Effects of active ingredients in three kidney-tonifying Chinese herbal drugs on gene expression profile of bone marrow stromal cells from a rat model of corticosterone-induced osteoporosis

Objective: To observe the effects of icariin, psoralen and oleanolic acid, the three active ingredients of Yinyanghuo (Herba Epimedii Brevicornus), Buguzhi (Fructus Psoraleae) and Nuzhenzi (Fructus Ligustri Lucidi), respectively, on gene expression profile of bone marrow stromal cells (BMSCs) from rats with corticosterone-induced osteoporosis. Methods: Fifty Sprague-Dawley rats were randomly divided into normal control group, untreated group, icariin group, psoralen group and oleanolic acid group (the last three groups are called treatment groups). Rats in untreated group and treatment groups were subcutaneously injected with corticosterone once a day for 14 d while rats in normal control group were injected isodose of olive oil. Rats in the treatment groups were intragastrically administered with icarrin, or psoralen, or oleanolic acid at 20 mg/(kg·d), respectively, 5 d prior to modeling for 19 d. The body weight of rats was recorded on the 1st, 4th, 7th, 11th, and 14th day after modeling, respectively. All rats were sacrificed and the fourth lumbar vertebrae were harvested for micro-CT scanning to evaluate bone mass. BMSCs were obtained ex vivo by the methods of bone marrow adherent culture. The mRNAs of BMSCs were detected by using gene chip technique on the 7th day of culture. Results: There was no significant difference in body weight of rats between untreated group and treatment groups. Micro-CT showed no significant difference in lumbar vertebral morphometry between the untreated and the normal control, or the untreated and treatment groups. In microarray, icariin, psoralen and oleanolic acid changed expressions of 11, 12 and 15 genes compared to the normal level, respectively. These three active ingredients all acted on 5 genes involving osteoblast differentiation, cell cycle regulation, cell metabolism and Notch signal pathway. Conclusion: Traditional Chinese herbal drugs with the effect of tonifying the kidney may promote BMSCs to differentiate into osteoblasts by regulating BMSCs cycles and cell metabolism, and show therapeutic effect on osteoporosis. However, the exact mechanisms need to be further studied.