Geraniin promotes osteoblast proliferation and differentiation via the activation of Wnt/β-catenin pathway

Melatonin antagonizes bone loss induced by mechanical unloading via IGF2BP1-dependent m6A regulation

Disuse bone loss is prone to occur in individuals who lack mechanical stimulation due to prolonged spaceflight or extended bed rest, rendering them susceptible to fractures and placing an enormous burden on social care; nevertheless, the underlying molecular mechanisms of bone loss caused by mechanical unloading have not been fully elucidated. Numerous studies have focused on the epigenetic regulation of disuse bone loss; yet limited research has been conducted on the impact of RNA modification bone formation in response to mechanical unloading conditions. In this study, we discovered that m6A reader IGF2BP1 was downregulated in both osteoblasts treated with 2D clinostat and bone tissue in HLU mice. Supplementing IGF2BP1 could promote osteoblast proliferation and partially alleviate the adverse effects of mechanical unloading on bone formation. Mechanistically, IGF2BP1 inhibited the degradation of Lef1 mRNA by directly binding to its mRNA and recognizing the m6A modification. Furthermore, LEF1 promoted osteoblast proliferation by upregulating c-Myc and Cyclin D1 expression, as well as participated in mediating IGF2BP1-induced osteoblast activity under mechanical unloading. Notably, Melatonin (MT) might participate in the regulation of the IGF2BP1/LEF1 axis, thereby regulating the proliferation of osteoblasts and bone formation. Collectively, this study revealed a new insight into the regulation of the MT/IGF2BP1/LEF1 pathway in the process of unloading-induced bone loss, which could potentially contribute to establishing therapeutic strategies for disuse osteoporosis.

Natural Compounds for Bone Remodeling: Targeting osteoblasts and relevant signaling pathways

In the process of bone metabolism and bone remodeling, bone marrow mesenchymal stem cells (BM-MSCs) differentiate into osteoblasts (OBs) under certain conditions to enable the formation of new bone, and normal bone reconstruction and pathological bone alteration are closely related to the differentiation and proliferation functions of OBs. Osteogenic differentiation of BM-MSCs involves multiple signaling pathways, which function individually but interconnect intricately to form a complex signaling regulatory network. Natural compounds have fewer adverse effects than chemically synthesized drugs, optimize bone health, and are more suitable for long-term use. In this paper, we focus on OBs, summarize the current research progress of signaling pathways related to OBs differentiation, and review the molecular mechanisms by which chemically synthesized drugs with potential anti-osteoporosis properties regulate OBs-mediated bone formation.

Wnt/β-catenin signaling pathway: proteins' roles in osteoporosis and cancer diseases and the regulatory effects of natural compounds on osteoporosis

Osteoblasts are mainly derived from mesenchymal stem cells in the bone marrow. These stem cells can differentiate into osteoblasts, which have the functions of secreting bone matrix, promoting bone formation, and participating in bone remodeling. The abnormality of osteoblasts can cause a variety of bone-related diseases, including osteoporosis, delayed fracture healing, and skeletal deformities. In recent years, with the side effects caused by the application of PTH drugs, biphosphonate drugs, and calmodulin drugs, people have carried out more in-depth research on the mechanism of osteoblast differentiation, and are actively looking for natural compounds for the treatment of osteoporosis. The Wnt/β-catenin signaling pathway is considered to be one of the important pathways of osteoblast differentiation, and has become an important target for the treatment of osteoporosis. The Wnt/β-catenin signaling pathway, whether its activation is enhanced or its expression is weakened, will cause a variety of diseases including tumors. This review will summarize the effect of Wnt/β-catenin signaling pathway on osteoblast differentiation and the correlation between the related proteins in the pathway and human diseases. At the same time, the latest research progress of natural compounds targeting Wnt/β-catenin signaling pathway against osteoporosis is summarized.

