Radix Paeoniae Rubra stimulates osteoclast differentiation by activation of the NF-κB and mitogen-activated protein kinase pathways

The mechanism of action of paeoniae radix rubra-angelicae sinensis radix drug pair in the treatment of rheumatoid arthritis through PI3K/AKT/NF-κB signaling pathway

Objective: To investigate the effects and mechanisms of Paeoniae radix rubra-Angelicae sinensis radix (P-A) drug pair in the treatment of rheumatoid arthritis (RA). Methods: Mass spectrometry was employed to accurately characterize the main components of the P-A drug pair. Network pharmacology was used to analyze the main components and pathways of the P-A drug pair in the treatment of RA, and Discovery Studio software was used to molecularly dock the key proteins on the pathway with their corresponding compounds. The levels of serum TNF-a, IL-1β, and IL-6 were measured by enzyme linked immunosorbent assay (ELISA). The histopathology of the ankle joint was observed by hematoxylin-eosin (HE) staining, and the positive expression of p-PI3K, p-IKK, p-NF-κB, and p-AKT in the synovial tissue of the ankle joint was detected by immunohistochemical analysis. Finally, the expression of PI3K, IKK, and AKT and their phosphorylation levels were determined by western blot in each group of rats. Results: Network pharmacology combined with molecular docking analysis revealed that the pharmacodynamic mechanism of the P-A drug pair for the treatment of RA may be related to the contents of caffeic acid, quercetin, paeoniflorin, and baicalein in the regulation of the expression of the PI3K/AKT/NF-κB signaling pathway and the targets of PIK3CA, PIK3R1, AKT1, HSP90AA1 and IKBKB in the pathway. Compared with the model group, the P-A drug pair significantly improved the pathological changes of the synovial tissue and reduced feet swelling in RA model rats. Moreover, it regulated the levels of TNF-α, IL-1β, and IL-6 in serum (p < 0.05). The results of the immunohistochemical analysis and western blot showed that the expression of PI3K, IKK, NF-κB, and AKT decreased after phosphorylation in the synovial tissue (p < 0.05). Conclusion: The P-A drug pair exhibited an inhibitory effect on the hyperactivation of the PI3K/AKT/NF-κB signaling pathway in the synovial membrane of RA rats. The mechanism may be related to the downregulation of the phosphorylation levels PI3K, IKK, NF-κB, and AKT, which in turn decreased inflammatory cell infiltration and synovial membrane proliferation.

Clinical evidence construction of East Asian herbal medicine for inflammatory pain in rheumatoid arthritis based on integrative data mining approach

BACKGROUND

Rheumatoid arthritis (RA) is a chronic inflammatory disease that leads to a significant social burden. East Asian herbal medicine (EAHM) has long been used to treat RA. Therefore, a systematic study of how EAHM treatments can be developed into new drugs using specific materials is needed.

METHODS

Eleven databases containing literature in English, Korean, Chinese, and Japanese were searched for randomized controlled trials comparing EAHM with conventional medicine (CM). A meta-analysis was performed on the variable data to assess their effects on inflammatory pain. Subsequently, we searched for core materials and combinations of core material-based data mining methods.

RESULTS

A total of 186 trials involving 19,716 patients with RA met the inclusion criteria. According to the meta-analysis, EAHM had a significantly superior effect on continuous pain intensity, tender joint count, and response rate. Patients treated with EAHM had a significantly reduced incidence of adverse events compared with those treated with CM. Based on additional analysis of the EAHM formula data included in this meta-analysis, 21 core materials and five core herbal combinations were identified.

CONCLUSION

EAHM remedies for RA have the adequate potential for use as candidate materials for treating inflammatory pain in RA. The candidate core herbs evaluated in this study act on multiple pathways and are expected to provide pain relief, sustained inflammation suppression, immune regulation, and prevention of joint destruction. It seems worthwhile to conduct follow-up research on drug development using the core materials derived from this review.

