Ursolic acid inhibits multiple cell survival pathways leading to suppression of growth of prostate cancer xenograft in nude mice

Ursolic acid alleviates cancer cachexia by inhibiting STAT3 signaling pathways in C2C12 myotube and CT26 tumor-bearing mouse model

Cancer cachexia, a multi-organ disorder resulting from tumor and immune system interactions, prominently features muscle wasting and affects the survival of patients with cancer. Ursolic acid (UA) is known for its antioxidant, anti-inflammatory, and anticancer properties. However, its impact on cancer cachexia remains unexplored. This study aimed to assess the efficacy of UA in addressing muscle atrophy and organ dysfunction in cancer cachexia and reveal the mechanisms involved. UA dose-dependently ameliorated C2C12 myotube atrophy. Mechanistically, it inhibited the expression of muscle-specific RING finger containing protein 1 (MURF1) and the phosphorylation of signal transducer and activator of transcription 3 (STAT3), and upregulated the mRNA or protein levels of myogenic differentiation antigen and myogenin in cultured C2C12 myotubes treated with conditioned medium. In vivo, UA protected CT26 tumor-bearing mice against loss of body weight, as well as increased skeletal muscle and epididymal fat without affecting tumor growth. Additionally, UA increased food intake in CT26 tumor-bearing mice. The mRNA expression of tumor necrosis-α and interleukin 6 was significantly downregulated in the intestine, gastrocnemius, and heart tissues following 38 d UA administration. UA treatment reversed the levels of myocardial function indicators, including creatine kinase, creatine kinase-MB, lactate dehydrogenase, car-dial troponin T, and glutathione. Finally, UA treatment significantly inhibited the expression of MURF1, the phosphorylation of nuclear factor kappa-B p65, and STAT3 in the gastrocnemius muscle and heart tissues of cachexic mice. Our findings suggest that UA is a promising natural compound for developing dietary supplements for cancer cachexia therapy owing to its anti-catabolic effects.

Effects of curcumin and ursolic acid in prostate cancer: A systematic review

The major barriers to phytonutrients in prostate cancer therapy are non-specific mechanisms and bioavailability issues. Studies have pointed to a synergistic combination of curcumin (CURC) and ursolic acid (UA). We investigate this combination using a systematic review process to assess the most likely mechanistic pathway and human testing in prostate cancer. We used the PRISMA statement to screen titles, abstracts, and the full texts of relevant articles and performed a descriptive analysis of the literature reviewed for study inclusion and consensus of the manuscript. The most common molecular and cellular pathway from articles reporting on the pathways and effects of CURC (n = 173) in prostate cancer was NF-κB (n = 25, 14.5%). The most common molecular and cellular pathway from articles reporting on the pathways and effects of UA (n = 24) in prostate cancer was caspase 3/caspase 9 (n = 10, 41.6%). The three most common molecular and cellular pathway from articles reporting on the pathways and effects of both CURC and UA (n = 193) in prostate cancer was NF-κB (n = 28, 14.2%), Akt (n = 22, 11.2%), and androgen (n = 19, 9.6%). Therefore, we have identified the potential synergistic target pathways of curcumin and ursolic acid to involve NF-κB, Akt, androgen receptors, and apoptosis pathways. Our review highlights the limited human studies and specific effects in prostate cancer.

Inhibition of the interaction between Hippo/YAP and Akt signaling with ursolic acid and 3'3-diindolylmethane suppresses esophageal cancer tumorigenesis

Hippo/YAP signaling hinders cancer progression. Inactivation of this pathway contributes to the development of esophageal cancer by activation of Akt. However, the possible interaction between Akt and Hippo/YAP pathways in esophageal cancer progression is unclear. In this study, we found that ursolic acid (UA) plus 3'3-diindolylmethane (DIM) efficiently suppressed the oncogenic Akt/Gsk-3β signaling pathway while activating the Hippo tumor suppressor pathway in esophageal cancer cells. Moreover, the addition of the Akt inhibitor LY294002 and the PI3K inhibitor 3-methyladenine enhanced the inhibitory effects of UA plus DIM on Akt pathway activation and further stimulated the Hippo pathway, including the suppression of YAP nuclear translocation in esophageal cancer cells. Silencing YAP under UA plus DIM conditions significantly increased the activation of the tumor suppressor PTEN in esophageal cancer cells, while decreasing p-Akt activation, indicating that the Akt signaling pathway could be down-regulated in esophageal cancer cells by targeting PTEN. Furthermore, in a xenograft nude mice model, UA plus DIM treatment effectively diminished esophageal tumors by inactivating the Akt pathway and stimulating the Hippo signaling pathway. Thus, our study highlights a feedback loop between the PI3K/Akt and Hippo signaling pathways in esophageal cancer cells, implying that a low dose of UA plus DIM could serve as a promising chemotherapeutic combination strategy in the treatment of esophageal cancer.

Mesoporous Silica Nanoparticles as a Gene Delivery Platform for Cancer Therapy

Cancer remains a major global health challenge. Traditional chemotherapy often results in side effects and drug resistance, necessitating the development of alternative treatment strategies such as gene therapy. Mesoporous silica nanoparticles (MSNs) offer many advantages as a gene delivery carrier, including high loading capacity, controlled drug release, and easy surface functionalization. MSNs are biodegradable and biocompatible, making them promising candidates for drug delivery applications. Recent studies demonstrating the use of MSNs for the delivery of therapeutic nucleic acids to cancer cells have been reviewed, along with their potential as a tool for cancer therapy. The major challenges and future interventions of MSNs as gene delivery carriers for cancer therapy are discussed.

Natural compounds ursolic acid and digoxin exhibit inhibitory activities to cancer cells in RORγ-dependent and -independent manner

Natural compounds ursolic acid (UA) and digoxin isolated from fruits and other plants display potent anti-cancer effects in preclinical studies. UA and digoxin have been at clinical trials for treatment of different cancers including prostate cancer, pancreatic cancer and breast cancer. However, they displayed limited benefit to patients. Currently, a poor understanding of their direct targets and mechanisms of action (MOA) severely hinders their further development. We previously identified nuclear receptor RORγ as a novel therapeutic target for castration-resistant prostate cancer (CRPC) and triple-negative breast cancer (TNBC) and demonstrated that tumor cell RORγ directly activates gene programs such as androgen receptor (AR) signaling and cholesterol metabolism. Previous studies also demonstrated that UA and digoxin are potential RORγt antagonists in modulating the functions of immune cells such as Th17 cells. Here we showed that UA displays a strong activity in inhibition of RORγ-dependent transactivation function in cancer cells, while digoxin exhibits no effect at clinically relevant concentrations. In prostate cancer cells, UA downregulates RORγ-stimulated AR expression and AR signaling, whereas digoxin upregulates AR signaling pathway. In TNBC cells, UA but not digoxin alters RORγ-controlled gene programs of cell proliferation, apoptosis and cholesterol biosynthesis. Together, our study reveals for the first-time that UA, but not digoxin, acts as a natural antagonist of RORγ in the cancer cells. Our finding that RORγ is a direct target of UA in cancer cells will help select patients with tumors that likely respond to UA treatment.

Ursolic Acid against Prostate and Urogenital Cancers: A Review of In Vitro and In Vivo Studies

Prostate cancer is the second most diagnosed form of cancer in men worldwide and accounted for roughly 1.3 million cases and 359,000 deaths globally in 2018, despite all the available treatment strategies including surgery, radiotherapy, and chemotherapy. Finding novel approaches to prevent and treat prostate and other urogenital cancers effectively is of major importance. Chemicals derived from plants, such as docetaxel and paclitaxel, have been used in cancer treatment, and in recent years, research interest has focused on finding other plant-derived chemicals that can be used in the fight against cancer. Ursolic acid, found in high concentrations in cranberries, is a pentacyclic triterpenoid compound demonstrated to have anti-inflammatory, antioxidant, and anticancer properties. In the present review, we summarize the research studies examining the effects of ursolic acid and its derivatives against prostate and other urogenital cancers. Collectively, the existing data indicate that ursolic acid inhibits human prostate, renal, bladder, and testicular cancer cell proliferation and induces apoptosis. A limited number of studies have shown significant reduction in tumor volume in animals xenografted with human prostate cancer cells and treated with ursolic acid. More animal studies and human clinical studies are required to examine the potential of ursolic acid to inhibit prostate and other urogenital cancers in vivo.

