ABSTRACT
BACKGROUND: Migu tablet, a Chinese drug for kidney invigorating, is effective on preventing and treating osteoporosis, but the concrete mechanism of pharmacology is still not clear. Transforming growth factor-β1(TGF-β1) is an important cytokine, which can regulate bone resorption and formation.OBJECTIVE: To investigate the effect of kidney invigorating recipe on mRNA expression of TGF-β1 of osteoblast.DESIGN: A completely randomized controlled study was conducted.SETTING: Department of Traumatic Orthopedics, Union Hospital Affiliated to Tongji Medical College of Huazhong University of Science and Technology.MATERIALS: This experiment was conducted at the laboratory for bone metabolism of integration of Chinese and western medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology from May 2003 to April 2004. Experimental rats: Totally 16 newborn SD rats of clean degree were involved. Experimental drug: Medical liquor of Migu tablet was prepared in the Department of Traumatic Orthopedics,Union Hospital Affiliated to Tongji Medical College, Huazhong University of Science and Technology. The subscription was mainly composed of Chinese herbs such as Herba Epimedii, Cortex Eucommiae, Semen Juglandis,Radix Rehmanniae, Radix Achyranthis Bidentatae. and so on. Positive control drug: which was recombinant basic fibroblastic growth factor (rbFGF), was purchased from Beijing Banding Company. Negative control group was subdivided into negative control of probe and antibody METHODS: 100,1 000,5 000,10 000 mg/L Chinese herb Migu tablet liquor for kidney invigorating and positive control drug 5 μg/L rbFGF were added into the osteoblasts of cranial bones of newly born SD rats separated and cultured in vitro. 24 hours later, nuclear acid molecular in situ hybridization of osteoblasts were analyzed by self-made digoxin-labeled TGF-β1 cDNA probe . The mean absorbance of positive particles representing the mRNA expression of TGF-β1. A total of 40 osteoblasts were randomly chosen from each group under 200-fold amplification. The average absorbance of hybridized particles of the cells was measured with TJTY-300 automatic image analyzer.MAIN OUTCOME MEASURES: mRNA expression of TGF-β1 in osteoblasts of each group.RESULTS: Automatic image analyzer showed that the TGF-β1 mRNA expressions of Migu liquor groups whose concentration were 5 000 mg/L and 10 000 mg/L were respectively 1.18 times and 1.30 times that of control group, with a significant difference. [The mean absorbance's of hybridized particles of the cells in the 5 000,10 000 mg/L Migu liquor groups and negative control were 0.213 67±0.015 00,0.237 03±0.021 73,0.181 27±0.015 28 ,respectively, P ＜ 0.05 and P ＜ 0.01].Although the mean absorbance ( 0.254 45±0.020 81)of the hybridized particles of the cells in the 5 μg/L recombinant rbFGF was higher than those of 5 000,10 000 mg/L Migu liquor groups, but there was no significant difference(P ＞ 0.05).CONCLUSION: Migu tablet for kidney invigorating can stimulate the secretion and synthesis of TGF-β1 in osteoblasts, thus promote bone formation and inhibit bone resorption.