Vitexicarpin Induces Apoptosis and Inhibits Metastatic Properties via the AKT-PRAS40 Pathway in Human Osteosarcoma.

Osteosarcoma, which has poor prognosis after metastasis, is the most common type of bone cancer in children and adolescents. Therefore, plant-derived bioactive compounds are being actively developed for cancer therapy. Artemisia apiacea Hance ex Walp. is a traditional medicinal plant native to Eastern Asia, including China, Japan, and Korea. Vitexicarpin (Vitex), derived from A. apiacea, has demonstrated analgesic, anti-inflammatory, antitumour, and immunoregulatory properties; however, there are no published studies on Vitex isolated from the aerial parts of A. apiacea. Thus, this study aimed to evaluate the antitumour activity of Vitex against human osteosarcoma cells. In the present study, Vitex (>99% purity) isolated from A. apiacea induced significant cell death in human osteosarcoma MG63 cells in a dose- and time-dependent manner; cell death was mediated by apoptosis, as evidenced by the appearance of cleaved-PARP, cleaved-caspase 3, anti-apoptotic proteins (Survivin and Bcl-2), pro-apoptotic proteins (Bax), and cell cycle-related proteins (Cyclin D1, Cdk4, and Cdk6). Additionally, a human phosphokinase array proteome profiler revealed that Vitex suppressed AKT-dependent downstream kinases. Further, Vitex reduced the phosphorylation of PRAS40, which is associated with autophagy and metastasis, induced autophagosome formation, and suppressed programmed cell death and necroptosis. Furthermore, Vitex induced antimetastatic activity by suppressing the migration and invasion of MMP13, which is the primary protease that degrades type I collagen for tumour-induced osteolysis in bone tissues and preferential metastasis sites. Taken together, our results suggest that Vitex is an attractive target for treating human osteosarcoma.

Osteogenic Activities of Trifolirhizin as a Bioactive Compound for the Differentiation of Osteogenic Cells.

Plant extracts are widely used as traditional medicines. Sophora flavescens Aiton-derived natural compounds exert various beneficial effects, such as anti-inflammatory, anticancer, antioxidant, and antiregenerative activities, through their bioactive compounds, including flavonoids and alkaloids. In the present study, we investigated the biological effects of an S. flavescens-derived flavonoid, trifolirhizin (trifol), on the stimulation of osteogenic processes during osteoblast differentiation. Trifol (>98% purity) was successfully isolated from the root of S. flavescens and characterized. Trifol did not exhibit cellular toxicity in osteogenic cells, but promoted alkaline phosphatase (ALP) staining and activity, with enhanced expression of the osteoblast differentiation markers, including Alp, ColI, and Bsp. Trifol induced nuclear runt-related transcription factor 2 (RUNX2) expression during the differentiation of osteogenic cells, and concomitantly stimulated the major osteogenic signaling proteins, including GSK3ß, ß-catenin, and Smad1/5/8. Among the mitogen-activated protein kinases (MAPKs), Trifol activated JNK, but not ERK1/2 and p38. Trifol also increased the osteoblast-mediated bone-forming phenotypes, including transmigration, F-actin polymerization, and mineral apposition, during osteoblast differentiation. Overall, trifol exhibits bioactive activities related to osteogenic processes via differentiation, migration, and mineralization. Collectively, these results suggest that trifol may serve as an effective phytomedicine for bone diseases such as osteoporosis.

Xanol Promotes Apoptosis and Autophagy and Inhibits Necroptosis and Metastasis via the Inhibition of AKT Signaling in Human Oral Squamous Cell Carcinoma.

