Abstract: BACKGROUND: The therapeutic effect of Jintiange capsule on primary osteoporosis has been confirmed by clinical research evidence and recommended by clinical application guidelines, but its effects and targets against secondary osteoporosis remain unclear.
OBJECTIVE: To explore the therapeutic target and mechanism of Jintiange capsule in the treatment of secondary osteoporosis.
METHODS: Twenty-four female Sprague-Dawley rats were randomly divided into four groups (n=6 per group): blank group (with no treatment), model group, Jintiange capsule group, and positive control group. Animal models of osteoporosis were prepared in the latter three groups by intragastric administration of retinoic acid. Fourteen days after modeling, the model group was intragastrically given normal saline, while the Jintiange capsule and positive control groups were given Jintiange capsule and alendronate sodium, respectively, for 14 days. After treatment, the femurs were taken for micro-CT scanning and tandem mass tags quantitative proteomics. Bioinformatics was used to analyze the function, signal pathway and protein interaction of the differential proteins and to screen the core proteins.
RESULTS AND CONCLUSION: Compared with the blank group, bone volume fraction, trabecular thickness and trabecular number of the femur were significantly decreased (P < 0.05) and trabecular separation was significantly increased (P < 0.05) in the model group. Compared with the model group, bone volume fraction, trabecular thickness and trabecular number of the femur were increased (P < 0.05) and trabecular separation was decreased (P < 0.05) in the positive control and Jintiange capsule groups. A total of 2 749 differential proteins were screened between the model group and the blank group, involved in multiple biological processes such as ATP metabolism, hypoxia response, and cellular iron homeostasis as well as signal pathways such as ferroptosis, hypoxia-inducible factor 1 signal pathway, and fatty acid metabolism. A total of 773 differential proteins were screened between Jintiange capsule group and model group, involved in biological processes such as ossification, hydrogen peroxide biosynthesis, and hypoxia reaction as well as signal pathways such as hypoxia-inducible factor 1 signal pathway, fatty acid metabolism, and oxidative phosphorylation. A total of 453 targets of Jintiange capsule for treating osteoporosis were identified, including 49 primary core proteins, such as transferrin, ribosomal protein S14, and ribosomal protein S21, and 15 secondary core proteins, such as ribosomal protein S6, ribosomal protein S20, and ribosomal protein S2. These findings indicate that Jintiange capsule may negatively regulate ferroptosis by down-regulating long chain lipoacyl-CoA synthase 1, arachidonic acid-15- lipooxygenase, transferrin, and CREB binding protein to inhibit lipid peroxidation and iron accumulation, thereby modifying osteopenia and trabecular bone microstructure damage in osteoporotic rats.

Key words: Jintiange capsule, osteoporosis, proteomics, retinoic acid, ferroptosis