Ursolic Acid Analogs as Potential Therapeutics for Cancer

Ursolic acid (UA) is a pentacyclic triterpene isolated from a large variety of vegetables, fruits and many traditional medicinal plants. It is a structural isomer of Oleanolic Acid. The medicinal application of UA has been explored extensively over the last two decades. The diverse pharmacological properties of UA include anti-inflammatory, antimicrobial, antiviral, antioxidant, anti-proliferative, etc. Especially, UA holds a promising position, potentially, as a cancer preventive and therapeutic agent due to its relatively non-toxic properties against normal cells but its antioxidant and antiproliferative activities against cancer cells. Cell culture studies have shown interference of UA with multiple pharmacological and molecular targets that play a critical role in many cells signaling pathways. Although UA is considered a privileged natural product, its clinical applications are limited due to its low absorption through the gastro-intestinal track and rapid elimination. The low bioavailability of UA limits its use as a therapeutic drug. To overcome these drawbacks and utilize the importance of the scaffold, many researchers have been engaged in designing and developing synthetic analogs of UA via structural modifications. This present review summarizes the synthetic UA analogs and their cytotoxic antiproliferative properties reported in the last two decades.

Nimbolide enhances the antitumor effect of docetaxel via abrogation of the NF-κB signaling pathway in prostate cancer preclinical models

Prostate cancer is the second most frequent type of cancer that affects men. Docetaxel (DTX) administration is the front-line therapy for patients with advanced prostate cancer and unfortunately, half of these patients develop resistance to DTX which could be due to its ability to activate the NF-κB pathway. The combinational effect of DTX and nimbolide on proliferation, apoptosis, activation of NF-κB, DNA binding ability of NF-κB, and expression of NF-κB-targeted gene products was investigated. The antitumor and antimetastatic effect of DTX or NL alone or in combination was also examined. The co-administration of NL and DTX resulted in a significant loss of cell viability with enhanced apoptosis in DTX-sensitive/resistant prostate cancer cells. NL abrogated DTX-triggered NF-κB activation and expression of its downstream antiapoptotic factors (survivin, Bcl-2, and XIAP). The combination of NL and DTX significantly reduced the DNA binding ability of NF-κB in both cell types. NL significantly enhanced the antitumor effect of DTX and reduced metastases in orthotopic models of prostate cancer. NL abolishes DTX-induced-NF-κB activation to counteract cell proliferation, tumor growth, and metastasis in the prostate cancer models.

Licorice (Glycyrrhiza glabra L.)-Derived Phytochemicals Target Multiple Signaling Pathways to Confer Oncopreventive and Oncotherapeutic Effects

Cancer is a highly lethal disease, and its incidence has rapidly increased worldwide over the past few decades. Although chemotherapeutics and surgery are widely used in clinical settings, they are often insufficient to provide the cure for cancer patients. Hence, more effective treatment options are highly needed. Although licorice has been used as a medicinal herb since ancient times, the knowledge about molecular mechanisms behind its diverse bioactivities is still rather new. In this review article, different anticancer properties (antiproliferative, antiangiogenic, antimetastatic, antioxidant, and anti-inflammatory effects) of various bioactive constituents of licorice (Glycyrrhiza glabra L.) are thoroughly described. Multiple licorice constituents have been shown to bind to and inhibit the activities of various cellular targets, including B-cell lymphoma 2, cyclin-dependent kinase 2, phosphatidylinositol 3-kinase, c-Jun N-terminal kinases, mammalian target of rapamycin, nuclear factor-κB, signal transducer and activator of transcription 3, vascular endothelial growth factor, and matrix metalloproteinase-3, resulting in reduced carcinogenesis in several in vitro and in vivo models with no evident toxicity. Emerging evidence is bringing forth licorice as an anticancer agent as well as bottlenecks in its potential clinical application. It is expected that overcoming toxicity-related obstacles by using novel nanotechnological methods might importantly facilitate the use of anticancer properties of licorice-derived phytochemicals in the future. Therefore, anticancer studies with licorice components must be continued. Overall, licorice could be a natural alternative to the present medication for eradicating new emergent illnesses while having just minor side effects.

Induction of Autophagy by Ursolic Acid Promotes the Elimination of Trypanosoma cruzi Amastigotes From Macrophages and Cardiac Cells

Chagas disease, caused by the parasite Trypanosoma cruzi, is an infectious illness endemic to Latin America and still lacks an effective treatment for the chronic stage. In a previous study in our laboratory, we established the protective role of host autophagy in vivo during T. cruzi infection in mice and proposed this process as one of the mechanisms involved in the innate immune response against this parasite. In the search for an autophagy inducer that increases the anti-T. cruzi response in the host, we found ursolic acid (UA), a natural pentacyclic triterpene with many biological actions including autophagy induction. The aim of this work was to study the effect of UA on T. cruzi infection in vitro in the late infection stage, when the nests of intracellular parasites are forming, in both macrophages and cardiac cells. To test this effect, the cells were infected with T. cruzi for 24 h and then treated with UA (5–10 µM). The data showed that UA significantly decreased the number of amastigotes found in infected cells in comparison with non-treated cells. UA also induced the autophagy response in both macrophages and cardiac cells under the studied conditions, and the inhibition of this pathway during UA treatment restored the level of infection. Interestingly, LC3 protein, the main marker of autophagy, was recruited around amastigotes and the acidic probe LysoTracker localized with them, two key features of xenophagy. A direct cytotoxic effect of UA was also found on trypomastigotes of T. cruzi, whereas epimastigotes and amastigotes displayed more resistance to this drug at the studied concentrations. Taken together, these data showed that this natural compound reduces T. cruzi infection in the later stages by promoting parasite damage through the induction of autophagy. This action, in addition to the effect of this compound on trypomastigotes, points to UA as an interesting lead for Chagas disease treatment in the future.

Brassinin Enhances Apoptosis in Hepatic Carcinoma by Inducing Reactive Oxygen Species Production and Suppressing the JAK2/STAT3 Pathway

Plants from the family Brassicaceae produce brassinin (BSN), which is an essential indole phytoalexin. BSN can kill certain types of cancer cells. Using hepatocarcinoma (HCC) cells, we examined the molecular mechanisms of BSN. We found that HCC cell growth was suppressed and apoptosis was induced by BSN via the downregulation of the JAK/STAT3 pathway. The cytoplasmic latent transcription factor STAT3, belonging to the STAT family, acted as both a signal transducer and an activator and was linked to tumor progression and decreased survival. BSN incubation caused HCC cells to produce reactive oxygen species (ROS). By activating caspase-9/-3 and PARP cleavage, Bcl-2 was reduced, and apoptosis was increased. BSN inhibited constitutive STAT3, JAK2, and Src phosphorylation. The JAK/STAT signaling cascade was confirmed by siRNA silencing STAT3 in HCC cells. BSN also suppressed apoptosis by Z-Val-Ala-Asp-Fluoromethylketone (Z-VAD-FMK), an apoptotic inhibitor. N-acetylcysteine (NAC) inhibited the production of ROS and diminished BSN-induced apoptosis. Our findings suggested that BSN has potential as a treatment for cancer.