Geraniin: A dietary ellagitannin as a modulator of signalling pathways in cancer progression

Cancer remains a global health challenge, necessitating the exploration of novel therapeutic agents. Current treatment options are unable to overwhelm and cure the cancer burden. Hence, identifying new bioactive molecular entities with potent anticancer activity is the need of the hour. Ellagitannin Geraniin (GN) is one such evidence-based novel bioactive molecular entity (BME) available from different natural sources that can effectively combat cancer. This narrative review attempts to investigate the potential of BME-GN from 2005 to 2023 as an efficient molecular anti-cancer therapeutic against diverse cancers. We provide information on GN's pharmacological advantages, metabolite profile, and capacity to modulate multiple molecular targets involved in the hallmarks of cancer. Using the search terms "Geraniin," "Gallic acid," "Ellagitannin," "pharmacological properties," "health," "antioxidant," "apoptosis," "disease management," "anti-proliferative," "in vitro," "anti-inflammatory," "anti-angiogenic," "in vivo," and "clinical trials," We searched the scientific literature using Scopus, Web of Science, Google Scholar, and PubMed. We removed publications that included overlap or equivalent content and used the most recent review on each issue as our primary reference. From an initial pool of 430 articles, 52 studies met the search criteria. These studies collectively provide substantial in vitro, in vivo, and clinical evidence of GN's potential to combat diverse cancers. Mechanistic insights revealed its involvement in fostering apoptosis, anti-inflammatory, and modulation of key signalling pathways implicated in the hallmarks of cancer. GN's pleiotropic pharmacological and molecular therapeutic properties strongly suggest its potential as a promising anticancer agent.

BushenHuoxue formula promotes osteogenic differentiation via affecting Hedgehog signaling pathway in bone marrow stem cells to improve osteoporosis symptoms

BACKGROUND

The BushenHuoxue formula (BSHX) has been previously demonstrated to ameliorate osteoporosis, but the mechanisms underlying this phenomenon are currently unclear. The present study aims at investigating the mechanisms that BSHX induces osteogenesis.

METHODS

We established an osteoporosis model in rats by bilateral ovariectomy and then treated the rats with an osteogenic inducer (dexamethasone, β-sodium glycerophosphate and Vitamin C) and BSHX. After that, bone marrow density and histopathological bone examination were evaluated by using HE staining and immunohistochemistry, respectively. We also assessed the differentiation of bone marrow mesenchymal stem cells (BMSCs) into osteoblasts by using immunofluorescence staining. ALP, BMP, and COL1A1 levels were determined by ELISA. We identified genes involved in pathogenesis of osteoporosis through Gene Expression Omnibus (GEO) database and subsequently selected Hedgehog signaling-related genes Shh, Ihh, Gli2, and Runx2 for assessment via qRT-PCR and ELISA, Western blotting. Network pharmacology analysis was performed to identify bioactive metabolites of BSHX.

RESULTS

BSHX treatment in osteoporosis model rats promoted tightening of the morphological structure of the trabecular bone and increased the bone mineral density (BMD). BSHX also increased levels of osteoblast makers ALP, BMP, and COL1A1. Additionally, bioinformatics analysis of the GEO dataset showed that Hedgehog signaling pathway was involved in pathogenesis of osteoporosis, especially related genes Shh, Ihh, Gli2, and Runx2. Remarkably, BHSX upregulated these genes indispensably involved in the osteogenesis-related Hedgehog signaling pathway in both bone tissue and BMSCs. Importantly, we identified that quercetin was the active compounds that involved in the mechanism of BSHX-improved OP via affecting Hedgehog-related genes.

CONCLUSION

Our results indicate that BSHX promotes osteogenesis by improving BMSC differentiation into osteoblasts via increased expression of Hedgehog signaling-related genes Shh, Ihh, Gli2, and Runx2, and quercetin was the bioactive compound of BSHX.

Height-Related Polygenic Variants Are Associated with Metabolic Syndrome Risk and Interact with Energy Intake and a Rice-Main Diet to Influence Height in KoGES

