Zinc modifies the effect of phyto-oestrogens on osteoblast and osteoclast differentiation in vitro

Coumarins as versatile therapeutic phytomolecules: A systematic review

BACKGROUND

Coumarins, abundantly distributed in a plethora of biologically active compounds, serve as a fundamental motif in numerous natural products, drugs, and therapeutic leads. Despite their small size, they exhibit a diverse range of biological activities, intriguing researchers with their immense pharmacological potential.

PURPOSE

This study consolidates the evidence regarding the essential role of coumarins in modern drug discovery, exploring their broad-spectrum pharmaceutical effects, structural versatility, and mechanisms of action across various domains.

METHODS

For literature search, we utilized PubMed, Google scholar, and SciFinder databases. Keyword and keyword combinations such as "coumarins", "natural coumarins", "specific natural coumarins for particular diseases", and "therapeutic effects" were employed to retrieve relevant studies. The search encompassed articles published between 2005 and 2023. Selection criteria included studies reporting on the pharmacological activities of natural coumarins against various diseases.

RESULTS

The results highlight the therapeutic potential of natural coumarins against various diseases, demonstrating anti-cancer, anti-oxidant, and anti-inflammatory activities. They also act as monoamine oxidase inhibitors and phosphodiesterase inhibitors, and as anti-thrombotic, anti-diabetic, and hepatoprotective agents. They also show efficacy against diabetic nephropathy, neurodegenerative diseases, microbial infections and many other diseases.

CONCLUSION

This review underscores the significant role of natural coumarins in medicinal chemistry and drug discovery. Their diverse biological activities and structural versatility make them promising therapeutic agents. This study serves as a catalyst for further research in the field, aiming to address emerging challenges and opportunities in drug development.

Effect of hyperoside on osteoporosis in ovariectomized mice through estrogen receptor α/ITGβ3 signaling pathway

Osteoporosis is a highly prevalent bone metabolic disease in menopause due to estrogen deficiency. Hyperoside is a main compound in Semen cuscutae. Our team previously reported that Semen cuscutae has anti osteoporosis effect on ovariectomized mice by inhibiting bone resorption of osteoclasts. However, it is still unclear whether hyperoside affects osteoclast differentiation and bone resorption, and whether its anti-osteoporosis effect is related to an estrogen-like effect. This study investigates the potential mechanism of hyperoside's anti-osteoporotic effect by examining its impact on osteoclast differentiation and its relationship with the estrogen receptor. DXA, Micro-CT, TRAP staining, HE, and ELISA were used to assess the impact of hyperoside on OVX-induced osteoporosis. The effect of hyperoside on octeoclast differentiation was evaluated using TRAP activity assay, TRAP staining, F-actin staining. The activation of the estrogen receptor by hyperoside and its relationship with osteoclast differentiation were detected using dual-luciferase reporter assay and estrogen receptor antagonists. Our findings revealed that hyperoside (20-80 mg/kg) protect against OVX-induced osteoporosis, including increasing BMD and BMC and improving bone microstructure. Hyperoside inhibited osteoclast differentiation in a concentration dependent manner, whereas estrogen receptor α antagonists reversed its inhibitory effect osteoclast differentiation. Western blot results suggested that hyperoside inhibited TRAP, RANKL, c-Fos and ITG β3 protein expression in osteoclast or femoral bone marrow of ovariectomized mice. Our findings suggest that hyperoside inhibits osteoclast differentiation and protects OVX-induced osteoporosis through the ERα/ITGβ3 signaling pathway.

Marein Prevented LPS-Induced Osteoclastogenesis by Regulating the NF-κB Pathway In Vitro

Many bone diseases such as osteolysis, osteomyelitis, and septic arthritis are caused by gram-negative bacterial infection, and lipopolysaccharide (LPS), a bacterial product, plays an essential role in this process. Drugs that inhibit LPS-induced osteoclastogenesis are urgently needed to prevent bone destruction in infective bone diseases. Marein, a major bioactive compound of Coreopsis tinctoria, possesses anti-oxidative, anti-inflammatory, anti-hypertensive, anti-hyperlipidemic, and anti-diabetic effects. In this study, we measured the effect of marein on RAW264.7 cells by CCK-8 assay and used TRAP staining to determine osteoclastogenesis. The levels of osteoclast-related genes and NF-κB-related proteins were then analyzed by western blot, and the levels of pro-inflammatory cytokines were quantified by ELISA. Our results showed that marein inhibited LPS-induced osteoclast formation by osteoclast precursor RAW264.7 cells. The effect of marein was related to its inhibitory function on expressions of pro-inflammatory cytokines and osteoclast-related genes containing RANK, TRAF6, MMP-9, CK, and CAII. Additionally, marein leads to markedly inhibited NF-κB signaling pathway activation in LPS-induced RAW264.7 cells. Concurrently, when the NF-κB signaling pathway was inhibited, osteoclast formation and pro-inflammatory cytokine expression were decreased. Collectively, marein could inhibit LPS-induced osteoclast formation in RAW264.7 cells via regulating the NF-κB signaling pathway. Our data demonstrate that marein might be a potential drug for bacteria-induced bone destruction disease. Our findings provide new insights into LPS-induced bone disease.

