Abstract: ObjectiveTo study the influence of water and alcohol extracting process from Herba Leonuri on acute toxicity and the damage degree of toxicity target organs. MethodsUV spectrophotometry was used to measure the content of total alkaloids and the method of acute toxicity was used to compare the difference of acute toxicity between different extracting processes, and recording its toxic symptoms, cumulative mortality and weight change in mice. Seven days after administration, blood was taken and the contents of serum biochemical indicators were detected while the liver and kidney were taken for organ coefficient. ResultsThe contents of total alkaloids in alcohol extracts and water extracts from Herba Leonuri were separately 0.82% and 0.50%. The LD50 of alcohol extracts from Herba Leonuri is 118.68 g·kg-1,which is equal to 276.9 times of 70 kg human daily dried medicinal herb dose. The 95% confidence interval is 112.84~124.89 g·kg-1, which is equal to 263.3~291.4 times of 70 kg human daily dried medicinal herb dose. The MTD of water extracts form Herba Leonuri is 88.0 g·kg-1, which is equal to 205.3 times of 70 kg human daily dried medicinal herb dose. Alcohol extraction and water extraction from Herba Leonuri all could lead to significant increase (P<0.001) of mice's BUN and Cr levels. Kidney coefficient increased significantly, compared with normal control group, the statistical tests showed varying degree difference. Compared with water extract, the BUN and Cr levels in group 1~4 of alcohol extraction increased (P>0.05). Kidney coefficient increased significantly, and the statistical test showed that only group 1 of alcohol extraction had very significant difference. The group 1 and 2 of alcohol extraction and water extraction from Herba Leonuri showed increased ALT and AST. Compared with normal control group, the statistical tests showed the varying degree difference. Group 1 of alcohol extraction could lead to liver coefficient increase which showed very significant difference (P<0.01). Compared with water extract, the ALT level and liver coefficient of group 1 of alcohol extraction showed very significant difference(P<0.01). Liver and kidney pathology showed that there were no obvious pathological changes in liver and kidney tissues of mice. ConclusionAcute toxicity test showed that the toxicity target organs of Herba Leonuri were mainly kidney and liver. It proved that the BUN and Cr levels significantly increased, the ALT and AST levels increased, liver and kidney coefficients increased. The toxicity of kidney was higher than that of liver, and the toxicity of alcohol extract is higher than that of water extract. Combined with assay data of alcohol and water extracts from Herba Leonuri, it is suggested that the toxicity of Herba Leonuri's extracts and total alkaloids content showed a certain correlation, and we need to further explore the correlation of total alkaloids and renal toxicity.

Key words: Herba Leonuri, water extract, alcohol extract, acute toxicity