Choosing Kinase Inhibitors for Androgen Deprivation Therapy-Resistant Prostate Cancer

Androgen deprivation therapy (ADT) is a systemic therapy for advanced prostate cancer (PCa). Although most patients initially respond to ADT, almost all cancers eventually develop castration resistance. Castration-resistant PCa (CRPC) is associated with a very poor prognosis, and the treatment of which is a serious clinical challenge. Accumulating evidence suggests that abnormal expression and activation of various kinases are associated with the emergence and maintenance of CRPC. Many efforts have been made to develop small molecule inhibitors to target the key kinases in CRPC. These inhibitors are designed to suppress the kinase activity or interrupt kinase-mediated signal pathways that are associated with PCa androgen-independent (AI) growth and CRPC development. In this review, we briefly summarize the roles of the kinases that are abnormally expressed and/or activated in CRPC and the recent advances in the development of small molecule inhibitors that target kinases for the treatment of CRPC.

Role for Plant-Derived Antioxidants in Attenuating Cancer Cachexia

Cancer cachexia is the progressive muscle wasting and weakness experienced by many cancer patients. It can compromise the response to gold standard cancer therapies, impair functional capacity and reduce overall quality of life. Cancer cachexia accounts for nearly one-third of all cancer-related deaths and has no effective treatment. The pathogenesis of cancer cachexia and its progression is multifactorial and includes increased oxidative stress derived from both the tumor and the host immune response. Antioxidants have therapeutic potential to attenuate cancer-related muscle loss, with polyphenols, a group of plant-derived antioxidants, being the most widely investigated. This review describes the potential of these plant-derived antioxidants for treating cancer cachexia.

Anticancer activity of ursolic acid on retinoblastoma cells determined by bioinformatics analysis and validation

Background

This article aims to explore whether ursolic acid (UA) inhibits the progression of retinoblastoma (Rb) by regulating stearoyl-CoA desaturase (SCD).

Methods

The Gene Expression Omnibus (GEO) database was used to filter the chip, then the GEO2R software was used to analyze the microarray data (GSE97508, GSE24673, and GSE110811). Gene set enrichment analysis (GSEA) was used to analyze the relationship between the expression level of SCD and the proliferation, migration, invasion, and inflammation in Rb patients. SO-RB50 and Y79 cell proliferation, migration, and invasion were assessed by the CCK-8 assay, the colony formation assay, the Transwell assay, and the wound scratch test. The protein expression levels of SCD were measured by western blot. The mRNA expression levels of IL-8, IL-6, CXCL1, and CCL2 were measured by RT-qPCR. The protein expression levels of IL-8 and IL-6 were measured by ELISA. A xenograft nude mouse model was established to evaluate the effect of UA on tumor growth in male BALB/c mice.

Results

The expression levels of SCD were related to cell proliferation, migration, invasion, and inflammation. UA inhibited SO-RB50 and Y79 cell proliferation, migration, and invasion. At the same time, UA suppressed tumor growth in the xenograft nude mouse model. Overexpression of SCD promoted SO-RB50 and Y79 cell proliferation, migration, invasion, and inflammation, while SCD knockout inhibited SO-RB50 and Y79 cell proliferation, migration, invasion, and inflammation. Importantly, UA inhibited the proliferation, migration, and invasion of Rb cells through SCD inhibition.

Conclusions

UA inhibited the proliferation, migration, and invasion of Rb cells through SCD. This provides a new scientific basis for targeted therapy of Rb.

p21-Activated kinase 1 (PAK1) in aging and longevity: An overview

The p21-activated kinases (PAKs) belong to serine/threonine kinases family, regulated by ∼21 kDa small signaling G proteins RAC1 and CDC42. The mammalian PAK family comprises six members (PAK1-6) that are classified into two groups (I and II) based on their domain architecture and regulatory mechanisms. PAKs are implicated in a wide range of cellular functions. PAK1 has recently attracted increasing attention owing to its involvement in oncogenesis, tumor progression, and metastasis as well as several life-limiting diseases and pathological conditions. In Caenorhabditis elegans, PAK1 functions limit the lifespan under basal conditions by inhibiting forkhead transcription factor DAF-16. Interestingly, PAK depletion extended longevity and attenuated the onset of age-related phenotypes in a premature-aging mouse model and delayed senescence in mammalian fibroblasts. These observations implicate PAKs as not only oncogenic but also aging kinases. Therefore, PAK-targeting genetic and/or pharmacological interventions, particularly PAK1-targeting, could be a viable strategy for developing cancer therapies with relatively no side effects and promoting healthy longevity. This review describes PAK family proteins, their biological functions, and their role in regulating aging and longevity using C. elegans. Moreover, we discuss the effect of small-molecule PAK1 inhibitors on the lifespan and healthspan of C. elegans.

Targeting Inflammatory Signaling in Prostate Cancer Castration Resistance

Although castration-resistant prostate cancer (CRPC) as a whole, by its name, refers to the tumors that relapse and/or regrow independently of androgen after androgen deprivation therapy (ADT), untreated tumor, even in early-stage primary prostate cancer (PCa), contains androgen-independent (AI) PCa cells. The transformation of androgen-dependent (AD) PCa to AI PCa under ADT is a forced evolutionary process, in which the small group of AI PCa cells that exist in primary tumors has the unique opportunity to proliferate and expand selectively and dominantly, while some AD PCa cells that have escaped from ADT-induced death acquire the capability to survive in an androgen-depleted environment. The adaptation and reprogramming of both PCa cells and the tumor microenvironment (TME) under ADT make PCa much stronger than primary tumors so that, currently, there are no effective therapeutic methods available for the treatment of CRPC. Many mechanisms have been found to be related to the emergence and maintenance of PCa castration resistance; in this review, we focus on the role of inflammatory signaling in both PCa cells and the TME for the emergence and maintenance of CRPC and summarize the recent advances of therapeutic strategies that target inflammatory signaling for the treatment of CRPC.

Role of Pentacyclic Triterpenoid Acids in the Treatment of Bladder Cancer

Bladder cancer carries a poor prognosis and has proven resistance to chemotherapy. Pentacyclic Triterpenoid Acids (PTAs) are natural bioactive compounds that have a well-known impact on cancer research because of their cytotoxic and chemopreventive activities. This review focuses on bladder cancer which can no longer be successfully treated by DNA damaging drugs. Unlike most of the existing drugs against bladder cancer, PTAs are non-toxic to normal cells. Collecting findings from both in vitro and in vivo studies, it has been concluded that PTAs may serve as promising agents in future bladder cancer therapy. In this review, the roles of various PTAs in bladder cancer have been explored, and their mechanisms of action in the treatment of bladder cancer have been described. Specific PTAs have been shortlisted from each of the chief skeletons of pentacyclic triterpenoids, which could be effective against bladder cancer because of their mode of action. This review thereby throws light on the multi targets and mechanisms of PTAs, which are responsible for their selective anticancer effects and provides guidelines for further research and development of new natural antitumor compounds.

Molecular Basis of Prostate Cancer and Natural Products as Potential Chemotherapeutic and Chemopreventive Agents

Prostate cancer is the second most common malignant cancer in males. It involves a complex process driven by diverse molecular pathways that closely related to the survival, apoptosis, metabolic and metastatic characteristics of aggressive cancer. Prostate cancer can be categorized into androgen dependent prostate cancer and castration-resistant prostate cancer and cure remains elusive due to the developed resistance of the disease. Natural compounds represent an extraordinary resource of structural scaffolds with high diversity that can offer promising chemical agents for making prostate cancer less devastating and curable. Herein, those natural compounds of different origins and structures with potential cytotoxicity and/or in vivo anti-tumor activities against prostate cancer are critically reviewed and summarized according to the cellular signaling pathways they interfere. Moreover, the anti-prostate cancer efficacy of many nutrients, medicinal plant extracts and Chinese medical formulations were presented, and the future prospects for the application of these compounds and extracts were discussed. Although the failure of conventional chemotherapy as well as involved serious side effects makes natural products ideal candidates for the treatment of prostate cancer, more investigations of preclinical and even clinical studies are necessary to make use of these medical substances reasonably. Therefore, the elucidation of structure-activity relationship and precise mechanism of action, identification of novel potential molecular targets, and optimization of drug combination are essential in natural medicine research and development.

