Flavonoid-enriched apple fraction AF4 induces cell cycle arrest, DNA topoisomerase II inhibition, and apoptosis in human liver cancer HepG2 cells

A comprehensive review of phytoconstituents in liver cancer prevention and treatment: targeting insights into molecular signaling pathways

Primary liver cancer is a type of cancer that develops in the liver. Hepatocellular carcinoma is a primary liver cancer that usually affects adults. Liver cancer is a fatal global condition that affects millions of people worldwide. Despite advances in technology, the mortality rate remains alarming. There is growing interest in researching alternative medicines to prevent or reduce the effects of liver cancer. Recent studies have shown growing interest in herbal products, nutraceuticals, and Chinese medicines as potential treatments for liver cancer. These substances contain unique bioactive compounds with anticancer properties. The causes of liver cancer and potential treatments are discussed in this review. This study reviews natural compounds, such as curcumin, resveratrol, green tea catechins, grape seed extracts, vitamin D, and selenium. Preclinical and clinical studies have shown that these medications reduce the risk of liver cancer through their antiviral, anti-inflammatory, antioxidant, anti-angiogenic, and antimetastatic properties. This article discusses the therapeutic properties of natural products, nutraceuticals, and Chinese compounds for the prevention and treatment of liver cancer.

The clinicopathological significance of TOP2A expression in malignant peritoneal mesothelioma

BACKGROUND

Malignant peritoneal mesothelioma (MPM) is a rare malignant tumor with a high mortality rate and extremely poor prognosis. TOP2A expression is associated with cell proliferation and cell cycle progression. We aimed to demonstrate the expression profile of TOP2A in MPM and its correlation with clinicopathological features.

METHODS

Clinicopathological information from 100 MPM cases was collected at Beijing Shijitan Hospital, Capital Medical University. Immunohistochemistry (IHC) was performed to evaluate TOP2A levels. The associations between TOP2A levels and clinicopathological features or prognosis were analyzed. Clinical follow-up data were reviewed to determine correlations among the pathological prognostic factors using the Kaplan-Meier estimator and univariate/multivariate Cox proportional hazards regression models.

RESULTS

Among the 100 MPM patients, there were 48 males and 52 females, with a median age of 54 years (range: 24-72 years). The cutoff curve was used to find the boundary value of the TOP2A-positive rate. TOP2A positive rate ≥ 11.97 % accounted for 48 % in tumor tissue. The TOP2A-positive rate was not associated with sex, age, asbestos exposure, peritoneal carcinomatosis index (PCI) score, or completeness of cytoreduction (CC) score in MPM. Univariate analysis revealed survival-related pathological parameters, including asbestos exposure, CA125, histological type, PCI score, CC score, Ki-67 index, and TOP2A positive rate. Multivariate analysis identified that asbestos exposure history, PCI score, Ki-67 proliferation index and TOP2A positive rate in tissue are independent prognostic factors.

CONCLUSIONS

High expression of TOP2A is linked to better prognosis of MPM.

The Design and Synthesis of a New Series of 1,2,3-Triazole-Cored Structures Tethering Aryl Urea and Their Highly Selective Cytotoxicity toward HepG2

Target cancer drug therapy is an alternative treatment for advanced hepatocellular carcinoma (HCC) patients. However, the treatment using approved targeted drugs has encountered a number of limitations, including the poor pharmacological properties of drugs, therapy efficiency, adverse effects, and drug resistance. As a consequence, the discovery and development of anti-HCC drug structures are therefore still in high demand. Herein, we designed and synthesized a new series of 1,2,3-triazole-cored structures incorporating aryl urea as anti-HepG2 agents. Forty-nine analogs were prepared via nucleophilic addition and copper-catalyzed azide-alkyne cycloaddition (CuAAC) with excellent yields. Significantly, almost all triazole-cored analogs exhibited less cytotoxicity toward normal cells, human embryonal lung fibroblast cell MRC-5, compared to Sorafenib and Doxorubicin. Among them, 2m’ and 2e exhibited the highest selectivity indexes (SI = 14.7 and 12.2), which were ca. 4.4- and 3.7-fold superior to that of Sorafenib (SI = 3.30) and ca. 3.8- and 3.2-fold superior to that of Doxorubicin (SI = 3.83), respectively. Additionally, excellent inhibitory activity against hepatocellular carcinoma HepG2, comparable to Sorafenib, was still maintained. A cell-cycle analysis and apoptosis induction study suggested that 2m’ and 2e likely share a similar mechanism of action to Sorafenib. Furthermore, compounds 2m’ and 2e exhibit appropriate drug-likeness, analyzed by SwissADME. With their excellent anti-HepG2 activity, improved selectivity indexes, and appropriate druggability, the triazole-cored analogs 2m’ and 2e are suggested to be promising candidates for development as targeted cancer agents and drugs used in combination therapy for the treatment of HCC.

Study of Selected Flavonoid Structures and Their Potential Activity as Breast Anticancer Agents

Flavonoids contain pharmacological effects that help to protect cells from damage. However, the anticancer activity of flavonoids is related to their modulation of signal transduction pathways within cancer cells. Natural substances such as flavonoids have immune-stimulating anti-tumor effect that could lower breast cancer risk. However, various diseases included Alzheimer’s and cancer disease are associated with flavonoids intake due to their ability as antioxidant agent to alter essential cellular enzyme’s function. Therefore, through interaction between flavonoids and Cytochrome P450 (CYP) family enzymes led to make them chemopreventive agents for breast cancer. In this analysis, the chemo-informatics properties of 5 selective flavonoid derivatives and their efficiency as anti-breast cancer drugs were evaluated. Flavonoid ligands were docked with the predicted protein, which is human placental aromatase complexes with exemestane, a breast cancer drug (3S7S). Based on various docking energies, the molecular characteristics and bioactivity score of the following components, C₁₅H₁₂O₆ 2-(3,4-dihydroxyphenyl)-5,7-dihydroxy-2,3-dihydro-4H-chromen-4-one and C₁₅H₁₂O₅ 5,8-dihydroxy-2-(4-hydroxyphenyl)-2,3-dihydro-4H-chromen-4-one showed greatest molecular properties and bioactivity docking scores of −8.633117 and −8.633117 kcal/mol respectively. Therefore, both compounds could be considered antitumor agent.

