ABSTRACT
BACKGROUND: Neuroscience and brain science researches have paid attention to the effect of astragalus membranaceus in the treatment of neurologic impairment disease and neural regeneration. Studying astragalus membranaceus effects on neural stem cells are becoming a new research direction. OBJECTIVE: To explore the effects of astragalus injection on biological viability of rat neural stem cells. METHODS: Neural stem cells of Wistar rats were separated and cultured. Immunofluorescence staining was applied to identify the neural stem cells. The purified cells were gained by the second subcultivation in vitro, and then the cells were randomly divided into control group and astragalus injection groups with various concentrations (50, 200, 400 g/L) to culture for 6, 12 and 24 hours. The activity of cells was tested by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay, and then the immunohistochemistry was applied to detect the expressions of neuron-specific enolase and glial fibril ary acidic protein in the 50 g/L astragalus injection group after induced for 7 days. RESULTS AND CONCLUSION: The viability of neural stem cells increased significantly after intervention with different concentrations of astragalus injection for 6 hours as compared with the control group (P 0.05). Compared with the control group, the cells in the 50 g/L astragalus group differentiated rapidly, and the number of positive cells for neuron-specific enolase was increased significantly (P < 0.05). The neural stem cells proliferation was hastened, and its differentiation was promoted by the interference of astragalus injection.
ABSTRACT
BACKGROUND: When central nervous system is injured, re-expression of nestin protein may enhance the anti-injury ability of cells and be advantageous to the repair of focus of injury.OBJECTIVE: To explore the reaction of nerve stem cell (NSC) in permanent brain ischemia through NSC migration and the change of nestin protein expression.DESIGN: A randomized and controlled verification research with experimental animals as subjects.SETTING: Anatomy teaching and research offices in a training school and a university.MATERIALS: The experiment was done in the Teaching and Research Office of Humane Anatomy in Medical College of Xi'an Jiaotong University from October 1999 to January 2001. Totally 75 healthy SD rats were selected and randomly divided into normal control group, experiment group and sham-operation group. Twenty-five animals were in each group. Heads of animals were cut and brain was got out at the 1st, 3rd, 7th, 14th and 28thdays after operation, 5 animals at each time.METHODS: The model was rats with permanent cerebral ischemia. Immunohistochemical dyeing methods were used to observe NSC migration,change of marker of NSC and nestin protein at the 1st, 3rd, 7th, 14th and 28th day after cerebral ischemia.MAIN OUTCOME MEASURES: ①Results of immunohostochemicaldyeing. ②Migration length of nestin+ cells in anterior subentricular zone (SZa) region of brain tissue at normal status and at different time points after cerebral ischemia. ③Number variation of nestin+ cells at different timepoits after ischemia near the ischemic region.RESULTS: Through nestin immunohistochemical dyeing, it was found that NSC in normal brain tissue mainly existed in subependymal zone (SEZ)region. NSC of SEZ migrated in the direction of ischemic region along ventri- corpus callosum after ischemia. Among them, it reached the farthest at the 7th day after ischemia. More nestin+ cells appeared near ischemic region at the 1st day, and then reduced little by little 3 days later.CONCLUSION: NSC has certain reactive ability to ischemic brain injury.Expression of nestin protein near ischemic region may be a kind of protection to injury.
ABSTRACT
Objective To study the factors affecting the accumulation of hydrolysable tannins in cultured mycelia of Inonotus obliquus. Methods Taking dry weight of mycelia and hydrolysable tannin content as index, different carbon and nitrogen sources, pH levels, and metal ions were evaluated for the accumulation of hydrolysable tannins in the submerged culture of I. obliquus. Results The optimal carbon and nitrogen sources were glucose and peptone. Optimal initial pH value was 5.5. The accumulation of hydrolysable tannins was greatly enhanced in the medium with the presence of Cu2+ at 0.8 mmol/L, Co2+ and Zn2+ at 1.6 mmol/L, Mn2+ at 1 mmol/L, and NH4+ at 4 mmol/L when compared to the control. Conclusion The accumulation of hydrolysable tannins is maximized in the medium containing glucose and peptone with pH value at 5.5. Supplementation of Cu2+, Co2+, Zn2+, and Mn2+ into the medium is an effective method for further increasing the accumulation of hydrolysable tannins in cultured mycelia of I. obliquus.