Parthenolide induces apoptosis in colitis-associated colon cancer, inhibiting NF-κB signaling

Parthenolide Phytosomes Attenuated Gentamicin-Induced Nephrotoxicity in Rats via Activation of Sirt-1, Nrf2, OH-1, and NQO1 Axis

Nephrotoxicity is a serious complication that limits the clinical use of gentamicin (GEN). Parthenolide (PTL) is a sesquiterpene lactone derived from feverfew with various therapeutic benefits. However, PTL possesses low oral bioavailability. This study aimed to evaluate the therapeutic protective effects of PTL-phytosomes against GEN-induced nephrotoxicity in rats. The PTL was prepared as phytosomes to improve the pharmacological properties with a particle size of 407.4 nm, and surface morphology showed oval particles with multiple edges. Rats were divided into six groups: control, nano-formulation plain vehicle, PTL-phytosomes (10 mg/kg), GEN (100 mg/kg), GEN + PTL-phytosomes (5 mg/kg), and GEN + PTL-phytosomes (10 mg/kg). The administration of PTL-phytosomes alleviated GEN-induced impairment in kidney functions and histopathological damage, and decreased kidney injury molecule-1 (KIM-1). The anti-oxidative effect of PTL-phytosomes was demonstrated by the reduced malondialdehyde (MDA) concentration and increased superoxide dismutase (SOD) and catalase (CAT) activities. Furthermore, PTL-phytosomes treatment significantly enhanced sirtuin 1 (Sirt-1), nuclear factor erythroid-2-related factor-2 (Nrf2), NAD(P)H quinone dehydrogenase 1 (NQO1), and heme oxygenase-1 (HO-1). Additionally, PTL-phytosomes treatment exhibited anti-inflammatory and anti-apoptotic properties in the kidney tissue. These findings suggest that PTL-phytosomes attenuate renal dysfunction and structural damage by reducing oxidative stress, inflammation, and apoptosis in the kidney.

Nano Parthenolide Improves Intestinal Barrier Function of Sepsis by Inhibiting Apoptosis and ROS via 5-HTR2A

Background

Intestinal barrier dysfunction is an important complication of sepsis, while the treatment is limited. Recently, parthenolide (PTL) has attracted much attention as a strategy of sepsis, but whether nano parthenolide (Nano PTL) is therapeutic in sepsis-induced intestinal barrier dysfunction is obscured.

Methods

In this study, cecal ligation and puncture (CLP)-induced sepsis rats and lipopolysaccharide (LPS)-stimulated intestinal epithelial cells (IECs) were used to investigate the effect of PTL on intestinal barrier dysfunction. Meanwhile, we synthesized Nano PTL and compared the protective effect of Nano PTL with ordinary PTL on intestinal barrier function in septic rats and IECs. Network pharmacology and serotonin 2A (5-HTR2A) inhibitor were used to explore the mechanism of PTL on the intestinal barrier function of sepsis.

Results

The encapsulation rate of Nano PTL was 95±1.5%, the drug loading rate was 11±0.5%, and the average uptake rate of intestinal epithelial cells was 94%. Ordinary PTL and Nano PTL improved the survival rate and survival time of septic rats, reduced the mean arterial pressure and the serum level of inflammatory cytokines, and protected the liver and kidney functions in vivo, and increased the value of transmembrane resistance (TEER) reduced the reactive oxygen species (ROS) and apoptosis in IECs in vitro through 5-HTR2A. Nano PTL had better effect than ordinary PTL.

Conclusion

Ordinary PTL and Nano PTL can protect the intestinal barrier function of septic rats by inhibiting apoptosis and ROS through up-regulating 5-HTR2A, Nano PTL is better than ordinary PTL.

Traditional Medicinal Plants as a Source of Inspiration for Osteosarcoma Therapy

Osteosarcoma is one of the most common types of bone cancers among paediatric patients. Despite the advances made in surgery, chemo-, and radiotherapy, the mortality rate of metastatic osteosarcoma remains unchangeably high. The standard drug combination used to treat this bone cancer has remained the same for the last 20 years, and it produces many dangerous side effects. Through history, from ancient to modern times, nature has been a remarkable source of chemical diversity, used to alleviate human disease. The application of modern scientific technology to the study of natural products has identified many specific molecules with anti-cancer properties. This review describes the latest discovered anti-cancer compounds extracted from traditional medicinal plants, with a focus on osteosarcoma research, and on their cellular and molecular mechanisms of action. The presented compounds have proven to kill osteosarcoma cells by interfering with different pathways: apoptosis induction, stimulation of autophagy, generation of reactive oxygen species, etc. This wide variety of cellular targets confer natural products the potential to be used as chemotherapeutic drugs, and also the ability to act as sensitizers in drug combination treatments. The major hindrance for these molecules is low bioavailability. A problem that may be solved by chemical modification or nano-encapsulation.

