骨碎补总黄酮对去卵巢大鼠下颌骨显微结构及最大载荷的影响

Effects of drynaria total flavonoids on trabecular microstructure and maximum strength of mandible in ovariectomy rat model

目的应用Micro-CT和骨生物力学技术,探讨骨碎补总黄酮对去卵巢大鼠的下颌骨显微结构及最大载荷的影响。方法40只3月龄雌性SD大鼠,随机分为5组:假手术组(sham operation group,Sham)、去卵巢模型组(ovariectomized group,OVX)、骨碎补总黄酮高剂量组(high-dose drynaria total flavonoids group,GB-H)、骨碎补总黄酮低剂量组(low-dose drynaria total flavonoids group,GB-L)和戊酸雌二醇组(Estradiol Valerate group,EV),建模成功后连续给药12 w。实验结束后,取下颌骨进行显微CT扫描及三维重建,然后进行最大载荷测量。结果与Sham组相比,OVX组大鼠下颌骨微结构:骨密度、相对骨体积、骨小梁厚度、骨小梁数目明显减小(P<0.05),骨表面积体积比、骨小梁间隙明显增高(P<0.05);下颌骨的最大载荷明显减少(P<0.05)。与OVX组相比,EV组大鼠下颌骨微结构获得良好修复,最大载荷也明显修复。骨碎补总黄酮低剂量组相对骨体积、骨小梁数目较OVX组显著升高(P<0.05),骨小梁间隙显著减小(P<0.05)。骨碎补总黄酮高剂量组疗效优于低剂量组,大鼠下颌骨的相对骨体积、骨表面积体积比、骨小梁间隙、骨小梁数目以及下颌骨骨密度均得到一定程度修复,下颌骨最大载荷也较OVX组显著增加(P<0.05)。结论骨碎补总黄酮能够修复去卵巢大鼠下颌骨微结构,提高下颌骨骨密度和最大载荷,这将可能为颌骨骨质疏松的防治提供一种新的途径。

Objective To investigate the effects of drynaria total flavonoids on trabecular microstructure and maximum strength of mandible in a rat model of bone loss induced by ovariectomy and to compare the effects of drynaria total flavonoids and Estradiol Valerate. Methods 40 three-month-old female Sprague-Dawley rats were randomly divided into 5 groups（ n = 8 each group） ：sham operation group（ Sham）,ovariectomized group（ OVX）,low-dose drynaria total flavonoids group（ GB-L）,high-dose drynaria total flavonoids group（ GB-H） and Estradiol Valerate group（ EV）. After the model was successfully established,the rats were intragastric administrated medicine continuously for twelve weeks. The mandible was analyzed by micro-CT and the biomechanics values of maximum stress were tested by the three point bending test. Results Micro-CT data showed that bone volume/total volume（ BV/TV）,trabecular thickness（ Tb. Th）,trabecular number（ Tb. N） and trabecular bone mineral density（ BMD） in the OVX group were significantly lower than those in the Sham group（ P〈0. 05）,whereas the trabecular separation （ Tb. Sp） and bone surface/bone volume ratio（ BS/BV） were significantly greater in the OVX group than those for the Sham group（ P〈0. 05）. Maximum strength decreased significantly in the OVX group（ P〈0. 05）. Compared with the OVX group,the microCT data showed that trabecular microstructure was well repaired in the EV group,with maximum strength significantly improved（ P〈0. 05）. BV/TV and Tb. N in GB-L group were significantly higher than that in OVX group（ P〈0. 05）,and Tb. Sp was significantly lower than that in OVX group（ P〈0. 05）. GB-H group was significantly superior to GB-L group. In the GB-H group,the maximum strength was significantly improved,and several of the Micro-CT parameters（ BV/TV,BS/BV,Tb. Sp,Tb. N and BMD） were well repaired（ P〈0. 05）. Conclusion Drynaria total flavonoids could greatly improve the trabecular microstructure as well as the maximum strength of mandible in a rat model of osteoporosis induced by ovariectomy and may be an effective way to prevent mandible osteoporosis.