Recent Advances of Osterix Transcription Factor in Osteoblast Differentiation and Bone Formation

With increasing life expectations, more and more patients suffer from fractures either induced by intensive sports or other bone-related diseases. The balance between osteoblast-mediated bone formation and osteoclast-mediated bone resorption is the basis for maintaining bone health. Osterix (Osx) has long been known to be an essential transcription factor for the osteoblast differentiation and bone mineralization. Emerging evidence suggests that Osx not only plays an important role in intramembranous bone formation, but also affects endochondral ossification by participating in the terminal cartilage differentiation. Given its essentiality in skeletal development and bone formation, Osx has become a new research hotspot in recent years. In this review, we focus on the progress of Osx's function and its regulation in osteoblast differentiation and bone mass. And the potential role of Osx in developing new therapeutic strategies for osteolytic diseases was discussed.

In vitro osteogenesis of rat bone marrow mesenchymal cells on PEEK disks with heat-fixed apatite by CO2 laser bonding

Background

Polyether-ether-ketone (PEEK) is increasingly being used for spinal applications. However, because of its biologically inactive nature, there are risks of false joint loosening and sinking. PEEK materials are coated with apatite to enhance the osteoconductive properties. In this study, we aimed to evaluate whether strontium apatite stimulate osteogenesis on the surface of PEEK by using the CO₂ laser technique.

Methods

We prepared non-coated disks, laser-exposed disks without apatite, and four types of apatite-coated by laser PEEK disks (hydroxyapatite (HAP), strontium hydroxyapatite (SrHAP), silicate-substituted strontium apatite (SrSiP), and silicate-zinc-substituted strontium apatite (SrZnSiP)). A part of the study objective was testing various types of apatite coatings. Bone marrow mesenchymal cells (BMSCs) of rats were seeded at a density of 2 × 10⁴/cm² onto each apatite-coated, non-coated, and laser-irradiated PEEK disks. The disks were then placed in osteogenic medium, and alkaline phosphatase (ALP) staining and Alizarin red staining of BMSCs grown on PEEK disks were performed after 14 days of culture. The concentrations of osteocalcin (OC) and calcium in the culture medium were measured on days 8 and 14 of cell culture. Furthermore, mRNA expression of osteocalcin, ALP, runt-related transcription factor 2 (Runx2), collagen type 1a1 (Col1a1), and collagen type 4a1 (Col4a1) was evaluated by qPCR.

Results

The staining for ALP and Alizarin red S was more strongly positive on the apatite-coated PEEK disks compared to that on non-coated or laser-exposed without coating PEEK disks. The concentration of osteocalcin secreted into the medium was also significantly higher in case of the SrHAP, SrSiP, and SrZnSiP disks than that in the case of the non-coated on day14. The calcium concentration in the PEEK disk was significantly lower in all apatite-coated disks than that in the pure PEEK disks on day 14. In qPCR, OC and ALP mRNA expression was significantly higher in the SrZnSiP disks than that in the pure PEEK disks.

Conclusions

Our findings demonstrate that laser bonding of apatite—along with trace elements—on the PEEK disk surfaces might provide the material with surface property that enable better osteogenesis.

Supplementary information

Supplementary information accompanies this paper at 10.1186/s12891-020-03716-1.

Conditional mouse models support the role of SLC39A14 (ZIP14) in Hyperostosis Cranialis Interna and in bone homeostasis

Hyperostosis Cranialis Interna (HCI) is a rare bone disorder characterized by progressive intracranial bone overgrowth at the skull. Here we identified by whole-exome sequencing a dominant mutation (L441R) in SLC39A14 (ZIP14). We show that L441R ZIP14 is no longer trafficked towards the plasma membrane and excessively accumulates intracellular zinc, resulting in hyper-activation of cAMP-CREB and NFAT signaling. Conditional knock-in mice overexpressing L438R Zip14 in osteoblasts have a severe skeletal phenotype marked by a drastic increase in cortical thickness due to an enhanced endosteal bone formation, resembling the underlying pathology in HCI patients. Remarkably, L438R Zip14 also generates an osteoporotic trabecular bone phenotype. The effects of osteoblastic overexpression of L438R Zip14 therefore mimic the disparate actions of estrogen on cortical and trabecular bone through osteoblasts. Collectively, we reveal ZIP14 as a novel regulator of bone homeostasis, and that manipulating ZIP14 might be a therapeutic strategy for bone diseases.

