ABSTRACT
Objective:To study the protective effect of alendronate combined with Lactobacillus rhamnosus on bone loss in ovariectomized mice.Methods:Fifty female C57BL/6 mice were divided into 5 equal groups ( n=10). Ovariotomy was performed in groups A, B, C and D while a sham operation was performed in group E. Group A was subjected to combined administration of alendronate and Lactobacillus rhamnosus, group B to administration of alendronate, group C to administration of Lactobacillus rhamnosus, and groups D and E to administration of physiological saline only. At 3 months after operation, all the mice were sacrificed to harvest their femurs. Micro CT scanning was performed to detect the bone mineral density (BMD), trabecular relative volume, bone surface area/bone volume, and trabecular thickness and number of trabecular bone. Three-point bending test was used to detect the maximum load, stiffness, ultimate load, Young＇s modulus, and fracture energy. Osteocalcin and alkaline phosphatase levels were measured using blood samples from the mice eyeballs. The 2 groups were compared in terms of all the above indexes. Results:The BMD [(669.87±67.87) mg/cm 3], maximum load [(14.35±0.75) N] and fracture energy [(1,497.43±38.29) J/m 2] in group A were significantly higher than those in group B [(520.07±9.01) mg/cm 3, (11.94±0.82) N and(1,277.61±35.12) J/m 2] and group C [(388.15±25.61) mg/cm 3, (11.10±0.93) N and (1,115.27±63.24) J/m 2] (all P<0.05). The osteocalcin level in group A [(22.25±1.78) ng/mL] was significantly higher than that in group B [(19.08±1.45) ng/mL] and group D [(19.33±1.66) ng/mL] (both P<0.05). The alkaline phosphatase level in group A [(83.21±9.69) ng/mL] was significantly lower than that in group C [(113.16±14.44) ng/mL] and group D [(137.96±14.01) g/mL] (both P<0.05). Conclusion:Alendronate combined with Lactobacillus rhamnosus may play a synergistic role in prevention of bone loss in ovariectomized mice, because combined administration of the two is more effective than administration of either of the two.