CCL3 Promotes Proliferation of Colorectal Cancer Related with TRAF6/NF-κB Molecular Pathway

Chemokine C-C motif chemokine ligand 3 (CCL3) plays an important role in the invasion and metastasis of malignant tumors. For developing new therapeutic targets and antitumor drugs, the effect of chemokine CCL3 and the related cytokine network on colorectal cancer should be investigated. This study used cell, tissue, and animal experiments to prove that CCL3 is highly expressed in colorectal cancer and confirmed that CCL3 can promote the proliferation of cancer cells, and its expression is closely related to TRAF6/NF-κB molecular pathway. In addition, protein chip technology was used to examine colorectal cancer tissue samples and identify the key factors of chemokine CCL3 and the toll-like receptors/nuclear factor-κB (TLR/NF-κB) pathway in cancer and metastatic lymph nodes. Furthermore, the lentiviral vector technology was employed for transfection to construct interference and overexpression cell lines. The experimental results reveal the mechanism of CCL3 and TNF receptor-associated factor 6 (TRAF6)/NF-κB pathway-related factors and their effects on the proliferation of colon cancer cells. Finally, the expression and significance of CCL3 in colorectal cancer tissues and its correlation with clinical pathology were studied by immunohistochemistry. Also, the results confirmed that CCL3 and C-C motif chemokine receptor 5 (CCR5) were expressed in adjacent tissues, colorectal cancer tissues, and metastatic cancer. The expression level was correlated with the clinical stage and nerve invasion. The expression of chemokine CCL3 and receptor CCR5 was positively correlated with the expression of TRAF6 and NF-κB and could promote the proliferation, invasion, and migration of colorectal cancer cells through TRAF6 and NF-κB.

Parthenolide Suppresses T Helper 17 and Alleviates Experimental Autoimmune Encephalomyelitis

T helper (Th) cells play crucial roles in inflammation and adaptive immune system. Importantly, Th17 cells, a major pathogenic Th cell subset, are involved in the pathogenesis of multiple sclerosis (MS) and its classical animal modal experimental autoimmune encephalomyelitis (EAE). Previous studies have shown that parthenolide (PTL), a sesquiterpene lactone, possesses potent anti-cancer and anti-inflammatory activities. However, the immunosuppressive effect of PTL on the pathogenic Th17 cell and MS is unclear. In this study, we showed that PTL treatment could alleviate clinical symptoms by inhibiting inflammatory cell infiltration, reducing inflammation and demyelination of CNS. In addition, the mRNA expression of cytokines and inflammatory factors in CD4⁺ T cells, especially Th1 and Th17 cells, reduced in both CNS and peripheral immune tissue of EAE mice. Furthermore, PTL could inhibit the reactivation of MOG-specific T cells and the differentiation of naïve CD4⁺ T cells into Th17 cells in vitro. We also found that PTL inhibited nuclear factor kappa B (NF-κB) signaling and retinoid-related orphan receptor-γt (RORγt) in mouse Th17 cell and human Jurkat cell line. Taken together, our data demonstrated a critical immune-suppressive effect of PTL on autoimmune inflammation through regulating Th17 cells and the NF-κB/RORγt pathway.

Dimethylaminoparthenolide (DMAPT) as an alternative approach for treatment of Familial Mediterranean Fever (FMF)

OBJECTIVES

Familial Mediterranean Fever (FMF) is a hereditary auto-inflammatory disorder that is caused by mutations in the Mediterranean fever (MEFV) gene and is associated with an increase in pro-inflammatory cytokines, such as interleukin-1β (IL-1β) and interleukin-18 (IL-18), leading to excess inflammation. Colchicine is a common drug widely used for treatment of FMF attacks, but about 5-15% of the patients show resistance to the regular colchicine treatment. In this study, we used dimethylamino-parthenolide (DMAPT), as a small molecule inhibitor of Nuclear factor-κB (NF-κB), NLR family Pyrin domain containing 3 (NLRP3), and cysteine-aspartic acid protease 1(Caspase-1) on FMF-derived peripheral blood mononuclear cells (PBMCs).

