| Objective To study the dynamic intervention of Liuwei Dihuang Decoction on the expression of p38, ERK1/2 phosphorylated protein and mRNA in the femoral MAPK signal pathway of PMOP model rats and its mechanism. Methods Pregnant female SD rats (SPF grade) aged from 6 months to 8 months were randomly divided into 5 groups after numbering and weighing. Except the blank group, all the other groups were made by ovariectomy. The drug was administered continuously for 90 days from the 5th day after the model was established. Bone mineral density (BMD) of femur of rats in each group was measured by dual-energy X-ray absorptiometry at 30 days, 60 days and 90 days after operation. Western Blot was used to detect the expression of p-p38 and p-ERK1/2 in femur of rats in each group. Real-time fluorescence quantitative PCR( RT-qPCR) was used to detect the expression of p38 and ERK1/2 mRNA in femur of rats in each group. Results Compared with the blank group, the femoral bone mineral density in the model group decreased at 60 days and 90 days (P<0.05). Compared with the model group, Liu（jiu）can up-regulate the expression of p-p38, p-ERK1/2 and ERK1/2 mRNA in the femur of the model rats on the 30th, 60th and 90th day after PMOP (P<0.05, P<0.01) and the expression of p38 mRNA in the femur of the model rats on the 60th and 90th day after PMOP (P<0.01). However, Liu（sheng）could only regulate the expression of p-p38, p-ERK1/2 and mRNA in the femur of 90 days after operation (P<0.05, P<0.01) and the expression of p-ERK1/2 in the femur of 30 days and 60 days after operation (P< 0.05). Conclusion Liu（jiu）and Liu（sheng） can both interfere with postmenopausal osteoporosis, and its mechanism may be related to the fact that the decoction can regulate p38 and ERK1/2 proteins in MAPK pathway, make them undergo protein phosphorylation modification, activate osteogenesis-related factors, increase BMD and improve PMOP. Among them, the intervention of Liu (jiu) began in the early and middle stages of menopause. |