Novel A-Ring Chalcone Derivatives of Oleanolic and Ursolic Amides with Anti-Proliferative Effect Mediated through ROS-Triggered Apoptosis

A series of A-ring modified oleanolic and ursolic acid derivatives including C28 amides (3-oxo-C2-nicotinoylidene/furfurylidene, 3β-hydroxy-C2-nicotinoylidene, 3β-nicotinoyloxy-, 2-cyano-3,4-seco-4(23)-ene, indolo-, lactame and azepane) were synthesized and screened for their cytotoxic activity against the NCI-60 cancer cell line panel. The results of the first assay of thirty-two tested compounds showed that eleven derivatives exhibited cytotoxicity against cancer cells, and six of them were selected for complete dose-response studies. A systematic study of local SARs has been carried out by comparative analysis of potency distributions and similarity relationships among the synthesized compounds using network-like similarity graphs. Among the oleanane type triterpenoids, C2-[4-pyridinylidene]-oleanonic C28-morpholinyl amide exhibited sub-micromolar potencies against 15 different tumor cell lines and revealed particular selectivity for non-small cell lung cancer (HOP-92) with a GI50 value of 0.0347 μM. On the other hand, superior results were observed for C2-[3-pyridinylidene]-ursonic N-methyl-piperazinyl amide 29, which exhibited a broad-spectrum inhibition activity with GI50 < 1 μM against 33 tumor cell lines and <2 μM against all 60 cell lines. This compound has been further evaluated for cell cycle analysis to decipher the mechanism of action. The data indicate that compound 29 could exhibit both cytostatic and cytotoxic activity, depending on the cell line evaluated. The cytostatic activity appears to be determined by induction of the cell cycle arrest at the S (MCF-7, SH-SY5Y cells) or G0/G1 phases (A549 cells), whereas cytotoxicity of the compound against normal cells is nonspecific and arises from apoptosis without significant alterations in cell cycle distribution (HEK293 cells). Our results suggest that the antiproliferative effect of compound 29 is mediated through ROS-triggered apoptosis that involves mitochondrial membrane potential depolarization and caspase activation.

Ursolic Acid and Related Analogues: Triterpenoids with Broad Health Benefits

Ursolic acid (UA) is a well-studied natural pentacyclic triterpenoid found in herbs, fruit and a number of traditional Chinese medicinal plants. UA has a broad range of biological activities and numerous potential health benefits. In this review, we summarize the current data on the bioavailability and pharmacokinetics of UA and review the literature on the biological activities of UA and its closest analogues in the context of inflammation, metabolic diseases, including liver and kidney diseases, obesity and diabetes, cardiovascular diseases, cancer, and neurological disorders. We end with a brief overview of UA’s main analogues with a special focus on a newly discovered naturally occurring analogue with intriguing biological properties and potential health benefits, 23-hydroxy ursolic acid.

Diosgenin attenuates tumor growth and metastasis in transgenic prostate cancer mouse model by negatively regulating both NF-κB/STAT3 signaling cascades

Prostate cancer (PCa) is a common disease among men especially in the old age. The deregulated activation of oncogenic and pro-survival transcription factors has been linked with tumor progression in PCa patients. The consequence of diosgenin treatment on NF-κB/STAT3 activation in PCa cells as well as transgenic mouse model was determined. We also validated the hypothesis of targeting these transcription factors using in silico proteomics simulation model. Diosgenin abrogated NF-κB/STAT3 activation and this action was caused as a result of suppression of protein kinases and reporter gene activity that led to a substantial reduction in the expression of various tumorigenic gene products. In vivo, diosgenin (2% w/w) when mixed in diet and fed to mice abrogated tumor progression in transgenic mice. Diosgenin was also detected in serum and was well absorbed orally. Overall, our data highlights the promising efficacy of diosgenin in PCa therapy.

Perspectives on natural compounds in chemoprevention and treatment of cancer: an update with new promising compounds

Cancer is the second deadliest disease worldwide. Although recent advances applying precision treatments with targeted (molecular and immune) agents are promising, the histological and molecular heterogeneity of cancer cells and huge mutational burdens (intrinsic or acquired after therapy) leading to drug resistance and treatment failure are posing continuous challenges. These recent advances do not negate the need for alternative approaches such as chemoprevention, the pharmacological approach to reverse, suppress or prevent the initial phases of carcinogenesis or the progression of premalignant cells to invasive disease by using non-toxic agents. Although data are limited, the success of several clinical trials in preventing cancer in high-risk populations suggests that chemoprevention is a rational, appealing and viable strategy to prevent carcinogenesis. Particularly among higher-risk groups, the use of safe, non-toxic agents is the utmost consideration because these individuals have not yet developed invasive disease. Natural dietary compounds present in fruits, vegetables and spices are especially attractive for chemoprevention and treatment because of their easy availability, high margin of safety, relatively low cost and widespread human consumption. Hundreds of such compounds have been widely investigated for chemoprevention and treatment in the last few decades. Previously, we reviewed the most widely studied natural compounds and their molecular mechanisms, which were highly exploited by the cancer research community. In the time since our initial review, many promising new compounds have been identified. In this review, we critically review these promising new natural compounds, their molecular targets and mechanisms of anticancer activity that may create novel opportunities for further design and conduct of preclinical and clinical studies.

Bioassay-Guided Identification of the Antiproliferative Compounds of Cissus trifoliata and the Transcriptomic Effect of Resveratrol in Prostate Cancer Pc3 Cells

The bioassay-guided fractionation of a CHCl₃-MeOH extract from the stems of Cissus trifoliata identified an active fraction against PC3 prostate cancer cells. The treatment for 24 h showed an 80% reduction in cell viability (p ≤ 0.05) by a WST-1 assay at a concentration of 100 μg/mL. The HPLC-QTOF-MS analysis of the fraction showed the presence of coumaric and isoferulic acids, apigenin, kaempferol, chrysoeriol, naringenin, ursolic and betulinic acids, hexadecadienoic and octadecadienoic fatty acids, and the stilbene resveratrol. The exposure of PC3 cells to resveratrol (IC₂₅ = 23 μg/mL) for 24 h induced significant changes in 847 genes (Z-score ≥ ±2). The functional classification tool of the DAVID v6.8 platform indicates that the underlying molecular mechanisms against the proliferation of PC3 cells were associated (p ≤ 0.05) with the process of differentiation and metabolism. These findings provide experimental evidence suggesting the potential of C. trifoliata as a promising natural source of anticancer compounds.

Promising Perspective to Facioscapulohumeral Muscular Dystrophy Treatment: Nutraceuticals and Phytochemicals

Facioscapulohumeral Muscular Dystrophy (FSHD) is in the top three list of all dystrophies with an approximate 1:8000 incidence. It is not a life-threatening disease; however, the progression of the disease extends over being wheelchair bound. Despite some drug trials continuing, including DUX4 inhibition, TGF-ß inhibition and resokine which promote healthier muscle, there is not an applicable treatment option for FSHD today. Still, there is a need for new agents to heal, stop or at least slow down muscle wasting. Current FSHD studies involving nutraceuticals as vitamin C, vitamin E, coenzyme Q10, zinc, selenium, and phytochemicals as curcumin or genistein, daidzein flavonoids provide promising treatment strategies. In this review, we present the clinical and molecular nature of FSHD and focus on nutraceuticals and phytochemicals that may alleviate FSHD. In the light of the association of impaired pathophysiological FSHD pathways with nutraceuticals and phytochemicals according to the literature, we present both studied and novel approaches that can contribute to FSHD treatment.

Ursolic Acid-Based Derivatives as Potential Anti-Cancer Agents: An Update

Ursolic acid is a pharmacologically active pentacyclic triterpenoid derived from medicinal plants, fruit, and vegetables. The pharmacological activities of ursolic acid have been extensively studied over the past few years and various reports have revealed that ursolic acid has multiple biological activities, which include anti-inflammatory, antioxidant, anti-cancer, etc. In terms of cancer treatment, ursolic acid interacts with a number of molecular targets that play an essential role in many cell signaling pathways. It suppresses transformation, inhibits proliferation, and induces apoptosis of tumor cells. Although ursolic acid has many benefits, its therapeutic applications in clinical medicine are limited by its poor bioavailability and absorption. To overcome such disadvantages, researchers around the globe have designed and developed synthetic ursolic acid derivatives with enhanced therapeutic effects by structurally modifying the parent skeleton of ursolic acid. These structurally modified compounds display enhanced therapeutic effects when compared to ursolic acid. This present review summarizes various synthesized derivatives of ursolic acid with anti-cancer activity which were reported from 2015 to date.

