Effect of Angelica sinensis on neural stem cell proliferation in neonatal rats following intrauterine hypoxia

摘要

BACKGROUND: Angelica sinensis is a widely used herb in Chinese traditional medicine. It has been shown to improve hypoxia in embryonic rats and reduce nestin expression in neural stem cells, resulting in proliferation of neural stem cells. OBJECTIVE: To study the protective effect of Angelica on neural stem cell proliferation in neonatal rats after intrauterine hypoxia. DESIGN, TIME AND SETTING: The randomized, controlled, experiment was performed at the Department of Histology and Embryology, Luzhou Medical College, China from July 2007 to January 2008. MATERIALS: Because gestational days 14-15 are a key stage in rat nervous system development, 21 healthy, pregnant Sprague Dawley rats (14 days after conception) were used for this study. Nestin monoclonal primary antibody was obtained from Chemicon, USA. Angelica parenteral solution (250 g/L) was obtained from Pharmaceutical Preparation Section, Second Affiliated Hospital of Wuhan University, China. METHODS: Rats were randomly divided into a control group (n = 5), a hypoxia group (n = 8), and an Angelica group (n = 8). Saline (8 mL/kg) was injected into the caudal vein of rats in the hypoxia group once a day for seven consecutive days. Intrauterine hypotonic hypoxia was induced using 13% O2 for two hours per day on three consecutive days. Rats in the Angelica group received injections of Angelica parenteral solution (250 g/L); all other protocols were the same as the hypoxia group. The control group procedures were identical to the hypoxia group, but under normal, non-hypoxic conditions. After birth, brain tissues were immediately obtained from neonatal rats and prepared for nestin immunohistochemistry. MAIN OUTCOME MEASURES: Nestin-positive cells in hippocampal CA3 area of neonatal rats in each group were quantified using image analysis to detect signal absorbance. RESULTS: The number of nestin-positive cells increased in the hippocampal CA3 area of neonatal rats in the hypoxia group. The number of nestin-positive cells was less in the Angelica group than in the hypoxia group. Integral absorbance of nestin-positive cells in the hippocampal CA3 area of neonatal rats was significantly higher in the hypoxia group, compared with the control group (P < 0.05). The integral absorbance of nestin positive cells was lower in the Angelica group, compared with the hypoxia group (P < 0.05). CONCLUSION: Intrauterine hypoxia, induced for 2 hours daily for three consecutive days, with an oxygen concentration of 13%, stimulated the proliferation of neural stem cells. Angelica injection has a protective effect on neural stem cells from neonatal rats following intrauterine hypoxia by decreasing proliferation of neural stem cells.