Huangjia Ruangan Granule Inhibits Inflammation in a Rat Model with Liver Fibrosis by Regulating TNF/MAPK and NF-κB Signaling Pathways

The Huangjia Ruangan granule (HJRG) is a clinically effective Kampo formula, which has a significant effect on liver fibrosis and early liver cirrhosis. However, the mechanism underlying HJRG in treating liver fibrosis remains unclear. In this study, carbon tetrachloride (CCl₄) was used to induce liver fibrosis in rats to clarify the effect of HJRG on liver fibrosis and its mechanism. Using network pharmacology, the potential mechanism of HJRG was initially explored, and a variety of analyses were performed to verify this mechanism. In the liver fibrosis model, treatment with HJRG can maintain the liver morphology, lower the levels of AST and ALT in the serum, and ameliorate pathological damage. Histopathological examinations revealed that the liver structure was significantly improved and fibrotic changes were alleviated. It can effectively inhibit collagen deposition and the expression of α-SMA, reduce the levels of the rat serum (HA, LN, PC III, and Col IV), and inhibit the expression of desmin, vimentin, and HYP content in the liver. Analyzing the results of network pharmacology, the oxidative stress, inflammation, and the related pathways (primarily the TNF signaling pathway) were identified as the potential mechanism of HJRG against liver fibrosis. Experiments confirmed that HJRG can significantly increase the content of superoxide dismutase and glutathione and reduce the levels of malondialdehyde and myeloperoxidase in the rat liver; in addition, HJRG significantly inhibited the content of proinflammatory cytokines (TNF-α, IL-1β, and IL-6) and reduced the expression of inflammatory regulators (Cox2 and iNOS). Meanwhile, treatment with HJRG inhibited the phosphorylation of NF-κB P65, IκBα, ERK, JNK, and MAPK P38. Moreover, HJRG treatment reversed the increased expression of TNFR1. The Huangjia Ruangan granule can effectively inhibit liver fibrosis through antioxidation, suppressing liver inflammation by regulating the TNF/MAPK and NF-κB signaling pathways, thereby preventing the effect of liver fibrosis.

Albiflorin Alleviates Ox-LDL-Induced Human Umbilical Vein Endothelial Cell Injury through IRAK1/TAK1 Pathway

Introduction

Atherosclerosis (AS) is a chronic inflammatory disease characterized by lipid metabolism disorder and vascular endothelial damage. Albiflorin (AF) has been certified to be effective in the therapy of certain inflammatory diseases, while the therapeutic effect and mechanism of AF on AS have not been fully elucidated. Material and Methods. Model cells for AS were created by inducing oxidized low-density lipoprotein (Ox-LDL) in human umbilical vein endothelial cells (HUVECs). After processing with AF and interleukin-1 receptor-associated kinase 1- (IRAK1-) overexpressed plasmid, cell viability was assessed by CCK-8; cholesterol efflux was tested using liquid scintillation counter; IL-6 and TNF-α levels were determined with ELISA kits; ROS and apoptosis were confirmed using Flow cytometry. Besides, IRAK1-TAK1 pathway and apoptosis- and mitochondrial fusion-related proteins were monitored with western blotting analysis.

Results

Our results verified that AF could not only dramatically accelerate viability and cholesterol efflux but also attenuate inflammation, ROS production, and apoptosis in Ox-LDL-induced HUVECs. Meanwhile, AF could prominently prevent the activation of IRAK1-TAK1 pathway, downregulate apoptosis-related proteins, and upregulate mitochondrial fusion-related proteins in Ox-LDL-induced HUVECs. Moreover, we testified that IRAK1 overexpression memorably could reverse suppression of AF on inflammation, apoptosis, and IRAK1-TAK1 pathway and enhancement of AF on viability, cholesterol efflux, and mitochondrial fusion in Ox-LDL-induced HUVECs.

Conclusions

By blocking the IRAK1/TAK1 pathway, AF can significantly slow the course of AS, suggesting that it could be a viable therapeutic option for AS.