Vitamin-Containing Antioxidant Formulation Reduces Carcinogen-Induced DNA Damage through ATR/Chk1 Signaling in Bronchial Epithelial Cells In Vitro

Lung cancer has the highest mortality rate worldwide and is often diagnosed at late stages, requiring genotoxic chemotherapy with significant side effects. Cancer prevention has become a major focus, including the use of dietary and supplemental antioxidants. Thus, we investigated the ability of an antioxidant formulation (AOX1) to reduce DNA damage in human bronchial epithelial cells (BEAS-2B) with and without the combination of apple peel flavonoid fraction (AF4), or its major constituent quercetin (Q), or Q-3-O-d-glucoside (Q3G) in vitro. To model smoke-related genotoxicity, we used cigarette-smoke hydrocarbon 4-[(acetoxymethyl)nitrosamino]-1-(3-pyridyl)-1-butanone (NNKOAc) as well as methotrexate (MTX) to induce DNA damage in BEAS-2B cells. DNA fragmentation, γ-H2AX immunofluorescence, and comet assays were used as indicators of DNA damage. Pre-exposure to AOX1 alone or in combination with AF4, Q, or Q3G before challenging with NNKOAc and MTX significantly reduced intracellular reactive oxygen species (ROS) levels and DNA damage in BEAS-2B cells. Although NNKOAc-induced DNA damage activated ATM-Rad3-related (ATR) and Chk1 kinase in BEAS-2B cells, pre-exposure of the cells with tested antioxidants prior to carcinogen challenge significantly reduced their activation and levels of γ-H2AX (p ≤ 0.05). Therefore, AOX1 alone or combined with flavonoids holds promise as a chemoprotectant by reducing ROS and DNA damage to attenuate activation of ATR kinase following carcinogen exposure.

An Overview of Hepatocellular Carcinoma with Emphasis on Dietary Products and Herbal Remedies

The most common principal malignant tumor that accounts for ∼80% of cases of liver cancer across the world is hepatocellular carcinoma (HCC). It is a multifacetedillness that is caused by several risk factors and often progresses in the context of underlying cirrhosis. It is tremendously difficult and essential for the screening of novel therapeutic medications to establish HCC preclinical models that are equivalent to clinical diseases settings, i.e., representing the tumor microenvironment of HCC. In the progress of HCC, numerous molecular cascades have been supposed to play a part. Sorafenib is the only drug permitted by the US Food and Drug Administration for the treatment of HCC. Yet because of the increasing resistance to the drug and its toxicity, clinical treatment methods are not completely adequate. Newer treatment therapy options are essential for the management of HCC in patients. Natural compounds can be afforded by the patients with improved results with less toxicity and fewer side effects, among different methods of liver cancer treatment. The treatment and management of HCC with natural drugs and their phytoconstituents are connected to several paths that can prevent the occurrence and progress of HCC in several ways. The present review summarizes the etiology of HCC, molecular pathways, newer therapeutic approaches, natural dietary products, herbal plants and phytoconstituents for HCC treatment.

Conjoint analysis for hepatic carcinoma with hub genes and multi-slice spiral CT

Hepatic carcinoma (HCC) is a common malignant tumor, with insidious onset and poor prognosis. However, more hub genes associated with hepatocellular carcinoma are unknown. And there are few researches about the conjoint analysis with the hub genes and multi-slice spiral computerized tomography (CT).A total of 100 HCC participates were recruited, who all received the examination of multi-slice spiral CT. Two expression profile data sets (GSE101728 and GSE101685) were downloaded from the Gene Expression Omnibus (GEO) database. GEO2R can perform a command to compare gene expression profiles between groups in order to identify differently expressed genes (DEGs). Functional annotation of DEGs via Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis was made with Database for Annotation, Visualization, and Integrated Discovery (DAVID). Construction and analysis of protein-protein interaction network were performed. Furthermore, the study could mine of hub genes and explore the correlation with the multi-slice CT. Real-time quantitative polymerase chain reaction (RT-qPCR) assay was used the exam the expression of hub genes.A total of 10 genes were identified as hub genes with degrees ≥10. The hub genes (NIMA Related Kinase 2 [NEK2], Anillin Actin Binding Protein [ANLN], DNA Topoisomerase II Alpha [TOP2A], Centromere Protein F [CENPF], Assembly Factor For Spindle Microtubules [ASPM], Cell Division Cycle 20 [CDC20], Cyclin Dependent Kinase 1 [CDK1], Cyclin B1 [CCNB1], Epithelial Cell Transforming 2 [ECT2], Cyclin B2 [CCNB2]) were identified from the Molecular Complex Detection (MCODE) network. These hub genes were highly expressed in HCC tissues, and when these genes were highly expressed, the survival prognosis of HCC patients was poor. The type of CT enhancement was significantly related with the expression of NEK2 (P < .001), ANLN (P < .001), and TOP2A (P = .006).The combination between the gene expression (NEK2, ANLN, and TOP2A) and type of CT enhancement might provide a new idea for future basic research and targeted therapy of HCC.

High expression of TOP2A in hepatocellular carcinoma is associated with disease progression and poor prognosis

Hepatocellular carcinoma (HCC) is a common malignant tumor in the clinic. Although there are increasing numbers of available treatment methods, their therapeutic effects are not satisfactory. The clinical indicators commonly used to predict the prognosis of HCC include tumor size, degree of cirrhosis, degree of tumor differentiation and tumor microvascular invasion; however, there are currently no molecular indicators that can predict the prognosis of HCC. Due to the differences in the progression of liver cancer among individuals, there is a growing need for prognostic biomarkers to accurately stratify patients for appropriate risk-adaptive treatment. The DNA topoisomerase 2-α (TOP2A) gene, which is located on human chromosome 17, encodes DNA topoisomerase IIα. Previous studies have demonstrated that TOP2A indicates a poor prognosis in patients with various types of tumors, but no such studies are currently available on HCC. By analyzing the differential expression of TOP2A in 50 pairs of tumor and paracancerous tissue samples in The Cancer Genome Atlas (TCGA) database, the present study revealed that the expression of TOP2A was significantly higher in tumor tissue compared with that in paracancerous tissue (P=6.319×10-16). In the collected clinical samples, the mRNA expression levels of TOP2A were significantly upregulated in HCC tumor tissues compared with those in the paracancerous tissues (P=6.40×10-3), suggesting that TOP2A was associated with the occurrence and development of liver cancer. In addition, the associations between TOP2A expression, clinicopathological features and prognosis were analyzed using a multi-center large sample dataset from TCGA database, and the results demonstrated that high expression of TOP2A was associated with a higher T stage, poorer clinical stage and higher histological grade compared with those in patients with low TOP2A expression. High expression of TOP2A was also identified to be associated with a poor prognosis of HCC, particularly in Asian populations. These results suggested that high expression of TOP2A in HCC tissues may be closely associated with tumor progression and metastasis, which may be used as a biological indicator to predict tumor prognosis in clinical practice.

