BackgroundThe natural compound morusin (Mor) acts as a potent tumor suppressor in non-small cell lung cancer (NSCLC), but its potential to sensitize DDP and its direct targets are less understood. This work aims to investigate the DDP-sensitizing effects of Mor and the underlying mechanisms.MethodsCell viability and drug synergy were assessed in NSCLC cells. Ferroptosis was evaluated by measuring lipid reactive oxygen species (ROS), iron accumulation, and the expression of ferroptosis markers. GDF15 was identified as a target via transcriptome sequencing. Its direct binding with Mor was confirmed by molecular docking. The ubiquitin-mediated degradation mechanism and its functional role in ferroptosis were validated using the proteasome inhibitor MG132, alongside GDF15 overexpression and knockdown models. Clinical relevance was assessed using TCGA database analysis.ResultsMor induces ferroptosis and significantly augments DDP sensitivity in both NSCLC and cisplatin-resistant A549 cells (A549/DDP). Mechanistically, Mor directly binds to GDF15 and promotes its ubiquitin-mediated degradation. Consequently, GDF15 overexpression reversed Mor-induced cytotoxicity and DDP sensitization. Furthermore, DDP exposure impairs intracellular GDF15 protein levels, and the Mor/DDP combination synergistically suppresses GDF15 in A549 cells. Notably, GDF15 expression is elevated in NSCLC cells compared to normal lung epithelial cells. However, A549/DDP cells exhibit diminished intracellular GDF15 protein relative to parental cells, while GDF15 transcription is upregulated. Knockdown of GDF15 augmented DDP sensitivity in resistant cells.ConclusionMor reverses DDP resistance by inducing GDF15 degradation and ferroptosis, suggesting that Mor-based combination therapy holds promise in treating NSCLC.

Overactivation of thioredoxin reductase 1 (TrxR1) is implicated in tumor development. This study aims to elucidate the efficacy and mechanisms by which neferine (Nef) exerts its anti-tumor effects in pancreatic cancer through targeting TrxR1. The results demonstrate that Nef directly binds to and inhibits the enzymatic activity of TrxR1, leading to an abnormal accumulation of reactive oxygen species (ROS) in mitochondria. This accumulation subsequently results in a decrease in mitochondrial membrane potential, DNA damage, and the activation of apoptotic pathways, characterized by changes in the Bax/Bcl-2 ratio and a cascade reaction involving caspases. Reversal experiments indicated that the ROS scavenger NAC significantly counteracted the inhibitory effects of Nef on pancreatic cancer cell proliferation and its induction of apoptosis. Genetic experiments confirmed that the knockdown of TrxR1 enhances the anti-pancreatic cancer effects of Nef. Furthermore, a nude mouse xenograft tumor model validated the in vivo efficacy of Nef in suppressing tumor growth via TrxR1 inhibition. Bioinformatic analysis suggested that elevated TrxR1 expression is associated with a poor prognosis in pancreatic cancer. Collectively, our results confirm that Nef is a novel inhibitor of TrxR1 and provide experimental evidence for a therapeutic strategy targeting TrxR1.

Seventeen new piericidin derivatives (1-17) and a new natural analog (18) featuring various oxidation, cyclization and cleavage on the side chain, were isolated from the culture extract of the marine-derived Streptomyces sp. DH-012, along with twelve known piericidins (19-30). The structures of compounds 1-17 were elucidated by analysis of NMR and MS spectroscopic data. The absolute configurations of 1-15 were determined by NMR and ECD calculations. All piericidins were tested for antibacterial activities, with 16 exhibiting more potent activity against multiple resistant "ESKAPE" pathogens, especially to Gram-negative bacteria, Escherichia coli and Klebsiella pneumoniae, with MIC values of 8 mu g/mL.

