Extract of Torreya nucifera Pericarps Exhibits a Parasiticidal Effect on the Nematode Parasite, Trichinella spiralis.

Benzimidazole derivatives can effectively treat nematode parasitic infections; however, some derivatives demand distinct administrative strategies depending on plasma concentration and patient conditions. Numerous studies have examined the potential of natural extracts to exert parasiticidal activity with minimal side effects. Herein, we examined the potential parasiticidal effects of Torreya nucifera extract. The pericarps of T. nucifera were extracted with methanol, dried, and the pellet was dissolved in hot water (Tn-Phw). We designed four individual mouse experiments to clarify the prophylactic and therapeutic effects of Tn-Phw on Trichinella spiralis infection. Also, 100 L1 larvae were isolated and treated with Tn-Phw (10 mg/mL) in vitro to confirm the killing effect. Furthermore, we microscopically examined the morphology of L1 larvae to confirm the parasite-killing effect and analyzed the morphology using a scanning electron microscope (SEM). The expression of three molting-related genes was confirmed to determine whether Tn-Phw induced morphological changes in L1 larvae. Following treatment with Tn-Phw, L1 larvae death was observed after 16 h. Following SEM examination, the healthy muscle larvae showed striated ridges and wrinkles; this was not observed in extract-treated muscle larvae. Expression levels of the three molting-related genes did not differ between the Tn-Phw-treated and control groups. T. spiralis-infected mice pretreated with Tn-Phw showed significantly reduced muscle larva infection when compared with control mice. In all experiments, treatment with Tn-Phw afforded preventive and therapeutic effects against T. spiralis infection and parasitism. Natural substances against nematode parasites could be developed as therapeutic agents with few side effects and enhanced parasiticidal efficacy.

Inhibitory Effect of Biotransformed-Fucoidan on the Differentiation of Osteoclasts Induced by Receptor for Activation of Nuclear Factor-κB Ligand.

Bone homeostasis is regulated by constant remodeling through osteogenesis by osteoblasts and osteolysis by osteoclasts and osteoporosis can be provoked when this balance is broken. Present pharmaceutical treatments for osteoporosis have harmful side effects and thus, our goal was to develop therapeutics from intrisincally safe natural products. Fucoidan is a polysaccharide extracted from many species of brown seaweed, with valuable pharmaceutical activities. To intensify the effect of fucoidan on bone homeostasis, we hydrolyzed fucoidan using AMG, Pectinex and Viscozyme. Of these, fucoidan biotransformed by Pectinex (Fu/Pec) powerfully inhibited the induction of tartrate-resistant acid phosphatase (TRAP) activity in osteoclasts differentiated from bone marrow macrophages (BMMs) by the receptor for activation of nuclear factor-κB ligand (RANKL). To investigate potential of lower molecular weight fucoidan it was separated into >300 kDa, 50-300 kDa, and <50 kDa Fu/Pec fractions by ultrafiltration system. The effects of these fractions on TRAP and alkaline phosphatase (ALP) activities were then examined in differentiated osteoclasts and MC3T3-E1 osteoblasts, respectively. Interestingly, 50-300 kDa Fu/Pec suppressed RANKL-induced osteoclasts differentiation from BMMs but did not synergistically enhance osteoblasts differentiation induced by osteogenic agents. In addition, this fraction inhibited the expressions of NFATc1, TRAP, OSCAR, and RANK, which are all key transcriptional factors involved in osteoclast differentiation, and those of Src, c-Fos and Mitf, as determined by RT-PCR. In conclusion, enzymatically low-molecularized 50-300 kDa Fu/Pec suppressed TRAP by downregulating RANKL-related signaling, contributing to the inhibition of osteoclasts differentiation, and represented a potential means of inducing bone remodeling in the background of osteoporosis.

Temporal Changes of Metabolic Indicators and Quality of Life by a Two-Day Patient Education Program for Metabolic Syndrome Patients.