MATERIALS AND METHODS

The effects of DMAPT and colchicine on metabolic activity and apoptosis of FMF-derived PBMCs were evaluated by MTT and Annexin V/PI assays, respectively. Also, the expression levels of NF-κB, NLRP3, MEFV, CASP1, and IL-1β mRNA were investigated using a TaqMan real-time PCR, and the protein levels of IL-1β, IL-18, and IL-37 were assessed via an enzyme-linked immunosorbent assay (ELISA) in LPS/ ATP-stimulated PBMCs.

RESULTS

DMAPT decreased the expression levels of NFκB (0.38±0.096, P<0.0001), NLRP3 (0.39±0.12, P<0.001), MEFV (0.384±0.145, P<0.001), CASP1 (0.48±0.13, P=0.0023), and IL-1β (0.09±0.09, P<0.0001) and reduced the secretion levels of IL-1β (8.92±5.3 vs. 149.85±20.92, P<0.0001), IL-18 (135±32.1 vs. 192±22.18, P=0.01), and IL-37 (27.5±6.3 vs. 78.19±14.3, P<0.0001) as compared to untreated cells.

CONCLUSION

Given the obtained results in comparison with previous research, the future clinical development of DMAPT could result in the expansion of new anti-inflammatory therapeutics for FMF disorder.

Parthenolide plays a protective role in the liver of mice with metabolic dysfunction‑associated fatty liver disease through the activation of the HIPPO pathway

Metabolic dysfunction‑associated fatty liver disease (MAFLD) is a serious threat to human health. Parthenolide (PAR) displays several important pharmacological activities, including the promotion of liver function recovery during hepatitis. The aim of the present study was to assess the effect of PAR on MAFLD in a mouse model. Body weight, liver to body weight ratios, histological score, alanine transaminase, aspartate transaminase, total cholesterol and triglyceride levels were determined to evaluate liver injury. Liver hydroxyproline concentrations were also assessed. The expression levels of lipid metabolism‑related genes (sterol regulatory element binding protein‑1c, fatty acid synthase, acetyl CoA carboxylase 1, stearoyl CoA desaturase 1 and carbohydrate response element‑binding protein, peroxisome proliferator‑activated receptor α, carnitine palmitoyl transferase 1α and acyl‑CoA dehydrogenase short chain), liver fibrosis‑associated genes (α‑smooth muscle actin, tissue inhibitor of metalloproteinase 1 and TGF‑β1), pro‑inflammatory cytokines (TNF‑α, IL‑1β and IL‑6) and oxidative stress‑associated enzymes (malondialdehyde, superoxide dismutase and glutathione peroxidase) were measured in mice with MAFLD. The expression levels of genes associated with the HIPPO pathway were also measured. In vivo experiments using a specific inhibitor of HIPPO signalling were performed to verify the role of this pathway in the effects of PAR. PAR exerted beneficial effects on liver injury, lipid metabolism, fibrosis, inflammation and oxidative stress in mice with MAFLD, which was mediated by activation of the HIPPO pathway.

Nodal-induced L1CAM/CXCR4 subpopulation sustains tumor growth and metastasis in colorectal cancer derived organoids

Background: Colorectal cancer (CRC) is currently the third leading cause for cancer-related mortality. Cancer stem cells have been implicated in colorectal tumor growth, but their specific role in tumor biology, including metastasis, is still uncertain. Methods: Increased expression of L1CAM, CXCR4 and NODAL was identified in tumor section of patients with CRC and in patients-derived-organoids (PDOs). The expression of L1CAM, CXCR4 and NODAL was evaluated using quantitative real-time PCR, western blotting, immunofluorescence, immunohistochemistry and flow cytometry. The effects of the L1CAM, CXCR4 and NODAL on tumor growth, proliferation, migration, invasion, colony-formation ability, metastasis and chemoresistance were investigated both in vitro and in vivo. Results: We found that human colorectal cancer tissue contains cancer stem cells defined by L1CAM^high/CXCR4^high expression that is activated by Nodal in hypoxic microenvironment. This L1CAM^high/CXCR4^high population is tumorigenic, highly resistant to standard chemotherapy, and determines the metastatic phenotype of the individual tumor. Depletion of the L1CAM^high/CXCR4^high population drastically reduces the tumorigenic potential and the metastatic phenotype of colorectal tumors. Conclusion: In conclusion, we demonstrated that a subpopulation of migrating L1CAM^high/CXCR4^high is essential for tumor progression. Together, these findings suggest that strategies aimed at modulating the Nodal signaling could have important clinical applications to inhibit colorectal cancer-derived metastasis.