Angelica keiskei Koidzumi (A. keiskei) is used as a traditional medicine, anti-aging agent, and health food, as well as to restore vitality. Xanthoangelol (xanol), a prenylated chalcone, is the predominant constituent of A. keiskei. Oral squamous cell carcinoma (OSCC), the most common malignancy, has a high proliferation rate and frequent metastasis. However, it is unknown whether xanol has anti-OSCC effects on apoptosis, autophagy, and necroptosis. In the present study, we purified xanol from A. keiskei and demonstrated that it suppressed cell proliferation and induced cytotoxicity in human OSCC. Xanol triggered apoptotic cell death by regulating apoptotic machinery molecules but inhibited necroptotic cell death by dephosphorylating the necroptotic machinery molecules RIP1, RIP3, and MLKL in human OSCC. We also found that xanol inhibited the PI3K/AKT/mTOR/p70S6K pathway and induced autophagosome formation by enhancing beclin-1 and LC3 expression levels and reducing p62 expression levels. Furthermore, we showed that xanol prevented the metastatic phenotypes of human OSCC by inhibiting migration and invasion via the reduction of MMP13 and VEGF. Finally, we demonstrated that xanol exerted anticancer effects on tumorigenicity associated with its transformed properties. Taken together, these findings demonstrate the anticancer effects and biological mechanism of action of xanol as an effective phytomedicine for human OSCC.

Machilin D Promotes Apoptosis and Autophagy, and Inhibits Necroptosis in Human Oral Squamous Cell Carcinoma Cells.

Oral squamous cell carcinoma (OSCC) accounts for about 90% of all head and neck cancers, the prognosis is very poor, and there are no effective targeted therapies. Herein, we isolated Machilin D (Mach), a lignin, from the roots of Saururus chinensis (S. chinensis) and assessed its inhibitory effects on OSCC. Herein, Mach had significant cytotoxicity against human OSCC cells and showed inhibitory effects against cell adhesion, migration, and invasion by inhibiting adhesion molecules, including the FAK/Src pathway. Mach suppressed the PI3K/AKT/mTOR/p70S6K pathway and MAPKs, leading to apoptotic cell death. We investigated other modes of programmed cell death in these cells and found that Mach increased LC3I/II and Beclin1 and decreased p62, leading to autophagosomes, and suppressed the necroptosis-regulatory proteins RIP1 and MLKL. Our findings provide evidence that the inhibitory effects of Mach against human YD-10B OSCC cells are related to the promotion of apoptosis and autophagy and inhibition of necroptosis and are mediated via focal adhesion molecules.

Suffruticosol A elevates osteoblast differentiation targeting BMP2-Smad/1/5/8-RUNX2 in pre-osteoblasts.

The Paeonia suffruticosa ANDR. (P. suffruticosa) is commonly used in traditional medicine for various purposes. Suffruticosol A (Suf-A), isolated from P. suffruticosa, is a beneficial compound with antibiofilm, antivirulence, and anti-inflammatory properties. The aim of the present study was to investigate the biological effects of Suf-A on osteogenic processes in pre-osteoblasts. It was determined here in that Suf-A (>98.02%), isolated from P. suffruticosa, showed no cytotoxicity at 0.1-30 µM; however, it induced cytotoxicity at 50-100 µM in pre-osteoblasts. Suf-A increased osteogenic alkaline phosphatase activity and expression levels of noncollagenous proteins. Adhesion and trans-migration on the extracellular matrix were potentiated by Suf-A, but not by wound-healing migration. Suf-A did not affect autophagy or necroptosis during osteoblast differentiation. We found that Suf-A increased runt-related transcription factor 2 (RUNX2) levels and mineralized matrix formation. RUNX2 expression was mediated by Suf-A-induced BMP2-Smad1/5/8 and mitogen-activated protein kinase signaling, as demonstrated by Noggin, a BMP2 inhibitor. These results suggest that Suf-A is a potential natural osteogenic compound.

Trifloroside Induces Bioactive Effects on Differentiation, Adhesion, Migration, and Mineralization in Pre-Osteoblast MC3T3E-1 Cells.

