Costunolide Inhibits Osteoclast Differentiation by Suppressing c-Fos Transcriptional Activity

Understanding the mechanistic potential of plant based phytochemicals in management of postmenopausal osteoporosis

Postmenopausal osteoporosis, an epidemic disorder is defined as a loss in bone mineral density and a greater possibility of fractures in older women. It is a multifactorial disease under the control of various genetic, hormonal, and environmental factors. Insufficiency of estrogen hormone, leads to postmenopausal osteoporosis. Hormone replacement therapy (HRT), despite being the most effective treatment, it is associated with the risk of breast cancer and cardiovascular disorders. This review seeks to compile the most recent information on medicinal plants and natural compounds used to treat and prevent postmenopausal osteoporosis. Furthermore, the origin, chemical constituents and the molecular mechanisms responsible for this therapeutic and preventive effect are also discussed. Literature research was conducted using PubMed, Science direct, Scopus, Web of Science, and Google Scholar. Different plant extracts and pure compounds exerts their antiosteoporotic activity by inhibition of RANKL and upregulation of OPG. RANKL signaling regulates osteoclast formation, characterized by increased bone turnover and osteoprotegrin is a decoy receptor for RANKL thereby preventing bone loss from excessive resorption. In addition, this review also includes the chemical structure of bioactive compounds acting on NFκB, TNF α, RUNX2. In conclusion, we propose that postmenopausal osteoporosis could be prevented or treated with herbal products.

Evolving Roles of Natural Terpenoids From Traditional Chinese Medicine in the Treatment of Osteoporosis

Osteoporosis (OP) is a systemic metabolic skeletal disease which can lead to reduction in bone mass and increased risk of bone fracture due to the microstructural degradation. Traditional Chinese medicine (TCM) has been applied in the prevention and treatment of osteoporosis for a long time. Terpenoids, a class of natural products that are rich in TCM, have been widely studied for their therapeutic efficacy on bone resorption, osteogenesis, and concomitant inflammation. Terpenoids can be classified in four categories by structures, monoterpenoids, sesquiterpenoids, diterpenoids, and triterpenoids. In this review, we comprehensively summarize all the currently known TCM-derived terpenoids in the treatment of OP. In addition, we discuss the possible mechanistic-of-actions of all four category terpenoids in anti-OP and assess their therapeutic potential for OP treatment.

The Effects of Sesquiterpene Lactones on the Differentiation of Human or Animal Cells Cultured In-Vitro: A Critical Systematic Review

Cellular differentiation is pivotal in health and disease. Interfering with the process of differentiation, such as inhibiting the differentiation of adipocytes and inducing the differentiation of cancer cells, is considered a therapeutic approach. Sesquiterpene lactones, primarily found in plants, have been attracted attention as differentiating/dedifferentiating agents tested on various human or animal cells. However, a consensus on sesquiterpene lactones’ effects and their mechanism of action is required. In this sense, through a systematic review, we have investigated the differentiating/dedifferentiating effects of sesquiterpene lactones on human or animal cells. 13 different cell lines originated from humans, mice, and rats, in addition to the effects of a total of 21 sesquiterpene lactones, were evaluated in the included studies. These components had either inducing, inhibiting, or no effect on the cells, mediating their effects through JAK-STAT, PI3K-Akt, mitogen-activated protein kinases, NFκB, PPARγ pathways. Although nearly all inducing and inhibiting effects were attributed to cancerous and normal cells, respectively, this is likely a result of a biased study design. Few studies reported negative results along with others, and no study was found reporting only negative results. As a result, not only are the effects and mechanism of action of sesquiterpene lactones not vivid but our knowledge and decisions are also misconducted. Moreover, there is a significant knowledge gap regarding the type of evaluated cells, other sesquiterpene lactones, and the involved signaling pathways. In conclusion, sesquiterpene lactones possess significant effects on differentiation status, leading to potentially efficient therapy of obesity, osteoporosis, and cancer. However, reporting negative results and further investigations on other cells, sesquiterpene lactones, and signaling pathways are highly suggested to pave the path of sesquiterpene lactones to the clinic more consciously.