A series of novel A2A adenosine receptor (AR) antagonists containing a pyrrolo[2,3-d]pyrimidin-2-amine skeleton were developed through a bioisosterism strategy based on human A2A AR structures. The synthesis of all targeted compounds was accomplished, and their inhibitory effectiveness against the A2A AR was assessed using cAMP assays. Notably, compounds 12a and 18e demonstrated superior inhibitory effects compared to the control compounds AB928 and ZM241385. Competitive radioligand binding experiments confirmed their high binding affinities to the A2A AR. Molecular docking studies revealed that the pyrrolo[2,3-d]pyrimidin-2-amine core moiety forms two π-π interactions with the aromatic residue Phe168, alongside forming hydrogen bonds with residues Glu169 and Asn253. This information elucidates the rationality of molecular design. Moreover, both compounds 12a and 18e exhibited negligible toxicity towards normal cell lines. Compound 12a also demonstrated favorable stabilities in liver microsomes and acceptable pharmacokinetic profiles in vivo. These findings underscore the promise of compound 12a as a leading candidate for further research and development, highlighting its potential therapeutic applications.

Despite the widespread presence of polyethylene terephthalate microplastics (PET MPs) in the environment, their biotoxicity, target organs, and underlying toxicological mechanism remain poorly understood. In this study, irregularly shaped PET MPs resembling those commonly found in natural environment were selected. Mice were orally administered different amounts of PET MPs (0, 5, 50, and 500 μg/day) for 17 weeks, after which relevant pathological and biochemical indicators were assessed. The results confirmed, for the first time, that PET MPs can induce oxidative stress, lipid accumulation, and apoptosis in liver cells, resulting in structural damage and functional abnormalities in the liver. Additionally, metabolomic analysis was combined with intestinal microbiota profiling to elucidate the potential toxicological mechanism. The data revealed that chronic exposure to high doses of PET MPs substantially altered the diversity of the intestinal flora. In particular, the relative abundances of Parasutterella, Muribaculum, and Turicibacter increased, accompanied by elevated levels of lipid metabolites such as linoleic acid, taurocholic acid, and sphingosine. These changes disrupted metabolic processes and accelerated lipid deposition in the mouse liver, thereby inducing hepatotoxicity. Moreover, a validation experiment confirmed that depletion of the gut microbiota in mice alleviated PET MPs-induced hepatotoxicity. These findings provide new insights into the toxicity of PET MPs in humans and other mammals.

Five new macrocyclic napyradiomycins with different types of scaffolds were isolated from marine-derived Streptomyces canus SJ-019. Compounds 1 and 2 are uniquely typified by a spirocyclic core, while 1, 2 and 4 also contain a unique macrolide structure not known in any other napyradiomycins. Compound 3 is composed of a dearomatized napyradiomycin core and an intramolecular double-arch bridge system. Compound 4 displays potent inhibition of Staphylococcus aureus, while C-type napyradiomycin 5 shows notable anti-inflammatory effect.

Objective: Morusin (Mor), a prenylated flavonoid isolated from the root bark of Morus alba L., exhibits potent anti-tumour effects; however, the molecular target of Mor is still not entirely clear. This study aimed to elucidate the mechanism of Mor against hepatocellular carcinoma (HCC) and identify potential molecular targets. Methods: Mitochondrial function was assessed by measuring the mitochondrial membrane potential, mitochondrial ultrastructure, oxygen consumption, and ATP levels. Mor-induced mitophagy was confirmed using western blotting, immunofluorescence, and fluorescent probes. Transcriptomics, flow cytometry, western blotting, qRT-PCR and biochemical assays were used to reveal the molecular mechanisms and targets of Mor against HCC. We further validated the interaction between Mor and the target proteins using molecular docking and biolayer interferometry (BLI). The inhibitory effect of Mor in vivo was evaluated using a Hep3B murine xenograft model. Results: Mor significantly reduced the ATP citrate lyase (ACLY) expression and inhibited ACLY activity in HCC cells. BLI analysis demonstrated a direct interaction between Mor and the ACLY active domain. Mor-induced ACLY inhibition led to ROS accumulation in HCC cells, which caused mitochondrial damage, triggered PINK1/Parkin-mediated mitophagy, and ultimately induced mitochondrial apoptosis. We further verified that ROS is crucial in the apoptotic action of Mor through experiments regarding an ROS scavenger. Mor also significantly inhibited tumour xenograft growth in vivo. In addition, analysis of human liver cancer clinical samples revealed elevated ACLY levels positively correlated with histologic grade. Conclusion: Collectively, our findings highlight Mor as a potent bioactive inhibitor of ACLY and a promising candidate for HCC therapy.

