Osthole improves therapy for osteoporosis through increasing autophagy of mesenchymal stem cells

Bone protective effects of the polysaccharides from Grifola frondosa on ovariectomy-induced osteoporosis in mice via inhibiting PINK1/Parkin signaling, oxidative stress and inflammation

BACKGROUND

Polysaccharides from Grifola frondosa(GFP) have gained worldwide attention owing to their promising biological activities and potential health benefits.

PURPOSE

This study aimed to investigate the effects of GFP on alleviation of osteoporosis in ovariectomized (OVX) mice and examine the underlying mechanism.

METHOD

A mouse model of postmenopausal osteoporosis was established by OVX method, Forty eight C57BL/6 female mice were randomly divided into Normal group, OVX alone (Model group, n = 8), OVX + 10 mg/kg GFP (GFP-L group, n = 8), OVX + 20 mg/kg GFP (GFP-M group, n = 8), OVX + 40 mg/kg GFP (GFP-H group, n = 8), OVX + 10 mg/kg Estradiol valerate (Positive group, n = 8).

RESULTS

The results showed that compared with Model group, the concentrations of interleukin (IL)-1β, interleukin (IL)-6 and Tumor necrosis factor-α (TNF-α) were significantly reduced, the activity of superoxide dismutase (SOD) and glutathione (GSH) were significantly increased, the content of myeloperoxidase (MPO) and malondialdehyde (MDA) were significantly reduced, and the proteins levels of PINK1, Parkin, Beclin-1 and LC3-II were significantly decreased in the GFP groups.

CONCLUSION

This study demonstrates that GFP alleviates ovariectomy-induced osteoporosis via reduced secretion of inflammatory cytokines, improvement in the oxidative stress status in the body, and inhibition of the PINK1/Parkin signaling pathway.

Natural compounds and mesenchymal stem cells: implications for inflammatory-impaired tissue regeneration

Inflammation is a common and important pathological process occurring in any part of the body and relating to a variety of diseases. Effective tissue repair is critical for the survival of impaired organisms. Considering the side effects of the currently used anti-inflammatory medications, new therapeutic agents are urgently needed for the improvement of regenerative capacities of inflammatory-impaired tissues. Mesenchymal stromal stem/progenitor cells (MSCs) are characterized by the capabilities of self-renewal and multipotent differentiation and exhibit immunomodulatory capacity. Due to the ability to modulate inflammatory phenotypes and immune responses, MSCs have been considered as a potential alternative therapy for autoimmune and inflammatory diseases. Natural compounds (NCs) are complex small multiple-target molecules mostly derived from plants and microorganisms, exhibiting therapeutic effects in many disorders, such as osteoporosis, diabetes, cancer, and inflammatory/autoimmune diseases. Recently, increasing studies focused on the prominent effects of NCs on MSCs, including the regulation of cell survival and inflammatory response, as well as osteogenic/adipogenic differentiation capacities, which indicate the roles of NCs on MSC-based cytotherapy in several inflammatory diseases. Their therapeutic effects and fewer side effects in numerous physiological processes, compared to chemosynthetic drugs, made them to be a new therapeutic avenue combined with MSCs for impaired tissue regeneration. Here we summarize the current understanding of the influence of NCs on MSCs and related downstream signaling pathways, specifically in pathological inflammatory conditions. In addition, the emerging concepts through the combination of NCs and MSCs to expand the therapeutic perspectives are highlighted. A promising MSC source from oral/dental tissues is also discussed, with a remarkable potential for MSC-based therapy in future clinical applications.

