Liquiritigenin reduces osteoclast activity in zebrafish model of glucocorticoid-induced osteoporosis

Exploring the osteogenic potential of chitosan-quercetin bio-conjugate: In vitro and in vivo investigations in osteoporosis models

Anti-osteoporotic agents are clinically employed to improve bone health and prevent osteoporotic fractures. In the current study, we investigated the potential of chitosan-quercetin bio-conjugate as an anti-osteoporotic agent. The conjugate was prepared and characterized by FTIR and found notable interactions between chitosan and quercetin. Treating mouse MSCs with the bioconjugate in osteogenic conditions for a week led to elevated expression of differentiation markers Runx2, ALP, and Col-I, as determined by real-time PCR analysis. Evaluation at the cellular level using alizarin red staining demonstrated enhanced calcium deposition in MSCs following treatment with the bioconjugate. Likewise, ELISA analysis showed significantly elevated levels of secretory osteocalcin and osteonectin in groups treated with the conjugate. To broaden our comprehension, we utilized a zebrafish-based in vivo model of dexamethasone-induced osteoporosis to investigate bone regeneration. Toxicity profiling with zebrafish larvae confirmed the bio-conjugate's compatibility at a concentration of 25 μg/ml, underscoring the significance of finding the right dosage. Furthermore, in zebrafish models of osteoporosis, the bio-conjugate demonstrated significant potential for bone regeneration, as indicated by improved bone calcification, callus formation, and overall bone healing in a tail fin fracture model. Additionally, the study revealed that the bio-conjugate inhibited osteoclastic activity, leading to reduced TRAP activity and hydroxyproline release, suggesting its effectiveness in mitigating bone resorption. In conclusion, our research provides compelling evidence for the osteogenic capabilities of the chitosan-quercetin bio-conjugate, highlighting its promising applications in regenerative medicine and the treatment of conditions like osteoporosis.

Phytotherapeutic approach for conquering menopausal syndrome and osteoporosis

Women face a significant change in their reproductive health as menopause sets in. It is marred with numerous physiological changes that negatively impact their quality of life. This universal, transition phase is associated with menopausal and postmenopausal syndrome, which may spread over 2-10 years. This creates a depletion of female hormones causing physical, mental, sexual and social problems and may, later on, manifest as postmenopausal osteoporosis leading to weak bones, causing fractures and ultimately morbidity and mortality. Menopausal hormone therapy generally encompasses the correction of hormone balance through various pharmacological agents, but the associated side effects often lead to cessation of therapy with poor clinical outcomes. However, it has been noticed that phytotherapeutics is trusted by women for the amelioration of symptoms related to menopause and for improving bone health. This could primarily be due to their reduced side effects and lesser costs. This review attempts to bring forth the suitability of phytotherapeutics/herbals for the management of menopausal, postmenopausal syndrome, and menopausal osteoporosis through several published research. It tries to enlist the available botanicals with their key constituents and mechanism of action for mitigating symptoms associated with menopause as well as osteoporosis. It also includes a list of a few herbal commercial products available for these complications. The article also intends to collate the findings of various clinical trials and patents available in this field and provide a window for newer research avenues in this highly important yet ignored health segment.

Chitosan derived chito-oligosaccharides promote osteoblast differentiation and offer anti-osteoporotic potential: Molecular and morphological evidence from a zebrafish model

This study delves into the potential of chito-oligosaccharides (COS) to promote osteoblast differentiation and prevent osteoporosis, utilizing experiments with mouse MSCs and the zebrafish model. The preliminary biocompatibility study affirms the non-toxic nature of COS across various concentrations. In the osteoblast differentiation study, COS enhances ALP activity and calcium deposition at the cellular level. Moreover, COS induces the upregulation of molecular markers, including Runx2, Type I collagen, ALP, osteocalcin, and osteonectin in mouse MSCs. Zebrafish studies further demonstrate COS's anti-osteoporotic effects, showcasing its ability to expedite fin fracture repair, vertebral mineralization, and bone mineralization in dexamethasone-induced osteoporosis models. The scale regenerative study reveals that COS mitigates the detrimental effects of dexamethasone induced osteoclastic activity, reducing TRAP and hydroxyproline levels while elevating the expression of Runx2a MASNA isoform, collagen2α, OC, and ON mRNAs. Additionally, COS enhances calcium and phosphorus levels in regenerated scales, impacting the bone-healthy calcium-to‑phosphorus ratio. The study also suggests that COS modulates the MMP3-Osteopontin-MAPK signaling pathway. Overall, this comprehensive investigation underscores the potential of COS to prevent and treat osteoporosis. Its multifaceted cellular and molecular effects, combined with in vivo bone regeneration and repair, propose that COS may be effective in addressing osteoporosis and related bone disorders. Nonetheless, further research is imperative to unravel underlying mechanisms and optimize clinical applications.