Adult height is inversely related to metabolic syndrome (MetS) risk, but its genetic impacts have not been revealed. The present study aimed to examine the hypothesis that adult height-related genetic variants interact with lifestyle to influence adult height and are associated with MetS risk in adults aged >40 in Korea during 2010–2014. Participants were divided into short stature (SS; control) and tall stature (TS; case) by the 85th percentile of adult height. The genetic variants linked to adult height were screened from a genome-wide association study in a city hospital-based cohort (n = 58,701) and confirmed in Ansan/Ansung plus rural cohorts (n = 13,783) among the Korean Genome and Epidemiology Study. Genetic variants that interacted with each other were identified using the generalized multifactor dimensionality reduction (GMDR) analysis. The interaction between the polygenic risk score (PRS) of the selected genetic variants and lifestyles was examined. Adult height was inversely associated with MetS, cardiovascular diseases, and liver function. The PRS, including zinc finger and BTB domain containing 38 (ZBTB38)_rs6762722, polyadenylate-binding protein-interacting protein-2B (PAIP2B)_rs13034890, carboxypeptidase Z (CPZ)_rs3756173, and latent-transforming growth factor beta-binding protein-1 (LTBP1)_rs4630744, was positively associated with height by 1.29 times and inversely with MetS by 0.894 times after adjusting for covariates. In expression quantitative trait loci, the gene expression of growth/differentiation factor-5 (GDF5)_rs224331, non-SMC condensin I complex subunit G (NCAPG)_rs2074974, ligand-dependent nuclear receptor corepressor like (LCORL)_rs7700107, and insulin-like growth factor-1 receptor (IGF1R)_rs2871865 was inversely linked to their risk allele in the tibial nerve and brain. The gene expression of PAIP2B_rs13034890 and a disintegrin and metalloproteinase with thrombospondin motifs-like-3 (ADAMTSL3)_rs13034890 was positively related to it. The PRS was inversely associated with MetS, hyperglycemia, HbA1c, and white blood cell counts. The wild type of GDF5_rs224331 (Ala276) lowered binding energy with rugosin A, D, and E (one of the hydrolyzable tannins) but not the mutated one (276Ser) in the in-silico analysis. The PRS interacted with energy intake and rice-main diet; PRS impact was higher in the high energy intake and the low rice-main diet. In conclusion, the PRS for adult height interacted with energy intake and diet patterns to modulate height and was linked to height and MetS by modulating their expression in the tibial nerve and brain.

Enhanced efficiency of calcium-derived oleoyl serine on osteoporosis via Wnt/β-catenin pathway

Osteoporosis is a common disease of the elderly that affects millions of patients worldwide. It is mainly characterized by low bone mineral density and increased risk of fracture due to the deterioration of the bone structure, leading to difficulties in functional recovery, reduced quality of life, increased disability risk and mortality in the population. It has already been a major public health problem. Osteoporosis is a chronic disease that is difficult to treat in the elderly population, so it is crucial to develop new drugs for the treatment of osteoporosis. Oleoyl serine, an endogenous fatty acyl amide found in bone, has been shown to have excellent anti-osteoporosis effects, but it is easily hydrolyzed by amidases in vivo. The aim of this study is to determine the anti-osteoporotic effect of calcium-derived oleoyl serine, a novel oleoyl serine derivative and the molecular mechanism underneath. In vitro experiments demonstrated that calcium-derived oleoyl serine suppressed the expression of Fabp4, and Cebpα while Alp, and Runx2 was significantly upregulated compared with the oleoyl serine group and control. With the activation of β-catenin, calcium-derived oleoyl serine restored the abnormal osteogenesis and lipogenesis, indicating calcium-derived oleoyl serine compared with oleoyl serine has better effects on promoting osteogenesis and suppressing lipogenesis. In vivo experiment agreed with these findings that calcium-derived oleoyl serine promotes osteogenesis and suppresses its lipogenesis to ameliorate osteoporosis via a β-catenin dependent method. It is a new candidate for treating osteoporosis.

Pyruvate Kinase M2 Promotes Hair Regeneration by Connecting Metabolic and Wnt/β-Catenin Signaling

Hair follicle stem cells (HFSCs) utilize glycolytic metabolism during their activation and anagen induction. However, the role of pyruvate kinase M2 (PKM2), which catalyzes the final step of glycolysis, in hair regeneration has not been elucidated. In this study, we investigated the expression pattern and activity of PKM2 during the depilation-induced anagen progression in mice. We found that TEPP-46, a selective activator of PKM2, enhanced hair re-growth and proliferation of HFSCs. PKM2 expression was increased via up-regulation of Wnt/β-catenin signaling, which is involved in hair regeneration. Moreover, a combined treatment with KY19382, a small molecule that activates Wnt/β-catenin signaling, and TEPP-46 significantly enhanced hair re-growth and wound-induced hair follicle neogenesis (WIHN). These results indicate that simultaneous activation of the PKM2 and Wnt/β-catenin signaling could be a potential strategy for treating alopecia patients.