Aucklandiae Radix and Vladimiriae Radix: A systematic review in ethnopharmacology, phytochemistry and pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Aucklandiae Radix (AR) and Vladimiriae Radix (VR), as commonly used traditional Chinese herbal medicine, were widely used in the treatment of gastrointestinal diseases. The two herbal medicines were warm, pungent and bitter. They entered the spleen, stomach, large intestine and gallbladder meridians, and had the effect of promoting qi circulation to relieve pain. It is usually used for chest and hypochondrium, abdominal fullness and pain, tenesmus, indigestion, and warming the middle to harmonize the stomach in clinically.

AIM OF THIS REVIEW

To provide a reference for the identification of traditional use, the material basis of efficacy and preclinical research between AR and VR, this review systematically summarized the similarities and differences in ethnopharmacology, phytochemistry and modern pharmacology.

MATERIALS AND METHODS

The literature information was collected systematically from the electronic scientific databases, including PubMed, Science Direct, Google Scholar, Web of Science, Geen Medical, China National Knowledge Infrastructure, as well as other literature sources, such as classic books of herbal medicine, master's thesis, doctoral thesis.

RESULTS

In the plateau areas of Sichuan Province, VR used to be regarded as substitute or local habit for AR, which is regularly used for chest, abdominal fullness and pain, diarrhea, and other related diseases. In Chinese Pharmacopoeia (ChP) 2020 edition, 145 prescription preparations with AR were collected, such as Xianglian Wan, Muxiang Shunqi Wan, Liuwei Muxiang San. However, only one prescription preparation (Jiuxiang Zhitong Wan) contained VR. Additionally, 237 and 254 chemical components were separately isolated and identified from AR and VR, 69 kinds of compounds were common among them, and the significant differences were presented in sesquiterpene lactones, monoterpenoids, triterpenoids and phenylpropanoids. Moreover, Costunolide (COS) and Dehydrocostus lactone (DEH), two main research objects of modern pharmacology, showed multiple pharmacological activities. Not only could they inhibit the activity of some cancer cells (such as breast cancer and leukemia cells), but they regulated the levels of various inflammatory factors (including TNF-α, NF-κB, IL-1β, IL-6) and repressed the growth and reproduction of various microorganisms (like Helicobacter pylori, Staphylococcus aureus).

CONCLUSION

COS and DEH as the common active components, provide a certain basis for local medicine about the substitution of VR for AR in Sichuan province of China in the past. In addition, the sesquiterpenoids are the main common compounds in AR and VR by collecting and collating a large number of literature and various data websites. Furthermore, AR and VR have significant differences in ethnopharmacology and phytochemistry, especially in sesquiterpene lactones, monoterpenoids, triterpenoids and phenylpropanoids, and are probably viewed as reference of a separate list of AR and VR in Chinese Pharmacopoeia.

Nanocapsules containing Saussurea lappa essential oil: Formulation, characterization, antidiabetic, anti-cholinesterase and anti-inflammatory potentials

Plant-based remedies have been widely used for the management of variable diseases due to their safety and less side effects. In the present study, we investigated Saussurea lappa CB. Clarke. (SL) given its largely reported medicinal effects. Specifically, our objective was to provide an insight into a new polymethyl methacrylate based nanocapsules as carriers of SL essential oil and characterize their biologic functions. The nanoparticles were prepared by nanoprecipitation technique, characterized and analyzed for their cytotoxicity, anti-inflammatory, anti-Alzheimer and antidiabetic effects. The results revealed that the developed nanoparticles had a diameter around 145 nm, a polydispersity index of 0.18 and a zeta potential equal to +45 mV and they did not show any cytotoxicity at 25 μg·mL^-1. The results also showed an anti-inflammatory activity (reduction in metalloprotease MMP-9 enzyme activity and RNA expression of inflammatory cytokines: TNF-α, GM-CSF and IL1β), a high anti-Alzheimer's effect (IC50 around 25.0 and 14.9 μg·mL^-1 against acetylcholinesterase and butyrylcholinesterase, respectively), and a strong antidiabetic effect (IC50 were equal to 22.9 and 75.8 μg·mL^-1 against α-amylase and α-glucosidase, respectively). Further studies are required including the in vivo studies (e.g., preclinical), the pharmacokinetic properties, the bioavailability and the underlying associated metabolic pathways.