A Probe into the Intervention Mechanism of Yiqi Huayu Jiedu Decoction on TLR4/NLRP3 Signal Pathway in Lipopolysaccharide-Induced Acute Respiratory Distress Syndrome (ARDS) Rats

Background

This study discusses the anti-inflammatory mechanism of Yiqi Huayu Jiedu decoction (YQHYJD) and studies the intervening effect of YQHYJD on the inflammatory cytokines in acute respiratory distress syndrome (ARDS) rats by inhibiting the TLR4/NLRP3 signal pathway. The aim of the probe is to provide evidence to support the identification of therapeutic targets in Chinese medicine treatment, which broadens the alternatives for the treatment of ARDS.

Method

A lipopolysaccharide (LPS)-induced ARDS model group is established on rats by tail vein injection. A medicine group is established on ARDS rats by prophylactic administration using YQHYJD. Materials are collected, and tests are conducted according to experimental processes.

Result

The rats in the medicine group gained weight compared with those in the ARDS model group. Pathological sections from the medicine group indicated improved condition in terms of pulmonary and interstitial edema in the lung tissues of rats compared with that from the ARDS model group. The percentage of neutrophil of the medicine group was significantly brought down compared with that of the ARDS model group (P < 0.001). Enzyme-linked immunosorbent assay (ELISA) was used to detect the changes in the level of inflammatory cytokines. It was observed that the levels of IL-1β and IL-18 in serum of the medicine group significantly decreased (P < 0.001 and P < 0.01), the contents of TLR4 and NLRP3 in bronchoalveolar lavage fluid (BALF) of the medicine group decreased, and the contents of TLR4 and NLRP3 in lung tissue homogenate of the medicine group significantly decreased (P < 0.05, P < 0.001, P < 0.01, and P < 0.05). In further mass spectrum identification of the proteins from the same animal groups, it was observed that the expressions of inflammatory proteins TNFRSF1, LBP, and NOS2 of the medicine group were reduced. The differences were statistically significant.

Conclusions

The pharmacological action of YQHYJD's anti-inflammatory mechanism is closely associated with the regulation of inflammatory cytokines TLR4, NLRP3, IL-1β, IL-18, TNFRSF1, LBP, and NOS2 on the TLR4/NLRP3 signal pathway.

To explore the Radix Paeoniae Rubra-Flos Carthami herb pair's potential mechanism in the treatment of ischemic stroke by network pharmacology and molecular docking technology

To explore the Radix Paeoniae Rubra-Flos Carthami herb pair's (RPR-FC) potential mechanism in treating ischemic stroke (IS) by network pharmacology and molecular docking technology.The Traditional Chinese Medicine Systems Pharmacology Database was used to screen the active components of the RPR-FC, and Cytoscape 3.8 software was used to construct a network map of its active components and targets of action. The GeneCards and OMIM databases were used to identify disease targets of IS, and the common targets were chosen as research targets and imported into the STRING database to construct a protein-protein interaction network map of these targets. R language software was used to analyze the enrichment of GO terms and KEGG pathways, and explore the mechanisms of these targets. Molecular docking technology was used to verify that the RPR-FC components had a good bonding activity with their potential targets.A total of 44 active components, which corresponded to 197 targets, were identified in the RPR-FC. There were 139 common targets between the herb pair and IS. GO functional enrichment analysis revealed 2253 biological process entries, 72 cellular components entries, and 183 molecular functions entries. KEGG pathway enrichment analysis was mainly related to the NF-kappa B signaling pathway, the TNF signaling pathway, apoptosis, the MAPK signaling pathway, the PI3K-Akt signaling pathway, the VEGF signaling pathway, etc. The molecular docking results showed the components that docked well with key targets were quercetin, luteolin, kaempferol, and baicalein.The active components (quercetin, luteolin, kaempferol, and baicalein) of the RPR-FC and their targets act on proteins such as MAPK1, AKT1, VEGFA, and CASP3, which are closely related to IS.1 These targets are closely related to the NF-kappa B signaling pathway, the MAPK signaling pathway, the PI3K-Akt signaling pathway, the VEGF signaling pathway, and other signaling pathways. These pathways are involved in the recovery of nerve function, angiogenesis, and neuronal apoptosis and the regulation of inflammatory factors, which may have a therapeutic effect on IS.