Metabolic syndrome (MetS) is a disease with a high prevalence that threatens the health of modern people. Patient education is essential to control MetS. This prospective study aimed to evaluate 6-month changes in health indicators following a two-day education program for patients with MetS aged 45 or older. Education about MetS, lifestyle modification, nutrition, and physical activity was provided. At 3 and 6 months after the program, participants visited for follow-up. Twenty-two patients completed the 6-month study. Waist circumference was reduced, and life quality and depression index improved in 3 and 6 months compared to pre-education. Blood pressure decreased, and anxiety index improved at three months. Nutritional knowledge was well maintained for 3 and 6 months. High-density lipoprotein-cholesterol levels increased at six months. Three out of twenty-two patients did not satisfy MetS criteria at the end of the study due to improved indicators. A two-day multidisciplinary education program positively affected health indicators in MetS patients. Participation in the program also help with life satisfaction and positive emotional condition. However, some indicators improved in 3 months, but the effect disappeared 6 months after the program.

Inhibition of Autophagy Promotes Hemistepsin A-Induced Apoptosis via Reactive Oxygen Species-Mediated AMPK-Dependent Signaling in Human Prostate Cancer Cells.

Chemotherapy is an essential strategy for cancer treatment. On the other hand, consistent exposure to chemotherapeutic drugs induces chemo-resistance in cancer cells through a variety of mechanisms. Therefore, it is important to develop a new drug inhibiting chemo-resistance. Although hemistepsin A (HsA) is known to have anti-tumor effects, the molecular mechanisms of HsA-mediated cell death are unclear. Accordingly, this study examined whether HsA could induce apoptosis in aggressive prostate cancer cells, along with its underlying mechanism. Using HsA on two prostate cancer cell lines, PC-3 and LNCaP cells, the cell analysis and in vivo xenograft model were assayed. In this study, HsA induced apoptosis and autophagy in PC-3 cells. HsA-mediated ROS production attenuated HsA-induced apoptosis and autophagy after treatment with N-acetyl-L-cysteine (NAC), a ROS scavenger. Moreover, autophagy inhibition by 3-MA or CQ is involved in accelerating the apoptosis induced by HsA. Furthermore, we showed the anti-tumor effects of HsA in mice, as assessed by the reduced growth of the xenografted tumors. In conclusion, HsA induced apoptosis and ROS generation, which were blocked by protective autophagy signaling.

Correlation between Metal Ions and Cytokines in the Saliva of Patients with Oral Lichenoid Lesions.

PURPOSE: We aimed to investigate the effect of metal ions from oral prostheses (OPs) released into the saliva of patients with oral lichenoid lesions (OLLs). MATERIALS AND METHODS: Subjects (n=183) were divided into four groups according to the presence or absence of OLL and OP. Concentrations of the metal ions titanium, chromium (Cr), cobalt (Co), nickel (Ni), palladium (Pd), silver (Ag), platinum (Pt), gold (Au), and zirconium (Zr) were measured using a laser-ablation microprobe inductively coupled to a plasma mass spectrometer. Saliva levels of interleukin (IL)-6, IL-1ß, IL-8, and tumor necrosis factor-α were detected using an enzyme-linked immunosorbent assay. The reticulation/keratosis, erythema, and ulceration (REU) scoring system was used to assess the severity of OLL. RESULTS: Mean concentrations of IL-6 and IL-8 were statistically higher in OLL patients with OPs. The concentration of Ni was high in OLL groups. The concentrations of Cr, Ni, and Au ions in the saliva were positively correlated with IL-8. REU scores were positively correlated with salivary concentrations of IL-6 and IL-8, as well as with concentrations of Cr, Ni, and Au. CONCLUSION: Increased concentrations of metal ions, especially Ni, in saliva were positively correlated with IL-8 and showed positive correlations with the severity of OLL.

Anti-Cancer Effects of RAW 264.7 Cells on Prostate Cancer PC-3 Cells.

Macrophages have the potential to re-programing tumor cells in the tumor microenvironments. Thus we investigated anti-cancer effects of M1-polarized macrophages by lipopolysaccharide (LPS) on the physiological properties of human prostate cancer PC-3 cells. To identify communications with immune cells and tumor cells, we performed in-direct way by using conditioned-media (CM) and analyzed tumor properties via quantitative polymerase chain reaction, enzyme-linked immunosorbent assay and western blot and flow cytometry. CM of M1-polarized macrophages induced apoptotic cell death in PC-3 cells, and it surprisingly suppressed tumor parameters including epithelial to mesenchymal transition (EMT), invasion, migration and angiogenesis. EMT specific markers, N-cadherin, snail-1, and TGF ß2 were diminished; however, E-cadherin was increased. In addition, migration markers, vimentin and CCL2 were down-regulated, and finally wound healing was also inhibited. Decreased expression of matrix metalloprotein (MMP)-9 and VEGFA might reduce the invasive and angiogenic abilities of PC-3 cells. These results suggested that co-culture with CM of M1-polarized macrophages showed higher anti-cancer effects on PC-3 cells. Thus, therapeutic targeting of macrophages toward PC-3 cells may represent a useful strategy to complement with the secreted molecules of RAW 264.7 cells as inhibitors of metastasis and anti-cancer agents.