Herbal and Natural Dietary Products: Upcoming Therapeutic Approach for Prevention and Treatment of Hepatocellular Carcinoma

The most common tumor linked with elevated death rates is considered the hepatocellular carcinoma (HCC), sometimes called the malignant hepatoma. The initiation and progression of HCC are triggered by multiple factors like long term alcohol consumption, metabolic disorders, fatty liver disease, hepatitis B and C infection, age, and oxidative stress. Sorafenib is the merely US Food and Drug Administration (FDA)-approved drug used to treat HCC. Several treatment methods are available for HCC therapy such as chemotherapy, immunotherapy and adjuvant therapy but they often lead to several side effects. Yet these treatment methods are not entirely adequate due to the increasing resistance to the drug and their toxicity. Many natural products help to prevent and treat HCC. A variety of pathways are associated with the prevention and treatment of HCC with herbal products and their active components. Accumulating research shows that certain natural dietary compounds are possible source of hepatic cancer prevention and treatments, such as black currant, strawberries, plum, grapes, pomegranate, cruciferous crops, tomatoes, French beans, turmeric, garlic, ginger, asparagus, and many more. Such a dietary natural products and their active constituents may prevent the production and advancement of liver cancer in many ways such as guarding against liver carcinogens, improving the effectiveness of chemotherapeutic medications, inhibiting the growth, metastasis of tumor cells, reducing oxidative stress, and chronic inflammation. The present review article represents hepatic carcinoma etiology, role of herbal products, their active constituents, and dietary natural products for the prevention and treatment of HCC along with their possible mechanisms of action.

Protective effect of apple polyphenols on chronic ethanol exposure-induced neural injury in rats

Apple polyphenols (AP) have attracted much attention due to their various bioactivities. In this study, the protective effect of AP against chronic ethanol exposure-induced neural injury as well as the possible mechanisms were investigated. Body weight, daily average food intake and daily average fluid intake were measured and daily average ethanol consumption was calculated. The influences of AP on motor behavior and memory were detected by locomotor activity test, rotarod test, beam walking test, and Y maze test and novel object recognition test, respectively. The changes of blood ethanol concentration and the oxidative stress were also measured. AP improved chronic ethanol exposure-induced the inhibition of body weight and the decrease of daily average food intake, but did not influence the daily average fluid intake and the daily average ethanol intake, indicating that the improve effect of AP did not result from the decrease of ethanol intake. Motor activity and motor coordination were not influenced after chronic ethanol exposure though the blood ethanol concentration was higher than that in control group. AP improved significantly chronic ethanol-induced the memory impairment and the hippocampal CA1 neurons damage. Further studies found that AP decreased the contents of NO and MDA and increased the levels of T-AOC and GSH in the hippocampus of rats. These results suggest that AP exerts a protective effect against chronic ethanol-induced memory impairment through improving the oxidative stress in the hippocampus.

Apple Peel Flavonoid Fraction 4 Suppresses Breast Cancer Cell Growth by Cytostatic and Cytotoxic Mechanisms

Many dietary flavonoids possess anti-cancer activities. Here, the effect of apple peel flavonoid fraction 4 (AF4) on the growth of triple-negative (MDA-MB-231, MDA-MB-468), estrogen receptor-positive (MCF-7), and HER2-positive (SKBR3) breast cancer cells was determined and compared with the effect of AF4 on normal mammary epithelial cells and dermal fibroblasts. AF4 inhibited breast cancer cell growth in monolayer cultures, as well as the growth of MCF-7 spheroids, without substantially affecting the viability of non-malignant cells. A sub-cytotoxic concentration of AF4 suppressed the proliferation of MDA-MB-231 cells by inhibiting passage through the G₀/G₁ phase of the cell cycle. AF4-treated MDA-MB-231 cells also exhibited reduced in vitro migration and invasion, and decreased Akt (protein kinase B) signaling. Higher concentrations of AF4 were selectively cytotoxic for MDA-MB-231 cells. AF4 cytotoxicity was associated with the intracellular accumulation of reactive oxygen species. Importantly, intratumoral administration of AF4 suppressed the growth of MDA-MB-231 xenografts in non-obese diabetic severe combined immunodeficient (NOD-SCID) female mice. The selective cytotoxicity of AF4 for breast cancer cells, combined with the capacity of sub-cytotoxic AF4 to inhibit breast cancer cell proliferation, migration, and invasion suggests that flavonoid-rich AF4 (and its constituents) has potential as a natural therapeutic agent for breast cancer treatment.

Natural Products Mediated Targeting of Virally Infected Cancer

The role of viral infection in developing cancer was determined in the start of 20th century. Until now, 8 different virus-associated cancers have been discovered and most of them progressed in immunosuppressed individuals. The aim of the present study is to look into the benefits of natural products in treating virally infected cancers. The study focuses on bioactive compounds derived from natural sources. Numerous pharmaceutical agents have been identified from plants (vincristine, vinblastine, stilbenes, combretastatin, and silymarin), marine organisms (bryostatins, cephalostatin, ecteinascidins, didemnin, and dolastatin), insects (cantharidin, mastoparan, parectadial, and cecropins), and microorganisms (vancomycin, rhizoxin, ansamitocins, mitomycin, and rapamycin). Beside these, various compounds have been observed from fruits and vegetables which can be utilized in anticancer therapy. These include curcumin in turmeric, resveratrol in red grapes, S-allyl cysteine in allium, allicin in garlic, catechins in green tea, and β-carotene in carrots. The present study addresses various types of virally infected cancers, their mechanism of action, and the role of different cell surface molecules elicited during viral binding and entry into the target cell along with the anticancer drugs derived from natural products by targeting screening of bioactive compounds from natural sources.