Gentianae Scabrae Radix is used in traditional medicine and is known to possess bioactive compounds, including secoiridoid glycosides, flavonoids, lignans, and triterpenes. Trifloroside (TriFs) is a secoiridoid glycoside known for its antioxidant activity; however, its other effects have not been studied. In the present study, we investigated the biological effects of TriFs isolated from the roots of Gentianae Scabrae Radix using pre-osteoblast MC3T3E-1 cells. No cellular toxicity was observed with 1 µM TriFs, whereas 5-100 µM TriFs showed a gradual increase in cell viability. Alkaline phosphatase staining and microscopic observations revealed that 1-10 µM TriFs stimulated osteogenic activity during early osteoblast differentiation. Trifloroside also increased mineral apposition during osteoblast maturation. Biochemical analyses revealed that TriFs promoted nuclear RUNX2 expression and localization by stimulating the major osteogenic BMP2-Smad1/5/8-RUNX2 pathway. Trifloroside also increased p-GSK3ß, ß-catenin, p-JNK, and p-p38, but not Wnt3a, p-AKT, and p-ERK. Moreover, TriFs increased the MMP13 levels and promoted cell migration and adhesion. In contrast, TriFs-induced osteoblast differentiation and maturation had negligible effects on autophagy and necrosis. Our findings suggest that TriFs induces osteogenic effects through differentiation, adhesion, migration, and mineral apposition. Therefore, TriFs is suggested as a potential drug target in osteoblast-mediated bone diseases.

Suffruticosol B Is an Osteogenic Inducer through Osteoblast Differentiation, Autophagy, Adhesion, and Migration.

Suffruticosol B (Suf-B) is a stilbene found in Paeonia suffruticosa ANDR., which has been traditionally used in medicine. Stilbenes and their derivatives possess various pharmacological effects, such as anticancer, anti-inflammatory, and anti-osteoporotic activities. This study aimed to explore the bone-forming activities and mechanisms of Suf-B in pre-osteoblasts. Herein, >99.9% pure Suf-B was isolated from P. suffruticosa methanolic extracts. High concentrations of Suf-B were cytotoxic, whereas low concentrations did not affect cytotoxicity in pre-osteoblasts. Under zero levels of cytotoxicity, Suf-B exhibited bone-forming abilities by enhancing alkaline phosphatase enzyme activities, bone matrix calcification, and expression levels with non-collagenous proteins. Suf-B induces intracellular signal transduction, leading to nuclear RUNX2 expression. Suf-B-stimulated differentiation showed increases in autophagy proteins and autophagosomes, as well as enhancement of osteoblast adhesion and transmigration on the ECM. These results indicate that Suf-B has osteogenic qualities related to differentiation, autophagy, adhesion, and migration. This also suggests that Suf-B could have a therapeutic effect as a phytomedicine in skeletal disorders.

Latifolin, a Natural Flavonoid, Isolated from the Heartwood of Dalbergia odorifera Induces Bioactivities through Apoptosis, Autophagy, and Necroptosis in Human Oral Squamous Cell Carcinoma.

Oral squamous cell carcinoma (OSCC) is the most common malignant neoplasm with frequent metastasis and high mortality in the oral cavity. Plant-derived natural compounds are actively progressing as a trend for cancer treatment. Latifolin (Latif), is a natural flavonoid isolated from the heartwood of Dalbergia odorifera T. Chen (D. odorifera) has been known to have beneficial effects on anti-aging, anti-carcinogenic, anti-inflammatory, and cardio-protective activities. However, the anti-cancer effects of Latif are unknown in OSCC. Herein, as a result of analysis in terms of the aggressive features of OSCCs, we found that Latif significantly inhibited the cell proliferation of human YD-8 and YD-10B OSCCs, and caused the anti-metastatic activities by effectively blocking cell migration, invasion, and adhesion via the inactivation of focal adhesion kinase (FAK)/non-receptor tyrosine kinase (Src). Moreover, we found that Latif induced apoptotic cell death to suppress the cell survival and proliferation of YD-10B OSCCs by targeting PI3K/AKT/mTOR/p70S6K signaling. Finally, we analyzed in terms of autophagy and necroptosis, which are other mechanisms of programmed cell death and survival compared to apoptosis in YD-10B OSCCs. We found that Latif suppressed autophagic-related proteins and autophagosome formation, and also Latif inhibited necroptosis by dephosphorylating necroptosis-regulatory proteins (RIP1, RIP3, and MLKL). Given these findings, our results provided new evidence for Latif's biological effect and mechanism in YD-10B OSCCs, suggesting that Latif may be a new candidate for patients with OSCCs.

