Influence of ginsenoside on expression of brain-derived neurotrophic factor and receptor tyrosine kinase B in the medial septum of aged rats

Liang Zeng; Haihua Zhao; Yongli Lü; Wenbo Dai

摘要：BACKGROUND: It has been shown that ginsenoside, the effective component of ginseng, can enhance expression of choline acetyl transferase, as well as brain-derived neurotrophic factor (BDNF) and its receptor tyrosine kinase B (TrkB), in cholinergic neurons of the basal forebrain.OBJECTIVE: To qualitatively and quantitatively verify the influence of ginsenoside on expression of BDNF and its receptor, TrkB, in the medial septum of aged rats, and to provide a molecular basis for clinical application.DESIGN, TIME AND SETTING: A contrast study, which was performed in the Department of Anatomy, China Medical University, and the Department of Anatomy, Shenyang Medical College between December 2005 and May 2007.MATERIALS: Thirty-five, healthy, female, Sprague Dawley rats were selected for this study. Ginsenoside (81% purity) was provided by Jilin Ji'an Wantai Chinese Medicine Factory; anti-BDNF antibody, anti-TrkB antibody, and their kits were provided by Wuhan Boster Company.METHODS: A total of 35 rats were divided into three groups: young (four months old), aging (26 months old), and ginsenoside. Rats in the ginsenoside group were administered ginsenoside (25mg/kg/d) between 17 months and 26 months.MAIN OUTCOME MEASURES: Immunohistochemistry and in situ hybridization were used to measure expression of BDNF and TrkB in the medial septum of aged rats, and the detected results were expressed as gray values.RESULTS: ①Qualitative detection: using microscopy, degenerative neurons were visible in the medial septum in the aging group. However, neuronal morphology in the ginsenoside group was similar to neurons in the young group.②Quantitative detection: the mean gray value of BDNF-positive and TrkB-positive products in the aging group were significantly higher than in the young group (t=3.346,4.169, P<0.01); however, the mean gray value in the ginsenoside group was significantly lower than in the aging group (t=2.432,2.651, P<0.01).CONCLUSION: Ginsenoside can increase expression of BDNF and TrkB in the medial septum and delay the natural degeneration in aged rats.