An insight into the potent medicinal plant Phyllanthus amarus Schum. and Thonn

Phyllanthus amarus Schum. and Thonn., a globally distributed herb is known for its several therapeutic potentials. P. amarus has a long history of use in the traditional system of medicine for over 2000 years owing to its wide array of secondary metabolites that confer significant medicinal attributes. Research on various aspects including ethnobotany, phytochemistry to bioactivity, or pharmacological studies has been conducted over the past several decades on this potent herb. P. amarus extracts have shown a broad range of pharmacological activities like hepatoprotective, antioxidant, antiviral, antimicrobial, antidiabetic, anti-inflammatory, anticancer, antimalarial, nephroprotective, diuretic, and several other properties. The present review compiles and covers literature and research of several groups across past decades to date and focuses on how the therapeutic significance of this plant can be further explored for future research either as herbal formulations, alternative medicine, or in the pharmaceutical industry.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13237-022-00409-z.

Juglans regia L. extract promotes osteogenesis of human bone marrow mesenchymal stem cells through BMP2/Smad/Runx2 and Wnt/β-catenin pathways

Background

The present study investigates the effects of Juglans regia L. (walnut, JRL) leaves extract on osteogenesis of human bone marrow mesenchymal stem cells (hBMSCs).

Methods

hBMSCs were incubated with different concentrations of JRL extract (10, 20, 40, or 80 μM). Cell proliferation was evaluated by Cell Counting Kit-8 assay (CCK-8) assay. ALP activity and Alizarin Red staining were used to assess the osteogenesis of BMSCs. Western blot was performed to measure the levels of proteins.

Results

Our results showed all concentrations of JRL extract had no significant effect on cell proliferation. JRL extract concentration-dependently promoted osteoblastic differentiation and cell autophagy of hBMSCs, characterized by the increased expression of pro-osteogenic markers alkaline phosphatase (ALP), osteocalcin (BGLAP), osterin, and osteoprotegerin (OPG) and autophagy marker proteins (LC3II, Beclin-1, and p62). Furthermore, JRL extract stimulated the activation BMP2/Smad/Runx2 and Wnt/β-catenin signaling pathways in hBMSCs, which play key roles in osteogenesis differentiation. Meanwhile, BMP inhibitor (Noggin) and Wnt antagonist Dickkopf-1 (DKK1) both reversed the increases of BGLAP, osterin, and OPG expression induced by JRL extract.

Conclusions

Our findings indicate that JRL extract regulated osteogenic differentiation and cell autophagy of hBMSCs through the BMP2/Smad/Runx2 and Wnt/β-catenin pathways.

Effect of Eucomis autumnalis on the Osteogenic Differentiation of Adipose Derived Stem Cells

Eucomis autumnalis subsp. autumnalis (Mill.) Chitt. (EASA) is a commonly used medicinal plant for the treatment of fractures, osteoarthritis, back pain, and wound healing in Southern Africa. In this study, the effects of water and acetone extracts of EASA on the viability, osteogenic differentiation, and mineralization of human adipose derived stem cells (hADSCs) were investigated in vitro. The results showed that both water and acetone extracts of EASA increased cell viability at concentrations between 10 to 50 µg/mL on day 7 and 14 of treatment. Osteogenic differentiation and mineralization of hADSCs was optimal at 5 μg/mL for the water extract and at 5 to 10 μg/ml for the acetone extract. A 5 µg/ml acetone extract up-regulated the expression of the ALP, Runx2, Col1a1, and osteocalcin genes. In addition, EASA up-regulated β-catenin, cyclin D1 and osteoprotegerin genes. The results suggest that EASA may likely up-regulate the expression of β-catenin, which subsequently up-regulates the osteogenic marker genes through Runx2. On the other hand, EASA also up-regulates cyclin D1 supporting the growth of precursor cells. Additionally, EASA upregulated the expression of osteoprotegerin (OPG) suggesting that it may inhibit bone resorption. The results of this study support the traditional use of the plant in bone healing.

Molecular Signaling Pathways and Essential Metabolic Elements in Bone Remodeling: An Implication of Therapeutic Targets for Bone Diseases