Phospholipase Cγ Signaling in Bone Marrow Stem Cell and Relevant Natural Compounds Therapy

Excessive bone resorption has been recognized play a major role in the development of bone-related diseases such as osteoporosis, rheumatoid arthritis, Paget's disease of bone, and cancer. Phospholipase Cγ (PLCγ) family members PLCγ1 and PLCγ2 are critical regulators of signaling pathways downstream of growth factor receptors, integrins, and immune complexes and play a crucial role in osteoclast. Ca2+ signaling has been recognized as an essential pathway to the differentiation of osteoclasts. With growing attention and research about natural occurring compounds, the therapeutic use of natural active plant-derived products has been widely recognized in recent years. In this review, we summarized the recent research on PLCγ signaling in bone marrow stem cells and the use of several natural compounds that were proven to inhibit RANKL-mediated osteoclastogenesis via modulating PLCγ signaling pathways.

Virtual screening and network pharmacology-based synergistic mechanism identification of multiple components contained in Guanxin V against coronary artery disease

BACKGROUND

Guanxin V (GXV), a traditional Chinese medicine (TCM), has been widely used to treat coronary artery disease (CAD) in clinical practice in China. However, research on the active components and underlying mechanisms of GXV in CAD is still scarce.

METHODS

A virtual screening and network pharmacological approach was utilized for predicting the pharmacological mechanisms of GXV in CAD. The active compounds of GXV based on various TCM-related databases were selected and then the potential targets of these compounds were identified. Then, after the CAD targets were built through nine databases, a PPI network was constructed based on the matching GXV and CAD potential targets, and the hub targets were screened by MCODE. Moreover, Metascape was applied to GO and KEGG functional enrichment. Finally, HPLC fingerprints of GXV were established.

RESULTS

A total of 119 active components and 121 potential targets shared between CAD and GXV were obtained. The results of functional enrichment indicated that several GO biological processes and KEGG pathways of GXV mostly participated in the therapeutic mechanisms. Furthermore, 7 hub MCODEs of GXV were collected as potential targets, implying the complex effects of GXV-mediated protection against CAD. Six specific chemicals were identified.

CONCLUSION

GXV could be employed for CAD through molecular mechanisms, involving complex interactions between multiple compounds and targets, as predicted by virtual screening and network pharmacology. Our study provides a new TCM for the treatment of CAD and deepens the understanding of the molecular mechanisms of GXV against CAD.

Naturally-Occurring Alkaloids of Plant Origin as Potential Antimicrobials against Antibiotic-Resistant Infections

Antibiotic resistance is now considered a worldwide problem that puts public health at risk. The onset of bacterial strains resistant to conventional antibiotics and the scarcity of new drugs have prompted scientific research to re-evaluate natural products as molecules with high biological and chemical potential. A class of natural compounds of significant importance is represented by alkaloids derived from higher plants. In this review, we have collected data obtained from various research groups on the antimicrobial activities of these alkaloids against conventional antibiotic-resistant strains. In addition, the structure–function relationship was described and commented on, highlighting the high potential of alkaloids as antimicrobials.

Artemisia iwayomogi (Dowijigi) inhibits lipopolysaccharide-induced inflammation in RAW264.7 macrophages by suppressing the NF-κB signaling pathway