Differential Anti-Proliferative and Anti-Migratory Activities of Ursolic Acid, 3-O-Acetylursolic Acid and Their Combination Treatments with Quercetin on Melanoma Cells

We evaluate how 3-acetylation modulates the in vitro activity of ursolic acid in melanoma cells alone or in combination treatments with quercetin. Anti-proliferative studies on A375 cells and adult human dermal fibroblasts included analyses on cell cycle distribution, caspase activity, phosphatidylserine translocation, cell morphology and Bax/Bcl-2 protein expression. Then, 2D and 3D migration of B16F10 cells were studied using scratch and Transwell assays, respectively. Ursolic acid and 3-O-acetylursolic acid have shown similar GI50 on A375 cells (26 µM vs. 32 µM, respectively) significantly increased both early and late apoptotic populations, activated caspases 3/7 (48-72 h), and enhanced Bax whilst attenuating Bcl-2 expression. Ursolic acid caused elevation of the sub-G1 population whilst its 3-acetyl derivative arrested cell cycle at S phase and induced strong morphological changes. Combination treatments showed that ursolic acid and quercetin act synergistically in migration assays but not against cell proliferation. In summary, 3-O-acetylursolic acid maintains the potency and overall apoptotic mechanism of the parent molecule with a more aggressive influence on the morphology of A375 melanoma cells but the 3-acetylation suppresses its anti-migratory properties. We also found that ursolic acid can act in synergy with quercetin to reduce cell migration.

Targeting the JAK/STAT Signaling Pathway Using Phytocompounds for Cancer Prevention and Therapy

Cancer is a prevalent cause of mortality around the world. Aberrated activation of Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway promotes tumorigenesis. Natural agents, including phytochemicals, exhibit potent anticancer activities via various mechanisms. However, the therapeutic potency of phytoconstituents as inhibitors of JAK/STAT signaling against cancer has only come into focus in recent days. The current review highlights phytochemicals that can suppress the JAK/STAT pathway in order to impede cancer cell growth. Various databases, such as PubMed, ScienceDirect, Web of Science, SpringerLink, Scopus, and Google Scholar, were searched using relevant keywords. Once the authors were in agreement regarding the suitability of a study, a full-length form of the relevant article was obtained, and the information was gathered and cited. All the complete articles that were incorporated after the literature collection rejection criteria were applied were perused in-depth and material was extracted based on the importance, relevance, and advancement of the apprehending of the JAK/STAT pathway and their relation to phytochemicals. Based on the critical and comprehensive analysis of literature presented in this review, phytochemicals from diverse plant origins exert therapeutic and cancer preventive effects, at least in part, through regulation of the JAK/STAT pathway. Nevertheless, more preclinical and clinical research is necessary to completely comprehend the capability of modulating JAK/STAT signaling to achieve efficient cancer control and treatment.

Solubilization and delivery of Ursolic-acid for modulating tumor microenvironment and regulatory T cell activities in cancer immunotherapy

Ursolic acid (UA) is a potent triterpenoid compound found in plants and fruits with activities modulating key cell signaling pathways involving STATs, NF-κB, and TRAIL. But it's highly hydrophobic and very poorly soluble in nature. It had been prepared as nanocrystals, solid dispersion and loaded in nanoparticles but the achieved systemic exposure and circulation half-life were not ideal. We reported the development of UA-liposomes made by HPβCD assisted active loading. Compared to lipid suspensions of UA (Lipid-UA) with similar lipid composition, the novel process enabled the formation of UA-Ca crystalline structures inside the liposomes and therefore sustained release of UA in vivo. While the UA-liposomes were not generally toxic towards 4T1 triple negative breast cancer cells, they could effectively modulate CD4+CD25+Foxp3+ T cells from 4T1 tumor bearing mouse by inhibiting STAT5 phosphorylation and IL-10 secretion. In vivo administration of UA-liposomes at 10 mg/kg dose led to reduced numbers of myeloid derived suppressor cells (MDSCs) and regulatory T cells (Tregs) residing in tumor tissues. These changes signified the correction of the tumor mediated immune-suppressive microenvironment. The UA-liposomes treatment alone was already effective in deterring tumor growth. Such a formulation may be highly promising as an immunotherapy agent and be combined with chemotherapeutics or targeted drugs.

Natural Compounds in Prostate Cancer Prevention and Treatment: Mechanisms of Action and Molecular Targets

Prostate cancer (PCa) represents a major cause of cancer mortality among men in developed countries. Patients with recurrent disease initially respond to androgen-deprivation therapy, but the tumor eventually progresses into castration-resistant PCa; in this condition, tumor cells acquire the ability to escape cell death and develop resistance to current therapies. Thus, new therapeutic approaches for PCa management are urgently needed. In this setting, natural products have been extensively studied for their anti-PCa activities, such as tumor growth suppression, cell death induction, and inhibition of metastasis and angiogenesis. Additionally, numerous studies have shown that phytochemicals can specifically target the androgen receptor (AR) signaling, as well as the PCa stem cells (PCSCs). Interestingly, many clinical trials have been conducted to test the efficacy of nutraceuticals in human subjects, and they have partially confirmed the promising results obtained in vitro and in preclinical models. This article summarizes the anti-cancer mechanisms and therapeutic potentials of different natural compounds in the context of PCa prevention and treatment.

The Phytosterol Peniocerol Inhibits Cell Proliferation and Tumor Growth in a Colon Cancer Xenograft Model

Objective: This study aimed to evaluate the cytotoxic activity of peniocerol against human colon cancer cell lines and its antitumor effect in vivo in a xenograft model using nu/nu mice.

Materials and Methods: SW-620, HCT-15, and HCT-116 colon cancer cell lines were treated with peniocerol for cytotoxicity by crystal violet technique. Cell apoptosis induction was detected by flow cytometry, and the antitumor activity of peniocerol was evaluated in a xenograft model of HCT-116 in nu/nu mice. After treatment, the effect of peniocerol was analyzed in histological sections of tumors by immunohistochemistry using DAPI, anti-PCNA, and PARP-1 antibodies.

Results: Peniocerol inhibited cell growth and induced apoptosis in vitro in a time and dose-dependent manner. Besides, peniocerol administration (30 or 15 mg/kg) inhibited tumor growth and induced apoptosis in the xenograft mice. The lack of peniocerol toxicity was proved by a biochemical blood analysis of healthy nu/nu mice administrated with this sterol.

Conclusions: Our results proved that peniocerol induces apoptosis in vitro and in vivo assays.

Ursolic acid promotes apoptosis and mediates transcriptional suppression of CT45A2 gene expression in non-small-cell lung carcinoma harbouring EGFR T790M mutations

BACKGROUND AND PURPOSE

In non-small-cell lung carcinoma (NSCLC) patients, the L858R/T790M mutation of the epithelial growth factor receptor (EGFR) is a major cause of acquired resistance to EGFR-TKIs treatment that limits their therapeutic efficacy. Identification of drugs that can preferentially kill the NSCLC harbouring L858R/T790M mutation is therefore critical. Here, we have evaluated the effects of ursolic acid, an active component isolated from herbal sources, on erlotinib-resistant H1975 cells that harbour the L858R/T790M mutation.

EXPERIMENTAL APPROACH

Gene expression omnibus (GEO) profiles analyses was applied to detect differentially expressed genes in NSCLC cells harbouring EGFR mutation. AnnexinV-FITC/PI, TUNEL staining, MTT, wound healing, RT-PCR, qRT-PCR, western blots, immunostaining, dual-luciferase reporters and ChIP-PCR were utilized to investigate the effects of ursolic acid in vitro and in vivo.