The SIRT1/Nrf2 signaling pathway mediates the anti-pulmonary fibrosis effect of liquiritigenin

BACKGROUND

At present, the treatment options available for idiopathic pulmonary fibrosis are both limited and often come with severe side effects, emphasizing the pressing requirement for innovative therapeutic alternatives. Myofibroblasts, which hold a central role in pulmonary fibrosis, have a close association with the Smad signaling pathway induced by transforming growth factor-β1 (TGF-β1) and the transformation of myofibroblasts driven by oxidative stress. Liquiritigenin, an active compound extracted from the traditional Chinese herb licorice, boasts a wide array of biomedical properties, such as anti-fibrosis and anti-oxidation. The primary objective of this study was to examine the impact of liquiritigenin on bleomycin-induced pulmonary fibrosis in mice and the underlying mechanisms.

METHODS

The anti-pulmonary fibrosis and anti-oxidant effects of liquiritigenin in vivo were tested by HE staining, Masson staining, DHE staining and bio-chemical methods. In vitro, primary mouse lung fibroblasts were treated with TGF-β1 with or without liquiritigenin, the effects of liquiritigenin in inhibiting differentiation of myofibroblasts and facilitating the translocation of Nrf2 were valued using Quantitative real-time polymerase chain reaction (Q-PCR), western blotting and immunofluorescence. Nrf2 siRNA and SIRT1 siRNA were used to investigate the mechanism underlies liquiritigenin's effect in inhibiting myofibroblast differentiation.

RESULTS

Liquiritigenin displayed a dose-dependent reduction effect in bleomycin-induced fibrosis. In laboratory experiments, it was evident that liquiritigenin possessed the ability to enhance and activate sirtuin1 (SIRT1), thereby facilitating the nuclear translocation of Nrf2 and mitigating the oxidative stress-induced differentiation of primary mouse myofibroblasts. Moreover, our investigation unveiled that SIRT1 not only regulated myofibroblast differentiation via Nrf2-mediated antioxidant responses against oxidative stress but also revealed liquiritigenin's activation of SIRT1, enabling direct binding to Smad. This led to decreased phosphorylation of the Smad complex, constrained nuclear translocation, and suppressed acetylation of the Smad complex, ultimately curtailing the transcription of fibrotic factors. Validation in live subjects provided substantial evidence for the anti-fibrotic efficacy of liquiritigenin through the SIRT1/Nrf2 signaling pathway.

CONCLUSIONS

Our findings imply that targeting myofibroblast differentiation via the SIRT1/Nrf2 signaling pathway may constitute a pivotal strategy for liquiritigenin-based therapy against pulmonary fibrosis.

Flavonoids from Dalbergia cochinchinensis: Impact on osteoclastogenesis

Background/purpose

Dalbergia cochinchinensi has been widely used in traditional medicine because of its flavonoids. This study examined which components in D. cochinchinensis were capable of reducing or even stimulating the formation of bone-resorbing osteoclasts.

Materials and methods

We have isolated subfamilies of chalcones (isoliquiritigenin, butein), flavones (7-hydroxy-6-methoxyflavone) and neoflavanoids (5-methoxylatifolin), and performed an in vitro bioassay on osteoclastogenesis. The flavonoids were tested for their potential to change the expression of tartrate-resistant acid phosphatase (TRAP) and cathepsin K (CTSK) in murine bone marrow cultures being exposed to RANKL, M-CSF and TGF-β1 using RT-PCR, histochemistry and immunoassay.