Microplastics are a growing concern as pollutants that impact both public health and the environment. However, the toxic effects of polypropylene microplastics (PP-MPs) are not well understood. This study aimed to investigate the effects of PP-MPs on cardiotoxicity and its underlying mechanisms. The cardiotoxicity of exposure to different amounts of PP-MPs were investigated in both ICR mice and H9C2 cells. Our results demonstrated that sub-chronic exposure to 5 and 50 mg/L PP-MPs led to myocardial structural damage, apoptosis, and fibrosis in mice cardiomyocytes. Flow cytometry analysis revealed that PP-MPs could decrease mitochondrial membrane potential and induce apoptosis in H9C2 cells. Western blotting revealed decreased expression of Bcl-2, poly(ADP-ribose) polymerase (PARP) and caspase 3 and increased expression of Bax, cleaved-PARP, and cleaved-caspase 3 in PP-MPs-treated cardiac tissue and H9C2 cells. These results confirmed the apoptotic effects induced by PP-MPs. Moreover, PP-MPs treatment triggered oxidative stress, as evidenced by the increased levels of malondialdehyde; reduction in glutathione peroxidase, superoxide dismutase, and catalase activities in mice cardiac tissues; and increased reactive oxygen species levels in H9C2 cells. Finally, western blotting demonstrated that exposure to PP-MPs significantly reduced the expression levels of Nrf2 and p-ERK proteins associated with MAPK-Nrf2 pathway in both cardiac tissue and H9C2 cells. Overall, our findings indicate that PP-MPs can induce cardiomyocyte apoptosis through MAPK-Nrf2 signaling pathway, which is triggered by oxidative stress. This study provides a foundation for determining the effects of PP-MPs on cardiotoxicity and their underlying mechanisms.

BACKGROUND:Tiliroside (TIL) is a flavonoid compound that exists in a variety of edible plants. These dietary plants are widely used as food and medicine to treat various diseases. However, the effect of TIL on pancreatic cancer (PC) and its underlying mechanisms are unclear.PURPOSE:This study aims to reveal the anti-PC effect of TIL and clarify its mechanism.METHODS:The inhibitory effects of TIL on PC growth were studied both in vitro and in vivo. Flow cytometry, transmission electron microscopy, immunofluorescence, biochemical analyses, RT-qPCR, genetic ablation, and western blotting were employed to evaluate ferroptosis, autophagy, and iron regulation. Additionally, RNA sequencing (RNA-seq), biomolecular layer interferometry (BLI), and molecular simulation analysis were combined to identify TIL molecular targets. The clinicopathological significance of Calpain-2 (CAPN2) was determined through immunohistochemistry (IHC) on a PC tissue microarray.RESULTS:Herein, we showed that TIL was an effective anti-PC drug. CAPN2 was involved in the TIL - induced elevation of the labile iron pool (LIP) in PC cells. TIL directly bound to and inhibited CAPN2 activity, resulting in AKT deactivation and decreased expression of glucose transporters (GLUT1 and GLUT3) in PC cells. Consequently, TIL impaired ATP and NADPH generation, inducing autophagy and ROS production. The accumulation of TIL-induced ROS combined with LIP iron causes the Fenton reaction, leading to lipid peroxidation. Meanwhile, TIL-induced reduction of free iron ions promoted autophagic degradation of ferritin to regulate cellular iron homeostasis, which further exacerbated the death of PC cells by ferroptosis. As an extension of these in vitro findings, our murine xenograft study showed that TIL inhibited the growth of PANC-1 cells. Additionally, we showed that CAPN2 expression levels were related to clinical prognoses in PC patients.CONCLUSION:We identify TIL as a potent bioactive inhibitor of CAPN2 and an anti-PC candidate of natural origin. These findings also highlight CAPN2 as a potential target for PC treatment.