KEY RESULTS

The cancer/testis antigen family 45 member A2 (CT45A2) was highly expressed in H1975 cells. Ectopic expression of CT45A2 in H1975 cells increased cell proliferation and motility in vitro. Silencing the CT45A2 expression strongly attenuated H1975 cells motility and growth. The anti-cancer effect of ursolic acid was critically dependent on CT45A2 expression in H1975 cells. Ursolic acid suppressed CT45A2 gene transcription mediated by transcriptional factor TCF4 and β-catenin signalling.

CONCLUSIONS AND IMPLICATIONS

CT45A2 is a novel oncogene for NSCLC with an EGFR T790 mutation. Ursolic acid induced apoptosis and inhibited proliferation of H1975 cells by negatively regulating the β-catenin/TCF4/CT45A2 signalling pathway. Therefore, ursolic acid may be a potential candidate treatment for NSCLC harbouring the EGFR-L858R/T790M mutation.

Naturally occurring anti-cancer compounds: shining from Chinese herbal medicine

Numerous natural products originated from Chinese herbal medicine exhibit anti-cancer activities, including anti-proliferative, pro-apoptotic, anti-metastatic, anti-angiogenic effects, as well as regulate autophagy, reverse multidrug resistance, balance immunity, and enhance chemotherapy in vitro and in vivo. To provide new insights into the critical path ahead, we systemically reviewed the most recent advances (reported since 2011) on the key compounds with anti-cancer effects derived from Chinese herbal medicine (curcumin, epigallocatechin gallate, berberine, artemisinin, ginsenoside Rg3, ursolic acid, silibinin, emodin, triptolide, cucurbitacin B, tanshinone I, oridonin, shikonin, gambogic acid, artesunate, wogonin, β-elemene, and cepharanthine) in scientific databases (PubMed, Web of Science, Medline, Scopus, and Clinical Trials). With a broader perspective, we focused on their recently discovered and/or investigated pharmacological effects, novel mechanism of action, relevant clinical studies, and their innovative applications in combined therapy and immunomodulation. In addition, the present review has extended to describe other promising compounds including dihydroartemisinin, ginsenoside Rh2, compound K, cucurbitacins D, E, I, tanshinone IIA and cryptotanshinone in view of their potentials in cancer therapy. Up to now, the evidence about the immunomodulatory effects and clinical trials of natural anti-cancer compounds from Chinese herbal medicine is very limited, and further research is needed to monitor their immunoregulatory effects and explore their mechanisms of action as modulators of immune checkpoints.

An Investigation on the Therapeutic Potential of Butein, A Tretrahydroxychalcone Against Human Oral Squamous Cell Carcinoma

Background:

Oral squamous cell carcinoma (OSCC) is one of the most predominant cancers in India. With advances in the field of oncology, a number of therapies have emerged; however, they are minimally effective. Consequently, there is a need to develop safe and effective regimens for the treatment of OSCC. Butein, a tetrahydroxychalcone has been found to exhibit potent antioxidant, anti-inflammatory, and also anti-tumor effects against several cancer types. However, its effect on OSCC is not studied yet.

Methods:

The effect of butein on the viability, apoptosis, migration and invasion of OSCC cells was evaluated using MTT, colony formation, PI/FACS, live and dead, scratch wound healing, and matrigel invasion assays. Further Western blot analysis was done to evaluate the expression of different proteins involved in the regulation of cancer hallmarks.

Results:

This is the first report exemplifying the anti-cancer effect of butein against OSCC. Our results showed that butein exhibited potent anti-proliferative, cytotoxic, anti-migratory, and anti-invasive effects in OSCC cells. It suppressed the expression of NF-κB and NF-κB-regulated gene products such as COX-2, survivin and MMP-9 which are involved in the regulation of different processes like proliferation, survival, invasion, and metastasis of OSCC cells.

Conclusion

Collectively, these results suggest that butein has immense potential in the management of OSCC. Nonetheless, in vivo validation is critical before moving to clinical trials.

Investigating the Multi-Target Pharmacological Mechanism of Hedyotis diffusa Willd Acting on Prostate Cancer: A Network Pharmacology Approach

Hedyotis diffusa Willd (HDW) is one of the most well-known herbs used in the treatment of prostate cancer. However, the potential mechanisms of its anti-tumor effects have not been fully explored. Here, we applied a network pharmacology approach to explore the potential mechanisms of HDW against prostate cancer (PCa). We obtained 14 active compounds from HDW and 295 potential PCa related targets in total to construct a network, which indicated that quercetin and ursolic acid served as the main ingredients in HDW. Mitogen-activated Protein Kinase 8 (MAPK8), Interleukin 6 (IL6), Vascular Endothelial Growth Factor A (VEGFA), Signal Transducer and Activator of Transcription 3 (STAT3), Jun Proto-Oncogene (JUN), C-X-C Motif Chemokine Ligand 8 (CXCL8), Interleukin-1 Beta (IL1B), Matrix Metalloproteinase-9 (MMP9), C-C Motif Chemokine Ligand 2 (CCL2), RELA Proto-Oncogene (RELA), and CAMP Responsive Element Binding Protein 1 (CREB1) were identified as key targets of HDW in the treatment of PCa. The protein-protein interaction (PPI) cluster demonstrated that CREB1 was the seed in this cluster, indicating that CREB1 plays an important role in connecting other nodes in the PPI network. This enrichment demonstrated that HDW was highly related to translesion synthesis, unfolded protein binding, regulation of mitotic recombination, phosphatidylinositol and its kinase-mediated signaling, nucleotide excision repair, regulation of DNA recombination, and DNA topological change. The enrichment results also showed that the underlying mechanism of HDW against PCa may be due to its coordinated regulation of several cancer-related pathways, such as angiogenesis, cell differentiation, migration, apoptosis, invasion, and proliferation.

Fangchinoline, a Bisbenzylisoquinoline Alkaloid can Modulate Cytokine-Impelled Apoptosis via the Dual Regulation of NF-κB and AP-1 Pathways

Fangchinoline (FCN) derived from Stephaniae tetrandrine S. Moore can be employed to treat fever, inflammation, rheumatism arthralgia, edema, dysuria, athlete’s foot, and swollen wet sores. FCN can exhibit a plethora of anti-neoplastic effects although its precise mode of action still remains to be deciphered. Nuclear factor-κB (NF-κB) and activator protein-1 (AP-1) can closely regulate carcinogenesis and thus we analyzed the possible action of FCN may have on these two signaling cascades in tumor cells. The effect of FCN on NF-κB and AP-1 signaling cascades and its downstream functions was deciphered using diverse assays in both human chronic myeloid leukemia (KBM5) and multiple myeloma (U266). FCN attenuated growth of both leukemic and multiple myeloma cells and repressed NF-κB, and AP-1 activation through diverse mechanisms, including attenuation of phosphorylation of IκB kinase (IKK) and p65. Furthermore, FCN could also cause significant enhancement in TNFα-driven apoptosis as studied by various molecular techniques. Thus, FCN may exhibit potent anti-neoplastic effects by affecting diverse oncogenic pathways and may be employed as pro-apoptotic agent against various malignancies.

Ursolic acid: An overview on its cytotoxic activities against breast and colorectal cancer cells

Ursolic acid (UA) is a pentacyclic triterpene of the ursane type. As a common chemical constituent among species of the family Lamiaceae, UA possesses a broad spectrum of pharmacological properties. This overview focuses on the anticancer properties of UA against breast cancer (BC) and colorectal cancer (CRC) that are most common among women and men, respectively. In vitro studies have shown that UA inhibited the growth of BC and CRC cell lines through various molecular targets and signaling pathways. There are several in vivo studies on the cytotoxic activity of UA against BC and CRC. UA also inhibits the growth of other types of cancer. Studies on structural modifications of UA have shown that the -OH groups at C3 and at C28 are critical factors influencing the cytotoxic activity of UA and its derivatives. Some needs for future research are suggested. Sources of information were from ScienceDirect, Google Scholar and PubMed.