Plant-Derived Natural Products in Cancer Research: Extraction, Mechanism of Action, and Drug Formulation

Cancer is one of the main causes of death globally and considered as a major challenge for the public health system. The high toxicity and the lack of selectivity of conventional anticancer therapies make the search for alternative treatments a priority. In this review, we describe the main plant-derived natural products used as anticancer agents. Natural sources, extraction methods, anticancer mechanisms, clinical studies, and pharmaceutical formulation are discussed in this review. Studies covered by this review should provide a solid foundation for researchers and physicians to enhance basic and clinical research on developing alternative anticancer therapies.

Apoptosis Exerts a Vital Role in the Treatment of Colitis-Associated Cancer by Herbal Medicine

Colitis-associated cancer (CAC) is known as inflammatory bowel disease (IBD)-developed colorectal cancer, the pathogenesis of which involves the occurrence of apoptosis. Western drugs clinically applied to CAC are often single-targeted and exert many adverse reactions after long-term administration, so it is urgent to develop new drugs for the treatment of CAC. Herbal medicines commonly have multiple components with multiple targets, and most of them are low-toxicity. Some herbal medicines have been reported to ameliorate CAC through inducing apoptosis, but there is still a lack of systematic review. In this work, we reviewed articles published in Sci Finder, Web of Science, PubMed, Google Scholar, CNKI, and other databases in recent years by setting the keywords as apoptosis in combination with colitis-associated cancer. We summarized the herbal medicine extracts or their compounds that can prevent CAC by modulating apoptosis and analyzed the mechanism of action. The results show the following. (1) Herbal medicines regulate both the mitochondrial apoptosis pathway and death receptor apoptosis pathway. (2) Herbal medicines modulate the above two apoptotic pathways by affecting signal transductions of IL-6/STAT3, MAPK/NF-κ B, Oxidative stress, Non-canonical TGF-β1, WNT/β-catenin, and Cell cycle, thereby ameliorating CAC. We conclude that following. (1) Studies on the role of herbal medicine in regulating apoptosis through the Ras/Raf/ERK, WNT/β-catenin, and Cell cycle pathways have not yet been carried out in sufficient depth. (2) The active constituents of reported anti-CAC herbal medicine mainly include polyphenols, terpenoids, and saccharide. Also, we identified other herbal medicines with the constituents mentioned above as their main components, aiming to provide a reference for the clinical use of herbal medicine in the treatment of CAC. (3) New dosage forms can be utilized to elevate the targeting and reduce the toxicity of herbal medicine.

Synergy between parthenolide and arsenic trioxide in adult T-cell leukemia/lymphoma cells in vitro

OBJECTIVES

Adult T-cell leukemia/lymphoma (ATLL) is an aggressive lymphoid malignancy with low survival rate and distinct geographical distribution. In search for novel chemotherapeutics against ATLL, we investigated the combinatorial effects of parthenolide, a sesquiterpene lactone with valuable pharmaceutical activities, and arsenic trioxide (ATO) in vitro.

MATERIALS AND METHODS

MT2 cells, an ATLL cell line, were treated with increasing concentrations of parthenolide (1.25, 2.5, and 5 μg/ml) and ATO (2, 4, 8, and 16 µM) to determine their IC50. Then, cells were treated with a combination of sub-IC50 concentrations of parthenolide (1 μg/ml) and ATO (2 µM) for 72 hr. Cell viability and cell cycle changes were assessed by Alamar blue and PI staining, respectively. To understand the mechanisms responsible for observed effects, expression of CD44, NF-κB (REL-A), BMI-1, and C-MYC were investigated by real-time PCR.

RESULTS

Assessment of cell viability indicated that parthenolide significantly increased the toxicity of ATO, as confirmed by accumulation of MT2 cells in the sub G1 phase of the cell cycle. Moreover, molecular analysis revealed significant down-regulation of CD44, NF-κB (REL-A), BMI-1, and C-MYC upon combinatorial administration of parthenolide and ATO in comparison with relevant controls.

CONCLUSION

Taken together, present results showed that parthenolide significantly enhanced the toxicity of ATO in MT2 cells. Therefore, the future possible clinical impact of our study could be combinatorial use of parthenolide and ATO as a novel and more effective approach for ATLL.