Results

We could confirm that isoliquiritigenin and butein significantly lower the expression of TRAP and CTSK in this setting. Moreover, histochemistry supported the decrease of TRAP by the chalcones. We further observed a trend towards an increase of osteoclastogenesis in the presence of 5-methoxylatifolin and 7-hydroxy-6-methoxyflavone, particular in bone marrow cultures being exposed to RANKL and M-CSF. Consistently, the anti-inflammatory activity was restricted to isoliquiritigenin and butein in murine RAW 264.7 inflammatory macrophages stimulated by lipopolysaccharide (LPS). With respect to osteoblastogenesis, neither of the flavonoids but butyrate, a short chain fatty acid, increased the osteogenic differentiation marker alkaline phosphatase activity in ST2 murine mesenchymal cells.

Conclusion

We have identified two flavonoids from D. cochinchinensis with a potential pro-osteoclastogenic activity and confirm the anti-osteoclastogenic activity of isoliquiritigenin and butein.

An Ethnopharmaceutical Study on the Hypolipidemic Formulae in Taiwan Issued by Traditional Chinese Medicine Pharmacies

Globally, approximately one-third of ischemic heart diseases are due to hyperlipidemia, which has been shown to cause various metabolic disorders. This study was aimed to disassemble and analyze hypolipidemic formulae sold by traditional Chinese medicine (TCM) pharmacies. Using commonly used statistical parameters in ethnopharmacology, we identified the core drug combination of the hypolipidemic formulae, thereby exploring the strategy by which the Taiwanese people select hypolipidemic drugs. Most important of all, we preserved the inherited knowledge of TCM. We visited 116 TCM pharmacies in Taiwan and collected 91 TCM formulae. The formulae were mainly disassembled by macroscopical identification, and the medicinal materials with a relative frequency of citation (RFC) >0.2 were defined as commonly used medicinal materials. Subsequently, we sorted the information of medicinal materials recorded in the Pharmacopeia, searched for modern pharmacological research on commonly used medicinal materials using PubMed database, and visualized data based on the statistical results. Finally, the core hypolipidemic medicinal materials used in folk medicine were obtained. Of the 91 TCM formulae collected in this study, 80 traditional Chinese medicinal materials were used, belonging to 43 families, predominantly Lamiaceae. Roots were the most commonly used part as a medicinal material. There were 17 commonly used medicinal materials. Based on medicinal records in Pharmacopeia, most flavors and properties were warm and pungent, the majority traditional effects were “tonifying and replenishing” and “blood-regulating.” Besides, the targeted diseases searching from modern pharmacological studies were diabetes mellitus and dyslipidemia. The core medicinal materials consisted of Astragalus mongholicus Bunge and Crataegus pinnatifida Bunge, and the core formulae were Bu-Yang-Huan-Wu-Tang and Xie-Fu-Zhu-Yu-Tang. In addition, 7 groups of folk misused medicinal materials were found. Although these TCMs have been used for a long period of time, their hypolipidemic mechanisms remain unclear, and further studies are needed to validate their safety and efficacy.

Zebrafish models for glucocorticoid-induced osteoporosis

Glucocorticoid-induced osteoporosis (GIOP) is the most common form of secondary osteoporosis due to excessive or long-term glucocorticoid administration, disturbing the homeostasis between bone formation and bone resorption. The bone biology of zebrafish shares a high degree of similarities with mammals. In terms of molecular level, genes and signaling pathways related to skeletogenesis are also highly correlated between zebrafish and humans. Therefore, zebrafish have been utilized to develop multiple GIOP models. Taking advantage of the transparency of zebrafish larvae, their skeletal development and bone mineralization can be readily visualized through in vivo staining without invasive experimental handlings. Moreover, the feasibility of using scales or fin rays to study bone remodeling makes adult zebrafish an ideal model for GIOP research. Here, we reviewed current zebrafish models for GIOP research, focused on the tools and methods established for examining bone homeostasis. As an in vivo, convenient, and robust model, zebrafish have an advantage in performing high-throughput drug screening and could be used to investigate the action mechanisms of therapeutic drugs.

Traditional Chinese Medicine as a Promising Strategy for the Treatment of Alzheimer's Disease Complicated With Osteoporosis

Alzheimer’s disease (AD) and osteoporosis (OP) are progressive degenerative diseases caused by multiple factors, placing a huge burden on the world. Much evidence indicates that OP is a common complication in AD patients. In addition, there is also evidence to show that patients with OP have a higher risk of AD than those without OP. This suggests that the association between the two diseases may be due to a pathophysiological link rather than one disease causing the other. Several in vitro and in vivo studies have also proved their common pathogenesis. Based on the theory of traditional Chinese medicine, some classic and specific natural Chinese medicines are widely used to effectively treat AD and OP. Current evidence also shows that these treatments can ameliorate both brain damage and bone metabolism disorder and further alleviate AD complicated with OP. These valuable therapies might provide effective and safe alternatives to major pharmacological strategies.

