Zoledronic Acid and Post-Menopausal Osteoporosis

A recently published article in Experimental Biology and Medicine (Volume 246, Issue 15, August 2021) examines the effects of zoledronic acid in post-menopausal osteoporosis. The study, led by Dr. Jian Liao, Professor of Prosthodontics and Implant at the Hospital of Stomatology of Guizhou Medical University in Guizhou (China), reports that zoledronic acid reverses mandible (jawbone) loss in an animal model of post-menopausal osteoporosis.   
Osteoporosis occurs when the body loses or does not make enough bone, resulting in weak bones that are more susceptible to fracture. Osteoporosis can also compromise the effectiveness of procedures that require bone growth such as dental implants. Postmenopausal women have the greatest risk of developing osteoporosis because menopause decreases the production of estrogen, a hormone that protects against excessive bone loss. Zoledronic acid inhibits bone resorption and is an effective treatment for osteoporosis. Nonetheless, the effects of zoledronic acid on bones involved in dental implant procedures and bone cells have not been fully elucidated. 
In this study, Yu-Ting Cheng and colleagues examined the effects of zoledronic acid on bone cells in an animal model of osteoporosis, ovariectomized rats that do not produce estrogen.  Ovariectomy resulted in loss of bone mass in the mandible or jawbone. Bone loss was accompanied by increased activation of RANKL-NF-κB signaling in osteoclasts, cells responsible for bone resorption. Treatment with a single low dose of zoledronic acid counteracted loss of bone mass as well as osteoclast activation and enhanced RANKL-NF-κB signaling. Dr. Liao said, “In post-menopausal osteoporosis, due to the lack of estrogen, formation and activation of osteoclasts are enhanced, thus enhancing bone resorption and resulting in the loss of bone mass. Our study suggests that low-dose zoledronic acid may inhibit mandibular resorption by inhibiting the NF-κB signal pathway. We are currently examining the specific site of action, phosphorylation events, and downstream effector molecules for zoledronic acid.”
Dr. Steven R. Goodman, Editor-in-Chief of Experimental Biology & Medicine, said, “Zoledronic acid effectively promotes the process of bone formation around implanted teeth while inhibiting bone resorption. Liao et al used an ovariectomized rat model to study the mechanism of estrogen deficiency caused mandibular bone loss observed in post-menopausal women while determining the mode of action of zoledronic acid. They find that bone mass loss is due to enhancing apoptosis of osteoblasts and inhibiting apoptosis of osteoclasts. They further demonstrate that, in osteoclasts, this is based upon activation of RANKL-NF-kB signaling. They demonstrate that zoledronic acid modulates osteoclast apoptosis through activation of the nuclear factor kappa-B signaling pathway in this rat model. Their findings support the use of zoledronic acid in the success of dental implants.”
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Source: Experimental Biology and Medicine