kavain, Yangonin, dihydromethysticin, and methysticin was possible in less than 4 min on an Aquity UPC2 BEH 1.7 µm column, in combination with a mobile phase comprising CO2 and methanol with diethylamine. The column temperature had a great impact on the results because only at 70 °C could kavain and Yangonin be fully resolved. With correlation coefficients above 0.998, recovery rates between 95.9 and 104.1 % as well as limit of detection values below 1.5 ng on-column, the procedure fulfilled all validation requirements and was well suited for the quantitative analysis of commercial products containing P. methysticum root powder and/or extract. All of them contained the target analytes, however, the absolute content of lactones was quite variable. Accordingly, depending on the product, the total daily intake of lactones varied from 56 to 312 mg. Concerning speed, selectivity, and environmental friendly operation, this supercritical fluid chromatography approach surpasses all previously reported ones.
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Quantitative Determination of Lactones in Piper methysticum (Kava-Kava) by Supercritical Fluid Chromatography
Planta Medica, 2017Co-Authors: Adele Murauer, Markus GanzeraAbstract:A fast and validated supercritical fluid chromatography method for the quantitative determination of major lactones in Piper methysticum, a plant used against nervous anxiety, stress, and restlessness, was developed. The baseline separation of dihydrokavain, demethoxyYangonin, kavain, Yangonin, dihydromethysticin, and methysticin was possible in less than 4 min on an Aquity UPC2 BEH 1.7 µm column, in combination with a mobile phase comprising CO2 and methanol with diethylamine. The column temperature had a great impact on the results because only at 70 °C could kavain and Yangonin be fully resolved. With correlation coefficients above 0.998, recovery rates between 95.9 and 104.1 % as well as limit of detection values below 1.5 ng on-column, the procedure fulfilled all validation requirements and was well suited for the quantitative analysis of commercial products containing P. methysticum root powder and/or extract. All of them contained the target analytes, however, the absolute content of lactones was quite variable. Accordingly, depending on the product, the total daily intake of lactones varied from 56 to 312 mg. Concerning speed, selectivity, and environmental friendly operation, this supercritical fluid chromatography approach surpasses all previously reported ones.
Changyuan Wang - One of the best experts on this subject based on the ideXlab platform.
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Yangonin inhibits ethanol induced hepatocyte senescence via mir 194 fxr axis
European Journal of Pharmacology, 2021Co-Authors: Renchao Dong, Changyuan Wang, Xiaohui Wang, Kexin Liu, Huijun Sun, Lu Wang, Kai Huang, Qiang MengAbstract:Abstract Chronic alcohol assumption has been recognized as a major cause of alcoholic liver disease (ALD), which ranges from alcoholic steatohepatitis to fibrosis and hepatocellular carcinoma. Alcoholic liver disease has become the leading cause of liver-related health problem in the world. Herewith, effective therapeutic strategy for alcoholic liver disease is necessary. Yangonin (Yan), a bioactive compound extract from Kava, has been reported to exert hepatoprotective effects via Farnesoid X receptor (FXR) activation. The present study aims to investigate whether Yan ameliorated the ethanol-stimulated liver injury and further to elucidate the mechanisms in vivo and in vitro. Yan improved cell viabilities via cell count kit-8 (CCK-8) methods and obviously reduced aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC) and total triglyceride (TG) levels. We detected miR-194 levels in ethanol-induced LO2 cells and male C57BL/6 mice by quantitative real-time PCR. Also, the effects of miR-194 on modulating cellular senescence via targeting FXR were further verified. The cellular senescence markers p16, p21, telomerase activity and senescence-related β-galactosidase (SA-β-gal) were evaluated by quantitative real-time PCR and Western blot. Also, LO2 cells or liver tissues were stained with special primary antibodies and 4′,6′-Diamidino-2-phenylindole (DAPI). The cell cycle was detected by flow cytometry. We observed that Yan significantly inhibited ethanol-induced cellular senescence via FXR activation (P
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Yangonin inhibits ethanol-induced hepatocyte senescence via miR-194/FXR axis