Engineering and Preclinical Evaluation of Western Reserve Oncolytic Vaccinia Virus Expressing A167Y Mutant Herpes Simplex Virus Thymidine Kinase.

Viral replication of thymidine kinase deleted (tk-) vaccinia virus (VV) is attenuated in resting normal cells, enabling cancer selectivity, however, replication potency of VV-tk- appears to be diminished in cancer cells. Previously, we found that wild-type herpes simplex virus (HSV)-tk (HSV-tk) disappeared in most of the recombinant VV after multiple screenings, and only a few recombinant VV containing naturally mutated HSV-tk remained stable. In this study, VV-tk of western reserve (WR) VV was replaced by A167Y mutated HSV-tk (HSV-tk418m), to alter nucleoside selectivity from broad spectrum to purine exclusive selectivity. WOTS-418 remained stable after numerous passages. WOTS-418 replication was significantly attenuated in normal cells, but cytotoxicity was almost similar to that of wild type WR VV in cancer cells. WOTS-418 showed no lethality following a 5 × 108 PFU intranasal injection, contrasting WR VV, which showed 100% lethality at 1 × 105 PFU. Additionally, ganciclovir (GCV) but not BvdU inhibited WOTS-418 replication, confirming specificity to purine nucleoside analogs. The potency of WOTS-418 replication inhibition by GCV was > 10-fold higher than that of our previous truncated HSV-tk recombinant OTS-412. Overall, WOTS-418 demonstrated robust oncolytic efficacy and pharmacological safety which may delegate it as a candidate for future clinical use in OV therapy.

Local Injection of Growth Hormone for Temporomandibular Joint Osteoarthritis.

PURPOSE: Osteoarthritis (OA) of the temporomandibular joint (TMJ) elicits cartilage and subchondral bone defects. Growth hormone (GH) promotes chondrocyte growth. The aim of this study was to evaluate the efficacy of intra-articular injections of GH to treat TMJ-OA. MATERIALS AND METHODS: Monosodium iodoacetate (MIA) was used to induce OA in the TMJs of rats. After confirming the induction of OA, recombinant human GH was injected into the articular cavities of rats. Concentrations of GH and IGF-1 were measured in the blood and synovial fluid, and OA grades of cartilage and subchondral bone degradation were recorded by histological examination and micro-computed tomography. RESULTS: MIA-induced OA in the rat TMJ upregulated insulin-like growth factor-1 (IGF-1) rather than GH levels. GH and IGF-1 concentrations were increased after local injection of GH, compared with controls. Locally injected GH lowered osteoarthritic scores in the cartilage and subchondral bone of the TMJ. CONCLUSION: Intra-articular injection of GH improved OA scores in rat TMJs in both cartilage and subchondral bone of the condyles without affecting condylar bone growth. These results suggest that intra-articular injection of human GH could be a suitable treatment option for TMJ-OA patients in the future.

Engineering and Characterization of Oncolytic Vaccinia Virus Expressing Truncated Herpes Simplex Virus Thymidine Kinase.

Oncolytic viruses are a promising class of anti-tumor agents; however, concerns regarding uncontrolled viral replication have led to the development of a replication-controllable oncolytic vaccinia virus (OVV). The engineering involves replacing the native thymidine kinase (VV-tk) gene, in a Wyeth strain vaccinia backbone, with the herpes simplex virus thymidine kinase (HSV-tk) gene, which allows for viral replication control via ganciclovir (GCV, an antiviral/cytotoxic pro-drug). Adding the wild-type HSV-tk gene might disrupt the tumor selectivity of VV-tk deleted OVVs; therefore, only engineered viruses that lacked tk activity were selected as candidates. Ultimately, OTS-412, which is an OVV containing a mutant HSV-tk, was chosen for characterization regarding tumor selectivity, sensitivity to GCV, and the influence of GCV on OTS-412 anti-tumor effects. OTS-412 demonstrated comparable replication and cytotoxicity to VVtk- (control, a VV-tk deleted OVV) in multiple cancer cell lines. In HCT 116 mouse models, OTS-412 replication in tumors was reduced by >50% by GCV (p = 0.004); additionally, combination use of GCV did not compromise the anti-tumor effects of OTS-412. This is the first report of OTS-412, a VV-tk deleted OVV containing a mutant HSV-tk transgene, which demonstrates tumor selectivity and sensitivity to GCV. The HSV-tk/GCV combination provides a safety mechanism for future clinical applications of OTS-412.

