AIM: To investigate the protective effect of extraction A of polygonatum odoratum (EA-PAOA) on the immune hepatic injury in mice and study its protective mechanisms. METHODS: ①The experiment was carried out in the immunological laboratory of Jinzhou Medical College from June to October 2004. Fifty Kunming mice (common grade) were selected and randomized into five groups with ten mice in each group: normal control group, model control group, test 1 (EA-PAOA 0.5 g/Kg) group, test 2 (EA-PAOA 1 g/Kg) group and test 3 (EA-PAOA 2 g/Kg) group. ②The EA-PAOA was extracted from dry root and petiol with water-ethanol method (30 mL/L ethanol). ③Saline was injected into abdominal cavity of mice in the normal control group and the model control group. Mice in the test 1, test 2 and test 3 groups were given with the corresponding EA-PAOA through intraperitoneal injection, respectively, once 0.5 mL into every mice, 3 times per day, for 4 days. Eight hours after the last injection, the mice in the model control and three test groups, respectively, received intravenous injections of concanavalin A (20 mg/kg) 0.5 mL, except these in the normal control group were injected with saline. Then the immune liver injury mice were prepared. ④Blood gained from the picked eyeball were collected at eight hours after intravenous injections of concanavalin A, and then kept in hypothermia. The liver was reserved for routine light microscopy so as to observe the pathological changes of liver tissue (hematoxylin-eosin staining). The spleen was aimed to do lymphocyte proliferation experiment and T-cell proliferactive activity tests with MTT. The level of alanine aminotransferase was tested with Kit made from Nanjing Jiancheng Bioengineering Institute. ⑤The analysis of variance was applied to the compare of computation data.RESULTS: Totally 50 Kumming mice were involved in the result analysis. ①Pathological change of liver tissue: Obvious immune hepatic injury appeared in the mice of the model control group. However, the three test groups had improved in different extent dramatically as compared with the model control group.
②Effect of EA-PAOA on serum ALT: The level of serum ALT in the model control group was higher significantly than that in the normal control group (t=13.8, P < 0.01). The level of serum ALT in the three test groups was lower than that in the model control group, and had most significant difference between the test 3 group and the model control group, especially (t=5.62,P < 0.01), and existed dose-dependent relation. ③Effect of EA-PAOA on conversion and proliferation of T-lymphocytes: The concanavalin A stimulated the lienal lymphocytes of every group cultured in vitro. The stimulate-index was higher in the model control group than that in the normal control group dramatically (t=9.02,P < 0.01). It was lower markedly in the three test groups than that in the model control group (t=6.99-11.06,P < 0.01), and had dose-dependent relation. ④Effect of EA-PAOA on T-cell of lienal tissue: The number of CD4+ T and CD8+ T lymphocytes in spleen and the proportion were insignificant (P > 0.05). CONCLUSION: ①The EA-PAOA can inhibit the liver injury and improve the liver microcirculation. ②The EA-PAOA can obviously inhibit T-cell proliferactive activity and dose-dependent relation. One of anti-liver injury mechanisms is that the EA-PAOA can obviously inhibit T-cell proliferactive activity to decrease the level of cell factor, and then all the effects lead to inhibit the injury by the multiplation of T-cell. ③In the early stage, the liver injury is only due to lots of immunocytes collecting in liver and its secretion and destroyed function increased dramatically, but the number does not increase markedly.