Dusuqing granules (DSQ) suppress inflammation in Klebsiella pneumonia rat via NF-κB/MAPK signaling

Active fractions from Jingfang Baidu Powder alleviate Klebsiella-induced Pneumonia by inhibiting TLR4/Myd88-ERK signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Jingfang Baidu Powder (JFBDP) is a classic traditional Chinese medicine prescription. Although Jingfang Baidu powder obtained a general consensus on clinical efficacy in treating pneumonia, there were many Chinese herbal drugs in formula, complex components, and large oral dosage, which brings certain obstacles to clinical application.

AIM OF THE STUDY

Therefore, screening of the active fraction that exerts anti-pneumonia helps improve the pharmaceutical preparation, improve the treatment compliance of patients, and further contribute to the clinical application, and the screening of the new active ingredients with anti-pneumonia. The histopathological observation, real-time quantitative PCR, western blotting, and immunofluorescence were applied to evaluate the anti-pneumonia efficacy of active fractions from JFBDP.

RESULTS

Three fractions from JFBDP inhibit the gene expression of IL-1β, IL-10, CCL3, CCL5, and CCL22 in lung tissue infected by Klebsiella at various degrees, and presented a good dose-response relationship. JF50 showed stronger anti-inflammatory effects among three fractions including JF30, JF50, and JF75. Besides, JF50 significantly reduced the protein expression of TLR4 and Myd88 in lung tissue infected with Klebsiella, and it also significantly inhibited p-ERK and p-NF-κB p65. JF50 significantly inhibits the protein expression of Caspase 3, Caspase 8, and Caspase 9 in lung tissue infected with Klebsiella at the dose of 25 mg/kg and 50 mg/kg.

CONCLUSION

JF50 improves lung pathological damage in Klebsiella pneumonia mice by inhibiting the TLR4/Myd88/NF-κB-ERK signaling pathway, and inhibiting apoptosis of lung tissue cells. These findings provide a reference for further exploring the active substance basis of Jingfang Baidu Powder in treating bacterial pneumonia.

Identification of bioactive ingredients and potential mechanisms of flowers of Hosta Plantaginea in treating pneumonia based on network pharmacology and experimental validation

Flowers of Hosta plantaginea (H. plantaginea), a widely utilized medicinal herb in Mongolian medicine, holds a significant historical background in terms of its medicinal applications. This herb is renowned for its ability to clear heat and detoxify the body, alleviate cough, and provide relief to the throat. However, the active ingredients and the potential mechanism of action remain ambiguity. The objective of this study was to conduct a comprehensive analysis of the efficacy of H. plantaginea in treating pneumonia, identify its active ingredients and unveil the pharmacological mechanism in the treatment of pneumonia. In vivo experiments demonstrate the plant's anti-pneumonia properties, while mass spectrometry analysis identifies 62 chemicals, with 14 absorbed into the bloodstream. Network pharmacology and Venn analysis reveal 195 targets of 52 active ingredients, with 49 gene targets common to H. plantaginea and pneumonia. Protein-protein interaction (PPI) network construction and enrichment analysis highlight the key targets and pathways such as AKT, EGFR, IL-17. Western blotting confirms downregulation of these pathways, indicating the anti-inflammatory effects of H. plantaginea in treating acute lung injury. Our findings showed that the treatment of ALI with the H. plantaginea exerts its anti-inflammatory effects through multiple components, targets, and pathways. This study established a solid experimental foundation for investigating the various components, targets, and pathways involved in the treatment of pneumonia using H. plantaginea. It offers valuable insights from multiple perspectives and can serve as a reference for the clinical application of this plant in pneumonia treatment.

Animal models of Klebsiella pneumoniae mucosal infections

Klebsiella pneumoniae is among the most relevant pathogens worldwide, causing high morbidity and mortality, which is worsened by the increasing rates of antibiotic resistance. It is a constituent of the host microbiota of different mucosa, that can invade and cause infections in many different sites. The development of new treatments and prophylaxis against this pathogen rely on animal models to identify potential targets and evaluate the efficacy and possible side effects of therapeutic agents or vaccines. However, the validity of data generated is highly dependable on choosing models that can adequately reproduce the hallmarks of human diseases. The present review summarizes the current knowledge on animal models used to investigate K. pneumoniae infections, with a focus on mucosal sites. The advantages and limitations of each model are discussed and compared; the applications, extrapolations to human subjects and future modifications that can improve the current techniques are also presented. While mice are the most widely used species in K. pneumoniae animal studies, they present limitations such as the natural resistance to the pathogen and difficulties in reproducing the main steps of human mucosal infections. Other models, such as Drosophila melanogaster (fruit fly), Caenorhabditis elegans, Galleria mellonella and Danio rerio (zebrafish), contribute to understanding specific aspects of the infection process, such as bacterial lethality and colonization and innate immune system response, however, they but do not present the immunological complexity of mammals. In conclusion, the choice of the animal model of K. pneumoniae infection will depend mainly on the questions being addressed by the study, while a better understanding of the interplay between bacterial virulence factors and animal host responses will provide a deeper comprehension of the disease process and aid in the development of effective preventive/therapeutic strategies.