Enzyme-Aided Extraction of Fucoidan by AMG Augments the Functionality of EPCs through Regulation of the AKT/Rheb Signaling Pathway.

The purpose of the present study is to improve the endothelial progenitor cells (EPC) activation, proliferation, and angiogenesis using enzyme-aided extraction of fucoidan by amyloglucosidase (EAEF-AMG). Enzyme-aided extraction of fucoidan by AMG (EAEF-AMG) significantly increased EPC proliferation by reducing the reactive oxygen species (ROS) and decreasing apoptosis. Notably, EAEF-AMG treated EPCs repressed the colocalization of TSC2/LAMP1 and promoted perinuclear localization of mTOR/LAMP1 and mTOR/Rheb. Moreover, EAEF-AMG enhanced EPC functionalities, including tube formation, cell migration, and wound healing via regulation of AKT/Rheb signaling. Our data provided cell priming protocols to enhance therapeutic applications of EPCs using bioactive compounds for the treatment of CVD.

Systemic Pharmacological Approach to Identification and Experimental Verification of the Effect of Anisi Stellati Fructus Extract on Chronic Myeloid Leukemia Cells.

Anisi stellati fructus (ASF) is the dried fruit of the Illicium verum Hook.f. tree. The aim of this research was to evaluate the antileukemic effect of ASF on chronic myeloid leukemia (CML) cells, which was hypothesized from the systemic pharmacological analysis of ASF, focusing on the combined effect of ASF extract (ASFE) and imatinib (IM). The compounds of ASF were identified using the Traditional Chinese Medicine Systems Pharmacology database and analysis platform. The target gene information was acquired from the UniProt database. The compound and target interaction network was generated from Cytoscape 3.7.1. Using this analysis, 10 compounds effective against CML cells were obtained. ASFE was prepared and analyzed by high-pressure liquid chromatography to provide experimental proof for the relationship between ASF and CML. The anti-p210Bcr-Abl effects of ASFE and ASFE + IM combination were evaluated by western blotting. Either ASFE alone or in combined treatment with IM on K-562 CML cells resulted in a significant reduction of the Bcr-Abl levels. As expected from the systemic analysis results, ASF had antileukemic activity, showing that it is a potential therapy for CML.

Acer palmatum thumb. Ethanol Extract Alleviates Interleukin-6-Induced Barrier Dysfunction and Dextran Sodium Sulfate-Induced Colitis by Improving Intestinal Barrier Function and Reducing Inflammation.

Ulcerative colitis is one inflammatory bowel disease (IBD) and is caused by diverse factors, including the extent and duration of intestinal inflammation. We investigated the effect of Acer palmatum thumb. ethanol extract (KIOM-2015E) on the expression of tight junction proteins and the levels of inflammation in the cell model induced with interleukin-6- (IL-6-) and mouse model of dextran sodium sulfate (DSS) induced with acute colitis. KIOM-2015E (100 mg/kg) was orally administered once per day to BALB/C mice with colitis induced by administration of 5% DSS in drinking water. KIOM-2015E did not affect viability in Caco-2 cells. Also, KIOM-2015E repaired the IL-6-induced intestinal barrier dysfunction in Caco-2 cells. Furthermore, KIOM-2015E recovered the loss of body weight and the abnormally short colon lengths in the DSS-induced model of acute colitis. Moreover, KIOM-2015E significantly inhibited the decrease of zonula occluden-1 and occludin in colonic tissue relative to the DSS-treated control group. KIOM-2015E also significantly inhibited the expression of IL-6 and tumor necrosis factor-α in the level of serum relative to the control group. Collectively, these data suggest that KIOM-2015E protects colitis principally by improving intestinal barrier function and promoting anti-inflammatory responses. In turn, these effects inhibit macrophage infiltration into the colon and thus may be a candidate treatment for IBD.

