Mechanism Of Rhizoma Drynariae On Postmenopausal Osteoporosis Based On Intestinal Flora

Objective:The model of postmenopausal osteoporosis(PMOP)was established by resecting the bilateral ovaries of rats.To observe the relationship between the expression level of Wnt/β-catenin related proteins in bone tissue of PMOP rats and the changes of intestinal flora structure and diversity in feces under the intervention of Drynariae.Methods:Eighteen SPF female SD rats were randomly divided into OVX group,SHAM group and OVXDF group,with 6 rats in each group.After 1 week of adaptive feeding,PMOP model was constructed in OVX group and OVXDF group,and the fat around the ovary was removed in SHAM group.After modeling,OVXDF group was given Drynariae decoction once a day,and the other two groups were given the same amount of normal saline.The dosage was adjusted every 2 weeks according to the body weight of rats.After12 weeks,abdominal aorta blood was collected under general anesthesia,and the contents of PINP and NTX-I in serum samples were detected by ELISA after centrifugation;Bilateral femurs of rats were separated,and the right femur was scanned by Micro-CT tomography to obtain the data of Tb.N,Tb.Th and Tb;The expressions of Wnt3 a,β-catenin and Runx2-related proteins in left femur were detected by Western-Blot;The community structure and diversity of intestinal flora in rats were determined by 16S rRNA amplicon sequencing.Result:1.Serum PINP and NTX-I contents in each groupCompared with SHAM group,PINP and NTX-I in OVX group were significantly different(P < 0.01).Compared with OVX group,PINP and NTX-I in OVXDF group were statistically different(P < 0.05)and(P < 0.01)respectively.2.Structural changes of bone trabeculae in each groupThe changes of Tb.N,Tb.Th and Tb.Sp in SHAM and OVX groups were statistically different(P < 0.01),and the same to OVX and OVXDF groups(P < 0.01).3.Expression of bone histamin in each groupThere were significant differences in Wnt3 a,β-catenin and RUNX2 in SHAM and OVX groups(P < 0.01),and the same to OVX and OVXDF groups(P < 0.01).4.Analysis of flora diversity index of each groupCompared with SHAM group,the changes of Chao1,Faith-pd and Shannon indexes in OVX group were statistically different(P < 0.05,P < 0.05,P < 0.01);Compared with OVX group,the changes of Chao1,Faith-pd and Shannon indexes in OVXDF group were statistically different(P < 0.05,P < 0.05,P < 0.01).5.Analysis of Phylum level composition structure of each groupThere were statistical differences in Firmicutes and Verrucomicrobia in SHAM and OVX groups,OVX and OVXDF groups(P < 0.01),but no statistical differences in Bacteroidetes(P > 0.05);6.Analysis of Genus level composition structure of each groupThere were significant differences between SHAM and OVX groups and OVX and OVXDF groups in the changes of Turicibacter and Akkermansia mucophilus(P < 0.01);There were no significant changes in Lactobacillus in SHAM and OVX groups(P > 0.05),but there were significant changes in OVX and OVXDF groups(P < 0.05).Conclusion:Drynariae can promote osteogenic function and inhibit osteoclast function in PMOP model rats,improve bone quality to a certain extent,relieve the damage of bone microstructure,and increase the expression of Wnt3 a,β-catenin and RUNX2 proteins to reduce bone loss.In addition,it can also increase the abundance and diversity of intestinal flora in PMOP model rats,regulate the proportion and number of beneficial flora,and play a role in improving bone health.Based on these results,it is speculated that Drynariae may reduce bone loss in PMOP model rats by regulating Wnt/β-catenin signaling pathway through improving intestinal flora composition.