Polystyrene nanoplastics induce glycolipid metabolism disorder via NF-κB and MAPK signaling pathway in mice

Nanoplastics-induced developmental and reproductive toxicity, neurotoxicity and immunotoxicity are a focus of widespread attention. However, the effects of nanoplastics (NPs) on glycolipid metabolism and the precise underlying mechanisms are unclear at present. Here, we showed that oral administration of polystyrene nanoparticles (PS-NPs) disrupts glycolipid metabolism, with reactive oxygen species (ROS) identified as a potential key signaling molecule. After PS-NPs treatment, excessive production of ROS induced the inflammatory response and activated the antioxidant pathway through nuclear factor-erythroid factor 2-related factor 2. The activation of nuclear factor-κB (NFκB) signaling pathway induced the phosphorylation of the mitogen-activated protein kinases (MAPK) signaling pathway, which induced the activation of extracellular regulated kinases (ERK) and p38. Constitutive activation of the MAPK signaling proteins induced high continued phosphorylation of insulin receptor substrate-1, in turn, leading to decreased protein kinase B (Akt) activity, which weakened the sensitivity of liver cells to insulin signals and induced insulin resistance. In parallel, phosphorylation of Akt led to loss of control of FoXO1, a key gene of gluconeogenesis, activating transcription of glucose-6-phosphatase (G6PC) and phosphoenolpyruvate carboxykinase (PEPCK) in a manner dependent on PGC1α. Moreover, the activated ERK promoted lipid accumulation through ERK-PPARγ cascades. Therefore, sterol regulatory element-binding protein-1 and levels of its downstream lipogenic enzymes, ACC-1, were up-regulated. Upon treatment with the antioxidant resveratrol, PS-NPs-induced glucose and lipid metabolic disorders were improved by inhibiting ROS-induced activation of NFκB and MAPK signaling pathway in mice. Based on above, PS-NPs exposure disrupts glycolipid metabolism in mice, with ROS identified as a potential key signaling molecule.

Anti-inflammatory effect of chlorogenic acid in Klebsiella pneumoniae-induced pneumonia by inactivating the p38MAPK pathway

INTRODUCTION

Pneumonia is an inflammation-related respiratory infection and chlorogenic acid (CGA) possesses a wide variety of bioactive properties, such as anti-inflammation and anti-bacteria.

AIM

This study explored the anti-inflammatory mechanism of CGA in Klebsiella pneumoniae (Kp)-induced rats with severe pneumonia.

METHODS

The pneumonia rat models were established by infection with Kp and treated with CGA. Survival rates, bacterial load, lung water content, and cell numbers in the bronchoalveolar lavage fluid were recorded, lung pathological changes were scored, and levels of inflammatory cytokines were determined by enzyme-linked immunosorbent assay. RLE6TN cells were infected with Kp and treated with CGA. The expression levels of microRNA (miR)-124-3p, p38, and mitogen-activated protein kinase (MAPK)-activated protein kinase 2 (MK2) in lung tissues and RLE6TN cells were quantified by real-time quantitative polymerase chain reaction or Western blotting. The binding of miR-124-3p to p38 was validated by the dual-luciferase and RNA pull-down assays. In vitro, the functional rescue experiments were performed using miR-124-3p inhibitor or p38 agonist.

RESULTS

Kp-induced pneumonia rats presented high mortality, increased lung inflammatory infiltration and the release of inflammatory cytokines, and enhanced bacterial load, while CGA treatment improved rat survival rates and the above situations. CGA increased miR-124-3p expression, and miR-124-3p inhibited p38 expression and inactivated the p38MAPK pathway. Inhibition of miR-124-3p or activation of the p38MAPK pathway reversed the alleviative effect of CGA on pneumonia in vitro.

