This study was conducted to observe the genotoxic effects of aqueous, methanol, hexane and dichloromethane extracts of “belacan” (shrimp paste) taken from three local districts in Melaka, Malaysia (Kelemak, Batang T...This study was conducted to observe the genotoxic effects of aqueous, methanol, hexane and dichloromethane extracts of “belacan” (shrimp paste) taken from three local districts in Melaka, Malaysia (Kelemak, Batang Tiga & Pantai Puteri). The umu test which was used as the screening test was conducted with and without the presence of metabolic activation system. Without the presence of metabolic activation system, aqueous extracts from Kelemak showed mutagenicity activity at 5 mg/ml with IR (Induction Rate) = 1.52 ± 0.57 and the methanol extracts showed mutagenic activities at 0.625 mg/ml and 5 mg/ml, which the IR was the highest at 5 mg/ml (2.08 ± 0.09). On the other hand, samples from Batang Tiga, Melaka showed mutagenic effects at all five concentrations for the dichloromethane extract, with IR = 2.09 ± 0.64 as the highest value at 1.25 mg/ml. Methanol extracts also showed positive results at 1.25 mg/ml and 2.5 mg/ml with IR = 1.70 ± 0.33 and IR = 2.12 ± 0.51 respectively, and aqueous extract at 0.625 mg/ml with IR = 1.54 ± 0.48 and 5 mg/ml with IR = 1.74 ± 0.50. There was a significant difference of the mean values of IR between the four different types of “belacan” extracts from Batang Tiga (p < 0.05). All four “belacan” extracts from Pantai Puteri, Melaka did not show any mutagenic effect. With the presence of metabolic activation system, there was no mutagenic effect observed in all four extracts from the three districts. Further study to analyze the contents in the food samples should be done in the future to determine the possible contents in the food samples that might be responsible for the mutagenic activities.展开更多
Objective To investgate the metabolism of terephthalic acid （TPA） in rats and its mechanism. Methods Metabolism was evaluated by incubating sodium terephthalate （NaTPA） with rat normal liver microsomes, or with mi...Objective To investgate the metabolism of terephthalic acid （TPA） in rats and its mechanism. Methods Metabolism was evaluated by incubating sodium terephthalate （NaTPA） with rat normal liver microsomes, or with microsomes pretreated by phenobarbital sodium, or with 3-methycholanthrene, or with diet control following a NADPH-generating system. The determination was performed by high performance liquid chromatography （HPLC）, and the mutagenic activation was analyzed by umu tester strain Salmonella typhimurium NM2009. Expression of CYP4B 1 mRNA was detected by RT-PCR. Results The amount of NaTPA （12.5-200 μmol-L^1） detected by HPLC did not decrease in microsomes induced by NADPH-generating system. Incubation of TPA （0.025-0.1 mmol-L^-1） with induced or noninduced liver microsomes in an NM2009 umu response system did not show any mutagenic activation. TPA exposure increased the expression of CYP4B1 mRNA in rat liver, kidney, and bladder. Contusion Lack of metabolism of TPA in liver and negative genotoxic data from NM2009 study are consistent with other previous short-term tests, suggesting that the carcinogenesis in TPA feeding animals is not directly interfered with TPA itself and/or its metabolites.展开更多
Advanced water treatment is commonly used to remove micropollutants such as pesticides,endocrine disrupting chemicals,and disinfection byproducts in modem drinking water treatment plants.However,little attention has b...Advanced water treatment is commonly used to remove micropollutants such as pesticides,endocrine disrupting chemicals,and disinfection byproducts in modem drinking water treatment plants.However,little attention has been paid to the changes in the genotoxicity of substances remaining in the water following the different water treatment processes.In this study,samples were collected from three drinking water treatment plants with different treatment processes.The treated water from each process was analyzed and compared for genotoxicity and the formation of organic compounds.The genotoxicity was evaluated by an umu test,and the acute and chronic toxicity was analyzed through Ecological Structure-Activity Relationship(ECOSAR).The results of the umu test indicated that biological activated carbon reduced the genotoxicity by 38%,77%,and 46%in the three drinking water treatment plants,respectively,while chlorination increased the genotoxicity.Gas chromatograph-mass spectrometry analysis revealed that halogenated hydrocarbons and aromatic compounds were major contributors to genotoxicity.The results of ECOSAR were not consistent with those of the umu test.Therefore,we conclude that genotoxicity cannot be determined using ECOSAR.展开更多