The Effects of Added Water and Grinding Temperature on Stability and Degradation Kinetics of Antioxidant Activity, Phenolic Compounds, and Ascorbic Acid in Ground Apples

The effects of added water (1:0 up to 1:4 apple:water w/v) and grinding temperature on browning and antioxidant capacity of apples were investigated. Grinding apple with addition of water decreased browning and loss of antioxidant activity when ground with water up to 1:3 ratio. Browning, antioxidant capacity, major phenolic compounds (chlorogenic acid, epicatechin, and procyanidin B2), and ascorbic acid in ground apple with water (1:1) were evaluated at grinding temperatures from 5 °C to 45 °C. The degradation of antioxidant activity, phenolic compounds, and ascorbic acid followed first-order kinetics. The temperature-dependent degradation was adequately modeled using the Arrhenius equation, and kinetic parameters such as k, t_1/2 , Q₁₀ , and Ea indicated that the grinding temperature was a key factor affecting retention of antioxidant activity, phenolics, and ascorbic acid contents in apple. PRACTICAL APPLICATION: The phenolic compounds and antioxidant activity of fruits and vegetables can be altered by processing such as thermal treatments and grinding. Therefore, it is important to evaluate and predict the quality characteristics of the fruits as affected by processing conditions. In this study, we found grinding conditions retard the changes in color and loss in phenolic compounds and antioxidant activity of ground apples. This new finding can be helpful for engineers and scientists to control and optimize the grinding system by retaining the high nutritional values of apple products.

Dietary phytochemicals in breast cancer research: anticancer effects and potential utility for effective chemoprevention

Cancerous tissue transformation developing usually over years or even decades of life is a highly complex process involving strong stressors damaging DNA, chronic inflammation, comprehensive interaction between relevant molecular pathways, and cellular cross-talk within the neighboring tissues. Only the minor part of all cancer cases are caused by inborn predisposition; the absolute majority carry a sporadic character based on modifiable risk factors which play a central role in cancer prevention. Amongst most promising candidates for dietary supplements are bioactive phytochemicals demonstrating strong anticancer effects. Abundant evidence has been collected for beneficial effects of flavonoids, carotenoids, phenolic acids, and organosulfur compounds affecting a number of cancer-related pathways. Phytochemicals may positively affect processes of cell signaling, cell cycle regulation, oxidative stress response, and inflammation. They can modulate non-coding RNAs, upregulate tumor suppressive miRNAs, and downregulate oncogenic miRNAs that synergically inhibits cancer cell growth and cancer stem cell self-renewal. Potential clinical utility of the phytochemicals is discussed providing examples for chemoprevention against and therapy for human breast cancer. Expert recommendations are provided in the context of preventive medicine.

Chemoprevention of intestinal tumorigenesis by the natural dietary flavonoid myricetin in APCMin/+ mice

Myricetin is a natural dietary flavonoid compound. We evaluated the efficacy of myricetin against intestinal tumorigenesis in adenomatous polyposis coli multiple intestinal neoplasia (APCMin/+) mice. Myricetin was given orally once a day for 12 consecutive weeks. APCMin/+ mice fed with myricetin developed fewer and smaller polyps without any adverse effects. Histopathological analysis showed a decreased number of dysplastic cells and degree of dysplasia in each polyp. Immunohistochemical and western blot analysis revealed that myricetin selectively inhibits cell proliferation and induces apoptosis in adenomatous polyps. The effects of myricetin were associated with a modulation the GSK-3β and Wnt/β-catenin pathways. ELISA analysis showed a reduced concentration of pro-inflammatory cytokines IL-6 and PGE2 in blood, which were elevated in APCMin/+ mice. The effect of myricetin treatment was more prominent in the adenomatous polyps originating in the colon. Further studies showed that myricetin downregulates the phosphorylated p38 MAPK/Akt/mTOR signaling pathways, which may be the mechanisms for the inhibition of adenomatous polyps by myricetin. Taken together, our data show that myricetin inhibits intestinal tumorigenesis through a collection of biological activities. Given these results, we suggest that myricetin could be used preventatively to reduce the risk of developing colon cancers.

Annurca Apple Nutraceutical Formulation Enhances Keratin Expression in a Human Model of Skin and Promotes Hair Growth and Tropism in a Randomized Clinical Trial

Several pharmaceutical products have been formulated over the past decades for the treatment of male and female alopecia, and pattern baldness, but relatively few metadata on their efficacy have been published. For these reasons, the pharmaceutical and medical attention has recently focused on the discovery of new and safer remedies. Particularly, great interest has been attracted by oligomeric procyanidin bioactivity, able to promote hair epithelial cell growth as well as to induce the anagen phase. Specifically, the procyanidin B2, a dimeric derivative extracted from apples, has demonstrated to be one of the most effective and safest natural compounds in promoting hair growth, both in vitro and in humans by topical applications. By evaluating the polyphenolic content of different apple varieties, we have recently found in the apple fruits of cv Annurca (AFA), native to Southern Italy, one of the highest contents of oligomeric procyanidins, and, specifically, of procyanidin B2. Thus, in the present work we explored the in vitro bioactivity of AFA polyphenolic extract as a nutraceutical formulation, named AppleMets (AMS), highlighting its effects on the cellular keratin expression in a human experimental model of adult skin. Successively, testing the effects of AMS on hair growth and tropism in healthy subjects, we observed significant results in terms of increased hair growth, density, and keratin content, already after 2 months. This study proves for the first time the impact of apple procyanidin B2 on keratin biosynthesis in vitro, and highlights its effect as a nutraceutical on human hair growth and tropism.

