| Objective To investigate the effect of thermal moxibustion on PI3K/AKT/mTOR signaling pathway in osteoporosis (OP) mice and osteoclasts. Methods Female KM mice were randomly divided into the sham operation group, model group (bilateral ovariectomy), estrogen group (0.2055 mg/kg estradiol valerate orally), moxibustion group (moxibustion at the Shenshu acupoint, dividing into thermal moxibustion group and non-thermal moxibustion group based on the tail temperature change of the mice). After 8 weeks of intervention, the femoral bone mineral density (BMD) of mice was measured with dual energy X-ray absorptiometry. RAW264.7 cells were induced by RANKL in vitro and divided into blank serum group, model serum group, estrogen serum group, thermal moxibustion serum group, and non-thermal moxibustion serum group, which were additioned with 10% serum of corresponding mice, respectively. After 6 days of intervention, osteoclast differentiation was detected with TRAP staining. MMP-9, CTSK, as well as p-PI3K, p-AKT, and p-mTOR expressions were detected with real-time fluorescent quantitative PCR (qPCR) and Western blotting in each cell group. Results Compared to those in the sham operation group, BMD in the model group decreased significantly (P<0.05), while BMD in the estrogen group, thermal moxibustion group, and non-thermal moxibustion group significantly increased. The increase degree of femoral BMD in the thermal moxibustion group was lower than that in the estrogen group, and higher than that in the non-thermal moxibustion group (P<0.05). After 6 days of serum intervention, compared to those in the blank serum group, the expression levels of CTSK, MMP-9, p-PI3K, p-AKT, and p-mTOR in osteoclasts from the model serum group were up-regulated, and the number of osteoclasts increased significantly (P<0.05). The above indexes in estrogen serum group, thermal moxibustion serum group and non-thermal moxibustion serum group were significantly reversed. The number of osteoclasts in the thermal moxibustion serum group was higher than that in the estrogen serum group, and lower than that in the non-thermal moxibustion serum group (P<0.05). Conclusion Thermal moxibustion inhibits osteoclast differentiation by regulating the PI3K/AKT/mTOR signaling pathway in osteoclasts. |