Salinomycin ameliorates oxidative hepatic damage through AMP-activated protein kinase, facilitating autophagy.

Salinomycin, a monocarboxylic ionophore in Streptomyces albus, has been studied as an anti-cancer agent. However, we wondered whether salinomycin has another effect such as an anti-oxidant and hepatic protectant, because some chemical drugs treating human diseases were sometimes related with their toxic effects. Therefore, this study was conducted to examine the effects of salinomycin against oxidative stress and mitochondrial impairment in vivo and in vitro as well as the cellular mechanisms of action. In hepatocyte, salinomycin inhibited arachidonic acid (AA) + iron-induced apoptosis, mitochondrial dysfunction and ROS production. As a molecular mechanism, salinomycin induced autophagy through AMP-activated protein kinase (AMPK) activation, as assessed by the accumulation of acidic vesicle organelles, p62 and LC3-II. Moreover, these protective effects were blocked by AMPK inhibition, which indicates the importance of AMPK in the process of salinomycin's effects. In mice, oral administration of salinomycin protected against carbon tetrachloride (CCl4)-induced oxidative stress and liver injury, and also activated AMPK as well as autophagy-related proteins in the liver. Collectively, salinomycin had the ability to protect hepatocytes against AA+iron-induced reactive oxygen species production and mitochondrial dysfunction, as well as CCl4-induced liver injury. Although this beneficial effect was demonstrated under severe oxidative stress, this study showed that salinomycin protected the liver against the oxidative stress and liver damage through AMPK and autophagy, and suggest that salinomycin has a possibility to treat a broad range of diseases.

Deoxypodophyllotoxin in Anthriscus sylvestris alleviates fat accumulation in the liver via AMP-activated protein kinase, impeding SREBP-1c signal.

Deoxypodophyllotoxin (DPT) is a naturally occurring flavolignan in Anthriscus sylvestris known as cow parsley or wild chervil, and has been reported to have inhibitory effects against several pathological processes including cancer, inflammation and infection. Here, we report the effects of DPT in the fatty liver induced by high fat diet in vivo as well as its regulatory mechanism related with the transcription factor for lipogenic genes such as sterol regulatory element binding protein-1c (SREBP-1c) in vitro. C57BL/6 mice were fed high fat diet for 10 weeks and also orally administrated with DPT for additional 4 weeks. 5 and 10 mg/kg of DPT decreased lipid accumulation in the liver induced by high fat diet, as indicated by histological parameters such as Oil Red O staining and hematoxylin & eosin as well as the contents of hepatic triglyceride and cholesterol. In hepatocytes, DPT inhibited the liver X receptor α-mediated SREBP-1c induction and expression of the lipogenic genes, including fatty acid synthase, acetyl-CoA carboxylase and stearoyl-CoA desaturase-1. Moreover, DPT induced AMP-activated protein kinase (AMPK) activation, which has been known to inhibit the expression of SREBP-1c in hepatocyte. Also this compound restored the dysregulation of AMPK and SREBP-1c induced by high fat diet in mice. In conclusion, we demonstrated that DPT significantly inhibited fatty liver by adjusting lipid metabolism coordinated with AMPK activation and SREBP-1c inhibition.

A Study of the Anti-Cancer Effects of the Hexane Fraction of the Methanol Extract of Forsythiae Fructus.

BACKGROUND: Forsythiae Fructus (FF) is a well-known medicinal herb derived from the dried fruits of Forsythia suspensa (Thunb.) Vahl. (Oleaceae). Recently, bioactive compounds isolated from hydrophobic solvent fractions of FF have been reported to have anti-oxidant, antibacterial, and anti-cancer effects. OBJECTIVE: Almost all herbal medicines are derived from water extracts, which suggests different extraction methods might enhance the practical efficacies of herbal medicines. In this study, the authors further investigated the most potential anti-cancer fraction, that is, the hexane fraction (FFH) of the methanol extract (FFM) of the dried fruits of Forsythia suspensa. MATERIALS AND METHODS: FFH was investigated by measuring its effects on the viability and apoptotic death of PC-3 cells (a prostate cancer cell line), on the expression levels of Bcl-2, Bax, cytochrome c, procaspase-9, procaspase-3 and PARP, and caspase-3 activity. RESULTS: FFH significantly accelerated apoptotic cell death and decreased the protein levels of Bcl-2, procaspase-9, and procaspase-3. CONCLUSION: FFH can act as a pro-oxidative agent and induce the apoptosis of prostate cancer cells. SUMMARY: Hexane fraction of the methanol extract of Forsythiae Fructus (FFH) at a concentration more than 50 µg/mL significantly reduced PC-3 cell viabilityFFH time and dose dependently elevated intracellular ROS levels and increased the proportion of cells arrested in the G0/G1 phaseFFH significantly accelerated apoptotic cell death and diminished the protein expression levels of Bcl-2, procaspase-9, and procaspase-3The protein expression levels of Bax, cytochrome c, and cleaved PARP were increased by FFH, and so was the caspase-3 activity. Abbreviations used: FF: Forsythiae Fructus; FFM: Methanol extract of Forsythiae Fructus; FFH: Hexane fraction of the methanol extract; DCFH-DA: 2',7'-dichlorodihydro-fluorescein diacetate.