In vitro polyphenol effects on apoptosis: An update of literature data

Polyphenols are secondary plant metabolites which have been studied extensively for their health-promoting properties, and which could also exert pharmacological activities ranging from anti-inflammatory effects, to cytotoxic activity against cancer cells. The main mechanism for programmed cell death is represented by apoptosis, and its dysregulation is involved in the etiopathology of cancer. As such, substances able to induce apoptosis in cancer cells could be used as new anticancer agents. The aim of this paper is to review literature data on the apoptotic effects of polyphenols and the molecular mechanisms through which they induce these effects in cancer cells. In addition, a brief summary of the new delivery forms used to increase the bioavailability, and clinical impact of polyphenols is provided. The studies reported show that many polyphenol rich plant extracts, originating from food and herbal medicine, as well as isolated polyphenols administered individually or in combination, can regulate cell apoptosis primarily through intrinsic and extrinsic mechanisms of action in in vitro conditions. Due to these promising results, the use of polyphenols in the treatment of cancer should therefore be deeply investigated. In particular, because of the low number of clinical trials, further studies are required to evaluate the anticancer activity of polyphenols in in vivo conditions.

Apple Flavonoids Suppress Carcinogen-Induced DNA Damage in Normal Human Bronchial Epithelial Cells

Scope

Human neoplastic transformation due to DNA damage poses an increasing global healthcare concern. Maintaining genomic integrity is crucial for avoiding tumor initiation and progression. The present study aimed to investigate the efficacy of an apple flavonoid fraction (AF4) against various carcinogen-induced toxicity in normal human bronchial epithelial cells and its mechanism of DNA damage response and repair processes.

Methods and Results

AF4-pretreated cells were exposed to nicotine-derived nitrosamine ketones (NNK), NNK acetate (NNK-Ae), methotrexate (MTX), and cisplatin to validate cytotoxicity, total reactive oxygen species, intracellular antioxidants, DNA fragmentation, and DNA tail damage. Furthermore, phosphorylated histone (γ-H2AX) and proteins involved in DNA damage (ATM/ATR, Chk1, Chk2, and p53) and repair (DNA-PKcs and Ku80) mechanisms were evaluated by immunofluorescence and western blotting, respectively. The results revealed that AF4-pretreated cells showed lower cytotoxicity, total ROS generation, and DNA fragmentation along with consequent inhibition of DNA tail moment. An increased level of γ-H2AX and DNA damage proteins was observed in carcinogen-treated cells and that was significantly (p ≤ 0.05) inhibited in AF4-pretreated cells, in an ATR-dependent manner. AF4 pretreatment also facilitated the phosphorylation of DNA-PKcs and thus initiation of repair mechanisms.

Conclusion

Apple flavonoids can protect in vitro oxidative DNA damage and facilitate repair mechanisms.

Natural Compounds as Anticancer Agents Targeting DNA Topoisomerases

DNA topoisomerases are important cellular enzymes found in almost all types of living cells (eukaryotic and prokaryotic). These enzymes are essential for various DNA metabolic processes e.g. replication, transcription, recombination, chromosomal decatenation etc. These enzymes are important molecular drug targets and inhibitors of these enzymes are widely used as effective anticancer and antibacterial drugs. However, topoisomerase inhibitors have some therapeutic limitations and they exert serious side effects during cancer chemotherapy. Thus, development of novel anticancer topoisomerase inhibitors is necessary for improving cancer chemotherapy. Nature serves as a repertoire of structurally and chemically diverse molecules and in the recent years many DNA topoisomerase inhibitors have been identified from natural sources. The present review discusses anticancer properties and therapeutic importance of eighteen recently identified natural topoisomerase inhibitors (from the year 2009 to 2015). Structural characteristics of these novel inhibitors provide backbones for designing and developing new anticancer drugs.

Inhibition of Cervical Cancer by Promoting IGFBP7 Expression Using Ellagic Acid from Pomegranate Peel

Background

The aim of this study was to explore the mechanism by which cervical cancer is inhibited by promoting IGFBP7 expression using ellagic acid from pomegranate peel extract.

Material/Methods

HeLa cells were divided into 6 groups: control group (NC), blank control group (BL), and IGFBP7 overexpression group (IGFBP7), and 2.5 uM, 5. 0 uM, and 10.0 uM ellagic acid-treated groups. The cell proliferation ability was detected and the degree of invasion in the 6 groups was measured by Transwell assay. The expression levels of IGFBP7 and AKT/mTOR in the 6 groups of cells were detected by RT-PCR technique.

Results

Compared with NC and BL groups, The IGFBP7 gene expressions of the IGFPB7 and ellagic acid-treated groups were significantly increased (P<0.05). There was a dose-effect dependence in the ellagic acid-treated groups. The invasion ability of the IGFBP7 group and ellagic acid-treated groups was significantly lower than that of NC and BL groups in HeLa cells (P<0.05). The apoptosis rate of the IGFBP7 group and ellagic acid-treated groups was significantly higher than that of the NC and BL groups in HeLa cells (P<0.05). AKT and mTOR mRNA and protein expressions of the IGFBP7 group and ellagic acid-treated groups were significantly lower than that of the NC and BL groups (P<0.05). There was a dose-effect dependence in the ellagic acid-treated groups.

Conclusions

The ellagic acid in pomegranate peel extract can inhibit the AKT/mTOR signaling pathway by enhancing the expression level of IGFBP7, which can inhibit the HeLa cells in cervical cancer.

An apple a day to prevent cancer formation: Reducing cancer risk with flavonoids

The purpose of this review is to update and discuss key findings from in vitro and in vivo studies on apple and its biocompounds, with a special focus on its anticancer role. Several studies have proposed that apple and its extracts exhibit a variety of biological functions that may contribute to health benefits including beneficial effects against chronic heart and vascular disorders, respiratory and pulmonary dysfunction, diabetes, obesity, and cancer. In this review, we summarize the molecular mechanism(s) of various components in apple, as established in previous studies that indicated their growth-inhibitory effects in various cancer cell types. Moreover, an attempt is made to delineate the direction of future studies that could lead to the development of apple components as a potent chemo-preventive/chemotherapeutic agent against cancer.