Applications of Sesquiterpene Lactones: A Review of Some Potential Success Cases

Sesquiterpene lactones, a vast range of terpenoids isolated from Asteraceae species, exhibit a broad spectrum of biological effects and several of them are already commercially available, such as artemisinin. Here the most recent and impactful results of in vivo, preclinical and clinical studies involving a selection of ten sesquiterpene lactones (alantolactone, arglabin, costunolide, cynaropicrin, helenalin, inuviscolide, lactucin, parthenolide, thapsigargin and tomentosin) are presented and discussed, along with some of their derivatives. In the authors’ opinion, these compounds have been neglected compared to others, although they could be of great use in developing important new pharmaceutical products. The selected sesquiterpenes show promising anticancer and anti-inflammatory effects, acting on various targets. Moreover, they exhibit antifungal, anxiolytic, analgesic, and antitrypanosomal activities. Several studies discussed here clearly show the potential that some of them have in combination therapy, as sensitizing agents to facilitate and enhance the action of drugs in clinical use. The derivatives show greater pharmacological value since they have better pharmacokinetics, stability, potency, and/or selectivity. All these natural terpenoids and their derivatives exhibit properties that invite further research by the scientific community.

Collateral Sensitivity of Parthenolide via NF-κB and HIF-α Inhibition and Epigenetic Changes in Drug-Resistant Cancer Cell Lines

Parthenolide (PT) is a sesquiterpene lactone isolated from Tanacetum parthenium. In this study, PT showed varying cytotoxic effects against different solid tumor cell lines. HCT116 (p53^+/+) colon carcinoma cells and their parental HCT116 knockout p53 (p53^-/-) cell lines showed a resistance degree of 2.36. On the other hand, wild-type U87.MG cells or cells transfected with a deletion-activated EGFR cDNA (U87.MGΔEGFR) exhibited slight sensitivity toward PT. Multidrug-resistant MDA-MB-231-BCRP cells were even more sensitive toward PT than sensitive MDA-MB-231-pcDNA cells with a resistance degree of 0.07 (collateral sensitivity). To the best of our knowledge, hypersensitivity (collateral sensitivity) in MDA-MB-231-BCRP cell line is reported in this study for the first time. We attempted to identify the mechanism of collateral sensitivity. Firstly, we found that PT bound to IKK preventing IκBα degradation and eventually inhibition of the nuclear factor kappa B (NF-κB) pathway. Down-regulation of hypoxia inducing factor 1-alpha (HIF-1α) in MDA-MB-231-BCRP resistant cells may be a second mechanism, since it is a target gene of NF-κB. Moreover, PT also showed epigenetic effect by inhibition of HDAC activity as shown using both molecular docking and HDAC activity assay. Based on COMPARE and hierarchical cluster analyses, we found gene expression profiles that predicted sensitivity or resistance of 47 tumor cell lines toward PT. Interestingly, pathway analyses of gene expression profiles revealed NF-κB and HIF signaling as top networks of these genes, cellular functions and canonical pathways influencing the activity of PT against tumor cells. In conclusion, PT exerted profound cytotoxic activity against various cancer cell lines mainly against BCRP-overexpressing tumor cells, suggesting PT as novel candidate for cancer treatment.

Comparison of the inhibition potential of parthenolide and micheliolide on various UDP-glucuronosyltransferase isoforms

Parthenolide (PTL) and micheliolide (MCL) are sesquiterpene lactones with similar structures, and both of them have been reported to exhibit multiple biochemical and pharmacological activities. This study aims to investigate the inhibition of these two compounds on the activity of UDP-glucuronosyltransferases (UGTs). In vitro incubation mixture for recombinant UGTs-catalyzed glucuronidation metabolism of 4-methylumbelliferone (4-MU) was utilized to investigate the inhibition potential. Inhibition kinetics (including inhibition type and parameters) were determined, and in silico docking was employed to elucidate the inhibition difference between PTL and MCL on UGT1A1. MCL showed no inhibition toward all the UGT isoforms, and PTL showed strong inhibition toward UGT1A1. The half-maximal inhibitory concentration (IC₅₀) of PTL on the activity of UGT1A1 was determined to be 64.4 μM. Inhibition kinetics determination showed that PTL exerted noncompetitive inhibition toward UGT1A1, and the inhibition kinetic constant (K_i) was determined to be 12.1 μM. In silico docking method has been employed to show that hydrogen bonds between PTL and the activity cavity of UGT1A1 contributed to the stronger inhibition of PTL on the activity of UGT1A1 than MCL. In conclusion, PTL can more easily induce drug-drug interaction (DDI) with clinical drugs mainly undergoing UGT1A1-catalyzed glucuronidation.