Functional Validation of Osteoporosis Genetic Findings Using Small Fish Models

The advancement of human genomics has revolutionized our understanding of the genetic architecture of many skeletal diseases, including osteoporosis. However, interpreting results from human association studies remains a challenge, since index variants often reside in non-coding regions of the genome and do not possess an obvious regulatory function. To bridge the gap between genetic association and causality, a systematic functional investigation is necessary, such as the one offered by animal models. These models enable us to identify causal mechanisms, clarify the underlying biology, and apply interventions. Over the past several decades, small teleost fishes, mostly zebrafish and medaka, have emerged as powerful systems for modeling the genetics of human diseases. Due to their amenability to genetic intervention and the highly conserved genetic and physiological features, fish have become indispensable for skeletal genomic studies. The goal of this review is to summarize the evidence supporting the utility of Zebrafish (Danio rerio) for accelerating our understanding of human skeletal genomics and outlining the remaining gaps in knowledge. We provide an overview of zebrafish skeletal morphophysiology and gene homology, shedding light on the advantages of human skeletal genomic exploration and validation. Knowledge of the biology underlying osteoporosis through animal models will lead to the translation into new, better and more effective therapeutic approaches.

Animal Model for Glucocorticoid Induced Osteoporosis: A Systematic Review from 2011 to 2021

Clinical and experimental data have shown that prolonged exposure to GCs leads to bone loss and increases fracture risk. Special attention has been given to existing emerging drugs that can prevent and treat glucocorticoid-induced osteoporosis GIOP. However, there is no consensus about the most relevant animal model treatments on GIOP. In this systematic review, we aimed to examine animal models of GIOP centering on study design, drug dose, timing and size of the experimental groups, allocation concealment, and outcome measures. The present review was written according to the PRISMA 2020 statement. Literature searches were performed in the PubMed electronic database via Mesh with the publication date set between April, 2011, and February 2021. A total of 284 full-text articles were screened and 53 were analyzed. The most common animal species used to model GIOP were rats (66%) and mice (32%). In mice studies, males (58%) were preferred and genetically modified animals accounted for 28%. Our work calls for a standardization of the establishment of the GIOP animal model with better precision for model selection. A described reporting design, conduction, and selection of outcome measures are recommended.

Fractions of Shen-Sui-Tong-Zhi Formula Enhance Osteogenesis Via Activation of β-Catenin Signaling in Growth Plate Chondrocytes

Background: Shen-sui-tong-zhi formula (SSTZF) has been used to treat osteoporosis for decades and shows excellent clinical efficacy. This article aims to explore the optimal anti-osteoporotic ingredient and its precise mechanisms in mice models.

Methods: In this study, we first screened the optimal anti-osteoporosis fraction of SSTZF extract in vivo, and then further explored the mechanism of its effects both in vivo and in vitro. Ten-week-old female C57BL/6J mice were administrated with each fraction of SSTZF. At 10 weeks after ovariectomy (OVX), femurs were collected for tissue analyses, including histology, micro-CT, biomechanical tests, and immunohistochemistry for ALP, FABP4, and β-catenin. Additionally, we also evaluated the mRNA expression level of ALP and FABP4 and the protein expression level of β-catenin after being treated with SSTZF extract in C₃H₁₀T1/2 cells. Moreover, we investigated the anti-osteoporosis effect of SSTZF extract on mice with β-catenin conditional knockout in growth plate chondrocytes (β-catenin^Gli1ER mice) through μCT, histology, and immunohistochemistry analyzes.

Results: At 10 weeks after treatment, osteoporosis-like phenotype were significantly ameliorated in SSTZF n-butanol extract (SSTZF-NB) group mice, as indicated by increased trabecular bone area and ALP content, and decreased lipid droplet area and FABP4 content. No such improvements were observed after being treated with other extracts, demonstrating that SSTZF-NB is the optimal anti-osteoporosis fraction. Additionally, the elevated β-catenin was revealed in both OVX mice and C₃H₁₀T1/2 cells with SSTZF-NB administered. Furthermore, a significant osteoporosis-like phenotype was observed in β-catenin^Gli1ER mice as expected. However, SSTZF-NB failed to rescue the deterioration in β-catenin^Gli1ER mice, no significant re-upregulated ALP and downregulated FABP4 were observed after being treated with SSTZF-NB, demonstrating that SSTZF-NB prevents bone loss mainly via β-catenin signaling.