Ginsenoside exhibits concentration-dependent dual effects on HepG2 cell proliferation via regulation of c-Myc and HNF-4α

Although ginsenoside can generally promote cell proliferation, it is reported to have anti-proliferative effects in hepatocellular carcinoma (HCC). Whether ginsenoside has concentration-dependent effects on HCC cell proliferation have not been clarified. Transcription factors c-Myc and hepatocyte nuclear factor (HNF)-4α are the most important opposite controllers of HCC cell proliferation. Whether and how ginsenoside regulates c-Myc and HNF-4α as well as their recruitment of the co-activator p300 to exhibit its effects on HCC cell proliferation are pending. In this study, it was found that low concentration ginsenoside promoted HepG2 cell proliferation while high concentration ginsenoside exhibited anti-proliferation effect. For low concentration ginsenoside treatment, c-Myc was up-regulated and the binding of p300 to c-Myc was promoted with obvious co-localization to activate HepG2 cell proliferation. However, for high concentration ginsenoside treatment, besides c-Myc, HNF-4α was also up-regulated might to exhibit an alternative effect. Furthermore, in contrast to the weakened binding and co-localization of c-Myc and p300, the binding of p300 to HNF-4α was enhanced with distinct co-localization to inhibit HepG2 cell proliferation for high concentration ginsenoside treatment. The results manifested that ginsenoside with low and high concentrations may differentially regulate c-Myc and HNF-4α as well as their recruitments of p300, to exhibit concentration-dependent dual effects on HepG2 cell proliferation.

A theoretical study on predicted protein targets of apple polyphenols and possible mechanisms of chemoprevention in colorectal cancer

We investigated the potential role of apple phenolic compounds in human pathologies by integrating chemical characterization of phenolic compounds in three apple varieties, computational approaches to identify potential protein targets of the compounds, bioinformatics analyses on data from public archive of gene expression data, and functional analyses to hypothesize the effects of the selected compounds in molecular pathways. Starting by the analytic characterization of phenolic compounds in three apple varieties, i.e. Annurca, Red Delicious, and Golden Delicious, we used computational approaches to verify by reverse docking the potential protein targets of the identified compounds. Direct docking validation of the potential protein-ligand interactions has generated a short list of human proteins potentially bound by the apple phenolic compounds. By considering the known chemo-preventive role of apple antioxidants' extracts against some human pathologies, we performed a functional analysis by comparison with experimental gene expression data and interaction networks, obtained from public repositories. The results suggest the hypothesis that chemo-preventive effects of apple extracts in human pathologies, in particular for colorectal cancer, may be the interference with the activity of nucleotide metabolism and methylation enzymes, similarly to some classes of anticancer drugs.

Cinnamomum verum component 2-methoxycinnamaldehyde: a novel antiproliferative drug inducing cell death through targeting both topoisomerase I and II in human colorectal adenocarcinoma COLO 205 cells

BACKGROUND

Cinnamomum verum is used to manufacture the spice cinnamon. In addition, the plant has been used as a Chinese herbal medication.

METHODS

We investigated the antiproliferative effect of 2-methoxycinnamaldehyde (2-MCA), a constituent of the cortex of the plant, and the molecular biomarkers associated with tumorigenesis in human colorectal adenocarcinoma COLO 205 cells. Specifically, cell viability was evaluated by colorimetric assay; apoptosis was determined by flow cytometry and morphological analysis with bright field, acridine orange, and neutral red stainings, as well as comet assay; topoisomerase I activity was determined by assay based upon DNA relaxation and topoisomerase II by DNA relaxation plus decatentation of kinetoplast DNA; lysosomal vacuolation and volume of acidic compartments (VACs) were determined by neutral red staining.

RESULTS

The results demonstrate that 2-MCA inhibited proliferation and induced apoptosis as implicated by mitochondrial membrane potential (ΔΨm) loss, activation of both caspase-3 and -9, increase of annexin V(+)PI(+) cells, as well as morphological characteristics of apoptosis. Furthermore, 2-MCA also induced lysosomal vacuolation with elevated VAC, cytotoxicity, and inhibitions of topoisomerase I as well as II activities. Additional study demonstrated the antiproliferative effect of 2-MCA found in a nude mice model.

CONCLUSIONS

Our data implicate that the antiproliferative activity of 2-MCA in vitro involved downregulation of cell growth markers, both topoisomerase I and II, and upregulation of pro-apoptotic molecules, associated with increased lysosomal vacuolation. In vivo 2-MCA reduced the tumor burden that could have significant clinical impact. Indeed, similar effects were found in other tested cell lines, including human hepatocellular carcinoma SK-Hep-1 and Hep 3B, lung adenocarcinoma A549 and squamous cell carcinoma NCI-H520, and T-lymphoblastic MOLT-3 (results not shown). Our data implicate that 2-MCA could be a potential agent for anticancer therapy.

Cuminaldehyde from Cinnamomum verum Induces Cell Death through Targeting Topoisomerase 1 and 2 in Human Colorectal Adenocarcinoma COLO 205 Cells

Cinnamomum verum, also called true cinnamon tree, is employed to make the seasoning cinnamon. Furthermore, the plant has been used as a traditional Chinese herbal medication. We explored the anticancer effect of cuminaldehyde, an ingredient of the cortex of the plant, as well as the molecular biomarkers associated with carcinogenesis in human colorectal adenocarcinoma COLO 205 cells. The results show that cuminaldehyde suppressed growth and induced apoptosis, as proved by depletion of the mitochondrial membrane potential, activation of both caspase-3 and -9, and morphological features of apoptosis. Moreover, cuminaldehyde also led to lysosomal vacuolation with an upregulated volume of acidic compartment and cytotoxicity, together with inhibitions of both topoisomerase I and II activities. Additional study shows that the anticancer activity of cuminaldehyde was observed in the model of nude mice. Our results suggest that the anticancer activity of cuminaldehyde in vitro involved the suppression of cell proliferative markers, topoisomerase I as well as II, together with increase of pro-apoptotic molecules, associated with upregulated lysosomal vacuolation. On the other hand, in vivo, cuminaldehyde diminished the tumor burden that would have a significant clinical impact. Furthermore, similar effects were observed in other tested cell lines. In short, our data suggest that cuminaldehyde could be a drug for chemopreventive or anticancer therapy.

Dietary Natural Products for Prevention and Treatment of Liver Cancer

Liver cancer is the most common malignancy of the digestive system with high death rate. Accumulating evidences suggests that many dietary natural products are potential sources for prevention and treatment of liver cancer, such as grapes, black currant, plum, pomegranate, cruciferous vegetables, French beans, tomatoes, asparagus, garlic, turmeric, ginger, soy, rice bran, and some edible macro-fungi. These dietary natural products and their active components could affect the development and progression of liver cancer in various ways, such as inhibiting tumor cell growth and metastasis, protecting against liver carcinogens, immunomodulating and enhancing effects of chemotherapeutic drugs. This review summarizes the potential prevention and treatment activities of dietary natural products and their major bioactive constituents on liver cancer, and discusses possible mechanisms of action.

