Genotoxicity study of Ortex Eucommiae decoction
HU Yan-ping,WANG Xin,SONG Jie,ZHANG Min,WANG Xiu-wen,LI Bo(National Center for Safety Evaluation of Drugs,National Institute for the Control of Pharmaceutical and Biological Products,Beijing,100176 P.R.China)
OBJECTIVE To investigate genotoxicity of Ortex eucommiae decoction using mouse lymphoma assay(MLA) and mouse bone marrow micronucleus test(MNT).METHODS In MLA,four dose levels of 2.5,5,10,20 mg(crude drug)·mL-1 was exposed with L5178Y cells for 3 hours with and without metabolic activation,then expressed for 2 days.The mutation frequency plates were prepared and incubated for 12 days.Colony size in each plate was scored,and the total mutation frequency and the percentage of small colony mutants were calculated and analyzed.In MNT,different doses(12.8,25.6,51.2 g·kg-1)were administered to three groups.The mice were adminstrated every 24 hours by oral gavage twice and sacrificed after 24 hours of the last administration and both femur bones were collected to prepare the smear.For each mouse,the number of micronucleated polychromatic erythrocytes(MNPCE) in 2000 polychromatic erythrocytes was counted,and the mean rate of MNPCE of each group was calculated.RESULTS In MLA,the results indicated that the total mutation frequency of dose levels showed a dose-dependent increase and there was statistical significant(P0.05) compared with negative control with or without metabolic activation;the percentage of small colony mutants was similar with positive control without metabolic activation,and there was a dose-dependent increase with metabolic activation.In MNT,the results indicated the decoction did not show inhibitory effect for bone marrow,and the rate of MNPCE of each group induced did not show significantly increase compared with negative control.CONCLUSION Ortex Eucommiae decoction induced tk gene mutation and chromosome damage in L5178Y cells with and without metabolic activation,suggesting that the test article may have potential genotoxicity for human bodies.Ortex Eucommiae decoction did not show chromosome damage of bone marrow cells in ICR mice,and it had not genotoxicity in vivo with metabolic activation in our experiment.
【CateGory Index】： R285
【CateGory Index】： R285