Chi3L1 is a therapeutic target in bone metabolism and a potential clinical marker in patients with osteoporosis.

BMP2 is clinically used as an ectopic bone inducer and plays a significant role in bone development, formation, and diseases. Chitinase 3-like 1 protein (Chi3L1) is found in the skeletal system. However, Chi3L1-mediated bone metabolism and aging-related bone erosion via BMP2 signaling have not yet been demonstrated. Herein, Chi3L1 increased BMP2-induced osteoblast differentiation in mesenchymal precursor cells and human primary osteoblasts. Chi3L1KO(-/-) showed abnormal bone development, and primary osteoblasts isolated from Chi3L1KO(-/-) exhibited impaired osteoblast differentiation and maturation. Chi3L1 also potentiated BMP2 signaling and RUNX2 expression in primary osteoblasts. Chi3L1 interacted with BMPRIa, which increased the surface expression of BMPRIa and promoted BMP2 signaling to induce osteoblast differentiation. Chi3L1KO(-/-) mice showed bone formation reduced with a decrease in RUNX2 expression in calvarial defects. Chi3L1KO(-/-) mice exhibited aging-related osteoporotic bone loss with decreases in the levels of RUNX2 and OPG, while serum PYD level and osteoclast number increased. Chi3L1 increased OPG via non-canonical BMP2 signaling in osteoblasts, which suppressed osteoclastogenesis in BMMs. Furthermore, ROC analysis showed that serum Chi3L1 level clinically decreased in osteoporosis patients. Our findings demonstrate that Chi3L1 promotes bone formation, suppresses osteoclastogenesis, and prevents aging-related osteoporosis.

Effects of Triterpene Soyasapogenol B from Arachis hypogaea (Peanut) on Differentiation, Mineralization, Autophagy, and Necroptosis in Pre-Osteoblasts.

Triterpenes are a diverse group of natural compounds found in plants. Soyasapogenol B (SoyB) from Arachis hypogaea (peanut) has various pharmacological properties. This study aimed to elucidate the pharmacological properties and mechanisms of SoyB in bone-forming cells. In the present study, 1-20 µM of SoyB showed no cell proliferation effects, whereas 30-100 µM of SoyB increased cell proliferation in MC3T3-E1 cells. Next, osteoblast differentiation was analyzed, and it was found that SoyB enhanced ALP staining and activity and bone mineralization. SoyB also induced RUNX2 expression in the nucleus with the increased phosphorylation of Smad1/5/8 and JNK2 during osteoblast differentiation. In addition, SoyB-mediated osteoblast differentiation was not associated with autophagy and necroptosis. Furthermore, SoyB increased the rate of cell migration and adhesion with the upregulation of MMP13 levels during osteoblast differentiation. The findings of this study provide new evidence that SoyB possesses biological effects in bone-forming cells and suggest a potentially beneficial role for peanut-based foods.

Effects of Scoparone on differentiation, adhesion, migration, autophagy and mineralization through the osteogenic signalling pathways.

Scoparone (SCOP), an active and efficient coumarin compound derived from Artemisia capillaris Thunb, has been used as a traditional Chinese herbal medicine. Herein, we investigated the effects of SCOP on the osteogenic processes using MC3T3-E1 pre-osteoblasts in in vitro cell systems. SCOP (C11 H10 O4 , > 99.17%) was purified and identified from A. capillaries. SCOP (0.1 to 100 µM concentrations) did not have cytotoxic effects in pre-osteoblasts; however, it promoted alkaline phosphatase (ALP) staining and activity, and mineralized nodule formation under early and late osteogenic induction. SCOP elevated osteogenic signals through the bone morphogenetic protein 2 (BMP2)-Smad1/5/8 pathway, leading to the increased expression of runt-related transcription factor 2 (RUNX2) with its target protein, matrix metallopeptidase 13 (MMP13). SCOP also induced the non-canonical BMP2-MAPKs pathway, but not the Wnt3a-ß-catenin pathway. Moreover, SCOP promoted autophagy, migration and adhesion under the osteogenic induction. Overall, the findings of this study demonstrated that SCOP has osteogenic effects associated with cell differentiation, adhesion, migration, autophagy and mineralization.