Inflammatory diseases are an important health concern and have a growing incidence worldwide. Thus, developing novel and safe drugs to treat these disorders remains an important pursuit. Artemisia iwayomogi, locally known as Dowijigi (DJ), is a perennial herb found primarily in Korea and is used to treat various diseases such as hepatitis, inflammation and immune disorders. In the present study, the anti-inflammatory effects of a polyphenolic extract from the DJ flower (PDJ) in lipopolysaccharide (LPS)-stimulated mouse macrophage RAW264.7 cells were investigated. Cell cytotoxicity was assessed using the MTT assay. The production of nitric oxide (NO) and prostaglandin E₂ (PGE₂) was measured by Griess and ELISA analysis, respectively. The expression levels of inducible nitric oxide (iNOS) and cyclooxygenase-2 (COX2) were examined by western blot analysis. Reverse transcription-quantitative PCR was performed to detect the mRNA expression levels of pro-inflammatory cytokines, including tumor necrosis factor α (TNFα), interleukin (IL)-6 and IL-1β, as well as COX2 and iNOS. The production of NO and PGE₂ was significantly decreased following treatment with PDJ. The mRNA expression levels of TNFα, IL-6, IL-1β, COX2 and iNOS were significantly decreased in LPS-induced PDJ co-treated cells compared with the group treated with LPS alone. Western blot analysis indicated that PDJ downregulated the LPS-induced expression of iNOS and COX2, as well as the expression of NF-κB proteins. In conclusion, the present study demonstrated that PDJ exerted anti-inflammatory effects in LPS-induced macrophage cells by suppressing the NF-κB signaling pathway. Therefore, PDJ may be used as a potential therapeutic agent in inflammation.

IGFBP7 acts as a negative regulator of RANKL-induced osteoclastogenesis and oestrogen deficiency-induced bone loss

OBJECTIVES

Insulin-like growth factor-binding protein 7 (IGFBP7) is a low-affinity insulin growth factor (IGF) binder that may play an important role in bone metabolism. We previously reported that IGFBP7 enhanced osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) via the Wnt/β-catenin signalling pathway. In this study, we tried to reveal its function in osteoclast differentiation and osteoporosis.

METHODS

We used both in vitro and in vivo studies to investigate the effects of IGFBP7 on RANKL-induced osteoclastogenesis and osteoporosis, together with the underlying molecular mechanisms of these processes.

RESULTS

We show that IGFBP7 inhibited receptor activation of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclastogenesis, F-actin ring formation and bone resorption, which was confirmed by using recombinant IGFBP7 protein, lentivirus and siRNA. The NF-κB signalling pathway was inhibited during this process. Moreover, in a mouse ovariectomy-induced osteoporosis model, IGFBP7 treatment attenuated osteoporotic bone loss by inhibiting osteoclast activity.

CONCLUSIONS

Taken together, these findings show that IGFBP7 suppressed osteoclastogenesis in vitro and in vivo and suggest that IGFBP7 is a negative regulator of osteoclastogenesis and plays a protective role in osteoporosis. These novel insights into IGFBP7 may facilitate the development of potential treatment strategies for oestrogen deficiency-induced osteoporosis and other osteoclast-related disorders.

Preparation, optimization and in vitro-in vivo evaluation of Shunxin sustained release granules

Background

Shunxinzufang decoction is tutors, empirical formula and has been used in Chinese patients of HFpEF for several years. The aim of this study was to make into sustained release granules and select the best formula for the preparation of Shunxin sustained release granules and to evaluate its in vivo and in vitro drug release behavior.

Methods

Response surface methodology and Center composite design were applied to screen the optimal formula of Shunxin sustained release granules. HPLC was used to detect indicative ingredients—paeoniflorin, calycosin-7-glucoside and ferulic acid in Shunxin sustained release granules. The in vitro sustained release character of indicative ingredients was investigated in simulated digestive fluids. In-vivo process of active components was studied through pharmacokinetics.

Results

The optimal formula of Shunxin sustained release granules consisted of 35% shunxinzufang extract and 65% HPMC/starch (HPMC/starch ratio = 2:1). Three indicative components can be separated well under selected HPLC conditions. Compared with Shunxinzufang extract, the active components of Shunxin sustained release granules have obvious sustained-release character and improved bioavailability.

Conclusion

Shunxin sustained release granules has obvious sustained-release character and improved bioavailability.

