Yukmijihwang-Tang Suppresses Receptor Activator of Nuclear Factor Kappa-B Ligand (RANKL)-Induced Osteoclast Differentiation and Prevents Ovariectomy (OVX)-Mediated Bone Loss

Abstract

Yukmijihwang-tang (YJ) has been used to treat diabetes mellitus, renal disorders, and cognitive impairment in traditional medicine. This study aimed to evaluate the anti-osteoporotic effect of YJ on ovariectomy (OVX)-induced bone loss in a rat and receptor activator of nuclear factor kappa-B ligand (RANKL)-mediated osteoclast differentiation in bone marrow macrophages (BMMs). YJ reduced the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells (MNCs) in an osteoclast/osteoblast co-culture system by regulating the ratio of RANKL/osteoprotegerin (OPG) by osteoblasts. Overall, YJ reduced TRAP-positive cell formation and TRAP activity and F-actin ring formation. Analysis of the underlying mechanisms indicated that YJ inhibited the activation of the nuclear factor of activated T cell cytoplasmic 1 (NFATc1) and c-Fos, resulting in the suppression of osteoclast differentiation-related genes such as TRAP, ATPase, H+ transporting, lysosomal 38 kDa, V0 subunit d2, osteoclast-associated receptor, osteoclast-stimulatory transmembrane protein, dendritic cell-specific transmembrane protein, matrix metalloproteinase-9, cathepsin K, and calcitonin receptor. YJ also inhibited the nuclear translocation of NFATc1. Additionally, YJ markedly inhibited RANKL-induced phosphorylation of signaling pathways activated in the early stages of osteoclast differentiation including the p38, JNK, ERK, and NF-κB. Consistent with these in vitro results, the YJ-administered group showed considerably attenuated bone loss in the OVX-mediated rat model. These results provide promising evidence for the potential novel therapeutic application of YJ for bone diseases such as osteoporosis.

Mechanisms by which kidney-tonifying Chinese herbs inhibit osteoclastogenesis: Emphasis on immune cells

“…Rehmanniae Radix Praeparata is the main nourish kidney-yin component of the Yukmijihwang-Tang, which inhibited RANKL-induced OC differentiation, resorption and fusion and OC differentiation in the coculture system of bone marrow cells (BMCs) and OBs and BMMs and downregulated OC-related genes, which may be related to the inhibition of the p38, JNK, ERK, and NF-κB signalling pathways. Han and Kim, (2021) ; Shim et al (2011) Moreover, the study found that it upregulated the expression of the immune-related gene IRF1 in the JAK/STAT pathway in PMOP patients with kidney yin deficiency. Chen et al (2017) However, its mechanism has not been explored with regard to immune cells.…”

“…(Rehmanniae Radix Praeparata). Zhou and Tang, (2016) Chinese formulae ( Han and Kim 2021 ), botanical drugs ( Liu et al 2017 ), and natural products ( Wang et al 2018b ) used to tonify the kidney have been proven to regulate OCs and OBs and improve bone structure and function to prevent and treat immune-mediated bone diseases with high clinical effectiveness and safety. Kidney-tonifying Chinese herbs have a direct regulatory effect on OCs, but in recent years, based on the close relationship between OCs and the immune system, research into kidney-tonifying herbs controlling OCs via the immune system has gained attention.…”