Review on the protective activity of osthole against the pathogenesis of osteoporosis

Osteoporosis (OP), characterized by continuous bone loss and increased fracture risk, has posed a challenge to patients and society. Long-term administration of current pharmacological agents may cause severe side effects. Traditional medicines, acting as alternative agents, show promise in treating OP. Osthole, a natural coumarin derivative separated from Cnidium monnieri (L.) Cusson and Angelica pubescens Maxim. f., exhibits protective effects against the pathological development of OP. Osthole increases osteoblast-related bone formation and decreases osteoclast-related bone resorption, suppressing OP-related fragility fracture. In addition, the metabolites of osthole may exhibit pharmacological effectiveness against OP development. Mechanically, osthole promotes osteogenic differentiation by activating the Wnt/β-catenin and BMP-2/Smad1/5/8 signaling pathways and suppresses RANKL-induced osteoclastogenesis and osteoclast activity. Thus, osthole may become a promising agent to protect against OP development. However, more studies should be performed due to, at least in part, the uncertainty of drug targets. Further pharmacological investigation of osthole in OP treatment might lead to the development of potential drug candidates.

Osthole inhibits malignant phenotypes and induces ferroptosis in KRAS-mutant colorectal cancer cells via suppressing AMPK/Akt signaling

PURPOSE

Ferroptosis is a form of cell death driven by iron-dependent lipid peroxidation. Intriguingly, KRAS-mutant cancers are particularly vulnerable to ferroptosis. Osthole is a natural coumarin extracted from Cnidium spp. and other Apiaceous plants. In the present study, we explored the antitumor potential of osthole in KRAS-mutant colorectal cancer (CRC) cells.

METHODS

Cell viability assay, EdU incorporation assay, flow cytometry, tumor xenograft model, western blot, immunochemistry staining, immunofluorescence, transcriptome RNA sequencing and quantitative reverse transcription-PCR were performed to evaluate the influence of osthole treatment on KRAS-mutant CRC cells.

RESULTS

We found that osthole treatment suppressed proliferation and tumor growth of KRAS-mutant CRC cell lines HCT116 and SW480. Moreover, osthole treatment increased ROS production and induced ferroptosis. Osthole treatment also promoted autophagy, but inhibition of autophagy by ATG7 knockdown or 3-MA showed no influence on osthole-induced ferroptosis. In comparison, osthole increased lysosomal activation, and co-treatment with lysosome inhibitor Baf-A1 attenuated osthole-induced ferroptosis. Besides, osthole treatment reduced the phosphorylation of AMPK, Akt and mTOR in HCT116 and SW480 cells, while restored AMPK signaling by AMPK agonist AICAR partially abrogated ferroptosis induced by osthole treatment. Finally, co-treatment with osthole increased the cytotoxicity of cetuximab in KRAS-mutant CRC cells in vitro and in vivo.

CONCLUSION

Our results suggested that the natural product osthole exerted its anticancer effects in KRAS-mutant CRC cells via inducing ferroptosis, and this was partially through inhibiting AMPK/Akt/mTOR signaling. Our results may expand our current knowledge for the use of osthole as an anticancer agent.

Cell death regulation: A new way for natural products to treat osteoporosis

Osteoporosis is a common metabolic bone disease that results from the imbalance of homeostasis within the bone. Intra-bone homeostasis is dependent on a precise dynamic balance between bone resorption by osteoclasts and bone formation by mesenchymal lineage osteoblasts, which comprises a series of complex and highly standardized steps. Programmed cell death (PCD) (e.g., apoptosis, autophagy, ferroptosis, pyroptosis, and necroptosis) is a cell death process that involves a cascade of gene expression events with tight structures. These events play a certain role in regulating bone metabolism by determining the fate of bone cells. Moreover, existing research has suggested that natural products derived from a wide variety of dietary components and medicinal plants modulate the PCDs based on different mechanisms, which show great potential for the prevention and treatment of osteoporosis, thus revealing the emergence of more acceptable complementary and alternative drugs with lower costs, fewer side effects and more long-term application. Accordingly, this review summarizes the common types of PCDs in the field of osteoporosis. Moreover, from the perspective of targeting PCDs, this review also discussed the roles of currently reported natural products in the treatment of osteoporosis and the involved mechanisms. Based on this, this review provides more insights into new molecular mechanisms of osteoporosis and provides a reference for developing more natural anti-osteoporosis drugs in the future.

