Effects Of Benefiting-bone Capsule On Notch Signal Pathway In Bone Tissue Of Ovariectomized Rats

Objective: To observe the effects of Benefiting-bone Capsule(BBC) on Notch signal pathway in bone tissue of ovariectomized rats, and study the Notch signaling pathway in the treatment of osteoporosis(OP) process. Methods: 1. 84 female SD rats of 3-month old were randomly divided into OVX group(n=70) and Sham group(n=14). The osteoporotie model was established by ovariectomy. 12 weeks after ovariectomy, when the OP was successfully affirmed by the bone mineral density(BMD). The rats in OVX group was randomly divided into OVX group, Low-dose BBC group(dose 0.71 g/kg?d), Middle-dose BBC group(dose 2.13 g/kg?d), High-dose BBC group(dose 6.39 g/kg?d) and positive group and the number of rat in each group was 14(n=14). 2. The BMD was measured by dual-energy X-ray.The biomechanica experimental detection was used to test the maximum load of femoral and vertebral. Microstructure of bones was observed by Micro CT and hematoxylin-eosin(HE) staining. And the expressions of estrogen(E2), bone gla protein(BGP) and osteoprotegerin(OPG) were obtained by ELISA. 3. Choose the best treated group. The mRNA expression levels of Runx 2, PPARγ, Notch 1 and Notch 2 mRNA were measured by QPCR. The protein of Jagged 2 was measured by Western-blotting. The expression of Jagged 1 protein was measured by Immunohistochemical technique. Results: 1. 12 weeks after ovarieetomy, the BMD of different parts of rats in OVX group was significantly lower than that of in Sham group(P<0.05). 2. After 12 weeks treatment, the BMD of different parts of rats in BBC and positive groups were significantly higher than that in OVX group(P<0.05). The maximum load of femoral, vertebral and the trabecular number, trabecular thickness in treated groups were also increase(P<0.05), while trabecular separation/spacing and trabecular bone pattern fator were decreased(P<0.05). Compared with the OVX group, the expressions of E2, BGP and OPG in treated groups were increased(P<0.05). 3. High dose-BBC at 6.39 g/kg?d had the best treatment effect on OP, which was similar with the sham group(P>0.05). 4. Compared with Sham group, the expressions of PPARγ, Notch 1, Notch 2 and Jagged1, 2 mRNA in OVX group were increased(P<0.05), while the protein of Runx 2 were decreased(P<0.05). Compared with OVX, the expression of Notch 1, Notch 2 and Jagged1, 2 mRNA was decreased(P<0.05), while the protein of Runx 2 were increased(P<0.05) in BBC-H group. Conclusion: 1. BBC has strong therapeutical effect on OP, can improve the BMD and increase the levels of E2, BGP and OPG. BBC also can increase the maximum load of femoral and vertebral, the bone mass, the trabecular number and trabecular thickness, decrease the trabecular separation/spacing and trabecular bone pattern fator. 2. BBC at 6.39 g/kg?d achieved the best treatment effect on OP, which was similar with the sham group. 3. BBC with 6.39 g/kg?d can decrease the expressions of PPARγ, Notch 1, Notch 2 mRNA and the quantity of bone marrow adipocyte. 4. BBC with 6.39 g/kg?d can down-regulating the expression of Jagged1 and Jagged 2 proteins in bone tissue. 5. BBC with 6.39 g/kg?d can interrupt the Notch signaling pathways receptor 1, 2 or ligand Jagged1, 2 thus block the Notch signal pathway, and reduce the the expression of PPARγ mRNA and promote the expression of Runx 2 mRNA in bone tissue to achieve effect for the treatment of OP.