Paeoniflorigenone regulates apoptosis, autophagy, and necroptosis to induce anti-cancer bioactivities in human head and neck squamous cell carcinomas.

ETHNOPHARMACOLOGICAL RELEVANCE: Paonia suffruticosa Andr. belonging to the family Paeoniaceae and has been used as a medicinal plant in Asian countries including China, Korea, and Japan. The roots of P. suffruticosa has been used in traditional medicine in various diseases including cancer and cardiovascular, female genital, and inflammatory diseases. AIM OF THE STUDY: Head and neck squamous cell carcinomas (HNSCCs) pathologically account for 90% of all head and neck cancers. However, effective targeted therapies for HNSCCs are insufficient and the prognosis is very poor, especially in patients with metastatic HNSCCs. To overcome the current limitations of available therapies for HNSCCs, pathological approaches using natural compounds are attracting attention. Our study aimed to demonstrate the anti-cancer effects of paeoniflorigenone (Paeo, 98.9% purity) isolated from the root bark of P. suffruticosa. MATERIALS AND METHODS: Our scientific methodology was performed as follows: cytotoxicity, morphological changes, and apototic DNA fragmentation were analyzed using MTT, light microscopy, and TUNEL assays. Protein expression, apoptosis, necroptosis, and autophagy were analyzed using Western blot and immunofluorescence assays. Cell migration and invasion were analyzed using wound healing and Boyden chamber assays. RESULTS: We demonstrated that Paeo significantly reduced cell proliferation and cell division, leading to caspase-dependent apoptotic cell death in human YD-10B HNSCC cells. This result was associated with PI3K/AKT/mTOR/p70S6K signaling in these cells. In addition, we investigated other programmed cell death mechanisms associated with apoptosis and found that Paeo inhibited necroptosis via dephosphorylation of key necroptotic proteins (RIP and MLKL), whereas Paeo induced autophagy via increased LC3I/II expression and autophagosome formation in human YD-10B HNSCC cells. The anti-metastatic effects of Paeo significantly suppressed cell migration and invasion in human YD-10B HNSCC cells. CONCLUSION: Overall, our results demonstrated that the bioactive compound, Paeo, exhibited anti-cancer bioactivities in human YD-10B HNSCC cells, suggesting that Paeo may be an attractive pathological approach for patients with human HNSCCs.

Falcarindiol Stimulates Apoptotic and Autophagic Cell Death to Attenuate Cell Proliferation, Cell Division, and Metastasis through the PI3K/AKT/mTOR/p70S6K Pathway in Human Oral Squamous Cell Carcinomas.

Human oral squamous cell carcinomas (OSCCs) have high cancer mortality and a 5-year survival rate lower than that of most other carcinomas. New therapeutic strategies are required for the treatment and prevention against OSCCs. An approach to cancer therapy using plant-derived natural compounds has been actively in progress as a trend. Falcarindiol (FALC), or its isolated form Ostericum koreanum Kitagawa (O. koreanum), is present in many food and dietary plants, especially in carrots, and this compound has a variety of beneficial effects. However, biological activity of FALC has not been reported in OSCCs yet. This study aimed to demonstrate the antitumor effects of FALC against OSCCs, YD-10B cells. In this study, FALC was selected as a result of screening for compounds isolated from various natural products in YD-10B cells. FALC suppressed cell growth, and FALC-induced apoptotic cell death was mainly accompanied by the dephosphorylation of PI3K, AKT, mTOR, and p70S6K. The apoptotic cell death was also associated with autophagy as evidenced by the expression of Beclin-1, the conversion of LC3-II, and the formation of autophagosome. FALC-induced autophagy was accompanied by MAPKs including ERK1/2 and p38. Furthermore, FALC caused the antimetastatic effects by inhibiting the migration and invasion of YD-10B cells. Taken together, the findings suggest the potential value of FALC as a novel candidate for therapeutic strategy against OSCCs.