Conclusion: SSTZF-NB enhances osteogenesis mainly via activation of β-catenin signaling in growth plate chondrocytes. SSTZF-NB is the optimal anti-osteoporosis fraction of SSTZF and it can be considered a salutary alternative therapeutic option for osteoporosis.

Fish Models of Induced Osteoporosis

Osteopenia and osteoporosis are bone disorders characterized by reduced bone mineral density (BMD), altered bone microarchitecture and increased bone fragility. Because of global aging, their incidence is rapidly increasing worldwide and novel treatments that would be more efficient at preventing disease progression and at reducing the risk of bone fractures are needed. Preclinical studies are today a major bottleneck to the collection of new data and the discovery of new drugs, since they are commonly based on rodent in vivo systems that are time consuming and expensive, or in vitro systems that do not exactly recapitulate the complexity of low BMD disorders. In this regard, teleost fish, in particular zebrafish and medaka, have recently emerged as suitable alternatives to study bone formation and mineralization and to model human bone disorders. In addition to the many technical advantages that allow faster and larger studies, the availability of several fish models that efficiently mimic human osteopenia and osteoporosis phenotypes has stimulated the interest of the academia and industry toward a better understanding of the mechanisms of pathogenesis but also toward the discovery of new bone anabolic or antiresorptive compounds. This mini review recapitulates the in vivo teleost fish systems available to study low BMD disorders and highlights their applications and the recent advances in the field.

Assessing the effects of textile leachates in fish using multiple testing methods: From gene expression to behavior

The textile industry, while of major importance in the world economy, is a toxic industry utilizing and emitting thousands of chemical substances into the aquatic environment. The aim of this project was to study the potentially harmful effects associated with the leaching of chemical residues from three different types of textiles: sportswear, children's bath towels, and denim using different fish models (cell lines, fish larvae and juvenile fish). A combination of in vitro and in vivo test systems was used. Numerous biomarkers, ranging from gene expression, cytotoxicity and biochemical analysis to behavior, were measured to detect effects of leached chemicals. Principle findings indicate that leachates from all three types of textiles induced cytotoxicity on fish cell lines (RTgill-W1). Leachates from sportswear and towels induced mortality in zebrafish embryos, and chemical residues from sportswear reduced locomotion responses in developing larval fish. Sportswear leachate increased Cyp1a mRNA expression and EROD activity in liver of exposed brown trout. Leachates from towels induced EROD activity and VTG in rainbow trout, and these effects were mitigated by the temperature of the extraction process. All indicators of toxicity tested showed that exposure to textile leachate can cause adverse reactions in fish. These findings suggested that chemical leaching from textiles from domestic households could pose an ecotoxicological threat to the health of the aquatic environment.

Isoliquiritigenin Derivatives Inhibit RANKL-Induced Osteoclastogenesis by Regulating p38 and NF-κB Activation in RAW 264.7 Cells

Bone diseases may not be imminently life-threatening or a leading cause of death such as heart diseases or cancers. However, as aging population grows in almost every part of the world, they surely impose significant socioeconomic burden on the society, not to mention the patients and their families. Osteoporosis is the most common type of bone disease, which frequently develops in seniors, especially in postmenopausal women. Although currently several anti-osteoclastic drugs designed to suppress excessive osteoclast activation, a major cause of osteoporosis, are commercially available, accompanying adverse effects ranging from mild to severe have been reported as well. Natural products have become increasingly popular because of their effectiveness with fewer side effects. Isoliquiritigenin (ILG), a natural flavonoid from licorice, has been reported to suppress osteoclast differentiation and activation. In the present study, newly synthesized ILG derivatives were screened for their anti-osteoporotic activity as more potent substitute candidates to ILG. Out of the 12 ILG derivatives tested, two compounds demonstrated significantly improved bone loss in vitro by inhibiting both osteoclastogenesis and osteoclast activity. The results of the present study indicate that these compounds may serve as a potential drug for osteoporosis and warrant further studies to evaluate their in vivo efficacy.