European journal of pharmacology, 2020Co-Authors: Renchao Dong, Changyuan Wang, Xiaohui Wang, Kexin Liu, Huijun Sun, Lu Wang, Kai Huang, Qiang MengAbstract:Abstract Chronic alcohol assumption has been recognized as a major cause of alcoholic liver disease (ALD), which ranges from alcoholic steatohepatitis to fibrosis and hepatocellular carcinoma. Alcoholic liver disease has become the leading cause of liver-related health problem in the world. Herewith, effective therapeutic strategy for alcoholic liver disease is necessary. Yangonin (Yan), a bioactive compound extract from Kava, has been reported to exert hepatoprotective effects via Farnesoid X receptor (FXR) activation. The present study aims to investigate whether Yan ameliorated the ethanol-stimulated liver injury and further to elucidate the mechanisms in vivo and in vitro. Yan improved cell viabilities via cell count kit-8 (CCK-8) methods and obviously reduced aspartate aminotransferase (AST), alanine aminotransferase (ALT), total cholesterol (TC) and total triglyceride (TG) levels. We detected miR-194 levels in ethanol-induced LO2 cells and male C57BL/6 mice by quantitative real-time PCR. Also, the effects of miR-194 on modulating cellular senescence via targeting FXR were further verified. The cellular senescence markers p16, p21, telomerase activity and senescence-related β-galactosidase (SA-β-gal) were evaluated by quantitative real-time PCR and Western blot. Also, LO2 cells or liver tissues were stained with special primary antibodies and 4′,6′-Diamidino-2-phenylindole (DAPI). The cell cycle was detected by flow cytometry. We observed that Yan significantly inhibited ethanol-induced cellular senescence via FXR activation (P
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Hepatoprotection of Yangonin against hepatic fibrosis in mice via farnesoid X receptor activation
International Immunopharmacology, 2019Co-Authors: Xiaohui Wang, Junqiao Wang, Changyuan Wang, Ting Fu, Jingjing Wu, Xiaodong Ma, Qiang MengAbstract:Abstract Hepatic fibrosis is a reversible would-healing response following chronic liver injury of different aetiologies and represents a major worldwide health problem. Up to date, there is no satisfactory drugs treated for liver fibrosis. The present study was to investigate hepatoprotection of Yangonin against liver fibrosis induced by thioacetamide (TAA) in mice and further to clarify the involvement of farnesoid X receptor (FXR) in vivo and in vitro. Yangonin treatment remarkably ameliorated TAA-induced liver injury by reducing relative liver weight, as well as serum ALT and AST activities. Moreover, Yangonin alleviated TAA-induced accumulation of bile acids through increasing the expression of bile acid efflux transporters such as Bsep and Mrp2, and reducing hepatic uptake transporter Ntcp expression, all of these are FXR-target genes. The liver sections stained by H&E indicated that the histopathological change induced by TAA was improved by Yangonin. Masson and Sirius red staining indicated the obvious anti-fibrotic effect of Yangonin. The mechanism of anti-fibrotic effect of Yangonin was that Yangonin reduced collagen content by regulating the genes involved in hepatic fibrosis including COL1-α1 and TIMP-1. Besides, Yangonin inhibited hepatic stellate cell activation by reducing TGF-β1 and α-SMA expression. In addition, Yangonin protected against TAA-induced hepatic inflammation via its inhibition of NF-κB and TNF-α. These hepatoprotective effects of Yangonin were abrogated by guggulsterone which is a FXR antagonist. In vitro experiment further demonstrated dose-dependent activation of FXR by Yangonin using dual-luciferase reporter assay. In summary, Yangonin produces hepatoprotection against TAA-induced liver fibrosis via FXR activation.
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Yangonin protects against estrogen-induced cholestasis in a farnesoid X receptor-dependent manner.
European journal of pharmacology, 2019Co-Authors: Renchao Dong, Junqiao Wang, Changyuan Wang, Xiaoguang Gao, Kexin Liu, Zhihao Liu, Huijun Sun, Qiang MengAbstract:Estrogen-induced cholestasis is a common etiology of hepatic diseases in women with contraceptives administration, pregnancy or hormone replacement therapy. Farnesoid X receptor (FXR) is a member of nuclear receptor super family of ligand-activated transcription factors that is highly expressed in liver. FXR is acknowledged to contribute to the bile acid homeostasis, as well as the pathogenesis and progression of cholestasis. Specific targeting of FXR is an innovative approach for the treatment of cholestasis. The current study aimed to verify the anti-cholestasis effect of Yangonin that is a natural product isolated from Kava via FXR signaling pathway in vivo and in vitro. The analyses of FXR gain- or loss-of-function were performed. Yangonin treatment ameliorates estrogen-induced cholestasis through increasing bile flow and biliary bile acid output. The mechanisms were an induction in the hepatic efflux transporters (Bsep and Mrp2) and an inhibition in hepatic uptake transporter (Ntcp) by Yangonin. Likewise, Yangonin through repressing Cyp7a1, Cyp8b1 and inducing Sult2a1 expression suppressed bile acid synthesis and promoted bile acid metabolism. Furthermore, Yangonin improved estrogen-induced inflammatory cell infiltration and the inflammation gene expression. In vitro experiments further consolidated that Yangonin alleviated estrogen-caused cholestasis via FXR activation. Noteworthily, the effects of Yangonin were enhanced by FXR expression plasmids but abrogated by FXR siRNA. In conclusion, Yangonin alleviates estrogen-induced cholestasis, due to FXR-mediated gene regulation.