11-O-Galloyl Bergenin from Corylopsis coreanas Leaves Induces Autophagy and Apoptosis in Human Osteosarcoma.

Osteosarcoma is the most common malignant bone-forming tumor, wherein most patients with high grade osteosarcomas are treated with chemotherapy. Despite this, survival for metastatic or relapsed osteosarcoma patients has remained at an overall 5-year survival rate of 20%. In particular, the extracts of Corylopsis coreana (Korean winter hazel), a cultivated woody plant in South Korea, have shown beneficial anti-inflammatory, anti-oxidative, anti-osteoclastic, and antihyperuricemic properties. Therefore, this study aimed to demonstrate the antitumor activities and underlying mechanism of 11-O-Galloyl bergenin (OGAL) isolated from Corylopsis coreanas leaves in human osteosarcoma cells. Herein, we found that OGAL inhibited MG63 cell proliferation and induced cellular apoptosis as evidenced by cleaved-PARP, cleaved-caspase 3, TUNEL-positive cells, and Annexin V-positive cells. Specifically, OGAL-induced apoptosis was accompanied by p53 and p21 upregulation, BAX expression, and decreased Bcl-2 and cdk2. Moreover, OGAL induced autophagy via AKT inactivation, LC3II upregulation, and MG63 cell autophagosome formation. OGAL-induced autophagy was also accompanied by increased p38 phosphorylation, whereas JNK and ERK1/2 activities were found to be unaffected upon examining the MAPK signaling pathway. Furthermore, wound healing and Boyden chamber assays showed that OGAL suppressed MG63 cell migration and invasion. Given these findings, this study provided evidence that OGAL has antitumor effects by apoptosis and autophagy enhancement through increased p53, AKT, and p38 signaling, suggesting that OGAL may be a potential therapeutic strategy for osteosarcoma treatment.

Calycosin-7-O-ß-Glucoside Isolated from Astragalus membranaceus Promotes Osteogenesis and Mineralization in Human Mesenchymal Stem Cells.

Stem cells have received attention in various diseases, such as inflammatory, cancer, and bone diseases. Mesenchymal stem cells (MSCs) are multipotent stem cells that are critical for forming and repairing bone tissues. Herein, we isolated calycosin-7-O-ß-glucoside (Caly) from the roots of Astragalus membranaceus, which is one of the most famous medicinal herbs, and investigated the osteogenic activities of Caly in MSCs. Caly did not affect cytotoxicity against MSCs, whereas Caly enhanced cell migration during the osteogenesis of MSCs. Caly increased the expression and enzymatic activities of ALP and the formation of mineralized nodules during the osteogenesis of MSCs. The osteogenesis and bone-forming activities of Caly are mediated by bone morphogenetic protein 2 (BMP2), phospho-Smad1/5/8, Wnt3a, phospho-GSK3ß, and phospho-AKT, inducing the expression of runt-related transcription factor 2 (RUNX2). In addition, Caly-mediated osteogenesis and RUNX2 expression were attenuated by noggin and wortmannin. Moreover, the effects were validated in pre-osteoblasts committed to the osteoblast lineages from MSCs. Overall, our results provide novel evidence that Caly stimulates osteoblast lineage commitment of MSCs by triggering RUNX2 expression, suggesting Caly as a potential anabolic drug to prevent bone diseases.

