柚皮苷对乳鼠成骨细胞增殖及c-fos、c-jun表达的影响

目的研究柚皮苷(naringin)对体外培养的小鼠成骨细胞增殖及c-fos和c-jun表达的影响。方法取第1代BALB/c小鼠颅盖骨成骨细胞,将柚皮苷以0.1、1、10μmol·L-1 3种浓度分别加入新生大鼠颅骨成骨细胞培养液中,MTT法观察各组对成骨细胞的增殖作用并绘制细胞生长曲线,用PNPP法测定成骨细胞内碱性磷酸酶(alkaliphos-phatase,ALP)活性,RT-PCR法检测成骨细胞c-fos和c-jun的转录水平。结果细胞生长曲线显示各组成骨细胞数量均随时间延长而增加,中、高浓度的柚皮苷能提高成骨细胞的ALP活性,促进c-fos mRNA表达(P<0.01),对成骨细胞c-jun mRNA表达增强作用不明显(P>0.05)。结论低浓度柚皮苷(0.1μmol·L-1)对骨更新作用不明显,而中、高浓度的柚皮苷(1、10μmol·L-1)能通过上调c-fos mRNA表达,促进成骨细胞的生成功能,增强骨更新。柚皮苷不是通过促进c-jun表达来促进成骨细胞增殖与分化的。

Effects of naringin on the expression of c-fos and c-jun genes and cell proliferation of rat osteoblasts

Aim To investigate the role of naringin in the differentiation of murine osteoblast,and to observe the expression of c-fos and c-jun in vitro.Methods The newborn BALB/c mice calvarial osteoblasts were cultured in MEM medium containing 10% NCS.naringin was supplemented into the culture medium of osteoblast at 0.1 μmol·L-1,1 μmol·L-1 and 10 μmol·L-1 respectively.MTT was used to observe the proliferation and to draw the growth curve.The osteoblasts alkaline phosphatase activity assays were performed with PNPP method,and mRNA expression levels of c-fos and c-jun were determined by RT-PCR.Results The growth curve showed that the osteoblasts number of each group had increased with time-course.High concentration and middle concentration of naringin significantly increased the alkaliphosphatase activity in osteoblasts in vitro.The mRNA expression levels of c-fos were up-regulated by high concentration and middle concentration of naringin(P<0.01).No enhancing effect of naringin on the gene expression of c-jun in osteoblastic(P>0.05).Conclusions Low dose of naringin(0.1 μmol·L-1)has no significant effect on bone turnover,but high and middle dose of naringin(1 μmol·L-1,10 μmol·L-1)can improve the function of bone formation and promote bone turnover,and elevate osteoblast activity via the up-regulation of the expression levels of c-fos.Naringin can not promote osteoblast proliferation and differentiation by up-regulating the expression of c-jun.