Synthesis and discovery of asiatic acid based 1,2,3-triazole derivatives as antitumor agents blocking NF-κB activation and cell migration

A series of asiatic acid (AA) based 1,2,3-triazole derivatives were designed, synthesized and subjected to a cell-based NF-κB inhibition screening assay. Among the tested compounds, compound 6k displayed impressive NF-κB inhibitory activity with an IC₅₀ value in the low micromolar range. A molecular docking study was performed to reveal key interactions between 6k and NF-κB in which the 1,2,3-triazole moiety and the hydroxyl groups of the AA skeleton were important for improving the inhibitory activity. Subsequently, surface plasmon resonance analysis validated the high affinity between compound 6k and NF-κB protein with an equilibrium dissociation constant (KD) value of 0.36 μM. Further studies showed that compound 6k observably inhibited the NF-κB DNA binding, nuclear translocation and IκBα phosphorylation. Moreover, in vitro antitumor activity screening showed that compound 6k (IC₅₀ = 2.67 ± 0.06 μM) exhibited the best anticancer activity against A549 cells, at least partly, by inhibition of the activity of NF-κB. Additionally, the treatment of A549 cells with compound 6k resulted in apoptosis induction potency and in vitro cell migration inhibition. Thus, we conclude that AA based 1,2,3-triazole derivatives may be potential NF-κB inhibitors with the ability to induce apoptosis and suppress cell migration.

Signal Transducer and Activator of Transcription (STATs) Proteins in Cancer and Inflammation: Functions and Therapeutic Implication

Signal Transducer and Activator of Transcription (STAT) pathway is connected upstream with Janus kinases (JAK) family protein and capable of integrating inputs from different signaling pathways. Each family member plays unique functions in signal transduction and crucial in mediating cellular responses to different kind of cytokines. STAT family members notably STAT3 and STAT5 have been involved in cancer progression whereas STAT1 plays opposite role by suppressing tumor growth. Persistent STAT3/5 activation is known to promote chronic inflammation, which increases susceptibility of healthy cells to carcinogenesis. Here, we review the role of STATs in cancers and inflammation while discussing current therapeutic implications in different cancers and test models, especially the delivery of STAT3/5 targeting siRNA using nanoparticulate delivery system.

FBXW7 in Cancer: What Has Been Unraveled Thus Far?

: The FBXW7 (F-box with 7 tandem WD40) protein encoded by the gene FBXW7 is one of the crucial components of ubiquitin ligase called Skp1-Cullin1-F-box (SCF) complex that aids in the degradation of many oncoproteins via the ubiquitin-proteasome system (UPS) thus regulating cellular growth. FBXW7 is considered as a potent tumor suppressor as most of its target substrates can function as potential growth promoters, including c-Myc, Notch, cyclin E, c-JUN, and KLF5. Its regulators include p53, C/EBP-δ, Numb, microRNAs, Pin 1, Hes-5, BMI1, Ebp2. Mounting evidence has indicated the involvement of aberrant expression of FBXW7 for tumorigenesis. Moreover, numerous studies have also shown its role in cancer cell chemosensitization, thereby demonstrating the importance of FBXW7 in the development of curative cancer therapy. This comprehensive review emphasizes on the targets, functions, regulators and expression of FBXW7 in different cancers and its involvement in sensitizing cancer cells to chemotherapeutic drugs.

Potential of Zerumbone as an Anti-Cancer Agent

Cancer is still a major risk factor to public health globally, causing approximately 9.8 million deaths worldwide in 2018. Despite advances in conventional treatment modalities for cancer treatment, there are still few effective therapies available due to the lack of selectivity, adverse side effects, non-specific toxicities, and tumour recurrence. Therefore, there is an immediate need for essential alternative therapeutics, which can prove to be beneficial and safe against cancer. Various phytochemicals from natural sources have been found to exhibit beneficial medicinal properties against various human diseases. Zerumbone is one such compound isolated from Zingiber zerumbet Smith that possesses diverse pharmacological properties including those of antioxidant, antibacterial, antipyretic, anti-inflammatory, immunomodulatory, as well as anti-neoplastic. Zerumbone has shown its anti-cancer effects by causing significant suppression of proliferation, survival, angiogenesis, invasion, and metastasis through the molecular modulation of different pathways such as NF-κB, Akt, and IL-6/JAK2/STAT3 (interleukin-6/janus kinase-2/signal transducer and activator of transcription 3) and their downstream target proteins. The current review briefly summarizes the modes of action and therapeutic potential of zerumbone against various cancers.

Casticin inhibits growth and enhances ionizing radiation-induced apoptosis through the suppression of STAT3 signaling cascade

Casticin (CTC), one of the major components of Vitex rotundifolia L., has been reported to exert significant beneficial pharmacological activities and can function as an antiprolactin, anticancer, anti-inflammatory, neuroprotective, analgesic, and immunomodulatory agent. This study aimed at investigating whether the proapoptotic effects of CTC may be mediated through the abrogation of signal transducers and activators of transcription-3 (STAT3) signaling pathway in a variety of human tumor cells. We found that CTC significantly decreased cell viability in a concentration-dependent manner and suppressed cell proliferation in 786-O, YD-8, and HN-9 cells. CTC also induced programmed cell death that was found to be mediated via caspase-3 activation and induction of poly(ADP-ribose) polymerase cleavage. Interestingly, CTC repressed both constitutive and interleukin-6-induced STAT3 activation in 786-O and YD-8 cells but only affected constitutive STAT3 phosphorylation in HN-9 cells. Moreover, CTC could potentiate ionizing radiation-induced apoptotic effects leading to the downregulation of STAT3 activation and thus may be used in combination with radiation against diverse malignancies.

Thymoquinone Inhibits Bone Metastasis of Breast Cancer Cells Through Abrogation of the CXCR4 Signaling Axis

Overexpression of chemokine receptor type 4 (CXCR4) has been found to be associated with increased cell proliferation, metastasis and also act as an indicator of poor prognosis in patients with breast cancer. Therefore, new agents that can abrogate CXCR4 expression have potential against breast cancer metastasis. In this study, we examined the potential effect of thymoquinone (TQ), derived from the seeds of Nigella sativa, on the expression and regulation of CXCR4 in breast cancer cells. TQ was found to inhibit the expression of CXCR4 in MDA-MB-231 triple negative breast cancer (TNBC) cells in a dose- and time-dependent manner. It was noted that suppression of CXCR4 by TQ was possibly transcriptionally regulated, as treatment with this drug caused down-regulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) activation and suppression of NF-κB binding to the CXCR4 promoter. Pretreatment with a proteasome inhibitor and/or lysosomal stabilization did not affect TQ induced suppression of CXCR4. Down-regulation of CXCR4 was further correlated with the inhibition of CXCL12-mediated migration and invasion of MDA-MB-231 cells. Interestingly, it was observed that the deletion of p65 could reverse the observed anti-invasive/anti-migratory effects of TQ in breast cancer cells. TQ also dose-dependently inhibited MDA-MB-231 tumor growth and tumor vascularity in a chick chorioallantoic membrane assay model. We also observed TQ (2 and 4 mg/kg) treatment significantly suppressed multiple lung, brain, and bone metastases in a dose-dependent manner in a metastasis breast cancer mouse model. Interestingly, H&E and immunohistochemical analysis of bone isolated from TQ treated mice indicated a reduction in number of osteolytic lesions and the expression of metastatic biomarkers. In conclusion, the results indicate that TQ primarily exerts its anti-metastatic effects by down-regulation of NF-κB regulated CXCR4 expression and thus has potential for the treatment of breast cancer.