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Yangonin protects against non-alcoholic fatty liver disease through farnesoid X receptor.
Phytomedicine : international journal of phytotherapy and phytopharmacology, 2018Co-Authors: Renchao Dong, Changyuan Wang, Kexin Liu, Zhihao Liu, Huijun Sun, Xiaokui Huo, Xiaobo Yang, Qiang MengAbstract:Abstract Backgroud Non-alcoholic fatty liver disease (NAFLD) is currently evolving as the most common liver disease worldwide. Dyslipidemia, pathoglycemia and insulin resistance are the major risk factors for the development of NAFLD. To date, no effective drug therapies for this condition have been approved. Purpose The present study was to investigate the protective effects of Yangonin, a kavalactone isolated from Kava, against NAFLD and further elucidate the mechanisms in vivo and in vitro. Study design A high-fat diet (HFD) induced mouse NAFLD model was used with or without Yangonin treatment. Methods The body weight, relative liver weight and serum biochemical indicators were measured. H&E and Oil Red O staining were used to identify the amelioration of the liver histopathological changes. Serum and hepatic triglyceride, free fatty acids and total cholesterol were analyzed. siRNA, quantitative real-time PCR and Western blot assay were used to clarify the mechanisms underlying Yangonin protection. Results Yangonin had obvious protective effects against NAFLD via farnesoid X receptor (FXR) activation. Through FXR activation, Yangonin attenuated lipid accumulation in the liver via inhibition of hepatic lipogenesis-related protein including sterol regulatory element-binding protein 1c (SREBP-1c), fatty acid synthetase (FAS), acetyl-CoA carboxylase 1 (ACC1) and stearoyl-CoA desaturase 1 (SCD1). Besides, Yangonin promoted lipid metabolism through an induction in genes required for lipoprotein lipolysis and fatty acid β-oxidation. Furthermore, Yangonin modulated blood glucose homeostasis through regulation of gluconeogenesis-related gene phosphoenol pyruvate carboxykinase (PEPCK) and glucose-6-phosphatase (G6Pase), and glycogen synthesis-related gene glycogen synthase kinase 3β (GSK3β) and pyruvate dehydrogenase (PDase). Also, Yangonin increased insulin sensitivity through upregulating phosphorylation of insulin responsive substrate 1, 2 (IRS-1 and IRS-2). Then, in vivo and in vitro evidence further demonstrated the involvement of FXR activation in Yangonin hepatoprotection. Conclusions Yangonin protects against NAFLD due to its activation of FXR signalling to inhibit hepatic lipogenesis and gluconeogenesis, and to promote lipid metabolism and glycogen synthesis, as well as insulin sensitivity.
Adele Murauer - One of the best experts on this subject based on the ideXlab platform.
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Quantitative Determination of Lactones in Piper methysticum (Kava-Kava) by Supercritical Fluid Chromatography
Planta Medica, 2017Co-Authors: Adele Murauer, Markus GanzeraAbstract:A fast and validated supercritical fluid chromatography method for the quantitative determination of major lactones in Piper methysticum, a plant used against nervous anxiety, stress, and restlessness, was developed. The baseline separation of dihydrokavain, demethoxyYangonin, kavain, Yangonin, dihydromethysticin, and methysticin was possible in less than 4 min on an Aquity UPC2 BEH 1.7 µm column, in combination with a mobile phase comprising CO2 and methanol with diethylamine. The column temperature had a great impact on the results because only at 70 °C could kavain and Yangonin be fully resolved. With correlation coefficients above 0.998, recovery rates between 95.9 and 104.1 % as well as limit of detection values below 1.5 ng on-column, the procedure fulfilled all validation requirements and was well suited for the quantitative analysis of commercial products containing P. methysticum root powder and/or extract. All of them contained the target analytes, however, the absolute content of lactones was quite variable. Accordingly, depending on the product, the total daily intake of lactones varied from 56 to 312 mg. Concerning speed, selectivity, and environmental friendly operation, this supercritical fluid chromatography approach surpasses all previously reported ones.