Autophagy: An important target for natural products in the treatment of bone metabolic diseases

Bone homeostasis depends on a precise dynamic balance between bone resorption and bone formation, involving a series of complex and highly regulated steps. Any imbalance in this process can cause disturbances in bone metabolism and lead to the development of many associated bone diseases. Autophagy, one of the fundamental pathways for the degradation and recycling of proteins and organelles, is a fundamental process that regulates cellular and organismal homeostasis. Importantly, basic levels of autophagy are present in all types of bone-associated cells. Due to the cyclic nature of autophagy and the ongoing bone metabolism processes, autophagy is considered a new participant in bone maintenance. Novel therapeutic targets have emerged as a result of new mechanisms, and bone metabolism can be controlled by interfering with autophagy by focusing on certain regulatory molecules in autophagy. In parallel, several studies have reported that various natural products exhibit a good potential to mediate autophagy for the treatment of metabolic bone diseases. Therefore, we briefly described the process of autophagy, emphasizing its function in different cell types involved in bone development and metabolism (including bone marrow mesenchymal stem cells, osteoblasts, osteocytes, chondrocytes, and osteoclasts), and also summarized research advances in natural product-mediated autophagy for the treatment of metabolic bone disease caused by dysfunction of these cells (including osteoporosis, rheumatoid joints, osteoarthritis, fracture nonunion/delayed union). The objective of the study was to identify the function that autophagy serves in metabolic bone disease and the effects, potential, and challenges of natural products for the treatment of these diseases by targeting autophagy.

Protective Effect of Rho-Associated Protein Kinase (ROCK) Activated by Bone Marrow Mesenchymal Stem Cells on Bone Strength and Osteoblasts in Rats with Osteoporosis

This study assesses BMSCs’ effect on bone strength and osteoblast activity in rats with osteoporosis. 40 SD female rats were assigned into normal (A) group, model (B) group, puerarin (C) group, and BMSCs (D) group followed by analysis of bone strength by small animal bone strength analyzer and the expression of ROCK1 protein in tibia by immunohistochemistry. The bone strength of group B was lower than group A (P < 0.05), and higher in groups C and D than group B (P < 0.05) with further higher in group D than group C (P < 0.05). Group A showed obvious mesh cancellous bone trabecular bone and continuity, compact structure, and group B cells appeared loose and irregular distribution, parts cancellous bone trabeculae decrease and part of the fracture, and arranged in sparse irregular distribution. The decrease of trabecular bone in group C and D is not more obvious than group B and the morphology in group D got better improved than in group C. Group B showed lower proliferation of osteoblasts and ALP activity than group A (P < 0.05) and the proliferation and ALP activity in groups C and D was increased significantly compared with group B (P < 0.05). ROCK1 expression was significantly lower in group B than group A (P < 0.05) higher in groups C and D than group B (P < 0.05). Bone marrow mesenchymal stem cells (BMSCs) can effectively increase the bone strength and activity of osteoblasts in rats with osteoporosis, and promote the activation of ROCK signal.

Osthole: an overview of its sources, biological activities, and modification development

Osthole, also known as osthol, is a coumarin derivative found in several medicinal plants such as Cnidium monnieri and Angelica pubescens. It can be obtained via extraction and separation from plants or total synthesis. Plenty of experiments have suggested that osthole exhibited multiple biological activities covering antitumor, anti-inflammatory, neuroprotective, osteogenic, cardiovascular protective, antimicrobial, and antiparasitic activities. In addition, there has been some research done on the optimization and modification of osthole. This article summarizes the comprehensive information regarding the sources and modification progress of osthole. It also introduces the up-to-date biological activities of osthole, which could be of great value for its use in future research.