Zinc-Induced Effects on Osteoclastogenesis Involves Activation of Hyperpolarization-Activated Cyclic Nucleotide Modulated Channels via Changes in Membrane Potential

Zinc is a trace element in the mammalian body, and increasing evidence shows its critical role in bone development and osteoclastogenesis. The relationships between zinc and voltage-gated ion channels have been reported; however, the effects of zinc on membrane potential and the related ion channels remain unknown. In this study, we found that zinc-induced hyperpolarization in RAW264.7 cells (RAW) was promoted by inhibition of hyperpolarization-activated cyclic nucleotide modulated channels (HCNs). In electrophysiological experiments with RAW-derived osteoclasts, HCNs were functional and generated hyperpolarization-activated inward currents (Ih) with properties similar to the Ih recorded in excitable cells such as neurons and cardiomyocytes. Quantitative PCR of HCN subunits HCN1 and HCN4 in RAW cells showed detectable levels of HCN1 mRNA and HCN4 expression was the highest of all four subunits. HCN4 knockdown decreased osteoclastic Ih and promoted osteoclastogenesis in the presence of zinc, but not in the absence of zinc. To determine the effect of membrane hyperpolarization on osteoclastogenesis, we developed a light-controllable membrane potential system in RAW cells by stably expressing the light-driven outward proton pump, Archaerhodopsin3 (Arch). Arch activation by yellow-green light hyperpolarizes the cell membrane. Light-induced hyperpolarization accelerated osteoclast differentiation in the presence of receptor activator of nuclear factor kappa-B ligand (RANKL). Thus, HCN activation reduced the hyperpolarization-related promotion of osteoclast differentiation in the presence of zinc. This study revealed the novel role of HCN and membrane potential in non-excitable osteoclasts.

A metabolomics study of the inhibitory effect of 17-beta-estradiol on osteoclast proliferation and differentiation

Estradiol is a major drug used clinically to alleviate osteoporosis, partly through inhibition of the activity of osteoclasts, which play a crucial role in bone resorption. So far, little is known about the effects of estradiol on osteoclast metabolism. In this study, ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC/MS)-based metabolomics strategy was used to investigate the metabolite response to 17β-estradiol in mouse osteoclast RAW264.7, a commonly used cell model for studying osteoporosis. Our results showed that the application of estradiol altered the levels of 27 intracellular metabolites, including lysophosphatidylcholines (LysoPCs), other lipids and amino acid derivants. The changes of all the 27 metabolites were observed in the study of estradiol induced osteoclast proliferation inhibition (1 μM estradiol applied), while the changes of only 18 metabolites were observed in the study of differentiation inhibition (0.1 μM estradiol applied). Further pathway impact analysis determined glycerophospholipid metabolism as the main potential target pathway of estradiol, which was further confirmed by LCAT (phosphatidylcholine-sterol acyltransferase) activity changes and lipid peroxidative product (MDA, methane dicarboxylic aldehyde) changes caused by estradiol. Additionally, we found that estradiol significantly decreased intracellular oxidative stress during cell proliferation but not during cell differentiation. Our study suggested that estradiol generated a highly condition-dependent influence on osteoclast metabolism.

Pueraria mirifica extract and puerarin enhance proliferation and expression of alkaline phosphatase and type I collagen in primary baboon osteoblasts

Phytoestrogen-rich Pueraria mirifica (PM) tuberous extract is a promising candidate for the development of anti-osteoporosis drugs for postmenopausal women, but its action has never been validated in humans or in non-human primates, which are more closely related to humans than rodents. In vitro study of non-human primate osteoblasts is thus fundamental to prepare for in vivo studies of phytoestrogen effects on primate bone. This study aimed to establish a culture system of baboon primary osteoblasts and to investigate the effects of PM extract and its phytoestrogens on these cells. Primary osteoblasts from adult baboon fibulae exhibited osteoblast characteristics in regard to proliferation, differentiation, mineralization, and estrogen receptor expression. They responded to 17β-estradiol by increased proliferation rate and mRNA levels of alkaline phosphatase (ALP), type I collagen, and osteocalcin. After being exposed for 48 h to 100 μg/ml PM extract, 1000 nM genistein, or 1000 nM puerarin, primary baboon osteoblasts markedly increased the rate of proliferation and mRNA levels of ALP and type I collagen without changes in Runx2, osterix, or osteocalcin expression. PM extract, genistein, and puerarin also decreased the RANKL/OPG ratio, suggesting that they could decrease osteoclast-mediated bone resorption. However, neither PM extract nor its phytoestrogens altered calcium deposition in osteoblast culture. In conclusion, we have established baboon primary osteoblast culture, which is a new tool for bone research and drug discovery. Furthermore, the present results provide substantial support for the potential of PM extract and its phytoestrogens to be developed as therapeutic agents against bone fragility.