Ellagic acid protects ovariectomy-induced bone loss in mice by inhibiting osteoclast differentiation and bone resorption

Osteoporosis is a devastating disease that features reduced bone quantity and microstructure, which causes fragility fracture and increases mortality, especially in the aged population. Due to the long-term side-effects of current drugs for osteoporosis, it is of importance to find other safe and effective medications. Ellagic acid (EA) is a phenolic compound found in nut galls, plant extracts, and fruits, and exhibits antioxidant and antineoplastic effects. Here, we showed that EA attenuated the formation and function of osteoclast dose-dependently. The underlying mechanism was further discovered by western blot, immunofluorescence assay, and luciferase assay, which elucidated that EA suppressed osteoclastogenesis and bone resorption mainly through attenuating receptor activator of nuclear factor-κB (NF-κB) ligand-induced NF-κB activation and extracellular signal-regulated kinase signaling pathways, accompanied by decreased protein expression of nuclear factor of activated T-cells calcineurin-dependent 1 and c-Fos. Moreover, EA inhibits osteoclast marker genes expression including Dc-stamp, Ctsk, Atp6v0d2, and Acp5. Intriguingly, we also found that EA treatment could significantly protect ovariectomy-induced bone loss in vivo. Conclusively, this study suggested that EA might have the therapeutic potentiality for preventing or treating osteoporosis.

C-phycocyanin attenuates RANKL-induced osteoclastogenesis and bone resorption in vitro through inhibiting ROS levels, NFATc1 and NF-κB activation

Excessive bone loss occurs in inflammatory disorders such as periodontitis and osteoporosis. The underlying mechanism is related to the differentiation of macrophages into multinucleated giant osteoclasts and their bone resorptive activity. C-Phycocyanin (C-PC) is a phycobiliprotein extracted from the blue-green algae, which has been shown to have various pharmacological effects. The role of C-PC on bone metabolism needs revelation. In this study, we determined the effectiveness of C-PC as an inhibitor of osteoclast differentiation, activity, and survival in vitro. We found that C-PC strongly inhibited the differentiation of macrophages to TRAP-positive osteoclasts, distinctive osteoclast specific podosomal organization, and dentine matrix resorption without any cytotoxicity. Also, it suppressed the expression of osteoclast specific markers, such as cathepsin K and integrin β3 at mRNA and protein levels. RANKL mediated signaling utilizes reactive oxygen species (ROS) for the differentiation of osteoclasts. C-PC attenuated RANKL stimulated ROS. Mechanistic studies indicate that C-PC has the potential to reduce osteoclast formation via blocking the degradation of cytosolic IκB-α and hence, the activation of downstream markers such as c-Fos and NFATc1. However, it does not have any effect on osteoblast-mediated bone formation in vitro. Collectively, our data suggest that C-PC may be utilized as a therapeutic agent that can target bone loss mediated by excessive osteoclastic bone resorption without affecting osteoblastic activity in bone.