CONCLUSION

CGA upregulated miR-124-3p expression and inactivated the p38MAPK pathway to downregulate inflammatory levels, facilitating the recovery of Kp-induced pneumonia rats.

Development of Drug-Resistant Klebsiella pneumoniae Vaccine via Novel Vesicle Production Technology

Drug resistance of Klebsiella pneumoniae severely threatens human health. Overcoming the mechanisms of K. pneumoniae resistance to develop novel vaccines against drug-resistant K. pneumoniae is highly desired. Here, we report a technology platform that uses high pressure to drive drug-resistant K. pneumoniae to pass through a gap, inducing the formation of stable artificial bacterial biomimetic vesicles (BBVs). These BBVs had little to no bacterial intracellular protein or nucleic acid and had high yields. BBVs were efficiently taken up by dendritic cells to stimulate their maturation. BBVs as K. pneumoniae vaccines had the dual functions of inducing bacteria-specific humoral and cellular immune responses to increase animals' survival rate and reduce pulmonary inflammation and bacterial loads. We believe that BBVs are new-generation technology for bacterial vesicle preparation. Establishment of this BBV vaccine platform can maximally expand preparation technology for vaccines against drug-resistant K. pneumoniae.

Emodin relieved lipopolysaccharide-evoked inflammatory damage in WI-38 cells by up-regulating taurine up-regulated gene 1

BACKGROUND

Neonatal pneumonia (NP) has a high fatality rate in neonatal illness. This research investigated the functions of emodin on lipopolysaccharide (LPS)-evoked inflammatory injury in WI-38 cells.

METHODS

Cell counting kit-8 (CCK-8) assay and flow cytometry were utilized for examining the impacts of LPS and emodin on viability and apoptosis, respectively. Taurine up-regulated gene 1 (TUG1) level was altered through cell transfection and investigated by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Moreover, RT-qPCR, western blot and enzyme-linked immunosorbent assay (ELISA) were utilized for investigating expressions of monocyte chemoattractant protein-1 (MCP-1) and interleukin (IL)-6. Western blot was carried out for investigating the levels of Bcl-2, Bax, pro-Caspase-3, cleaved-Caspase-3 and NF-κB and p38MAPK pathway-related proteins.

RESULTS

LPS treatment restrained cell viability, enhanced apoptosis, and expressions of inflammation-related IL-6 and MCP-1. Emodin alleviated LPS-evoked inflammatory injury and restrained the NF-κB and p38MAPK pathways. Furthermore, emodin positively regulated TUG1 expression and TUG1 silencing could reverse the efficacy of emodin on IL-6 and MCP-1 expressions. Finally, TUG1 regulates the expression of inflammatory factors through NF-κB and p38MAPK pathways.

CONCLUSION

Emodin alleviated LPS-evoked inflammatory injury by raising TUG1 expression via NF-κB and p38MAPK pathways in WI-38 cells.

Triptolide prevents bone loss via suppressing osteoclastogenesis through inhibiting PI3K-AKT-NFATc1 pathway

Bone loss (osteopenia) is a common complication in human solid tumour. In addition, after surgical treatment of gynaecological tumour, osteoporosis often occurs due to the withdrawal of oestrogen. The major characteristic of osteoporosis is the low bone mass with micro-architectural deteriorated bone tissue. And the main cause is the overactivation of osteoclastogenesis, which is one of the most important therapeutic targets. Inflammation could induce the interaction of RANKL/RANK, which is the promoter of osteoclastogenesis. Triptolide is derived from the traditional Chinese herb lei gong teng, presented multiple biological effects, including anti-cancer, anti-inflammation and immunosuppression. We hypothesized that triptolide could inhibits osteoclastogenesis by suppressing inflammation activation. In this study, we confirmed that triptolide could suppress RANKL-induced osteoclastogenesis in bone marrow mononuclear cells (BMMCs) and RAW264.7 cells and inhibited the osteoclast bone resorption functions. PI3K-AKT-NFATc1 pathway is one of the most important downstream pathways of RANKL-induced osteogenesis. The experiments in vitro indicated that triptolide suppresses the activation of PI3K-AKT-NFATc1 pathway and the target point located at the upstream of AKT because both NFATc1 overexpression and AKT phosphorylation could ameliorate the triptolide suppression effects. The expression of MDM2 was elevated, which demonstrated the MDM-p53-induced cell death might contribute to the osteoclastogenesis suppression. Ovariectomy-induced bone loss and inflammation activation were also found to be ameliorated in the experiments in vivo. In summary, the new effect of anti-cancer drug triptolide was demonstrated to be anti-osteoclastogenesis, and we demonstrated triptolide might be a promising therapy for bone loss caused by tumour.