Bone is one of the dynamic tissues in the human body that undergoes continuous remodelling through subsequent actions of bone cells, osteoclasts, and osteoblasts. Several signal transduction pathways are involved in the transition of mesenchymal stem cells into osteoblasts. These primarily include Runx2, ATF4, Wnt signaling and sympathetic signalling. The differentiation of osteoclasts is controlled by M-CSF, RANKL, and costimulatory signalling. It is well known that bone remodelling is regulated through receptor activator of nuclear factor-kappa B ligand followed by binding to RANK, which eventually induces the differentiation of osteoclasts. The resorbing osteoclasts secrete TRAP, cathepsin K, MMP-9 and gelatinase to digest the proteinaceous matrix of type I collagen and form a saucer-shaped lacuna along with resorption tunnels in the trabecular bone. Osteoblasts secrete a soluble decoy receptor, osteoprotegerin that prevents the binding of RANK/RANKL and thus moderating osteoclastogenesis. Moreover, bone homeostasis is also regulated by several growth factors like, cytokines, calciotropic hormones, parathyroid hormone and sex steroids. The current review presents a correlation of the probable molecular targets underlying the regulation of bone mass and the role of essential metabolic elements in bone remodelling. Targeting these signaling pathways may help to design newer therapies for treating bone diseases.

Artesunate promotes osteoblast differentiation through miR-34a/DKK1 axis

BACKGROUND

Osteoporosis is characterised by impairment of microarchitecture and bone mass. Therapeutic strategy promoting osteoblast differentiation is considered as a promising direction for the treatment of osteoporosis. Artesunate (ART) is related to osteoporosis, but the relationship between ART and osteogenic differentiation is still unknown.

METHODS

Cells proliferation were measured by MTT, ALP activity assay and Alizarin Red S staining were used to assess osteogenic differentiation of hBMSCs. Western blotting and qRT-PCR were applied for measuring expression of protein and mRNA, respectively. The relationship between miR-34a and Dickkopf-1 (DKK1) was detected by dual luciferase reporter assay.

RESULTS

The expression of osteoblasts differentiation related proteins (Runx2, OCN, and OPN) were significantly increased by ART. And ART accelerates the osteoblasts differentiation of hBMSCs through promoting Wnt signaling pathway by DKK1 inhibition. Significant higher expression of miR-34a and lower expression of DKK1 could be induced by ART. We firstly proved that miR-34a could bind DKK1 specifically.

CONCLUSION

ART could promote osteoblast differentiation through miR-34a/DKK1/Wnt pathway. Therefore, our findings may provide a new thought for the treatment of osteoporosis by ART through osteoblast differentiation promotion.

Polydatin improves osteogenic differentiation of human bone mesenchymal stem cells by stimulating TAZ expression via BMP2-Wnt/β-catenin signaling pathway

OBJECTIVES

Polydatin (PD), extracted from Polygonum cuspidatum, has shown potential therapeutic applications due to its antiosteoporotic and anti-inflammatory activities. Our previous study suggested that PD promotes the osteogenesis of human bone marrow stromal cells (hBMSCs) via the BMP2-Wnt/β-catenin pathway. The aim of our present study was to further explore the role of PD-mediated regulation of Tafazzin (TAZ), a transcriptional coactivator with a PDZ-binding motif, in osteogenesis.

MATERIALS AND METHODS

hBMSCs were isolated and treated with PD at various concentrations. Alizarin red staining and RT-qPCR were performed to identify calcium complex deposition in hBMSCs as well as the expression of specific osteoblast-related markers, respectively, in each group. Next, TAZ-silenced hBMSCs were generated by lentivirus-produced TAZ shRNA. After treatment with PD, the osteogenic abilities of the TAZ-silenced and control hBMSCs were estimated by ALP activity assay, and expression of the TAZ protein was detected by Western blot analysis and immunofluorescence staining. In vitro, an ovariectomized (OVX) mouse model was established and used to evaluate the effect of PD on bone destruction by micro-CT, immunohistochemistry, and ELISA.

RESULTS

In vitro, 30 μM PD significantly improved the proliferation and calcium deposition of hBMSCs and markedly stimulated the expression of the mRNAs RUNX2, Osteopontin, DLX5, β-catenin, TAZ, and Osteocalcin (OCN). Osteogenic differentiation induced by PD was blocked by lentivirus-mediated TAZ shRNA. Furthermore, Noggin (a regulator of bone morphogenic protein 2 (BMP2)) and DKK1 (an inhibitor of the Wnt/β-catenin pathway) were found to inhibit the increase in TAZ expression induced by PD. In vivo, PD prevented estrogen deficiency-induced bone loss in the OVX mouse model.

CONCLUSION

Taken together, our findings suggest that PD improved the osteogenic differentiation of hBMSCs and maintained the bone matrix in the OVX mouse model through the activation of TAZ, a potential target gene of the BMP2-Wnt/β-catenin pathway.