Polyethylene terephthalate microplastics (PET MPs) are widespread in natural environment, and can enter organisms and accumulate in the body, but its toxicity has not been well studied. Therefore, in order to investigate the toxic effects of PET microplastics on mammals, this study investigated the toxic effects of PET MPs on ICR mice and H9C2 cells by different treatment groups. The results indicated the cardiac tissue of mice in the PET-H (50 µg/mL) group showed significant capillary congestion, myocardial fiber breakage, and even significant fibrosis compared to the PET-C (control) group (P < 0.01). Results of the TUNEL assay demonstrated significant apoptosis in myocardial tissue in the PET-H and PET-M (5 µg/mL) groups (P < 0.01). Meanwhile, Western blotting showed increased expression of the apoptosis-related protein Bax and decreased expression of PARP, caspase-3, and Bcl-2 proteins in both myocardial tissues and H9C2 cells. In addition, flow cytometry confirmed that PET MPs decreased the mitochondrial membrane potential and apoptosis in H9C2 cells; however, this trend was reversed by N-acetylcysteamine application. Moreover, PET MP treatment induced the accumulation of reactive oxygen species (ROS) in H9C2 cells, while the MDA level in the myocardial tissue was elevated, and the activities of catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) were decreased (P < 0.01), indicating a change in the redox environment. In conclusion, PET MPs promoted cardiomyocyte apoptosis by inducing oxidative stress and activating mitochondria-mediated apoptotic processes, ultimately leading to myocardial fibrosis. This study provides ideas for the prevention of PET MP toxicity and promotes thinking about enhancing plastic pollution control.

Influenza epidemics persistently threaten global health. Vaccines based on virus-like particles (VLPs), which resemble the native conformation of viruses, have emerged as vaccine candidates. However, the production of VLPs via genetic engineering remains constrained by challenges such as low yields, high costs, and being time consuming. In this study, a novel VLP platform is developed that could mimic infection and confer influenza protection through fluorination-driven self-assembly. The VLPs closely mimick the key steps in viral infection including dendritic cell (DC) attachment and pH-responsive endo-lysosomal escape, which enhances DC maturation and antigen cross-presentation. It is also observed that the VLPs migrate from the injection site to the draining lymph nodes efficiently. Immunization with VLPs triggers both Th1 and Th2 cellular responses, thereby inducing an improved CD8+ T cell response along with strong antigen-specific antibody responses. In several infected mouse models, VLP vaccines ameliorate weight loss, lung virus titers, pulmonary pathologies, and confer full protection against H1N1, H6N2, H9N2, and mixed influenza viruses. Therefore, the results support the potential of VLPs as an effective influenza vaccine with improved immune potency against infection. A methodology to generate VLPs based on fluorophilic interactions, which can be a general approach for development of pathogenic VLPs, is reported.