Costunolide alleviates HKSA-induced acute lung injury via inhibition of macrophage activation

Staphylococcus aureus (S. aureus) infection leads to a severe inflammatory response and causes acute lung injury (ALI), eventually threatening human life. Therefore, it is of importance to find an agent to inhibit inflammation and reduce ALI. Here, we found that costunolide, a sesquiterpene lactone, displays anti-inflammatory effects and ameliorates heat-killed S. aureus (HKSA)-induced pneumonia. Costunolide treatment attenuated HKSA-induced murine ALI in which pulmonary neutrophil infiltration was inhibited, lung edema was decreased, and the production of pro-inflammatory cytokines was significantly reduced. In addition, costunolide dose-dependently inhibited the generation of IL-6, TNF-α, IL-1β, and keratinocyte-derived cytokine (KC), as well as the expression of iNOS, in HKSA-induced macrophages. Furthermore, costunolide attenuated the phosphorylation of p38 MAPK and cAMP response element-binding protein (CREB). Collectively, our findings suggested that costunolide is a promising agent for alleviating bacterial-induced ALI via the inhibition of the MAPK signaling pathways.

Costunolide-A Bioactive Sesquiterpene Lactone with Diverse Therapeutic Potential

Sesquiterpene lactones constitute a major class of bioactive natural products. One of the naturally occurring sesquiterpene lactones is costunolide, which has been extensively investigated for a wide range of biological activities. Multiple lines of preclinical studies have reported that the compound possesses antioxidative, anti-inflammatory, antiallergic, bone remodeling, neuroprotective, hair growth promoting, anticancer, and antidiabetic properties. Many of these bioactivities are supported by mechanistic details, such as the modulation of various intracellular signaling pathways involved in precipitating tissue inflammation, tumor growth and progression, bone loss, and neurodegeneration. The key molecular targets of costunolide include, but are not limited to, intracellular kinases, such as mitogen-activated protein kinases, Akt kinase, telomerase, cyclins and cyclin-dependent kinases, and redox-regulated transcription factors, such as nuclear factor-kappaB, signal transducer and activator of transcription, activator protein-1. The compound also diminished the production and/expression of proinflammatory mediators, such as cyclooxygenase-2, inducible nitric oxide synthase, nitric oxide, prostaglandins, and cytokines. This review provides an overview of the therapeutic potential of costunolide in the management of various diseases and their underlying mechanisms.

Costunolide inhibits matrix metalloproteinases expression and osteoarthritis via the NF‑κB and Wnt/β‑catenin signaling pathways

Osteoarthritis (OA) is a chronic joint disease involving cartilage erosion and matrix degradation. Costunolide is a sesquiterpene lactone that has been demonstrated to exert anti-inflammatory activities in a wide variety of cells. The aim of the present study was to investigate the effect of costunolide in OA treatment, using rat chondrocytes and an OA rat model, in which animals were subjected to destabilization of the medial meniscus. The results revealed that costunolide (2–6 µM) had no effect on chondrocyte viability or phenotype maintenance. Costunolide decreased the interleukin (IL)-1β-induced upregulation of matrix metalloproteinases (MMPs), inducible nitric oxide synthase, cyclooxygenase-2 and IL-6, and increased the expression of collagen II and transcription factor SOX-9, which were inhibited by IL-1β. Costunolide significantly decreased p65 phosphorylation induced by IL-1β and the translocation of p65 into the nucleus of rat chondrocytes, as observed by western blot analysis and immunofluorescence staining. In addition, activation of the Wnt/β-catenin signaling pathway was inhibited by costunolide, as demonstrated by the level of activation of β-catenin and the transfer of β-catenin into the nucleus induced by IL-1β. In vivo, cartilage treated with costunolide exhibited attenuated degeneration and lower Mankin scores compared with the OA group. The present study investigated the anti-osteoarthritic effects of costunolide, which exerted anti-inflammatory activities and inhibited MMPs expression. Taken together, these results indicate that costunolide may have a potential value in the treatment of OA.