Yak (Bos grunniens) bones collagen-derived peptides stimulate osteoblastic proliferation and differentiation via the activation of Wnt/β-catenin signaling pathway

BACKGROUND

As the world's population is transitioning gradually to an ageing stage, the incidence of osteoporosis is increasing annually. Yak bone is one of the major components of Tibetan medicine and it has mainly been associated with an improvement in bone health, for example against osteoporosis. However, the functional bioactive ingredients and the underlying mechanisms are still unclear.

RESULTS

Sequential purification of yak-bone hydrolysates was achieved by ultrafiltration, size exclusion chromatography, and semi-preparative reverse-phase high-performance liquid chromatography. After this, 35 novel peptides were identified by mass spectrometry analysis, of which peptide GPAGPPGPIGNV (GP-12) displayed the highest osteoblast proliferation-promoting activity, with an increase of 42.7% in cell growth. An in vitro stability study demonstrated that GP-12 was digested into smaller peptides (GP-9, GV-9, AV-10 and GP-11) after simulated gastrointestinal digestion and absorption (Caco-2 cell monolayers) experiments. However, some of them still can be absorbed intact through the (Caco-2 cell monolayers by a paracellular route (Papp: 5.36 ± 0.34 cm s^-1 ). Flow cytometry results indicated that GP-12 enhanced osteoblastic proliferation by inducing the alteration of the cell-cycle progression both from the G0/G1 to the S phase and from the S to the G2/M phase. Quantitative real-time polymerase chain reaction (PCR) and western blot results revealed that GP-12 induced osteoblastic proliferation and differentiation in a dose-response manner through the activation of a Wnt/β-catenin signaling pathway.

CONCLUSION

These findings highlighted that such peptides hold the promise of discovering candidates for functional and health-promoting foods, which could be potentially used for the treatment of osteoporosis. © 2020 Society of Chemical Industry.

LncRNA TUG1 was upregulated in osteoporosis and regulates the proliferation and apoptosis of osteoclasts

Background

Long non-coding RNA (LncRNA) TUG1 plays critical roles in the development of human cancers. Its inhibition has been proved to participate in ankylosing spondylitis, which is an inverse pathological procedure of osteoporosis. In the present study, we aim to investigate the role of lncRNA TUG1 in ankylosing spondylitis.

Materials and methods

Expressions of lncRNA TUG1 in plasma of 98 patients with osteoporosis and 60 healthy participants were detected by real-time quantitative PCR (RT-qPCR). Diagnostic values of lncRNA CASC11 for osteoclasts were performed by the ROC curve with osteoporosis patients as positive and healthy participants as negative. All experiments were repeated 3 times. Mean ± standard deviation was calculated.

Results

We found that plasma lncRNA TUG1 was upregulated in osteoporosis patients than in healthy participants. Upregulation of plasma lncRNA TUG1 distinguished osteoporosis patients from healthy participants. LncRNA TUG1 level increased with the advances of clinical stages. Over-expression of lncRNA TUG1 promoted the proliferation and inhibited the apoptosis of mice osteoclasts, while lncRNA TUG1 siRNA silencing played an opposite role. In addition, lncRNA TUG1 over-expression led to downregulated PTEN, while lncRNA TUG1 siRNA silencing played an opposite role.

Conclusion

Therefore, lncRNA TUG1 is upregulated in osteoporosis and regulates the proliferation and apoptosis of osteoclasts. lncRNA TUG1 knockdown may serve as a promising therapeutic target for osteoporosis by inhibiting the proliferation and promoting the apoptosis of osteoclasts through PTEN.

Modulation of cell signaling pathways by Phyllanthus amarus and its major constituents: potential role in the prevention and treatment of inflammation and cancer

The causal and functional connection between inflammation and cancer has become a subject of much research interest. Modulation of cell signaling pathways, such as those involving mitogen activated protein kinases (MAPKs), nuclear factor kappa β (NF-κB), phosphatidylinositol 3-kinase and protein kinase B (PI3K/Akt), and Wnt, and their outcomes play a fundamental role in inflammation and cancer. Activation of these cell signaling pathways can lead to various aspects of cancer-related inflammation. Hence, compounds able to modulate inflammation-related molecular targets are sought after in anticancer drug development programs. In recent years, plant extracts and their metabolites have been documented with potential in the prevention and treatment of cancer and inflammatory ailments. Plants possessing anticancer and anti-inflammatory properties due to their bioactive constituents have been reported to modulate the molecular and cellular pathways which are related to inflammation and cancer. In this review we focus on the flavonoids (astragalin, kaempferol, quercetin, rutin), lignans (phyllanthin, hypophyllanthin, and niranthin), tannins (corilagin, geraniin, ellagic acid, gallic acid), and triterpenes (lupeol, oleanolic acid, ursolic acid) of Phyllanthus amarus, which exert various anticancer and anti-inflammatory activities via perturbation of the NF-κB, MAPKs, PI3K/Akt, and Wnt signaling networks. Understanding the underlying mechanisms involved may help future research to develop drug candidates for prevention and new treatment for cancer and inflammatory diseases.