Inhibitory Effects of Antimicrobial Peptide JH-3 on Salmonella enterica Serovar Typhimurium Strain CVCC541 Infection-Induced Inflammatory Cytokine Release and Apoptosis in RAW264.7 Cells

The antibiotic resistance of Salmonella has become increasingly serious due to the increased use of antibiotics, and antimicrobial peptides have been considered as an ideal antibiotic alternative. Salmonella can induce macrophage apoptosis and thus further damage the immune system. The antimicrobial peptide JH-3 has been shown to have a satisfactory anti-Salmonella effect in previous research, but its mechanism of action remains unknown. In this study, the effects of JH-3 on macrophages infected with Salmonella Typhimurium CVCC541 were evaluated at the cellular level. The results showed that JH-3 significantly alleviated the damage to macrophages caused by S. Typhi infection, reduced the release of lactic dehydrogenase (LDH), and killed the bacteria in macrophages. In addition, JH-3 decreased the phosphorylation level of p65 and the expression and secretion of interleukin 2 (IL-2), IL-6, and tumor necrosis factor-α (TNF-α) by inhibiting the activation of the mitogen-activated protein kinase (MAPK) (p38) signaling pathway and alleviating the cellular inflammatory response. From confocal laser scanning microscopy and flow cytometry assays, JH-3 was observed to inhibit the release of cytochrome c in the cytoplasm; the expression of TNF-αR2, caspase-9, and caspase-8; to further weaken caspase-3 activation; and to reduce the S.-Typhi-induced apoptosis of macrophages. In summary, the mechanism by which JH-3 inhibits Salmonella infection was systematically explored at the cellular level, laying the foundation for the development and utilization of JH-3 as a therapeutic alternative to antibiotics.

The Effect of Overexpression of the Enhancer of Zeste Homolog 1 (EZH1) Gene on Aristolochic Acid-Induced Injury in HK-2 Human Kidney Proximal Tubule Cells In Vitro

Background

Acute kidney injury (AKI) involves the renal tubular epithelium. The enhancer of zeste homolog 1 (EZH1) gene has a role in cell development and differentiation. This study aimed to investigate the effect of overexpression of the EZH1 gene on aristolochic acid-induced injury in HK-2 human kidney proximal tubule epithelial cells in vitro.

Material/Methods

The HK-2 cells were cultured and treated with aristolochic acid and the effects of aristolochic acid-injury were evaluated using a cell counting kit-8 (CCK-8) assay. Overexpression of EZH1 used gene plasmid transfection into HK-2 cells. The cell apoptosis rate and levels of intracellular reactive oxygen species (ROS) were measured using flow cytometry. Quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot were performed to determine the expressions of inflammatory cytokines including interleukin (IL)-1β, IL-6, tumor necrosis factor-α (TNF-α), apoptosis-related genes, and the downstream target genes of NF-κB signaling pathway, including NFKBIA, CXCL8, and cyclin D1.

Results

Aristolochic acid inhibited HK-2 cell viability, induced cell apoptosis, increased the levels of ROS and inflammatory cytokines, including IL-1β, IL-6, TNF-α, and activated the NF-κB pathway. Overexpression the EZH1 gene inhibited HK-2 cell apoptosis, reduced ROS levels, and down-regulated the expressions of IL-1β, IL-6, TNF-α, Bax and Cyt C mRNA and protein, and increased the expressions of Bcl-2 and NFKBIA, CXCL8 and cyclin D1, indicating that overexpression of EZH1 suppressed NF-κB signaling in aristolochic acid-injured HK-2 cells.

Conclusions

Overexpression of EZH1 reduced HK-2 cell injury induced by aristolochic acid in vitro by inhibition of NF-κB signaling.