Exosomal miR-103a-3p ameliorates lipopolysaccharide-induced immune response in BEAS-2B cells via NF-κB pathway by targeting transducin β-like 1X related protein 1

Abnormal immune response contributes to pathophysiology of pneumonia and is recognized as a main factor for high incidence rate in children. The association between exosomes and inflammation has been reported in diverse cell types and diseases. The current study focuses on exploring the effects of exosomal miR-103a-3p on lipopolysaccharide (LPS)-induced inflammation, and investigates the underlying mechanisms. We proved that miR-103a-3p was lowly expressed in blood samples of pneumonia patients and LPS-induced lung cells, and overexpression of miR-103a-3p weaken the LPS-induced inflammation. Using luciferase reporter assay and immunoprecipitation assay, we demonstrated that miR-103a-3p directly binds to a specific region of transducin β-like 1X related protein 1 (TBL1XR1), mediating the NF-κB signalling pathway, thus regulating immune response. Taken together, our data revealed that miR-103a-3p functions as an anti-inflammatory gene in childhood pneumonia and can be applied as therapeutic targets for the treatment of childhood pneumonia in the future.

Degradable antimicrobial polycarbonates with unexpected activity and selectivity for treating multidrug-resistant Klebsiella pneumoniae lung infection in mice

Multidrug resistant (MDR) Klebsiella pneumoniae is a major cause of healthcare-associated infections around the world, with attendant high rates of morbidity and mortality. Progressive reduction in potency of antibiotics capable of treating MDR K. pneumoniae infections - including lung infection - as a consequence of escalating drug resistance provides the motivation to develop drug candidates targeting MDR K. pneumoniae. We recently reported degradable broad-spectrum antimicrobial guanidinium-functionalized polycarbonates with unique antimicrobial mechanism - membrane translocation followed by precipitation of cytosolic materials. These polymers exhibited high potency against bacteria with negligible toxicity. The polymer with ethyl spacer between the quanidinium group and the polymer backbone (pEt_20) showed excellent in vivo efficacy for treating MDR K. pneumoniae-caused peritonitis in mice. In this study, the structures of the polymers were optimized for the treatment of MDR Klebsiella pneumoniae lung infection. Specifically, in vitro antimicrobial activity and selectivity of guanidinium-functionalized polycarbonates containing the same number of guanidinium groups but of a shorter chain length and a structural analogue containing a thiouronium moiety as the pendent cationic group were evaluated. The polymers with optimal compositions and varying hydrophobicity were assessed against 25 clinically isolated K. pneumonia strains for antimicrobial activity and killing kinetics. The results showed that the polymers killed the bacteria more efficiently than clinically used antibiotics, and repeated use of the polymers did not cause drug resistance in K. pneumonia. Particularly, the polymer with butyl spacer (pBut_20) self-assembled into micelles at high concentrations, where the hydrophobic component was shielded in the micellar core, preventing interacting with mammalian cells. A subtle change in the hydrophobicity increased the antimicrobial activity while reducing in vivo toxicity. The in vivo efficacy studies showed that pBut_20 alleviated K. pneumonia lung infection without inducing damage to major organs. Taken together, pBut_20 is promising for treating MDR Klebsiella pneumoniae lung infection in vivo. STATEMENT OF SIGNIFICANCE: Multidrug resistant (MDR) Klebsiella pneumoniae is a major cause of healthcare-associated infections, with attendant high rates of morbidity and mortality. The progressive reduction in antibiotics capable of treating MDR K. pneumoniae infections - including lung infection - as a consequence of escalating drug resistance rates provides the motivation to develop drug candidates. In this study, we report a degradable guanidinium-functionalized polycarbonate with unexpected antimicrobial activity and selectivity towards MDR Klebsiella pneumoniae. A subtle change in polymer hydrophobicity increases antimicrobial activity while reducing in vivo toxicity due to self-assembly at high concentrations. The polymer with optimal composition alleviates Klebsiella pneumonia lung infection without inducing damage to major organs. The polymer is promising for treating MDR Klebsiella pneumoniae lung infection in vivo.

