RÉSUMÉ
Objective:To study the effect of Bushen Huatan prescription on helper T cell 17 (Th17)/T regulatory cells (Treg) balance of immune T cell subsets in the prevention and treatment of postmenopausal osteoporosis. Method:Sixty 6-month-old female SD rats were randomly divided into sham operation group, model group, estradiol valerate group (0.184 mg·kg<sup>-1</sup>) and Bushen Huatan prescription low, medium and high groups (4.7, 9.4, 18.8 g·kg<sup>-1</sup>) according to the random number table. All the groups except the sham operation group received ovariectomy to make postmenopausal osteoporosis model. Intragastric administration was started 1 week after operation, and the rats in model group and sham operation group received equal volume of normal saline, once a day for 12 weeks. Microcomputed tomography (Micro CT) was then used to detect bone mass and microstructure of rats, the contents of Forkhead box protein (Foxp3) and retinoic acid related nuclear orphan receptor (ROR<italic>γ</italic>t) in serum were detected by enzyme-linked immunosorbent assay (ELISA), the mRNA expression levels of Foxp3 and ROR<italic>γ</italic>t in bone tissues were detected by Real-time fluorescence quantitative polymerase chain reaction (Real-time PCR) and Western blot was used to detect the protein expression of Foxp3 and ROR<italic>γ</italic>t in bone tissues, the number of Th17 and Treg cells in each group was analyzed and compared by flow cytometry. Result:Compared with the sham operation group, the bone mass and trabeculae of the model group decreased (<italic>P</italic><0.01), the bone microstructure was destroyed, the concentration of Foxp3 in serum decreased, the concentration of ROR<italic>γ</italic>t increased (<italic>P</italic><0.01), the mRNA and protein expression levels of Foxp3 in bone tissues decreased, ROR<italic>γ</italic>t increased, the number of Treg cells in bone tissues decreased, number of Th17 cells increased (<italic>P</italic><0.01), and Th17/Treg ratio increased (<italic>P</italic><0.01) in model group. Compared with the model group, the bone mass in each treatment group increased (<italic>P</italic><0.05, <italic>P</italic><0.01), Foxp3 concentration in serum increased, ROR<italic>γ</italic>t concentration decreased (<italic>P</italic><0.01), the mRNA and protein expression levels of Foxp3 in bone tissues increased significantly (<italic>P</italic><0.05, <italic>P</italic><0.01), but no statistical difference was shown in mRNA expression between low dose group and the model group. In addition, the mRNA and protein expression of ROR<italic>γ</italic>t decreased (<italic>P</italic><0.05, <italic>P</italic><0.01), number of Treg cells increased, number of Th17 cells decreased (<italic>P</italic><0.05, <italic>P</italic><0.01), and Th17/Treg ratio decreased in treatment groups (<italic>P</italic><0.01). Conclusion:Bushen Huatan prescription can increase bone mass, improve bone microstructure, increase the number of Treg cells and decrease the number of Th17 cells in ovariectomized rats. It is concluded that Bushen Huatan prescription may play a role in preventing and treating postmenopausal osteoporosis by regulating Th17/Treg balance.
RÉSUMÉ
Objective:To explore the effect of Bushen Huatan prescription on serum lipopolysaccharide (LPS) and Toll-like receptor 4 (TLR4)/ myeloid cell differentiation protein 88 (MyD88)/nuclear transcription factor-<italic>κ</italic>B (NF-<italic>κ</italic>B) signaling pathway in rats with ovariectomy-induced osteoporosis. Method:Sixty SPF 6-month-old female rats were randomly divided into sham operation group, model group, estradiol valerate group and Bushen Huatan prescription low, medium and high dose groups.One week after modeling by bilateral ovariectomy, 8 rats in each group were selected to receive intragastric administration.The estradiol valerate group was given 0.184 mg·kg<sup>-1</sup> by gavage, and Bushen Huatan prescription low, middle and high dose groups were given 4.7, 9.4 and 18.8 g·kg<sup>-1</sup> by gavage, sham operation group and model group were given 0.9% saline 4 mL by gavage respectively.After 12 weeks of intervention, the rats were sacrificed for detection.Serum LPS was detected by enzyme linked immunosorbent assay (ELISA), while protein expressions of TLR4, MyD88 and phosphorylated (p)-NF-<italic>κ</italic>B p65 in bone tissue were detected by Western blot, and the mRNA expressions of TLR4, MyD88, NF-<italic>κ</italic>B p65, IL-1<italic>β</italic>, and IL-6 in bone tissue were detected by quantitative real-time polymerase chain reaction(PCR). Result:Compared with sham operation group, the serum LPS level as well as protein expression of TLR4, MyD88, p-NF-<italic>κ</italic>B p65 and mRNA expression of TLR4, MyD88, NF-<italic>κ</italic>B p65, IL-1<italic>β</italic>, and IL-6 significantly increased in model group(<italic>P</italic><0.05).Compared with the model group, serum LPS level, protein expression of TLR4, MyD88, and p-NF-<italic>κ</italic>B p65, mRNA levels of TLR4, MyD88, and NF-<italic>κ</italic>B p65 in bone tissues as well as downstream inflammatory factors IL-1<italic>β</italic>, IL-6 mRNA expression decreased to different degrees in estradiol valerate group and Bushen Huatan prescription high dose group(<italic>P</italic><0.05). Conclusion:Bushen Huatan prescription can reduce serum LPS content, regulate mRNA and protein expression of TLR4, MyD88, NF-<italic>κ</italic>B p65 and p-NF-<italic>κ</italic>B p65 in TLR4/MyD88/NF-<italic>κ</italic>B pathway, and down-regulate mRNA levels of IL-1<italic>β</italic> and IL-6 in bone tissues to improve bone microstructure and inhibit the development of postmenopausal osteoporosis (PMOP).