Effects of lactoferrin on proliferation and expressions of IGF-1/IGF-1R mRNA in rat osteoblasts

Objective To investigate the effects of lactoferrin on the proliferation of rat primary osteoblasts and the IGF-1 / IGF-1R mRNA expression therein. Methods Osteoblasts were separated by multi-enzyme digestion methods from the cranial bones of 6 newborn SD rats cultured. Lactoferrin of the concentrations of 0,0. 1,1,10,100, 1 000 μg / mL was administrated into the culture medium for 1,3,5,7 days. The proliferation of osteoblasts was detected by 3-( 4,5)-dimethylthiahiazo(-z-y1)-3,5-di- phenytetrazoliumromide test( MTT). The mRNA expression of Insulin-like growth factor 1( IGF-1) and Insulin-like growth factor 1 receptor( IGF-1R) were examined by Real timePCR respectively. Results The proliferation rates of the osteoblasts exposed to the lactoferrin of the concentrations of 1, 10,100,1 000 μg / mL for 1,3,5,7 days were all higher than those of the blank control group( P 0. 05),as time goes on,the number of osteoblasts were increased exposed to different concentrations of lactoferrin,the number of osteoblasts got the peak at the 100 μg / mL in the 7th days. The IGF-1 / IGF-1R mRNA expression of the osteoblasts exposed to 10,100,1 000 μg / mL lactoferrin were higher compared with the control group in each time( P 0. 05),The IGF-1 / IGF-1R mRNA expression of the osteoblasts exposed to various concentration of lactoferrin were significantly higher compared with the blank control group in 5,7day( P 0. 01). Conclusion Lactoferrin can increase the proliferation and the IGF-1 / IGF-1R mRNA expression in rat primary osteoblasts. It may be one of the mechanism of lactoferrin prevention and cure of osteoporosis.