Regulation of NF-κB/MAPK signaling pathway attenuates the acute lung inflammation in Klebsiella pneumonia rats by mollugin treatment

Present study evaluates the protective effect of mollugin against Klebsiella pneumonia (KP) and also postulates the possible mechanism of its action. Klebsiella pneumoniae (2.4 × 10⁸ CFU/ml) was used for the induction of KP. PMNs and WBC count was determined in the blood and bronchoalveolar lavage fluid (BALF) of Klebsiella pneumonia rat. Level of inflammatory cytokines in the blood of Klebsiella pneumonia rat was determined by ELISA methods. Moreover effect of mollugin was estimated by Western blot assay and RT-PCR method. Result of the study suggests that water content in lung was reduced in the mollugin treated group compared to pneumonia control group of rats. Count of PMNs and WBC were found to be reduced in mollugin treated group compared to pneumonia control group of rats. Level of inflammatory cytokines was also found to be reduced in the blood of mollugin treated group than pneumonia control group. Moreover treatment with mollugin attenuates the altered expression of p-MAPK, p-JNK and p-ERK protein and mRNA expression of NF-κB in the lung tissues of Klebsiella pneumonia rat. In conclusion, data of the study reveals that treatment with mollugin ameliorates Klebsiella pneumonia rat by reducing the lung inflammation. Inflammation of lung tissue was reduced by regulating the NF-κB/MAPK signaling pathway in mollugin treated group.

Protective impacts of long noncoding RNA taurine-upregulated 1 against lipopolysaccharide-evoked injury in MRC-5 cells through inhibition of microRNA-127

BACKGROUND

Pneumonia is a respiratory disease, which is triggered by pathogenic microorganisms or physical/chemical factors. Increasing evidence confirmed the vital impacts of long noncoding RNAs on various inflammatory diseases. Nonetheless, the influence of taurine-upregulated 1 (TUG1) in pneumonia remains vague. The research tried to disclose the protective impacts of TUG1 against lipopolysaccharide (LPS)-evoked injury in MRC-5 cells.

METHODS

MRC-5 cells were disposed with LPS to construct pulmonary injury model. Then, pc-TUG1 vector was transfected into MRC-5 cells and the influence of overexpressed TUG1 in cell viability, apoptosis, and pro-inflammatory cytokines in LPS-disposed cells were evaluated. The correlation between TUG1 and microRNA (miR)-127 was estimated via utilizing real-time quantitative polymerase chain reaction (RT-qPCR), meanwhile whether miR-127 affected the impacts of TUG1 on LPS-injured MRC-5 cells was explored. Besides, NF-κB and p38MAPK pathways were evaluated to understand the dormant mechanisms.

RESULTS

LPS administration apparently evoked inflammatory injury in MRC-5 cells by restraining cell viability, accelerating apoptosis, and enhancing TNF-α and IL-6 productions. But, TUG1 lightened LPS-evoked pro-inflammatory response in MRC-5 cells. In addition, miR-127 was repressed by overexpressed TUG1, meanwhile the protective impacts of TUG1 against LPS-evoked inflammatory injury in MRC-5 cells were overturned by overexpressed miR-127. Finally, we disclosed that TUG1 hindered the activation of NF-κB and p38MAPK pathways via restraining miR-127.

CONCLUSIONS

These explorations testified that taurine-upregulated 1 (TUG1) protected MRC-5 cells against lipopolysaccharide (LPS)-evoked inflammatory injury via hindering miR-127/NF-κB/p38MAPK axis.

Trichosanthis Pericarpium Aqueous Extract Protects H9c2 Cardiomyocytes from Hypoxia/Reoxygenation Injury by Regulating PI3K/Akt/NO Pathway

Trichosanthis Pericarpium (TP) is a traditional Chinese medicine for treating cardiovascular diseases. In this study, we investigated the effects of TP aqueous extract (TPAE) on hypoxia/reoxygenation (H/R) induced injury in H9c2 cardiomyocytes and explored the underlying mechanisms. H9c2 cells were cultured under the hypoxia condition induced by sodium hydrosulfite for 30 min and reoxygenated for 4 h. Cell viability was measured by MTT assay. The amounts of LDH, NO, eNOS, and iNOS were tested by ELISA kits. Apoptotic rate was detected by Annexin V-FITC/PI staining. QRT-PCR was performed to analyze the relative mRNA expression of Akt, Bcl-2, Bax, eNOS, and iNOS. Western blotting was used to detect the expression of key members in the PI3K/Akt pathway. Results showed that the pretreatment of TPAE remarkably enhanced cell viability and decreased apoptosis induced by H/R. Moreover, TPAE decreased the release of LDH and expression of iNOS. In addition, TPAE increased NO production and Bcl-2/Bax ratio. Furthermore, the mRNA and protein expression of p-Akt and eNOS were activated by TPAE pretreatment. On the contrary, a specific inhibitor of PI3K, LY294002 not only inhibited TPAE-induced p-Akt/eNOS upregulation but alleviated its anti-apoptotic effects. In conclusion, results indicated that TPAE protected against H/R injury in cardiomyocytes, which consequently activated the PI3K/Akt/NO signaling pathway.