Parthenolide suppresses hypoxia-inducible factor-1α signaling and hypoxia induced epithelial-mesenchymal transition in colorectal cancer

Activation of hypoxia-inducible factor 1α (HIF‑1α) is frequently observed in solid tumors and it has been associated with various pathophysiological processes, including epithelial‑mesenchymal transition (EMT). Previously, we reported that parthenolide (PT), an inhibitor of nuclear factor-κB (NF-κB), is a promising anticancer agent because it promotes apoptosis of human colorectal cancer (CRC). Here, we investigated a new molecular mechanism by which PT acts on HIF‑1α and hypoxia contributing to EMT by NF‑κB inhibition. Cell viability, DNA binding activity, vascular cell tube formation and cell motility were studied after treatment of PT in hypoxic or normoxic condition. Moreover, effects of PT on hypoxia signaling and hypoxia-induced EMT signaling were investigated. We also examined the inhibitory effect of PT on CRC progression in xenografts. We demonstrated that PT markedly inhibits hypoxia dependent HIF‑1α activity and angiogenesis by preventing NF-κB activation. We also report that PT decreases the level of proteins associated with glucose metabolism, angiogenesis, development and survival that are regulated by HIF‑1α. Furthermore, we verified that PT protects the morphological change from epithelial to mesenchymal state, inhibits matrix metalloproteinase (MMP) enzyme activity and decreases cell motility involved in the -regulation of the hypoxia-induced EMT markers. In addition, PT inhibits growth in CRC xenograft models and regulates NF‑κB, HIF‑1α and EMT specific marker in tissue specimens. Our data demonstrated that PT can inhibit HIF‑1α signaling and hypoxia-induced EMT, suggesting a novel molecular mechanism for HIF‑1α mediated cancer progression and metastasis.

Smad4 re-expression increases the sensitivity to parthenolide in colorectal cancer

Parthenolide (PT), a sesquiterpene lactone extracted from the plant feverfew, has been demonstrated to have anti-inflammatory and anticancer properties. Although PT has been revealed to markedly inhibit colorectal cancer cell proliferation, the inhibitory effects decrease with administration time. These findings revealed that colorectal cancer cells develop resistance to PT. However, the underlying mechanism is unclear. In the present study we observed significantly low expression of Smad4 in 3 PT-resistant cell lines (HCT‑116/PT, HT-29/PT and Caco-2/PT), which were obtained using in vitro concentration gradient-increased induction, but not in their parental cells. In the present study we used the lentiviral‑mediated transfection method to upregulate Smad4 in resistant colorectal cancer cell lines. Flow cytometry assay was used to assess cell apoptosis. Cell migration was detected using a QCM™ 24-well Fluorimetric Cell Migration Assay kit. Our study showed that Smad4 overexpression notably decreased the half maximal inhibitory concentration (IC50) values for PT in the 3 PT-resistant cell lines, and improved the inhibitory effects of PT on cell migration and enhanced apoptosis in vitro as well as suppressed xenografted tumors in a PT-resistant colorectal cancer mouse model. Further study by western blotting into the underlying mechanism demonstrated that Smad4 overexpression suppressed the expression of MDR1 in the resistant cells, and resulted in the accumulation of PT, which in turn promoted the expession of caspase-3 and Bax and inhibited the expression of Bcl-2 and the phosphorylation of NF-κB p65. In short, Smad4 re-expression may be crucial for enhancing the sensitivity and reversing the resistance to PT in PT-resistant colorectal cancer cells.

Chemopreventive Action by Ethanol-extracted Brazilian Green Propolis on Post-initiation Phase of Inflammation-associated Rat Colon Tumorigenesis

BACKGROUND/AIM

Propolis has since long been utilized in numerous folk medicines with a variety of medicinal properties. In this study, the effects of ethanol-extracted (EEP) and water-extracted (WEP) Brazilian green propolis on the post-initiation phase of inflammation-associated rat colon tumorigenesis were directly compared.

MATERIALS AND METHODS

Male F344 rats at 6 weeks of age were subcutaneously injected with 1,2-dimethylhydrazine (DMH) at 40 mg/kg body weight twice during the first week, followed by 1% dextran sodium sulfate (DSS) in drinking water for one week. After a 1-week no-treatment period, animals were administered either basal Oriental MF powdered diet, or 1% EEP or 1% WEP in the basal diet until week 32.

RESULTS

Post-initiation treatment with EEP significantly reduced the multiplicity of colorectal carcinomas compared to the control (0.40±0.13/rat vs. 2.29±0.84/rat, respectively, p<0.05), and EEP also reduced the tumor volume. Immunohistochemically, expression of inflammation-associated proteins inducible nitric oxide synthase, tumor necrotic factor alpha, nuclear factor kappa B and glutathione peroxidase-2 were significantly diminished in colorectal tumors from EEP-treated rats.