Geraniin promotes osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) via activating β-catenin: a comparative study between BMSCs from normal and osteoporotic rats

Abnormal osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) has been correlated with the pathogenesis of osteoporosis. Geraniin, a polyphenolic compound isolated from Phyllanthus amarus, is effective in preventing osteoporosis, but the mechanisms of action of geraniin and the impact of osteoporotic condition on drug action are not known. In this study we compared the proliferation and osteoblastic differentiation potential of BMSCs from normal rats with that from osteoporotic rats, and examined the responses of both BMSCs to geraniin in parallel. BMSCs of rats subjected to ovariectomy or sham operation were isolated and treated with geraniin. Cell proliferation was measured by CCK-8 assay. Osteoblastic differentiation was quantified by Alizarin Red S staining and alkaline phosphatase assay. Nuclear translocation of β-catenin was monitored by immunofluorescent staining. Expression of β-catenin was determined by Western blot and quantitative real-time polymerase chain reaction. Results showed that the proliferation and osteoblast formation of osteoporotic BMSCs decreased in comparison to that of normal BMSCs. Geraniin enhanced proliferation and osteoblastic differentiation of both BMSCs, but the responses of osteoporotic BMSCs to geraniin were less than those of normal BMSCs. Expression and nuclear accumulation of β-catenin in osteoporotic BMSCs were found to be diminished. Geraniin increased nuclear translocation and expression of β-catenin in both BMSCs. This study associated the osteogenic effect of geraniin to activation of Wnt/β-catenin signaling, and provided rationale for pharmacological investigation of geraniin in osteoporosis prevention and treatment.

Lycopene treatment inhibits activation of Jak1/Stat3 and Wnt/β-catenin signaling and attenuates hyperproliferation in gastric epithelial cells

Helicobacter pylori (H pylori) colonizes the human stomach and increases the risk of gastric diseases including gastric cancer. H pylori increases reactive oxygen species (ROS), which activate Janus-activator kinase 1 (Jak1)/signal transducers and activators of transcription 3 (Stat3) in gastric epithelial cells. ROS mediate hyperproliferation, a hallmark of carcinogenesis, by activating Wnt/β-catenin signaling in various cells. Lycopene is a potent antioxidant exhibiting anticancer effects. We hypothesized that lycopene may inhibit H pylori-induced hyperproliferation by suppressing ROS-mediated activation of Jak1/Stat3 and Wnt/β-catenin signaling, and β-catenin target gene expression in gastric epithelial cells. We determined cell viability, ROS levels, and the protein levels of phospho- and total Jak1/Stat3, Wnt/β-catenin signaling molecules, Wnt-1, lipoprotein-related protein 5, and β-catenin target oncogenes (c-Myc and cyclin E) in H pylori-infected gastric epithelial AGS cells. The Jak1/Stat3 inhibitor AG490 served as the control treatment. The significance of the differences among groups was calculated using the 1-way analysis of variance followed by Newman-Keuls post hoc tests. The results show that lycopene reduced ROS levels and inhibited Jak1/Stat3 activation, alteration of Wnt/β-catenin multiprotein complex molecules, expression of c-Myc and cyclin E, and cell proliferation in H pylori-infected AGS cells. AG490 similarly inhibited H pylori-induced cell proliferation, alteration of Wnt/β-catenin multiprotein complex molecules, and oncogene expression. H pylori increased the levels of Wnt-1 and its receptor lipoprotein-related protein 5; this increase was inhibited by either lycopene or AG490 in AGS cells. In conclusion, lycopene inhibits ROS-mediated activation of Jak1/Stat3 and Wnt/β-catenin signaling and, thus, oncogene expression in relation to hyperproliferation in H pylori-infected gastric epithelial cells. Lycopene might be a potential and promising nutrient for preventing H pylori-associated gastric diseases including gastric cancer.