Deoxypodophyllotoxin induces cytoprotective autophagy against apoptosis via inhibition of PI3K/AKT/mTOR pathway in osteosarcoma U2OS cells.

BACKGROUND: A natural compound deoxypodophyllotoxin (DPT) possesses potent anti-proliferative and anti-tumor properties on several cancer types. It triggers cell cycle arrest followed by apoptosis through various cellular processes. However, it is limited to the action mechanism of DPT-mediated cell death modes via apoptosis and autophagy. METHODS: Cell viability assay, morphological changes, annexin-V/propidium iodide (PI) assay, reactive oxygen species (ROS), acridine orange staining, and Western blot analyses were evaluated. RESULTS: We demonstrated that DPT induced both apoptosis and autophagy via production of mitochondrial reactive oxygen species (ROS). DPT suppressed the PI3K/AKT/mTOR signaling cascades to lead autophagy process, resulting from conversion of light chain 3-I (LC3-I) into LC3-II and acidic vesicular organelles (AVOs) formation. Even if DPT-induced ROS were occurred in both apoptosis and autophagy, inhibition of ROS generation enhanced cell viability. Otherwise, 3-methyladeine (3-MA) impeding on autophagy accelerated an apoptotic response caused by DPT. Therefore, these findings suggest that DPT triggers cytoprotective autophagy against cytotoxic apoptosis. CONCLUSION: Autophagy is required for cell survival by inhibition of apoptosis through down-regulation of PI3K/AKT/mTOR pathway against DPT-induced apoptosis in U2OS cells.

Moutan Cortex Protects Hepatocytes against Oxidative Injury through AMP-Activated Protein Kinase Pathway.

Moutan Cortex, the root bark of Paeonia suffruticosa ANDREWS in Ranunculaceae, has widely demonstrated analgesic, anti-spasmodic, and anti-inflammatory effects in various cancer and immune cell lines. Oxidative stress is associated with development of several diseases, including liver disease. We prepared the water extract of Moutan Cortex (MCE) to investigate the cytoprotective activities and its mechanism. MCE protected hepatocytes from arachidonic acid (AA)+iron induced oxidative stress, as indicated by reactive oxygen species (ROS) production and cell viability analysis. MCE also suppressed mitochondrial dysfunction in AA+iron-treated human hepatocyte-derived hepatocellular carcinoma cell line, HepG2 cells. In addition, MCE treatment induces AMP-activated protein kinase (AMPK) and liver kinase B1 phosphorylation, which play a role in inhibition of oxidative stress induced cell death. Moreover, one of the MCE compounds, chlorogenic acid, exerted protective effects against oxidative stress and apoptosis. Taken together, MCE protected hepatocytes against AA+iron-induced oxidative stress through AMPK activation, and may be a candidate for the treatment of liver disease.

Inhibition of Autophagy Promotes Salinomycin-Induced Apoptosis via Reactive Oxygen Species-Mediated PI3K/AKT/mTOR and ERK/p38 MAPK-Dependent Signaling in Human Prostate Cancer Cells.