N-Substituted Pyrido-1,4-Oxazin-3-Ones Induce Apoptosis of Hepatocellular Carcinoma Cells by Targeting NF-κB Signaling Pathway

Hepatocellular carcinoma (HCC) is a fatal disease and ranked fifth in cancer related mortality. Persistent activation of NF-κB is responsible for the oncogenesis, metastasis, tumor evasion, anti-apoptosis, angiogenesis and proliferation in HCC. Therefore, designing of chemically novel, biologically potent small molecules that target NF-κB signaling cascade have gained prominent clinical interest. Herein we synthesized a novel class of 4-(substituted)-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one by reacting 2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one with various alkyl halides by using combustion derived bismuth oxide. We evaluated the antiproliferative efficacy of newly synthesized compounds against HCC cells and identified 4-(4-nitrobenzyl)-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one (NPO) as lead anticancer agent. In addition, we investigated the effect of NPO on the DNA binding ability of NF-κB and NF-κB regulated luciferase expression in HCC cells. The results demonstrated that NPO can induce significant growth inhibitory effects in HepG2, HCCLM3 and Huh-7 cells in dose and time-dependent manner. Interestingly, NPO induced significant downregulation in p65 DNA binding ability, p65 phosphorylation and subsequent expression of NF-κB dependent luciferase gene expression in diverse HCC cell lines. Further, in silico docking analysis suggested that NPO can show direct physical interaction with NF-κB. Finally, NPO was found to significantly abrogate tumor growth at a dose of 50 mg/kg in an orthotopic mouse model. Thus, we report the potential anticancer effects of NPO as a novel inhibitor of NF-κB signaling pathway in HCC.

Discovery of antitumor ursolic acid long-chain diamine derivatives as potent inhibitors of NF-κB

A series of inhibitors of NF-κB based on ursolic acid (UA) derivatives containing long-chain diamine moieties were designed and synthesized as well as evaluated the antitumor effects. These compounds exhibited significant inhibitory activity to the NF-κB with IC50 values at micromolar concentrations in A549 lung cancer cell line. Among them, compound 8c exerted potent activity against the test tumor cell lines including multidrug resistant human cancer lines, with the IC50 values ranged from 5.22 to 8.95 μM. Moreover, compound 8c successfully suppressed the migration of A549 cells. Related mechanism study indicated compound 8c caused cell cycle arrest at G1 phase and triggered apoptosis in A549 cells through blockage of NF-κB signalling pathway. Molecular docking study revealed that key interactions between 8c and the active site of NF-κB in which the bulky and strongly electrophilic group of long-chain diamine moieties were important for improving activity.

Cytotoxic and NF-κB and mitochondrial transmembrane potential inhibitory pentacyclic triterpenoids from Syzygium corticosum and their semi-synthetic derivatives

Syzygium is a large genus of flowering plants, with several species, including the clove tree, used as important resources in the food and pharmaceutical industries. In our continuing search for anticancer agents from higher plants, a chloroform extract of the leaves and twigs of Syzygium corticosum collected in Vietnam was found to be active toward the HT-29 human colon cancer cell line. Separation of this extract guided by HT-29 cells and nuclear factor-kappa B (NF-κB) inhibition yielded 19 known natural products, including seven triterpenoids, three ellagic acid derivatives, two methylated flavonoids, a cyclohexanone, four megastigmanes, a small lactone, and an aromatic aldehyde. The full stereochemistry of (+)-fouquierol (2) was defined for the first time. Biological investigations showed that (+)-ursolic acid (1) is the major cytotoxic component of S. corticosum, which exhibited also potent activities in the NF-κB and mitochondrial transmembrane potential (MTP) inhibition assays conducted, with IC50 values of 31 nM and 3.5 µM, respectively. Several analogues of (+)-ursolic acid (1) were synthesized, and a preliminary structure-activity relationship (SAR) study indicated that the C-3 hydroxy and C-28 carboxylic acid groups and 19,20-dimethyl substitution are all essential in the mediation of the bioactivities observed for this triterpenoid.

Carrier-Free, Pure Nanodrug Formed by the Self-Assembly of an Anticancer Drug for Cancer Immune Therapy

Ursolic acid (UA) is a food-plant-derived natural product which has good anticancer activities and low toxicity. However, the poor water solubility of UA limits its application in clinic. To address this issue, we developed a carrier-free nanodrug by self-assembly of UA. Here, we showed that UA nanoparticles (NPs) have a near-spherical shape with a diameter of ∼150 nm. UA NPs exhibited higher antiproliferative activity; significantly caused apoptosis; decreased the expression of COX-2/VEGFR2/VEGFA; and increased the immunostimulatory activity of TNF-α, IL-6, and IFN-β and decreased the activity of STAT-3 in A549 cells in vitro. Furthermore, UA NPs could inhibit tumor growth and have the ability of liver protection in vivo. More importantly, UA NPs could significantly improve the activation of CD4+ T-cells, which indicated that UA NPs have the potential for immunotherapy. Overall, a carrier-free UA nanodrug may be a promising drug to further enhance their anticancer efficacy and immune function.

Novel 1,3,4-Oxadiazole Induces Anticancer Activity by Targeting NF-κB in Hepatocellular Carcinoma Cells

Aberrant activation of NF-κB is linked with the progression of human malignancies including hepatocellular carcinoma (HCC), and blockade of NF-κB signaling could be a potential target in the treatment of several cancers. Therefore, designing of novel small molecule inhibitors that target NF-κB activation is of prime importance in the treatment of several cancers. In the present work, we report the synthesis of series of 1,3,4-oxadiazoles, investigated their anticancer potential against HCC cells, and identified 2-(3-chlorobenzo[b]thiophen-2-yl)-5-(3-methoxyphenyl)-1,3,4-oxadiazole (CMO) as the lead compound. Further, we examined the effect of CMO on cell cycle distribution (flow cytometry), apoptosis (annexin V-propidium iodide-FITC staining), and phosphorylation of NF-κB signaling pathway proteins (IκB and p65) in HCC cells. We found that CMO induced antiproliferative effect in dose- and time-dependent manner. Also, CMO significantly increased the percentage of sub-G1 cell population and induced apoptosis. Furthermore, CMO found to decrease the phosphorylation of IκB (Ser 32) in the cytoplasmic extract and p65 (Ser 536) in the nuclear extract of HCC cells. It also abrogated the DNA binding ability and transcriptional activity of NF-κB. CMO induced the cleavage of PARP and caspase-3 in a time-dependent manner. In addition, transfection with p65 small interfering RNA blocks CMO-induced caspase-3/7 activation. Molecular docking analysis revealed that CMO interacts with the hydrophobic region of p65 protein. Thus, we are reporting CMO as an inhibitor of NF-κB signaling pathway.

Efficacy of ursolic acid against Echinococcus granulosus in vitro and in a murine infection model

BACKGROUND

Cystic echinococcosis is a global public health problem; however, the drugs (albendazole and mebendazole) currently recommended by WHO for its treatment, have limited efficacy. Therefore, novel drugs are required to provide more choices for the treatment of this disease.

METHODS

The anthelmintic effects of ursolic acid (UA) were tested on Echinococcus granulosus protoscoleces, germinal cells and metacestodes in vitro. The in vivo efficacy of UA was investigated in mice following secondary infection with E. granulosus. Furthermore, the corresponding ultrastructural damage induced by UA was evaluated by electron microscopy.

RESULTS

In vitro, 45.95 ± 5.30% of protoscoleces were killed by UA at 40 μg/ml, while the growth of more than 90% of germinal cells was inhibited by UA at 10 to 40 μg/ml. The same effect was observed in metacestodes 7 days after treatment with UA at 10, 20 and 40 μg/ml, and more than 50% of metacestodes showed loss of integrity at the end of the experiment. In vivo, metacestode weight was significantly reduced following oral administration of UA at 200 and 100 mg/kg (39.5 and 38.3%, respectively). Additionally, ultrastructural damage, such as alternations in germinal cell morphology and formation of vacuoles and lipid granules were observed in parasites treated with UA in vitro, while detachment of the germinal layer from the laminated layer was also seen in metacestodes in vivo.

CONCLUSIONS

UA was demonstrated to exert parasiticidal activity against E. granulosus in vitro and in vivo, thus implicating UA as a potential anti-echinococcosis agent.