Therapeutic Effects of Curcumin against Bladder Cancer: A Review of Possible Molecular Pathways

There are concerns about the increased incidence of cancer both in developing and developed countries. In spite of recent progress in cancer therapy, this disease is still one of the leading causes of death worldwide. Consequently, there have been rigorous attempts to improve cancer therapy by looking at nature as a rich source of naturally occurring anti-tumor drugs. Curcumin is a well-known plant-derived polyphenol found in turmeric. This compound has numerous pharmacological effects such as antioxidant, anti-inflammatory, antidiabetic and anti-tumor properties. Curcumin is capable of suppressing the growth of a variety of cancer cells including those of bladder cancer. Given the involvement of various signaling pathways such as PI3K, Akt, mTOR and VEGF in the progression and malignancy of bladder cancer, and considering the potential of curcumin in targeting signaling pathways, it seems that curcumin can be considered as a promising candidate in bladder cancer therapy. In the present review, we describe the molecular signaling pathways through which curcumin inhibits invasion and metastasis of bladder cancer cells.

Osthole enhances the immunosuppressive effects of bone marrow-derived mesenchymal stem cells by promoting the Fas/FasL system

Thanks to the advantages of easy harvesting and escape from immune rejection, autologous bone marrow‐derived mesenchymal stem cells (BMSCs) are promising candidates for immunosuppressive therapy against inflammation and autoimmune diseases. However, the therapy is still challenging because the immunomodulatory properties of BMSCs are always impaired by immunopathogenesis in patients. Because of its reliable and extensive biological activities, osthole has received increased clinical attention. In this study, we found that BMSCs derived from osteoporosis donors were ineffective in cell therapy for experimental inflammatory colitis and osteoporosis. In vivo and in vitro tests showed that because of the down‐regulation of Fas and FasL expression, the ability of osteoporotic BMSCs to induce T‐cell apoptosis decreased. Through the application of osthole, we successfully restored the immunosuppressive ability of osteoporotic BMSCs and improved their treatment efficacy in experimental inflammatory colitis and osteoporosis. In addition, we found the immunomodulatory properties of BMSCs were enhanced after osthole pre‐treatment. In this study, our data highlight a new approach of pharmacological modification (ie osthole) to improve the immune regulatory performance of BMSCs from a healthy or inflammatory microenvironment. The development of targeted strategies to enhance immunosuppressive therapy using BMSCs may be significantly improved by these findings.

Phytochemicals impact on osteogenic differentiation of mesenchymal stem cells

Medicinal plants have always been utilized for the prevention and treatment of the spread of different diseases all around the world. To name some traditional medicine that has been used over centuries, we can refer to phytochemicals such as naringin, icariin, genistein, and resveratrol gained from plants. Osteogenic differentiation and mineralization of stem cells can be the result of specific bioactive compounds from plants. One of the most appealing choices for therapy can be mesenchymal stem cells (MSCs) because it has a great capability of self-renewal and differentiation into three descendants, namely, endoderm, mesoderm, and ectoderm. Stem cell gives us the glad tidings of great advances in tissue regeneration and transplantation field for treatment of diseases. Using plant bioactive phytochemicals also holds tremendous promises in treating diseases such as osteoporosis. The purpose of the present review article thus is to investigate what are the roles and consequences of phytochemicals on osteogenic differentiation of MSCs.

High-Throughput Metabolomics Discovers Metabolic Biomarkers and Pathways to Evaluating the Efficacy and Exploring Potential Mechanisms of Osthole Against Osteoporosis Based on UPLC/Q-TOF-MS Coupled With Multivariate Data Analysis