GSK-3 inhibitors enhance TRAIL-mediated apoptosis in human gastric adenocarcinoma cells

Resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis has been reported in some cancer cells, including AGS human gastric adenocarcinoma cells. Reducing this resistance might shed light on the treatment of human gastric adenocarcinoma. In this study, we examined whether glycogen synthase kinase-3 (GSK-3) inhibitors can restore TRAIL responsiveness in gastric adenocarcinoma cells. The effect of two GSK-3 inhibitors, SB-415286, and LiCl, on apoptosis signaling of TRAIL in human gastric adenocarcinoma cell lines and primary gastric epithelial cells was analyzed. Both inhibitors can sensitize gastric adenocarcinoma cells, but not primary gastric epithelial cells, to TRAIL-induced apoptosis by increasing caspase-8 activity and its downstream signal transmission. Adding p53 siRNA can downregulate GSK-3 inhibitor-related sensitization to TRAIL-induced apoptosis and caspase-3 activity. GSK-3 inhibitors strongly activate the phosphorylation of JNK. Inhibition of JNK leads to earlier and more intense apoptosis, showing that the activation of JNK may provide anti-apoptotic equilibrium of pro-apoptotic cells. Our observations indicate that GSK-3 inhibitors can sentize AGS gastric adenocarcinoma cells to TRAIL-induced apoptosis. Therefore, in certain types of gastric adenocarcinoma, GSK-3 inhibitor might enhance the antitumor activity of TRAIL and mightbe a promising candidate for the treatment of certain types of gastric adenocarcinoma.

Isosteviol Derivative Inhibits Osteoclast Differentiation and Ameliorates Ovariectomy-Induced Osteoporosis

NC-8 (ent-16-oxobeyeran-19-N-methylureido) is an isosteviol-derived analogue with multiple biological effects, including anti-inflammation and anti-bacterial activities and inhibition of HBV viral surface antigen gene expression. In this study, we explored the effects of NC-8 on the formation of osteoclasts from RAW 264.7 cells. We found that NC-8 exerts the novel effect of inhibiting osteoclast-like cell formation. Our experiments showed that RANKL-induced ERK, p38, and JNK phosphorylation were inhibited by NC-8. An ovariectomy-induced osteoporosis animal model was used to examine the protective effects of oral treatment with NC-8. Serum analysis was used to examine markers of osteoblasts, osteoclasts, and renal and hepatic function in rats. Micro CT scanning and histological analysis were used to measure bone loss in ovariectomized rats. Oral administration of NC-8 effectively decreased excess bone resorption and significantly antagonized trabecular bone loss in ovariectomized rats. Serum analysis of C-terminal telopeptide of type-I collagen, an osteoclast marker, also showed that NC-8 administration inhibited excess bone resorption. Furthermore, serum analysis showed that renal and liver function were not affected by these doses of NC-8 during long-term treatment. Our results demonstrate that NC-8 inhibits osteoclast differentiation and effectively ameliorates ovariectomy-induced osteoporosis.

A paeonol derivative, YPH-PA3 promotes the differentiation of monocyte/macrophage lineage precursor cells into osteoblasts and enhances their autophagy

Previous studies have indicated that paeonol inhibits RANKL-induced osteoclastogenesis by inhibiting the ERK, p38, and NF-κB pathway. We modified paeonol to form a new compound, YPH-PA3, and found that it promoted osteoclastogenesis rather than inhibited it the way paeonol does. The aim of this study is to investigate the mechanisms involved in YPH-PA3-promoted osteoclastogenesis. YPH-PA3-promoted differentiation of RAW264.7 cells (human monocytes) into osteoclasts is activated through ERK/p38/JNK phosphorylation, affecting c-FOS, NF-κB, and NFATc2. Real-time quantitative PCR and western blot revealed an increased expression of autophagy-related markers during YPH-PA3-induced osteoclastogenesis. We also demonstrated the relationship between p62/LC3 localization and F-actin ring formation by double-labeling immunofluorescence. Knockdown of p62 small-interfering RNA (siRNA) attenuated YPH-PA3-induced expression of autophagy-related genes. Our study results indicated that p62 may play a role in YPH-PA3-induced autophagy and osteoclastogenesis, which may help to develop a novel therapeutic strategy against osteoclastogenesis-related diseases.