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Quantitative Determination of Lactones in Piper methysticum (Kava-Kava) by Supercritical Fluid Chromatography
Planta Medica, 2017Co-Authors: Adele Murauer, Markus GanzeraAbstract:A fast and validated supercritical fluid chromatography method for the quantitative determination of major lactones in Piper methysticum, a plant used against nervous anxiety, stress, and restlessness, was developed. The baseline separation of dihydrokavain, demethoxyYangonin, kavain, Yangonin, dihydromethysticin, and methysticin was possible in less than 4 min on an Aquity UPC2 BEH 1.7 µm column, in combination with a mobile phase comprising CO2 and methanol with diethylamine. The column temperature had a great impact on the results because only at 70 °C could kavain and Yangonin be fully resolved. With correlation coefficients above 0.998, recovery rates between 95.9 and 104.1 % as well as limit of detection values below 1.5 ng on-column, the procedure fulfilled all validation requirements and was well suited for the quantitative analysis of commercial products containing P. methysticum root powder and/or extract. All of them contained the target analytes, however, the absolute content of lactones was quite variable. Accordingly, depending on the product, the total daily intake of lactones varied from 56 to 312 mg. Concerning speed, selectivity, and environmental friendly operation, this supercritical fluid chromatography approach surpasses all previously reported ones.
Wouter H. J. Vaes - One of the best experts on this subject based on the ideXlab platform.
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Determination of kava lactones in food supplements by liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry.
Journal of chromatography. A, 2005Co-Authors: Ivana Bobeldijk, G Boonzaaijer, E J Spies-faber, Wouter H. J. VaesAbstract:Reversed-phase liquid chromatography and detection with atmospheric pressure chemical ionisation tandem mass spectrometry was used for the determination of kava extracts in herbal mixtures. One percent of kava extract can be detected, corresponding to approximately 0.05-0.2 mg/g of the individual kava lactones kavain, dihydrokavain, Yangonin, desmethoxyYangonin, methysticin and dihydromethysticin. Reliable quantification is obtained from concentrations of 0.25-1 mg/g, depending on the compound. At these concentration levels, the relative standard deviations were 10-14%. Validation showed good linearity and recoveries for all the kava lactones with the exception of Yangonin. During method development, degradation of Yangonin was observed. The degradation product was identified by nuclear magnetic resonance (NMR) as cis-Yangonin. The method was applied to the analysis of commercial herbal products available in the Dutch market before and after market restrictions of kava-containing preparations. The results showed that even though 'old' products contained kava extract, the new formulations were negative on kava lactones. cis-Yangonin was also present in the herbal products.
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Determination of kava lactones in food supplements by liquid chromatography–atmospheric pressure chemical ionisation tandem mass spectrometry
Journal of Chromatography A, 2005Co-Authors: Ivana Bobeldijk, G Boonzaaijer, E J Spies-faber, Wouter H. J. VaesAbstract:Reversed-phase liquid chromatography and detection with atmospheric pressure chemical ionisation tandem mass spectrometry was used for the determination of kava extracts in herbal mixtures. One percent of kava extract can be detected, corresponding to approximately 0.05-0.2 mg/g of the individual kava lactones kavain, dihydrokavain, Yangonin, desmethoxyYangonin, methysticin and dihydromethysticin. Reliable quantification is obtained from concentrations of 0.25-1 mg/g, depending on the compound. At these concentration levels, the relative standard deviations were 10-14%. Validation showed good linearity and recoveries for all the kava lactones with the exception of Yangonin. During method development, degradation of Yangonin was observed. The degradation product was identified by nuclear magnetic resonance (NMR) as cis-Yangonin. The method was applied to the analysis of commercial herbal products available in the Dutch market before and after market restrictions of kava-containing preparations. The results showed that even though 'old' products contained kava extract, the new formulations were negative on kava lactones. cis-Yangonin was also present in the herbal products. © 2005 Elsevier B.V. All rights reserved.
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Determination of kava lactones in food supplements by liquid chromatography-atmospheric pressure chemical ionisation tandem mass spectrometry
Journal of Chromatography A, 2005Co-Authors: Ivana Bobeldijk, G Boonzaaijer, E J Spies-faber, Wouter H. J. VaesAbstract:Reversed-phase liquid chromatography and detection with atmospheric pressure chemical ionisation tandem mass spectrometry was used for the determination of kava extracts in herbal mixtures. One percent of kava extract can be detected, corresponding to approximately 0.05-0.2 mg/g of the individual kava lactones kavain, dihydrokavain, Yangonin, desmethoxyYangonin, methysticin and dihydromethysticin. Reliable quantification is obtained from concentrations of 0.25-1 mg/g, depending on the compound. At these concentration levels, the relative standard deviations were 10-14%. Validation showed good linearity and recoveries for all the kava lactones with the exception of Yangonin. During method development, degradation of Yangonin was observed. The degradation product was identified by nuclear magnetic resonance (NMR) as cis-Yangonin. The method was applied to the analysis of commercial herbal products available in the Dutch market before and after market restrictions of kava-containing preparations. The results showed that even though 'old' products contained kava extract, the new formulations were negative on kava lactones. cis-Yangonin was also present in the herbal products. © 2005 Elsevier B.V. All rights reserved.