Dehydrocostus lactone (DHC) suppresses estrogen deficiency-induced osteoporosis

Osteoporosis is a chronic bone lytic disease, because of inadequate bone ossification and/or excessive bone resorption. Even though drugs are currently available for the treatment of osteoporosis, there remains an unmet need for the development of more specific novel agents with less adverse effects. Dehydrocostus lactone (DHC), a natural sesquiterpene lactone, was previously found to affect the differentiation of inflammatory cells by inhibiting NF-κB pathways, and garnered much interest for its anti-cancer properties via SOCS-mediated cell cycle arrest and apoptosis. As NF-κB pathway plays an essential role in osteoclast differentiation, we sought to discover the biological effects of DHC on osteoclast differentiation and resorptive activity, as well as the underlying mechanisms on these effects. Our research found that DHC inhibited RANKL-induced osteoclast differentiation, bone resorption and osteoclast specific genes expression via suppression of NF-κB and NFAT signaling pathways in vitro. We further demonstrated that DHC protected against ovariectomy (OVX)-induced bone loss in mice and the protective effect was mediated at least in part through the attenuation of NF-κB signaling pathway. Thus, this study provides insight that DHC might be used as a potential pharmacological treatment for osteoporosis.

Costunolide induces micronuclei formation, chromosomal aberrations, cytostasis, and mitochondrial-mediated apoptosis in Chinese hamster ovary cells

Costunolide (CE) is a sesquiterpene lactone well-known for its antihepatotoxic, antiulcer, and anticancer activities. The present study focused on the evaluation of the cytogenetic toxicity and cellular death-inducing potential of CE in CHO cells, an epithelial cell line derived from normal ovary cells of Chinese hamster. The cytotoxic effect denoting MTT assay has shown an IC₅₀ value of 7.56 μM CE, where 50% proliferation inhibition occurs. The oxidative stress caused by CE was confirmed based on GSH depletion induced cell death, conspicuously absent in N-acetylcysteine (GSH precursor) pretreated cells. The evaluation of genotoxic effects of CE using cytokinesis block micronucleus assay and chromosomal aberration test has shown prominent induction of binucleated micronucleated cells and aberrant metaphases bearing chromatid and chromosomal breaks, indicating CE's clastogenic and aneugenic potential. The apoptotic death in CE treated cells was confirmed by an increase in the number of cells in subG1 phase, exhibiting chromatin condensation and membranous phosphatidylserine translocation. The apoptosis induction follows mitochondrial mediation, evident from an increase in the BAX/Bcl-2 ratio, caspase-3/7 activity, and mitochondrial membrane permeability. CE also induces cytostasis in addition to apoptosis, substantiated by the reduced cytokinetic (replicative indices) and mitotic (mitotic indices and histone H3 Ser-10 phosphorylation) activities. Overall, the cellular GSH depletion and potential genotoxic effects by CE led the CHO cells to commit apoptosis and lowered cell division. The observed sensitivity of CHO cells doubts unintended adverse effects of CE on normal healthy cells, suggesting higher essentiality of further studies in order to establish its safety efficacy in therapeutic explorations.

Costunolide increases osteoblast differentiation via ATF4-dependent HO-1 expression in C3H10T1/2 cells

AIMS

Costunolide is a sesquiterpene lactones used in many herbal medicines, with well-established anti-inflammatory and anti-oxidant functions modulating endoplasmic reticulum (ER) stress pathways, and which promotes the expression of anti-oxidant genes. The aim of this study is to investigate whether costunolide is involved in osteoblast differentiation and, determine the mechanisms of differentiation in mesenchymal stem cells.

MAIN METHODS

The cytotoxicity of costunolide was identified using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The mRNA and protein expression levels of osteogenic genes were determined by RT-PCR and Western blot analysis. Alkaline phosphate (ALP) staining and Alizarin red S (ARS) staining were performed to evaluate ALP activity and matrix mineralization. Transcriptional activity was detected using a luciferase reporter assay.

