Zhuanggu Zhitong Capsule alleviates postmenopausal osteoporosis in ovariectomized rats by regulating autophagy through AMPK/mTOR signaling pathway

Zhitao Men; Chengjun Huang; Min Xu; Jiangtao Ma; Lei Wan; Jiachun Huang; Yanping Lin; Jiayao Yuan; Hong Huang; Hongxing Huang

doi:10.21037/atm-22-3724

Zhuanggu Zhitong Capsule alleviates postmenopausal osteoporosis in ovariectomized rats by regulating autophagy through AMPK/mTOR signaling pathway

Ann Transl Med. 2022 Aug;10(16):900. doi: 10.21037/atm-22-3724.

Authors

Zhitao Men^{1

2}, Chengjun Huang², Min Xu², Jiangtao Ma³, Lei Wan⁴, Jiachun Huang¹, Yanping Lin¹, Jiayao Yuan¹, Hong Huang⁴, Hongxing Huang⁴

Affiliations

¹ The Third Clinical Medical College of Guangzhou University of Chinese Medicine, Guangzhou, China.
² Department of Spinal Orthopedics, Liuzhou Traditional Chinese Medical Hospital, Liuzhou, China.
³ Department of department of Knee Joint, Luoyang Orthopedic-Traumatological Hospital, Luoyang, China.
⁴ Department of Osteoporosis, The Third Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China.

Abstract

Background: Postmenopausal osteoporosis (PMOP) is the most common primary osteoporosis, which is prone to fractures and affect the health and quality of life of the elderly and even shorten their lifetime. Traditional Chinese medicine can not only effectively improve osteoporosis and reduce fracture rate, but also have tonifying and analgesic effects. The purpose of this study was to investigate the effects of Zhuanggu Zhitong (ZGZT) Capsule on autophagy related genes and proteins in PMOP rats, so as to elucidate the molecular mechanism of tonifying deficiency and regulating stasis in the treatment of osteoporosis and analgesia.

Methods: The PMOP rat model was established by bilateral oophorectomy, and then the rats were randomly divided into control group, PMOP group, PMOP + ZGZT group and PMOP + E₂ group. The changes of mechanical pain threshold of rats were detected by von Frey filaments, and the changes of mechanical pain threshold of rats in each group were compared. Computed tomography (CT) and dual-energy X-ray were used to measure the bone mineral density of lumbar bone tissue. Enzyme-linked immunosorbent assay (ELISA) and tartrate-resistant acid phosphatase (TRAP) staining were used to detect inflammatory factors and bone metabolism related indicators. Hematoxylin-eosin (HE) staining was used to observe the tissue morphology of lumbar vertebra tissue. Western blot (WB) and quantitative polymerase chain reaction (qPCR) were used to detect AMPK/mTOR pathway- and autophagy-related factor expression.

Results: ZGZT can effectively restore the bone mineral density (BMD) of PMOP rats, improve the microstructure of lumbar vertebra of PMOP rats, restore the balance of bone metabolism, promote the expression of AMPK and autophagy related factors, inhibit the expression of mTOR and the release of inflammatory factors, and increase the mechanical pain threshold of PMOP rats, so as to effectively improve osteoporosis and relieving osteoporosis pain in PMOP rats.

Conclusions: ZGZT affects autophagy by regulating AMPK/mTOR pathway, restores the homeostasis of bone metabolism and inhibits the release of inflammatory factors. Moreover, the regulation of feedback pathways between bone metabolism and inflammatory factors finally plays the role of "bone strengthening" and "pain relieving". ZGZT may be a new treatment for PMOP and relieving osteoporotic pain.

Keywords: Adenosine 5’-monophosphate-activated protein kinase (AMPK); autophagy; inflammatory factor; mammalian target of rapamycin (mTOR); postmenopausal osteoporosis (PMOP).