Background: Combination therapy with other antineoplastic agent is a favorable approach for targeting the molecules involved in sorafenib resistance. Purpose: In the present study, we determined whether tiliroside, a natural flavonoid glycoside isolated from oriental paperbush flower, could improve the sensitivity of hepatocellular carcinoma (HCC) cells to sorafenib. Furthermore, we investigated the mechanisms and identified the potential drug targets of tiliroside. Methods: Synergy was performed using CalcuSyn. Transcriptomic studies were adopted to investigate whether tiliroside could induce ferroptosis and inhibit the nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway in HCC cells. Ferroptosis was analyzed using western blotting, flow cytometry, and transmission electron microscopy. Immunofluorescence, co-immunoprecipitation, and Nrf2 knockdown or overexpression were performed to confirm the involvement of Nrf2 in tiliroside-induced ferroptosis. Additionally, molecular docking and biolayer interferometry-based measurements were used to confirm the direct target of tiliroside. Finally, subcutaneous xenograft and orthotopic xenograft tumors in nude mice were used to assess the effects of tiliroside in vivo. Results: Tiliroside significantly enhanced the anti-HCC activity of sorafenib without any discernible side effects. Moreover, the combination of tiliroside and sorafenib induced synergistic effects against HCC in vitro. The inhibitory effects of tiliroside on HCC were antagonized by N-acetylcysteine and the ferroptosis inhibitor liproxstatin-1. Studies on the mechanism of action revealed that tiliroside could directly bind to TANK-binding kinase 1 (TBK1) and inhibit its enzymatic activity. Inhibition of TBK1 by tiliroside decreased the phosphorylation of serine 349 on sequestosome-1 (p62) and the affinity of p62 for kelch like ECH-associated protein 1 (Keap1) and promoted Keap1-mediated Nrf2 ubiquitination and degradation. The downstream target proteins of Nrf2, including glutathione peroxidase 4, ferritin heavy chain 1, and glucose-6-phosphate dehydrogenase, demonstrated similar results to that of Nrf2 protein, inducing ferroptosis in tiliroside-treated HCC cells. We extended these findings in vivo and found that tiliroside inhibited the growth of HepG2 tumors in both subcutaneous xenograft and orthotopic xenograft tumor models of HCC. Conclusion: Our findings imply that tiliroside is a potent TBK1 inhibitor and a candidate natural anti-cancer product that could function as a sensitizer of sorafenib in HCC treatment by targeting TBK1 to induce ferroptosis.

A series of novel dual A(2A)/A(2B) AR antagonists based on the triazole-pyrimidine-methylbenzonitrile core were designed and synthesised. The A(2A) AR antagonist cAMP functional assay results were encouraging for most target compounds containing quinoline or its open-ring bioisosteres. In addition, compound 7i displayed better inhibitory activity on A(2B) AR (IC50 14.12 nM) and higher potency in IL-2 production than AB928. Moreover, molecular docking studies were carried out to explain the rationality of molecular design and the activity of compound 7i. Further studies on 7f and 7i revealed good liver microsomes stabilities and acceptable in vivo PK profiles. This study provides insight into the future development of dual A(2A)/A(2B) AR antagonists for cancer immunotherapy.

Recent studies have verified that inducing reactive oxygen species (ROS) is one of the gemcitabine anti-tumor mechanisms of action. Human carbonyl reductase 1 (CBR1) plays an important role in protecting cells against oxidative damage. However, it is unclear whether CBR1 is involved in pancreatic cancer (PC) progression and resistance to gemcitabine. Based on the GEPIA database, we analyzed tumor tissue samples from PC patients using immunohistochemistry (IHC) and revealed that CBR1 was highly expressed in PC tissues and that this was significantly correlated with the clinicopathological features of PC. Genetic inhibition of CBR1 suppressed PC cell proliferation by regulating ROS generation. Furthermore, gemcitabine upregulated CBR1 expression, which could limit the anti-tumor activity of gemcitabine, and attenuation of CBR1 enhanced gemcitabine sensitivity in vitro and in vivo. Additionally, we report that chrysin directly binds to CBR1, which inhibited its enzymatic activity both at the molecular and cellular levels. Inhibition of CBR1 by chrysin increased cellular ROS levels and led to ROS-dependent autophagy, which resulted in the degradation of ferritin heavy polypeptide 1 (FTH1) and an increase in the intracellular free iron level that participates in ferroptosis in PC cells. Finally, our results showed that chrysin enhanced PC sensitivity to gemcitabine by inducing ferroptotic death in vitro and in vivo. Collectively, these findings indicate that CBR1 is a potential therapeutic target for PC treatment. In addition, we elucidated a novel mechanism underlying the anti-tumor effects of chrysin.