文摘This study was conducted to observe the genotoxic effects of aqueous, methanol, hexane and dichloromethane extracts of “belacan” (shrimp paste) taken from three local districts in Melaka, Malaysia (Kelemak, Batang Tiga & Pantai Puteri). The umu test which was used as the screening test was conducted with and without the presence of metabolic activation system. Without the presence of metabolic activation system, aqueous extracts from Kelemak showed mutagenicity activity at 5 mg/ml with IR (Induction Rate) = 1.52 ± 0.57 and the methanol extracts showed mutagenic activities at 0.625 mg/ml and 5 mg/ml, which the IR was the highest at 5 mg/ml (2.08 ± 0.09). On the other hand, samples from Batang Tiga, Melaka showed mutagenic effects at all five concentrations for the dichloromethane extract, with IR = 2.09 ± 0.64 as the highest value at 1.25 mg/ml. Methanol extracts also showed positive results at 1.25 mg/ml and 2.5 mg/ml with IR = 1.70 ± 0.33 and IR = 2.12 ± 0.51 respectively, and aqueous extract at 0.625 mg/ml with IR = 1.54 ± 0.48 and 5 mg/ml with IR = 1.74 ± 0.50. There was a significant difference of the mean values of IR between the four different types of “belacan” extracts from Batang Tiga (p < 0.05). All four “belacan” extracts from Pantai Puteri, Melaka did not show any mutagenic effect. With the presence of metabolic activation system, there was no mutagenic effect observed in all four extracts from the three districts. Further study to analyze the contents in the food samples should be done in the future to determine the possible contents in the food samples that might be responsible for the mutagenic activities.
基金This work was supported by the National Natural Science Foundation of China (No. 30170798), the Preliminary Study of an ImportantProject in the National Basic Research, MOST (No. 2001CCA04900) and the Greatest Project in the National Basic Research (No.2002CB512908).
文摘Objective To investgate the metabolism of terephthalic acid （TPA） in rats and its mechanism. Methods Metabolism was evaluated by incubating sodium terephthalate （NaTPA） with rat normal liver microsomes, or with microsomes pretreated by phenobarbital sodium, or with 3-methycholanthrene, or with diet control following a NADPH-generating system. The determination was performed by high performance liquid chromatography （HPLC）, and the mutagenic activation was analyzed by umu tester strain Salmonella typhimurium NM2009. Expression of CYP4B 1 mRNA was detected by RT-PCR. Results The amount of NaTPA （12.5-200 μmol-L^1） detected by HPLC did not decrease in microsomes induced by NADPH-generating system. Incubation of TPA （0.025-0.1 mmol-L^-1） with induced or noninduced liver microsomes in an NM2009 umu response system did not show any mutagenic activation. TPA exposure increased the expression of CYP4B1 mRNA in rat liver, kidney, and bladder. Contusion Lack of metabolism of TPA in liver and negative genotoxic data from NM2009 study are consistent with other previous short-term tests, suggesting that the carcinogenesis in TPA feeding animals is not directly interfered with TPA itself and/or its metabolites.
基金This study was supported by the National Natural Science Foundation of China(Grant Nos.51778323,51761125013 and 51290284)the National Science and Technology Major Project of China(Grant Nos.2012ZX07404-002,2017ZX07108-003 and 2017ZX07502003).
文摘Advanced water treatment is commonly used to remove micropollutants such as pesticides,endocrine disrupting chemicals,and disinfection byproducts in modem drinking water treatment plants.However,little attention has been paid to the changes in the genotoxicity of substances remaining in the water following the different water treatment processes.In this study,samples were collected from three drinking water treatment plants with different treatment processes.The treated water from each process was analyzed and compared for genotoxicity and the formation of organic compounds.The genotoxicity was evaluated by an umu test,and the acute and chronic toxicity was analyzed through Ecological Structure-Activity Relationship(ECOSAR).The results of the umu test indicated that biological activated carbon reduced the genotoxicity by 38%,77%,and 46%in the three drinking water treatment plants,respectively,while chlorination increased the genotoxicity.Gas chromatograph-mass spectrometry analysis revealed that halogenated hydrocarbons and aromatic compounds were major contributors to genotoxicity.The results of ECOSAR were not consistent with those of the umu test.Therefore,we conclude that genotoxicity cannot be determined using ECOSAR.