Recently, the interplay between autophagy and apoptosis has become an important factor in chemotherapy for cancer treatment. Inhibition of autophagy may be an effective strategy to improve the treatment of chemo-resistant cancer by consistent exposure to chemotherapeutic drugs. However, no reports have clearly elucidated the underlying mechanisms. Therefore, in this study, we assessed whether salinomycin, a promising anticancer drug, induces apoptosis and elucidated potential antitumor mechanisms in chemo-resistant prostate cancer cells. Cell viability assay, Western blot, annexin V/propidium iodide assay, acridine orange (AO) staining, caspase-3 activity assay, reactive oxygen species (ROS) production, and mitochondrial membrane potential were assayed. Our data showed that salinomycin alters the sensitivity of prostate cancer cells to autophagy. Pretreatment with 3-methyladenine (3-MA), an autophagy inhibitor, enhanced the salinomycin-induced apoptosis. Notably, salinomycin decreased phosphorylated of AKT and phosphorylated mammalian target of rapamycin (mTOR) in prostate cancer cells. Pretreatment with LY294002, an autophagy and PI3K inhibitor, enhanced the salinomycin-induced apoptosis by decreasing the AKT and mTOR activities and suppressing autophagy. However, pretreatment with PD98059 and SB203580, an extracellular signal-regulated kinases (ERK), and p38 inhibitors, suppressed the salinomycin-induced autophagy by reversing the upregulation of ERK and p38. In addition, pretreatment with N-acetyl-l-cysteine (NAC), an antioxidant, inhibited salinomycin-induced autophagy by suppressing ROS production. Our results suggested that salinomycin induces apoptosis, which was related to ROS-mediated autophagy through regulation of the PI3K/AKT/mTOR and ERK/p38 MAPK signaling pathways.

Salinomycin induces endoplasmic reticulum stress­mediated autophagy and apoptosis through generation of reactive oxygen species in human glioma U87MG cells.

Salinomycin is a polyether ionophore antibiotic that has recently been shown to induce cell apoptosis in human cancer cells displaying multiple mechanisms of drug resistance. In the present study, we explored the impact of salinomycin on the apoptosis and autophagy as well as the correlation between those effects and endoplasmic reticulum (ER) stress molecular mechanisms in human glioma U87MG cells. Apoptosis, autophagy and reactive oxygen species (ROS) were analyzed using flow cytometry. In addition, expression levels of apoptosis-, autophagy- and ER stress-related proteins were determined by western blotting. The results showed that salinomycin induced apoptosis, ER stress and autophagy in glioma cancer cell lines. In addition, salinomycin also induced ROS generation, and the ROS scavenger N-acetyl-L-cysteine was found to inhibit the salinomycin-induced apoptosis, ER stress and autophagy. The inhibition of ER stress with 4-phenylbutyric acid depressed salinomycin-induced apoptosis and autophagy. Salinomycin increased the expression of autophagy marker protein, LC3B, and accumulation of acidic vesicular organelles. Furthermore, pre-treatment with the autophagy inhibitor 3-methyladenine showed potential in increasing the apoptosis rate induced by salinomycin in the U87MG cells. Taken together, these results revealed that salinomycin induced apoptosis and autophagy via ER stress mediated by ROS, suggesting that ER stress by salinomycin plays a dual function in both promoting and suppressing cell death.

Salinomycin Induces Reactive Oxygen Species and Apoptosis in Aggressive Breast Cancer Cells as Mediated with Regulation of Autophagy.

BACKGROUND/AIM: Chemotherapy is a critical option for cancer treatment. However, consistent exposure to chemotherapeutic drugs promotes chemoresistance in cancer cells through diverse mechanisms. Accordingly, we investigated whether salinomycin, a monocarboxylic ionophore, could induce apoptosis in aggressive breast cancer cells or not, as well as its underlying mechanism. MATERIALS AND METHODS: Using salinomycin on two breast cancer cell lines, MCF-7 cells and MDA-MB-231 cells, cell viability, annexin V/propidium iodide staining, acridine orange staining, caspase-3/9 activity, reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) were assayed. RESULTS: In this study, salinomycin induced apoptosis and autophagy in MDA-MB-231 cells. Salinomycin-mediated ROS production led to mitochondrial dysfunction in MDA-MB-231 cells. Interestingly, treatment of N-acetyl-L-cysteine (NAC), a scavenger of ROS, attenuated salinomycin-induced apoptosis and autophagy. Moreover, autophagy inhibition is involved in acceleration of apoptosis induced by salinomycin. CONCLUSION: Salinomycin induced apoptosis and ROS production, that were blocked by autophagy, thus resulting in protecting cancer cells. This crosstalk of two different physiological responses (autophagy and apoptosis) induced by salinomycin might play pivotal roles in the relationship between autophagy and apoptosis of cancer cells.