Antimicrobial polymers as therapeutics for treatment of multidrug-resistant Klebsiella pneumoniae lung infection

Klebsiella pneumoniae (K. pneumoniae) is one of the most common pathogens in hospital-acquired infections. It is often resistant to multiple antibiotics (including carbapenems), and can cause severe pneumonia. In search of effective antimicrobials, we recently developed polyionenes that were demonstrated to be potent against a broad-spectrum of microbes in vitro. In this study, polyionenes containing rigid amide bonds were synthesized to treat multidrug-resistant (MDR) K. pneumoniae lung infection. The polyionene exhibited broad-spectrum activity against clinically-isolated MDR bacteria with low minimum inhibitory concentrations (MICs). It also demonstrated stronger antimicrobial activity against 20 clinical strains of K. pneumoniae and more rapid killing kinetics than imipenem and other commonly used antibiotics. Multiple treatments with imipenem and gentamycin led to drug resistance in K. pneumoniae, while repeated use of the polymer did not cause resistance development due to its membrane-disruption antimicrobial mechanism. Additionally, the polymer showed potent anti-biofilm activity. In a MDR K. pneumoniae lung infection mouse model, the polymer demonstrated lower effective dose than imipenem with negligible systemic toxicity. The polymer treatment significantly alleviated lung injury, markedly reduced K. pneumoniae counts in the blood and major organs, and decreased mortality. Given its potent in vivo antimicrobial activity, negligible toxicity and ability of mitigating resistance development, the polyionene may be used to treat MDR K. pneumoniae lung infection.

STATEMENT OF SIGNIFICANCE

Klebsiella pneumoniae (K. pneumoniae) is one of the most common pathogens in hospital-acquired infections, is often resistant to multiple antibiotics including carbapenems and can cause severe pneumonia. In this study, we report synthesis of antimicrobial polymers (polyionenes) and their use as antimicrobial agents for treatment of K. pneumoniae-caused pneumonia. The polymers have broad spectrum antibacterial activity against clinically isolated MDR bacteria, and eliminate MDR K. pneumoniae more effectively and rapidly than clinically used antibiotics. The polymer treatment also provides higher survival rate and faster bacterial removal from the major organs and the blood than the antibiotics. Repeated use of the polymer does not lead to resistance development. More importantly, at the therapeutic dose, the polymer treatment does not cause acute toxicity. Given its in vivo efficacy and negligible toxicity, the polymer is a promising candidate for the treatment of MDR K. pneumoniae-caused pneumonia.

A Matrine Derivative M54 Suppresses Osteoclastogenesis and Prevents Ovariectomy-Induced Bone Loss by Targeting Ribosomal Protein S5

Post-menopausal osteoporosis (PMOP) is a metabolic bone disorder characterized by low bone mass and micro-architectural deterioration of bone tissue. The over-activated osteoclastogenesis, which plays an important role in osteoporosis, has become an important therapeutic target. M54 was a bioactive derivative of the Chinese traditional herb matrine. We found that M54 could suppress RANKL-induced osteoclastogenesis in bone marrow mononuclear cells and RAW264.7 cells through suppressing NF-κB, PI3K/AKT, and MAPKs pathways activity in vitro, and prevent ovariectomy-induced bone loss in vivo. Our previous study has proved that ribosomal protein S5 (RPS5) was a direct target of M19, based on which M54 was synthesized. Thus we deduced that M54 also targeted RPS5. During osteoclastogenesis, the RPS5 level in RAW264.7 cells was significantly down-regulated while M54 could maintain its level. After RPS5 was silenced, the inhibitory effects of M54 on osteoclastogenesis were partially compromised, indicating that M54 took effects through targeting RPS5. In summary, M54 was a potential clinical medicine for post-menopause osteoporosis treatment, and RPS5 is a possible key protein in PMOP.