CONCLUSION

Suppression of inflammation and oxidative stress, which had been triggered by DMH and promoted by DSS, was a primary mechanism by which EEP suppressed carcinogenesis.

Anticancer Natural Compounds as Epigenetic Modulators of Gene Expression

Accumulating evidence shows that hallmarks of cancer include: "genetic and epigenetic alterations leading to inactivation of cancer suppressors, overexpression of oncogenes, deregulation of intracellular signaling cascades, alterations of cancer cell metabolism, failure to undergo cancer cell death, induction of epithelial to mesenchymal transition, invasiveness, metastasis, deregulation of immune response and changes in cancer microenvironment, which underpin cancer development". Natural compounds as bioactive ingredients isolated from natural sources (plants, fungi, marine life forms) have revolutionized the field of anticancer therapeutics and rapid developments in preclinical studies are encouraging. Natural compounds could affect the epigenetic molecular mechanisms that modulate gene expression, as well as DNA damage and repair mechanisms. The current review will describe the latest achievements in using naturally produced compounds targeting epigenetic regulators and modulators of gene transcription in vitro and in vivo to generate novel anticancer therapeutics.

Role of cancer-related inflammation in colon cancer

Chronic inflammation is one of the important mechanisms for the development of colon cancer, and the role of cancer-related inflammation (CRI) in tumor development is a hot research topic in recent years. Therefore, it is very important to clarify the effect and regulation of CRI in colon cancer. Accumulating evidence indicates that transcription factors, cytokines, chemokines, cyclooxygenase-2 and microRNAs play key roles in CRI. This review focuses on the research progress about these molecules in colon cancer.

Combined Parthenolide and Balsalazide Have Enhanced Antitumor Efficacy Through Blockade of NF-κB Activation

Balsalazide is a colon-specific prodrug of 5-aminosalicylate that is associated with a reduced risk of colon cancer in patients with ulcerative colitis. Parthenolide, a strong NF-κB inhibitor, has recently been demonstrated to be a promising therapeutic agent, promoting apoptosis of cancer cells. In the current study, the antitumor effect of balsalazide combined with parthenolide in human colorectal cancer cells and colitis-associated colon cancers (CAC) was investigated. The results demonstrate that the combination of balsalazide and parthenolide markedly suppress proliferation, nuclear translocation of NF-κB, IκB-α phosphorylation, NF-κB DNA binding, and expression of NF-κB targets. Apoptosis via NF-κB signaling was confirmed by detecting expression of caspases, p53 and PARP. Moreover, treatment of a CAC murine model with parthenolide and balsalazide together resulted in significant recovery of body weight and improvement in histologic severity. Administration of parthenolide and balsalazide to CAC mice also suppressed carcinogenesis as demonstrated by uptake of 18F-fluoro-2-deoxy-D-glucose (FDG) using micro-PET/CT scans. These results demonstrate that parthenolide potentiates the efficacy of balsalazide through synergistic inhibition of NF-κB activation and the combination of dual agents prevents colon carcinogenesis from chronic inflammation.

IMPLICATIONS

This study represents the first evidence that combination therapy with balsalazide and parthenolide could be a new regimen for colorectal cancer treatment. Mol Cancer Res; 15(2); 141-51. ©2016 AACR.

Discovery of Small Molecules That Induce Lysosomal Cell Death in Cancer Cell Lines Using an Image-Based Screening Platform

The lysosomal cell death (LCD) pathway is a caspase 3-independent cell death pathway that has been suggested as a possible target for cancer therapy, making the development of sensitive and specific high-throughput (HT) assays to identify LCD inducers highly desirable. In this study, we report a two-step HT screening platform to reliably identify such molecules. First, using a robust HT primary screen based on propidium iodide uptake, we identified compounds that kill through nonapoptotic pathways. A phenotypic image-based assay using a galectin-3 (Gal-3) reporter was then used to further classify hits based on lysosomal permeabilization, a hallmark of LCD. The identification of permeabilized lysosomes in our image-based assay is not affected by changes in the lysosomal pH, thus resolving an important limitation in currently used methods. We have validated our platform in a screen by identifying 24 LCD inducers, some previously known to induce LCD. Although most LCD inducers were cationic amphiphilic drugs (CADs), we have also identified a non-CAD LCD inducer, which is of great interest in the field. Our data also gave new insights into the biology of LCD, suggesting that lysosomal accumulation and acid sphingomyelinase inhibition are not sufficient or necessary for the induction of LCD. Overall, our results demonstrate a robust HT platform to identify novel LCD inducers that will also be very useful for gaining deeper insights into the molecular mechanism of LCD induction.

