[Effects of yigu capsule containing serum on the osteoblast differentiation and the expressions of osteoprotegerin and bone morphogenetic protein 2 after treatment by advanced glycation end products in vitro].

OBJECTIVE

To observe the effects of Yigu Capsule (YGC) containing serum on the differentiation and the expressions of osteoprotegerin (OPG) and bone morphogenetic protein 2 (BMP-2) in osteoblasts after treatment by advanced glycation end products (AGEs), and to explore the mechanisms of YGC for treating osteoporosis (OP).

METHODS

Forty 10-month-old female Sprague Dawley (SD) rats were randomly divided into four groups equally, i.e., the low dose YGC group, the moderate dose YGC group, the high dose YGC group, and the blank control group. The YGC containing serum and the control serum were prepared with the method of gastric perfusion. Primary osteoblasts of newborn SD rats was extracted and cultured, then they were passaged and divided into five groups, i. e., the vehicle control group, the model group, the low dose YGC group, the moderate dose YGC group, and the high dose YGC group. The model group was treated by AGEs (400 mg/L), the three YGC groups were treated by AGEs (400 mg/L) and YGC containing serum at different concentrations. Alkaline phosphatase (ALP) activity, type I collagen (ColI), bone gla protein (BGP), and mineralization of osteoblasts were tested using pNPP, ELISA, and Alizarin dyeing. The mRNA and protein levels of BMP-2 and OPG were respectively determined using RT-PCR and ELISA.

RESULTS

Primary osteoblasts from newborn SD rats could be used well in this experiment. Compared with the vehicle control group, the ALP, ColI, BGP, the mRNA and protein levels of BMP-2 and OPG of osteoblasts decreased in the model group, and the mineralized nodes were reduced, showing statistical difference (P<0.01). Compared with the model group, the ALP, ColI, BGP, the mRNA and protein levels of BMP-2 and OPG of osteoblasts increased in the three YGC groups, and the mineralized nodes increased in a dose-dependent manner, showing statistical difference (P<0.05, P<0.01).

CONCLUSIONS

YGC containing serum could promote the differentiation and mineralization of osteoblasts, and improve the expressions of OPG and BMP-2 after treatment by AGEs. These might be one of YGC's mechanisms for treating OP.