Discovery of a novel anticancer agent with both anti-topoisomerase I and II activities in hepatocellular carcinoma SK-Hep-1 cells in vitro and in vivo: Cinnamomum verum component 2-methoxycinnamaldehyde

Cinnamomum verum is used to make the spice cinnamon and has been used as a traditional Chinese herbal medicine for various applications. We evaluated the anticancer effect of 2-methoxycinnamaldehyde (2-MCA), a constituent of the bark of the plant, and its underlying molecular biomarkers associated with carcinogenesis in human hepatocellular carcinoma SK-Hep-1 cell line. The results show that 2-MCA suppressed proliferation and induced apoptosis as indicated by mitochondrial membrane potential loss, activation of caspase-3 and caspase-9, increase in the DNA content in sub-G1, and morphological characteristics of apoptosis, including blebbing of plasma membrane, nuclear condensation, fragmentation, apoptotic body formation, and long comet tail. In addition, 2-MCA also induced lysosomal vacuolation with increased volume of acidic compartments, suppressions of nuclear transcription factors NF-κB, cyclooxygenase-2, prostaglandin E₂ (PGE₂), and both topoisomerase I and II activities in a dose-dependent manner. Further study reveals the growth-inhibitory effect of 2-MCA was also evident in a nude mice model. Taken together, the data suggest that the growth-inhibitory effect of 2-MCA against SK-Hep-1 cells is accompanied by downregulations of NF-κB-binding activity, inflammatory responses involving cyclooxygenase-2 and PGE₂, and proliferative control involving apoptosis, both topoisomerase I and II activities, together with an upregulation of lysosomal vacuolation and volume of acidic compartments. Similar effects (including all of the above-mentioned effects) were found in other tested cell lines, including human hepatocellular carcinoma Hep 3B, lung adenocarcinoma A549, squamous cell carcinoma NCI-H520, colorectal adenocarcinoma COLO 205, and T-lymphoblastic MOLT-3 (results not shown). Our data suggest that 2-MCA could be a potential agent for anticancer therapy.

Molecular Mechanism of Cinnamomum verum Component Cuminaldehyde Inhibits Cell Growth and Induces Cell Death in Human Lung Squamous Cell Carcinoma NCI-H520 Cells In Vitro and In Vivo

Cinnamomum verum is used to make the spice cinnamon and has been used as a traditional Chinese herbal medicine. We evaluated the effects and the molecular mechanisms of cuminaldehyde (CuA), a constituent of the bark of Cinnamomum verum, on human lung squamous cell carcinoma NCI-H520 cells. Specifically, cell viability was evaluated by colorimetric assay; cytotoxicity by LDH release; apoptosis was determined by Western blotting, and morphological analysis with, acridine orange and neutral red stainings and comet assay; topoisomerase I activity was assessed using assay based upon DNA relaxation and topoisomerase II by DNA relaxation plus decatentation of kinetoplast DNA; lysosomal vacuolation and volume of acidic compartments (VAC) were evaluated with neutral red staining. The results show that CuA suppressed proliferation and induced apoptosis as indicated by an up-regulation of pro-apoptotic bax and bak genes and a down-regulation of anti-apoptotic bcl-2 and bcl-XL genes, mitochondrial membrane potential loss, cytochrome c release, activation of caspase 3 and 9, and morphological characteristics of apoptosis, including blebbing of the plasma membrane, nuclear condensation, fragmentation, apoptotic body formation, and comet with elevated tail intensity and moment. In addition, CuA also induced lysosomal vacuolation with increased VAC, cytotoxicity, as well as suppressions of both topoisomerase I and II activities in a dose-dependent manner. Further study revealed the growth-inhibitory effect of CuA was also evident in a nude mice model. Taken together, the data suggest that the growth-inhibitory effect of CuA against NCI-H520 cells is accompanied by downregulations of proliferative control involving apoptosis and both topoisomerase I and II activities, and upregulation of lysosomal with increased VAC and cytotoxicity. Similar effects were found in other cell lines, including human lung adenocarcinoma A549 cells and colorectal adenocarcinoma COLO 205 (results not shown). Our data suggest that CuA could be a potential agent for anticancer therapy.

Hypoxia-Targeted Drug Q6 Induces G2-M Arrest and Apoptosis via Poisoning Topoisomerase II under Hypoxia

In spite of the tremendous efforts dedicated to developing hypoxia-activated prodrugs, no agents yet have been approved for clinical therapy. In the present study, the hypoxic selective anti-cancer activity as well as the cellular target of a novel tirapazamine (TPZ) analogue, 7-methyl-3-(3-chlorophenyl)-quinoxaline-2-carbonitrile 1,4-dioxide (Q6) were investigated. Q6 implemented anti-cancer effects via poisoning topoisomerase II (topo II) under hypoxia. Modified trapped in agarose DNA immunostaining (TARDIS) assay showed more topo II-DNA cleavage complexes trapped by Q6 than TPZ at even lower concentration. In addition, by introducing ataxia-telangiectasia-mutated (ATM) kinase inhibitors caffeine and KU-60019, we displayed that Q6-triggered apoptosis was attributed, at least partially, to DNA double-strand breaks generated by the topo II-targeting effect. Collectively, Q6 stood out for its better hypoxia-selectivity and topo II-poisoning than the parental compound TPZ. All these data shed light on the research of Q6 as a promising hypoxia-activated prodrug candidate for human hepatocellular carcinoma therapy.