Parthenolide ameliorates Concanavalin A-induced acute hepatitis in mice and modulates the macrophages to an anti-inflammatory state

Parthenolide, the principal sesquiterpene lactone present in medicinal plants such as feverfew, has anti-microbial, anti-inflammatory and anticancer activities. In the present study, we investigated the protective role of parthenolide against acute hepatitis in mice. Mice acute hepatitis were induced by Concanavalin A and treated by parthenolide in vivo. Results shown that parthenolide remarkably reduced the congestion and necroinflammation of the mice livers with Concanavalin A-induced acute hepatitis. Meanwhile, parthenolide treatment recover the liver function which indicated by decreased the serum alanine transaminase and alkaline phosphatase activities and promoted the expression of Ki67 in the livers of these mice. In addition, parthenolide administration suppressed the Concanavalin A-induced immune reaction, as indicated by the number of F4/80, CD49b and CD4 cells present in the liver. Furthermore, parthenolide also significantly reduced the expression of pro-inflammatory cytokines such as IFN-γ, TNF-α, IL-17A, IL-1β and IL-6 in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in vitro. Moreover, parthenolide exposure decreased the phosphorylation of STAT3 and p38, and promoted the phosphorylation of p53 in RAW264.7 cells in vitro. In conclusion, parthenolide represents a drug candidate to protect the liver against Concanavalin A-induced acute hepatitis. The possible molecular mechanism involves the anti-inflammatory effects of parthenolide may by suppressing the STAT3/p38 signals and enhanced the p53 signals.

Bitter apricot essential oil induces apoptosis of human HaCaT keratinocytes

Psoriasis is a chronic skin disease that affects approximately 2% of the world's population. Conventional therapeutic approaches are not effective or necessarily safe for treating symptoms due to the serious side effects and resistance to currently prescribed drugs. Traditionally, in oriental medicine, apricot seed (Semen Armeniacae amarum) is used to treat skin diseases. However, the underlying mechanism of action has not been systematically elucidated. In the present study, the anti-proliferative effect of bitter apricot essential oil (BAEO) on cultured HaCaT cells was evaluated and the mechanism of action investigated. BAEO was isolated by hydrodistillation, and gas chromatography-mass spectrometry (GC-MS) analysis identified benzaldehyde (75.35%), benzoic acid (6.21%) and mandelonitrile (5.38%). HaCaT cell growth, measured by sulforhodamine B assay (SRB), was inhibited by BAEO with an IC50 value of 142.45 μg/ml. Apoptosis of HaCaT cells treated with BAEO was detected by cell cycle, flow cytometry, and western blot analyses. These measurements revealed G0/G1 cell cycle arrest, elevated numbers of early and late stage apoptotic cells, and caspases-3/8/9 and PARP activation. Z-VAD-FMK, a broad-spectrum caspase inhibitor, attenuated BAEO-induced apoptosis. Also, increased Bax and decreased Bcl-2 levels suggest that BAEO-induced apoptosis is mediated through both death receptor and mitochondrial pathways. Moreover, reduced Rel/NF-κB levels suggest that BAEO-mediated apoptosis is also associated with inhibition of the NF-κB pathway. These data suggest that BAEO is a naturally occurring material that functions as a potent pro-apoptotic factor for human keratinocytes. Thus, it is a promising candidate to treat psoriasis.

Ascorbic acid ameliorates oxidative stress and inflammation in dextran sulfate sodium-induced ulcerative colitis in mice

Ascorbic acid (AA) has been shown to exert beneficial effects, including mitigating oxidative stress and inhibiting inflammation. However, the preventative effect of vitamin C in chronic inflammatory diseases such as inflammatory bowel disease (IBD) remains unclear. In our study, we investigated the anti-inflammatory effects of AA and possible mechanism involved in inhibiting dextran sulfate sodium (DSS)-induced ulcerative colitis in mice. Male C57BL/6 mice were randomly divided to three groups: control group, DSS group, and DSS plus ascorbic acid treated group. Several clinical and inflammatory parameters as well as oxidative stress were evaluated. The results demonstrated that ascorbic acid significantly reduced clinical signs, inflammatory cytokines, myeloperoxidase (MPO) and malonaldehyde (MDA) activities, whereas the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were increased in DSS-induced mice. In addition, ascorbic acid was capable of inhibiting NF-κB, COX-2 and iNOS expression in the colonic. Taken together, these findings suggest that ascorbic acid contributes to the reduction of oxidative stress and inflammatory response in DSS-induced colitis and exerts the potential to prevent and clinical treatment of inflammatory bowel disease.