目的 研究低剂量化疗药吉西他滨(gemcitabine,GEM)能否增强人脐静脉内皮细胞(human umbilical vein en-dothelial cell,HUVEC)疫苗抗胰腺癌作用,并探讨其作用机制.方法 以Pan02小鼠胰腺癌细胞接种C57BL/6小鼠,建立皮下移植瘤模型,动物随机分为PBS组、GEM组、HUVEC组、HUVEC-GEM组,观察各组小鼠肿瘤生长及不良反应情况.通过小鼠免疫血清中HUVEC抗体检测实验、脾淋巴细胞增殖实验、细胞毒性T淋巴细胞杀伤实验及INF-γ测定实验确定GEM能否增强HUVEC疫苗诱导的免疫应答.结果 皮下移植瘤实验结果表明GEM引入HUVEC疫苗免疫方案后可以增强疫苗治疗性抗胰腺癌作用;酶联免疫实验结果证实GEM可以有效提升疫苗治疗组小鼠免疫血清中的HU-VEC抗体及IFN-γ水平;脾淋巴细胞增殖实验及CTL杀伤活性实验结果表明GEM可以有效增强HUVEC疫苗免疫小鼠的脾淋巴细胞转化活性和CTL杀伤能力.结论 低剂量GEM可以增强HUVEC疫苗诱导的免疫应答水平从而提升HUVEC疫苗的抗胰腺癌作用.

Chronic intermittent hypoxia (CIH) is the main symptom of obstructive sleep apnea syndrome (OSAS) and causes neural damage and cognitive deficits via neuroinflammation. Toll-like receptors (TLRs), especially TLR2, play an important role in neuroinflammation. However, the mechanisms by which TLR2 participates in CIH-induced cognitive deficits remain unclear. In this study, wild-type (WT) and TLR2 knock out (KO) mice were exposed to CIH for 8 weeks, and their social novelty discrimination, spatial learning and memory were severely compromised. Additionally, seriously damaged neurons and abnormally activated glia were observed in the CA1 and dentate gyrus (DG) areas of the hippocampus. Mechanistically, knocking out the TLR2 gene significantly alleviated these pathological changes and improved the behavioral performance. Together, these findings demonstrate that the TLR2-MyD88 signaling pathway might play an important role in CIH-induced cognitive deficits.

Nuciferine, a major aporphine alkaloid constituent of lotus leaves, is a raw material for obesity treatment. Extensive studies have revealed that obesity is associated with pancreatic cancer (PC). However, it has not been clarified whether nuciferine could be used in PC treatment or prevention. Here, we show that nuciferine could enhance the sensitivity of PC cells to gemcitabine in both cultured cells and the xenograft mouse model. The mechanism study demonstrated that nuciferine induced YAP Ser127 phosphorylation [pYAP(Ser127)] through AMPK-mediated 3-hydroxy-3-methyl-glutaryl-coA reductase (HMGCR) downregulation. Remarkably, wild-type YAP overexpression or YAP Ser127 mutant could resist to nuciferine and no longer sensitize PC cells to gemcitabine. Knockdown of AMPK attenuated pYAP(Ser127) induced by nuciferine. Moreover, knockdown of AMPK reversed nuciferine-mediated HMGCR downregulation. Notably, HMGCR inhibiting could restrain YAP by phosphorylation Ser 127, and therefore enhance the efficiency of gemcitabine in PC cells. In line with this consistent, overexpression of HMGCR reduced growth inhibition caused by nuciferine and/or gemcitabine treatment in PC cells. In summary, these results provide an effective supplementary agent and suggest a therapeutic strategy to reduce gemcitabine resistance in PC.

Our previous studies have indicated that human umbilical vein endothelial cell (HUVEC) vaccination appears to be a potentially promising anti-angiogenesis therapy, but the modest therapeutic anti-tumour efficiency limits its clinical use. This highlights the importance of identifying more potent therapeutic HUVEC vaccine strategies for clinical testing. In the present study, the immune-modulating doses of docetaxel (DOC) was combined with 1 × 106 viable HUVECs as a means to enhance the therapeutic anti-tumour efficiency of the HUVEC vaccine. Our results demonstrated that 5 mg/kg DOC administrated prior to HUVEC vaccine could most effectively assist HUVEC vaccine to display a remarkable suppression of tumour growth and metastasis as wells as a prolongation of survival time in a therapeutic procedure. CD31 immunohistochemical analysis of the excised tumours confirmed a significant reduction in vessel density after treatment with the HUVEC vaccine with 5 mg/kg DOC. Additionally, an increased HUVEC-specific antibody level, activated CTLs and an elevated IFN-γ level in cultured splenocytes were revealed after treatment with HUVEC vaccine with 5 mg/kg DOC. Finally, 5 mg/kg DOC coupled with the HUVEC vaccine led to induction of significant increases in CD8+ T cells and decrease in Tregs in the tumour microenvironment. Taken together, all the results verified that 5 mg/kg DOC could assist HUVEC vaccine to elicit strong HUVEC specific humoral and cellular responses, which could facilitate the HUVEC vaccine-mediated inhibition of cancer growth and metastasis. These findings provide the immunological rationale for the combined use of immune-modulating doses of DOC and HUVEC vaccines in patients with cancer.