Hypoxia-Targeted Drug Q6 Induces G2-M Arrest and Apoptosis via Poisoning Topoisomerase II under Hypoxia

In spite of the tremendous efforts dedicated to developing hypoxia-activated prodrugs, no agents yet have been approved for clinical therapy. In the present study, the hypoxic selective anti-cancer activity as well as the cellular target of a novel tirapazamine (TPZ) analogue, 7-methyl-3-(3-chlorophenyl)-quinoxaline-2-carbonitrile 1,4-dioxide (Q6) were investigated. Q6 implemented anti-cancer effects via poisoning topoisomerase II (topo II) under hypoxia. Modified trapped in agarose DNA immunostaining (TARDIS) assay showed more topo II–DNA cleavage complexes trapped by Q6 than TPZ at even lower concentration. In addition, by introducing ataxia-telangiectasia-mutated (ATM) kinase inhibitors caffeine and KU-60019, we displayed that Q6-triggered apoptosis was attributed, at least partially, to DNA double-strand breaks generated by the topo II-targeting effect. Collectively, Q6 stood out for its better hypoxia-selectivity and topo II-poisoning than the parental compound TPZ. All these data shed light on the research of Q6 as a promising hypoxia-activated prodrug candidate for human hepatocellular carcinoma therapy.

Paeoniflorin induces HepG2 cell apoptosis by regulating Caspase3 activation and nuclear factor kappa B signaling pathway

AIM: To explore the effect of paeoniflorin on apoptosis of HepG2 cells and the underlying mechanisms.

METHODS: HepG2 cells were treated with different concentrations of paeoniflorin (0.5, 1.0, and 2.0 mg/mL). The viability of cells was detected by MTT assay. Apoptotic cells were detected by Annexin V-FITC flow cytometry. Caspase3 activity was measured with a colorimetric assay kit. The expression of nuclear factor kappa-B (NF-κB) related proteins was detected by Western blot.

RESULTS: Compared with the control group, paeoniflorin at concentrations of 0.5, 1.0, and 2.0 mg/mL could reduce cell viability, and the inhibitory rate peaked at 48 h (P < 0.05). Compared with the control group, paeoniflorin at concentrations of 0.5, 1.0, and 2.0 mg/mL could promote cell apoptosis, increase Caspase3 activity, and suppress NF-κB p65 phosphorylation (P < 0.05). Paeoniflorin at concentrations of 1.0 and 2.0 mg/mL could suppress IκBα phosphorylation (P < 0.05).

CONCLUSION: Paeoniflorin induces apoptosis of HepG2 cells possibly via the NF-κB signal pathway.

Inhibition of growth and migration of oral and cervical cancer cells by citrus polyphenol

BACKGROUND/PURPOSE

It has been confirmed that polyphenolic compounds present in food have various pharmaceutical functions. The purpose of this study was to evaluate citrus polyphenol (CP) for dental applications. The culture medium with CP was developed to inhibit the proliferation of oral cancer cells. CP could be used as a supplemental compound for topical application for oral cancer patients.

METHODS

In this study, the metabolic activity and cell toxicity of CP (at concentrations of 1%, 0.1%, and 0.01%) for oral and cervical cancer cells were investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase assays (n = 6). Furthermore, the effects of CP on motilities of oral and cervical cancer cells were also evaluated using a scratch assay model.

RESULTS

We found that the growth of Ca9-22 and HeLa cells on tissue culture polystyrene was greatly inhibited when 1% CP was added to the medium. In addition, significant differences (p < 0.01) in cytotoxicities of oral and cervical cancer cells were observed after 6 days in the culture medium to which 1% CP was added. Furthermore, using a scratch assay model to evaluate the migratory abilities of oral and cervical cancer cells, it was also found that CP could inhibit the migratory abilities of cancer cells.

CONCLUSION

The results confirmed the feasibility of the topical application of CP as a supplemental compound for inhibition of cancer cell proliferation and migration.

Extracellular matrix as target for antitumor therapy

The aim of the present review is to survey the accumulated knowledge on the extracellular matrix (ECM) of tumors referring to its putative utility as therapeutic target. Following the traditional observation on the extensive morphological alteration in the tumor-affected tissue, the well-documented aberrant cellular regulation indicated that ECM components have an active role in tumor progression. However, due to the diverse functions and variable expression of proteoglycans, matrix proteins, and integrins, it is rather difficult to identify a comprehensive therapeutic target among ECM components. At present, the elevated level of heparanase and the prominent expression of αvβ5 integrin are considered as promising therapeutic targets. The inhibition of glycosaminoglycan offers another promising approach in the treatment of those tumors which are stimulated by proteoglycans. It can be ascertained that a selective ECM inhibitor would be a great asset to control metastasis driven by ECM-mediated signaling.

Fruit peel polyphenols demonstrate substantial anti-tumour effects in the model of breast cancer

PURPOSE

Fruit and vegetable intake is inversely correlated with cancer; thus, it is proposed that an extract of phytochemicals as present in whole fruits, vegetables, or grains may have anti-carcinogenic properties. Thus, the anti-tumour effects of fruit peel polyphenols (Flavin7) in the chemoprevention of N-methyl-N-nitrosourea-induced mammary carcinogenesis in female rats were evaluated.

METHODS

Lyophilized substance of Flavin7 (F7) was administered at two concentrations of 0.3 and 3 % through diet. The experiment was terminated 14 weeks after carcinogen administration, and mammary tumours were removed and prepared for histopathological and immunohistochemical analysis. In addition, using an in vitro cytotoxicity assay, apoptosis and proliferation after F7 treatment in human breast adenocarcinoma (MCF-7) cells were performed.

RESULTS

High-dose F7 suppressed tumour frequency by 58 % (P < 0.001), tumour incidence by 24 % (P < 0.05), and lengthened latency by 8 days (P > 0.05) in comparison with the control rats, whereas lower dose of F7 was less effective. Histopathological analysis of tumours showed significant decrease in the ratio of high-/low-grade carcinomas after high-dose F7 treatment. Immunohistochemical analysis of rat carcinoma cells in vivo found a significant increase in caspase-3 expression and significant decrease in Bcl-2, Ki67, and VEGFR-2 expression in the high-dose group. Both doses demonstrated significant positive effects on plasma lipid metabolism in rats. F7 significantly decreased survival of MCF-7 cells in vitro in MTT assay by dose- and time-dependent manner compared to control. F7 prevented cell cycle progression by significant enrichment in G1 cell populations. Incubation with F7 showed significant increase in the percentage of annexin V-/PI-positive MCF-7 cells and DNA fragmentation.

CONCLUSIONS

Our results reveal a substantial tumour-suppressive effect of F7 in the breast cancer model. We propose that the effects of phytochemicals present in this fruit extract are responsible for observed potent anti-cancer activities.