Postmenopausal osteoporosis (PMOP) is the most common metabolic bone illness among the elderly especially in postmenopausal women resulting from a reduction in bone mineral density, but there is no effective drug at present. The study was aimed at evaluating efficacy of osthole against osteoporosis using high-throughput metabolomics method. The blood samples for illustrating the pathological mechanism of PMOP and exploring the efficacy of osthole treatment (ST) were collected to perform metabolites and metabolic profiles and pathways analysis using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS) and pattern recognition methods. In addition, backbone weight, the bone density, and some vital biochemical indexes were also detected. A total of 28 metabolites were identified as biomarkers for ovariectomized-osteoporosis model, and ST could significantly regulate 19 of them including lysine, linoleic acid, 3-hydroxybutyric acid, prostaglandin F2a, taurocholic acid, LysoPC(15:0), l-carnitine, glucose, arginine, citric acid, corticosterone, ornithine, tryptophan, arachidonic acid, Cer(d18:0/18:0), glutamine, uric acid, 8-HETE, estriol, which mainly related with 13 metabolic pathways, such as linoleic acid metabolism, starch, and sucrose metabolism, arachidonic acid metabolism, alanine, aspartate and glutamate metabolism, arginine and proline metabolism, citrate cycle (TCA cycle), and arginine biosynthesis. The ovariectomized model (OVX) rats display a significant decrease bone density, TGF-β1, NO, and NOS level, and a significant increase bone weight, IL-6, TNF-α, and Ca 2+ level. These parameters in the ST rats were evidently improved as compared to the OVX group. ST effectively mitigated ovariectomy-induced osteoporosis in rats by affecting endogenous metabolite-related metabolic mechanism and showed the natural alternative with potential for the treatment of PMOP.

Cnidium lactone prevents bone loss in an ovariectomized rat model through the estrogen-α/BMP-2/Smad signaling pathway

BACKGROUND

The present study aimed to investigate the effect of cnidium lactone on ovariectomy (OVX)-induced bone loss and determine whether it exerts its effects by mediating the estrogen receptor-α (ERα)/bone morphogenetic protein-2 (BMP-2)/Smad signaling pathways.

METHODS

Fifty-five female rats were randomly assigned to the following treatment groups: the OVX group, the sham-operated (sham) group, and groups treated with cnidium lactone at different doses (10 mg/kg/day, 20 mg/kg/day, 30 mg/kg/day). Treatments were administered for 60 days. Search Tool for Interacting Chemicals (STITCH; http://stitch.embl.de) was used to identify the interaction between cnidium lactone and target proteins. Bone mineral density (BMD), mechanical strength, serum osteoblastic and osteoclastic markers, and hematoxylin and eosin (HE) staining of the distal femur were evaluated. Moreover, western blot analyses were also performed to evaluate the effect of cnidium lactone on the ERα/BMP-2/Smad signaling pathway.

RESULTS

Cnidium lactone treatment was associated with an increase in the BMD of the distal femur compared to that of the OVX group. Moreover, cnidium lactone significantly increased biomechanical properties in a dose-dependent manner compared to those of the OVX group (p < 0.05). Treatment with cnidium lactone significantly enhanced the BMP-2/Smad signaling pathway by up-regulating the expression of ERα, BMP-2, p-Smad1 and p-Smad4. Cnidium lactone treatment improved the microstructure of trabecular bone in the distal femurs of OVX rats, as shown by HE staining.

CONCLUSIONS

Cnidium lactone exerts potent antiosteoporotic activity in ovariectomized mice, and the underlying molecular mechanism may be related to the ERα/BMP-2/Smad signaling pathways.

Anti-Tumor Effects of Osthole on Different Malignant Tissues: A Review of Molecular Mechanisms

Cancer management and/or treatment require a comprehensive understanding of the molecular and signaling pathways involved. Recently, much attention has been directed to these molecular and signaling pathways, and it has been suggested that a number of biomolecules/players involved in such pathways, such as PI3K/Akt, NF-kB, STAT, and Nrf2 contribute to the progression, invasion, proliferation, and metastasis of malignant cells. Synthetic anti-tumor agents and chemotherapeutic drugs have been a mainstay in cancer therapy and are widely used to suppress the progression and, hopefully, halt the proliferation of malignant cells. However, these agents have some undesirable side-effects and, therefore, naturally-occurring compounds with high potency and fewer side-effects are now of great interest. Osthole is a plant-derived chemical compound that can inhibit the proliferation of malignant cells and provide potent anti-cancer effects in various tissues. Therefore, in this review, we presented the main findings concerning the potential anti-tumor effects of osthole and its derivatives and described possible molecular mechanisms by which osthole may suppress malignant cell proliferation in different tissues.