KEY FINDINGS

In this study, we determined that costunolide increased the expression of distal-less homeobox 5 (Dlx5), runt-related transcription factor 2 (Runx2), ALP, and osteocalcin (OC) in C3H10T 1/2 cells. Furthermore, costunolide increased ALP activity and matrix mineralization. Interestingly, costunolide increased ER stress by Bip, activating transcription factor 4 (ATF4) and C/EBP homologous protein (CHOP). However, it did not exert effects on expression of activating transcription factor 6 (ATF6). ATF4 activation has a protective role in oxidative stress, and its transcription induces anti-oxidant genes in cells. Heme oxygenase-1 (HO-1) is a major anti-oxidant enzyme, and is regulated by ATF4. We showed that costunolide treatment increased HO-1 expression. Furthermore, the HO-1 inhibitor, Sn(IV) Protoporphyrin IX dichloride (SnPP) was blocked costunolide-induced Runx2 expression.

SIGNIFICANCE

Our results revealed that costunolide-induced osteoblast differentiation is regulated by ATF4-dependent HO-1 expression.

Glycyrrhizae Radix Inhibits Osteoclast Differentiation by Inhibiting c-Fos-Dependent NFATc1 Expression

Osteoporosis results from imbalance between new bone formation and bone resorption leading to bone loss and is especially troublesome for postmenopausal women who suffer from estrogen deficiency. The ability of new therapeutic agents to treat this bone disease with minimal side effects has been extensively reported on and is continuously being sought out by researchers in this field. Thus, the purpose of this study was to investigate a natural herb that was already being used as a new treatment for osteoporosis. Here we found that water extract of Glycyrrhizae radix (GR) inhibits receptor activator of nuclear factor-[Formula: see text]B ligand (RANKL)-induced osteoclast differentiation in a dose-dependent manner without causing cytotoxicity. The mRNA expression of c-Fos, nuclear factor of activated T cells cytoplasmic 1 (NFATc1), tartrate-resistant acid phosphatase (TRAP), and osteoclast-associated receptor (OSCAR) was considerably inhibited by GR treatment. GR inhibited RANKL-mediated c-Fos and NFATc1 expression in a dose-dependent manner. GR inhibited the degradation of I-[Formula: see text]B in RANKL-stimulated BMMs. However, GR-mediated inhibition of osteoclast differentiation and osteoclast-specific gene expression, including NFATc1, was reversed by ectopic expression of c-Fos. Also, GR significantly inhibited osteoclast formation in mouse calvariae in the presence of IL-1 and prostaglandin E2 (PGE2). Taken together, these results suggest that GR inhibited osteoclast differentiation, raising the possibility that GR may serve as a useful drug for osteoporosis.

Harpagoside Inhibits RANKL-Induced Osteoclastogenesis via Syk-Btk-PLCγ2-Ca(2+) Signaling Pathway and Prevents Inflammation-Mediated Bone Loss

Harpagoside (HAR) is a natural compound isolated from Harpagophytum procumbens (devil's claw) that is reported to have anti-inflammatory effects; however, these effects have not been investigated in the context of bone development. The current study describes for the first time that HAR inhibits receptor activator of nuclear factor κB ligand (RANKL)-induced osteoclastogenesis in vitro and suppresses inflammation-induced bone loss in a mouse model. HAR also inhibited the formation of osteoclasts from mouse bone marrow macrophages (BMMs) in a dose-dependent manner as well as the activity of mature osteoclasts, including filamentous actin (F-actin) ring formation and bone matrix breakdown. This involved a HAR-induced decrease in extracellular signal-regulated kinase (ERK) and c-jun N-terminal kinase (JNK) phosphorylation, leading to the inhibition of Syk-Btk-PLCγ2-Ca(2+) in RANKL-dependent early signaling, as well as the activation of c-Fos and nuclear factor of activated T cells cytoplasmic 1 (NFATc1), which resulted in the down-regulation of various target genes. Consistent with these in vitro results, HAR blocked lipopolysaccharide (LPS)-induced bone loss in an inflammatory osteoporosis model. However, HAR did not prevent ovariectomy-mediated bone erosion in a postmenopausal osteoporosis model. These results suggest that HAR is a valuable agent against inflammation-related bone disorders but not osteoporosis induced by hormonal abnormalities.