Malignant melanoma is the most lethal type of skin cancer. Previous studies have shown that ailanthone has potent antitumor activity in a variety of cell lines. However, the anti-tumor effect of ailanthone on malignant melanoma remains unclear. To investigate the anti-tumor mechanisms of ailanthone in human melanoma B16 and mouse melanoma A375 cells, the cell counting kit-8 assay, colony formation assay, DNA content analysis, Hoechst 33258, and Annexin V-FITC/PI staining were used to assess cell proliferation, cell cycle distribution, and cell apoptosis, respectively. Western blotting was performed to evaluate the expression of cell cycle- and apoptosis-related proteins and regulatory molecules. The results showed that ailanthone significantly inhibited melanoma B16 and A375 cell proliferation as well as remarkably induced cell cycle arrest at the G0–G1 phase in B16 cells and the G2–M phase in A375 cells in a dose-dependent manner. Further investigation revealed that ailanthone promoted the expression of p21 and suppressed the expression of cyclin E in B16 cells or cyclin B in A375 cells through the PI3K-Akt signaling pathway. In addition, ailanthone induced B16 and A375 cell apoptosis via a caspase-dependent mechanism. Further studies showed that ailanthone remarkably downregulated Bcl-2 and upregulated Apaf-1 and Bax, and subsequently increased mitochondrial membrane permeabilization and released cytochrome c from the mitochondria in B16 cells and A375 cells. Taken together, ailanthone induces cell cycle arrest via the PI3K-Akt signaling pathway as well as cell apoptosis via the mitochondria-mediated apoptotic signaling pathway. Ailanthone may be potentially utilized as an anti-tumor agent in the management of malignant melanoma.

Astragalin (AG) is a biologically active flavonoid compound that can be extracted from a number of medicinal plants. However, the effects of AG on osteoblastic differentiation in mouse MC3T3-E1 cells and on bone formation in vivo have not been studied fully. In this study, we found that the activities of alkaline phosphatase (ALP) and mineralized nodules in MC3T3-E1 cells were both significantly increased after treatment with AG (5, 10, and 20 μM). Meanwhile, the mRNA and protein levels of osteoblastic marker genes in MC3T3-E1 cells after AG treatment were markedly increased compared with a control group. In addition, the levels of BMP-2, p-Smad1/5/9, and Runx2 were significantly elevated in AG-treated MC3T3-E1 cells. Moreover, we found that the protein levels of Erk1/2, p-Erk1/2, p38, p-p38, and p-JNK were also significantly increased in AG-treated MC3T3-E1 cells compared to those in the control group. Finally, in vivo experiments demonstrated that AG significantly promoted bone formation in an ovariectomized (OVX)-induced osteoporotic mouse model. This was evidenced by significant increases in the values of osteoblast-related parameters (BFR/BS, MAR, Ob.S/BS, and Ob.N/B.Pm) and bone histomorphometric parameters (BMD, BV/TV, Tb.Th, and Tb.N.) in OVX mice after AG treatment (5, 10, and 20 mg/kg). Collectively, these results demonstrated that AG may promote osteoblastic differentiation in MC3T3-E1 cells via the activation of the BMP and MAPK pathways and promote bone formation in vivo. These novel findings indicated that AG may be a useful bone anabolic agent for the prevention and treatment of osteoporosis.