Anti-tumor effects of jaceosidin on apoptosis, autophagy, and necroptosis in human glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the most aggressive and common malignant neoplasm. Nevertheless, a 5-year survival rate of patients with GBM has remained below 5%. Artemisia princeps PAMPANINI, used as a food and traditional medicine, have shown beneficial properties including anti-inflammatory, anti-oxidative, and anti-cancer activities. Thus, this study aimed to investigate biological mechanism of a bioactive compound, jaceosidin (JAC), isolated from A. princeps in human GBM T98G cells. Herein, as a result of analysis in terms of cancer survival and death, we found that JAC significantly reduced cell survival against T98G cells. In addition, JAC increased apoptotic cell death via changes on morphological and molecular phenotypes in T98G cells as evidenced by cellular shapes and DNA fragmentation. The apoptotic cell death was confirmed by the cleavage of caspase-3 and PARP, the downregulation of survivin and Bcl-2. Moreover, JAC decreased the expression of cyclinD1 and Cdks and increased the phosphorylation of EKR, JNK, and p38 MAPKs. Specifically, JAC suppressed the PI3K/AKT signaling and its downstream molecules including p70S6, GSK3ß, and ß-catenin. In addition, as a result of analysis in terms of metastasis using wound healing and Boyden chamber assays, JAC showed anti-migrative and anti-invasive activities. Finally, we analyzed in terms of autophagy and necroptosis that are modes of programmed cell survival and death different from apoptosis in T98G cells. We found that JAC inhibited autophgic regulatory proteins including Beclin-1, Atgs, and LC3A/B, thereby reducing autophagic-mediated cell survival, whereas JAC did not affect phosphorylation of key proteins in necroptosis, especially MLKL. Given these findings, our results provided novel evidences on the biological mechanisms of JAC in T98G cells, suggesting that JAC may be a therapeutic agent for patients with GBM.

Anti-cancer effects of Hederoside C, a pentacyclic triterpene saponin, through the intrinsic apoptosis and STAT3 signaling pathways in osteosarcoma.

Natural compounds have emerged as an approach in cancer therapy. Pulsatilla koreana Nakai is used as a traditional medicinal plant that found throughout China and Korea. However, anti-cancer effects of Hederoside C (HedC) isolated from P. koreana has not been investigated in osteosarcoma. The present study aimed to demonstrate anti-cancer functions of HedC against human osteosarcoma cells. Herein, we found that HedC suppressed the proliferation of MG63 cells and U2OS cells in the dose- and time-dependent manner, and caused intrinsic apoptosis pathways as evidenced by morphological changes, TUNEL-positive cells, cleaved-PARP, and cleaved-caspase 9 and 3. HedC increased p53, Bax, and p21, whereas HedC reduced Bcl-2. HedC-mediated apoptosis was accompanied by decreases in the mitogen-activated protein kinases (MAPKs) and STAT3 phosphorylation. Wound healing and Boyden chamber assays also showed the anti-metastatic effects of HedC by suppressing migration and invasion. In addition, the anti-cancer effects of HedC were observed in in vivo xenograft mice model, and HedC treatment induced the decreased PCNA and p-STAT3 as well as the increased p53 and cleaved caspase-3. Taken together, our results provide evidence that HedC might be an attractive therapeutic strategy against osteosarcoma.

Biological Mechanisms of Paeonoside in the Differentiation of Pre-Osteoblasts and the Formation of Mineralized Nodules.

Paeonia suffruticosa is a magnificent and long-lived woody plant that has traditionally been used to treat various diseases including inflammatory, neurological, cancer, and cardiovascular diseases. In the present study, we demonstrated the biological mechanisms of paeonoside (PASI) isolated from the dried roots of P. suffruticosa in pre-osteoblasts. Herein, we found that PASI has no cytotoxic effects on pre-osteoblasts. Migration assay showed that PASI promoted wound healing and transmigration in osteoblast differentiation. PASI increased early osteoblast differentiation and mineralized nodule formation. In addition, PASI enhanced the expression of Wnt3a and bone morphogenetic protein 2 (BMP2) and activated their downstream molecules, Smad1/5/8 and ß-catenin, leading to increases in runt-related transcription factor 2 (RUNX2) expression during osteoblast differentiation. Furthermore, PASI-mediated osteoblast differentiation was attenuated by inhibiting the BMP2 and Wnt3a pathways, which was accompanied by reduction in the expression of RUNX2 in the nucleus. Taken together, our findings provide evidence that PASI enhances osteoblast differentiation and mineralized nodules by regulating RUNX2 expression through the BMP2 and Wnt3a pathways, suggesting a potential role for PASI targeting osteoblasts to treat bone diseases including osteoporosis and periodontitis.

Paeonolide as a Novel Regulator of Core-Binding Factor Subunit Alpha-1 in Bone-Forming Cells.

Paeonia suffruticosa has been extensively used as a traditional medicine with various beneficial effects; paeonolide (PALI) was isolated from its dried roots. This study aimed to investigate the novel effects and mechanisms of PALI in pre-osteoblasts. Here, cell viability was evaluated using an MTT assay. Early and late osteoblast differentiation was examined by analyzing the activity of alkaline phosphatase (ALP) and by staining it with Alizarin red S (ARS). Cell migration was assessed using wound healing and Boyden chamber assays. Western blot and immunofluorescence analyses were used to examine the intracellular signaling pathways and differentiation proteins. PALI (0.1, 1, 10, 30, and 100 µM) showed no cytotoxic or proliferative effects in pre-osteoblasts. In the absence of cytotoxicity, PALI (1, 10, and 30 µM) promoted wound healing and transmigration during osteoblast differentiation. ALP staining demonstrated that PALI (1, 10, and 30 µM) promoted early osteoblast differentiation in a dose-dependent manner, and ARS staining showed an enhanced mineralized nodule formation, a key indicator of late osteoblast differentiation. Additionally, low concentrations of PALI (1 and 10 µM) increased the bone morphogenetic protein (BMP)-Smad1/5/8 and Wnt-ß-catenin pathways in osteoblast differentiation. Particularly, PALI (1 and 10 µM) increased the phosphorylation of ERK1/2 compared with BMP2 treatment, an FDA-approved drug for bone diseases. Furthermore, PALI-mediated early and late osteoblast differentiation was abolished in the presence of the ERK1/2 inhibitor U0126. PALI-induced RUNX2 (Cbfa1) expression and nuclear localization were also attenuated by blocking the ERK1/2 pathway during osteoblast differentiation. We suggest that PALI has biologically novel activities, such as enhanced osteoblast differentiation and bone mineralization mainly through the intracellular ERK1/2-RUNX2 signaling pathway, suggesting that PALI might have therapeutic action and aid the treatment and prevention of bone diseases, such as osteoporosis and periodontitis.

Limonoid Triterpene, Obacunone Increases Runt-Related Transcription Factor 2 to Promote Osteoblast Differentiation and Function.

Root bark of Dictamnus dasycarpus Turcz. has been widely used as a traditional medicine and is a well-known anti-inflammatory agent. We isolated limonoid triterpene, obacunone (Obac) from the dried root bark of D. dasycarpus. Obac has been reported to exhibit varieties of biological activities including anti-inflammatory, anti-cancer, and anti-oxidant effects. This study aimed to investigate the beneficial effects and biological mechanisms of Obac in osteoblast differentiation and bone matrix mineralization. In the present study, Obac at concentrations ranging from 1 to 100 µM showed no proliferation effects in MC3T3-E1. The treatment of Obac (1 and 10 µM) increased wound healing and migration rates in a dose-dependent manner. Alkaline phosphatase (ALP) staining and activity showed that Obac (1 and 10 µM) enhanced early osteoblast differentiation in a dose-dependent manner. Obac also increased late osteoblast differentiation in a dose-dependent manner, as indicated by the mineralized nodule formation of ARS staining. The effects of Obac on osteoblast differentiation was validated by the levels of mRNAs encoding the bone differentiation markers, including Alp, bone sialoprotein (Bsp), osteopontin (Opn), and osteocalcin (Ocn). Obac increased the expression of bone morphogenetic protein (BMP), and the phosphorylation of smad1/5/8, and the expression of runt-related transcription factor 2 (RUNX2); Obac also inhibited GSK3ß and upregulated the protein level of ß-catenin in a dose-dependent manner during osteoblast differentiation. Obac-mediated osteoblast differentiation was attenuated by a BMP2 inhibitor, Noggin and a Wnt/ß-catenin inhibitor, Dickkopf-1 (Dkk1) with the abolishment of RUNX2 expression and nuclear accumulation by Obac. Taken together, the findings of this study demonstrate that Obac has pharmacological and biological activates to promote osteoblast differentiation and bone mineralization through BMP2, ß-catenin, and RUNX2 pathways, and suggest that Obac might be a therapeutic effect for the treatment and prevention of bone diseases such as osteoporosis and periodontitis.