Dietary polyphenols in prevention and treatment of prostate cancer

Potential Antitumor Activity and Apoptosis Induction of Glossostemon bruguieri Root Extract against Hepatocellular Carcinoma Cells

Glossostemon bruguieri (moghat) is used as a nutritive and demulcent drink. This study was performed to investigate the antiproliferative effects of moghat root extract (MRE) and its apoptotic mechanism in hepatocellular carcinoma (HCC) cells, HepG2 and Hep3B. MTT assay, morphological changes, apoptosis enzyme linked immunosorbent assay, caspase and apoptotic activation, flow cytometry, and immunoblot analysis were employed. The IC₅₀ of MRE for HepG2 (910 ± 6 μg/ml) and for Hep3B (1510 ± 5 μg/ml) induced significant growth-inhibitory effects against HCC cells, with no cytotoxic effect on normal hepatocytes. MRE treatment induced apoptotic effects to HepG2 cells in a caspase-dependent manner and via upregulating p53/p21 and PCNA. The upregulation of p21 was controlled by p53 expression in HepG2 but not in Hep3B despite upregulation of Bax protein in both cell lines. Interestingly, p21 may be a remarkable switch to G1 arrest in HepG2 cells, but not in Hep3B cells. In addition, Fas- and mitochondria-mediated pathways were found to be involved in MRE-induced apoptosis in Hep3B cells. The GC-MS analysis of MRE revealed two major constituents of pharmaceutical importance: the flavonoid apigenin (17.04%) and the terpenoid squalene (11.32%). The data presented in this paper introduces G. bruguieri as a promising nontoxic herb with therapeutic potential for HCC. To the authors' knowledge, the present study provides the first report on the anticancer activity of MRE on HCC cells.

New insights into the antiangiogenic and proangiogenic properties of dietary polyphenols

Polyphenols can be found in natural products of plant origin, including vegetables, fruits, and beverages. A large number of these plant origin compounds are an integral part of the human diet and in the past decade evidence has shown their beneficial properties in human health, by acting in several cell signaling pathways. Among other beneficial effects, polyphenols have been associated with angiogenesis. Increasing evidence highlighting the ability of dietary polyphenols to influence angiogenesis by interfering with multiple signaling pathways is debated. Particular emphasis is given to the mechanisms that ultimately may induce the formation of capillary-like structures (by increasing endothelial cell proliferation, migration, and invasion) or, conversely, may inhibit the steps of angiogenesis leading to the inhibition/regress of vascular development. Dietary polyphenols can, therefore, be viewed as promising nutraceuticals but important aspects have still to be further investigated, to deep knowledge concerning their concentration-mediated effects, effect of specific polyphenols, and respective metabolites, to ensure their appropriate and effective usefulness as proangiogenic or antiangiogenic nutraceuticals.

Molecular Mechanisms and Metabolomics of Natural Polyphenols Interfering with Breast Cancer Metastasis

Metastatic cancers are the main cause of cancer-related death. In breast primary cancer, the five-year survival rate is close to 100%; however, for metastatic breast cancer, that rate drops to a mere 25%, due in part to the paucity of effective therapeutic options for treating metastases. Several in vitro and in vivo studies have indicated that consumption of natural polyphenols significantly reduces the risk of cancer metastasis. Therefore, this review summarizes the research findings involving the molecular mechanisms and metabolomics of natural polyphenols and how they may be blocking breast cancer metastasis. Most natural polyphenols are thought to impair breast cancer metastasis through downregulation of MMPs expression, interference with the VEGF signaling pathway, modulation of EMT regulator, inhibition of NF-κB and mTOR expression, and other related mechanisms. Intake of natural polyphenols has been shown to impact endogenous metabolites and complex biological metabolic pathways in vivo. Breast cancer metastasis is a complicated process in which each step is modulated by a complex network of signaling pathways. We hope that by detailing the reported interactions between breast cancer metastasis and natural polyphenols, more attention will be directed to these promising candidates as effective adjunct therapies against metastatic breast cancer in the clinic.

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.

Inhibition of cell proliferation and triggering of apoptosis by agrimonolide through MAP kinase (ERK and p38) pathways in human gastric cancer AGS cells

Data from the present study showed that agrimonolide exhibited a high anti-proliferation effect against human gastric cancer AGS cells. Flow cytometric analysis revealed that the number of total apoptotic cells increased after the treatment with the agrimonolide in a dose-dependent manner. In addition, it was found that agrimonolide-induced cell apoptosis was associated with the increase in the (Bcl-2 Associated X Protein, BAX)/(B-cell lymphoma-2, Bcl-2) ratio and the activation of cleaved caspase-3. MAPK (p38, c-Jun N-terminal kinase, and ERK1/2) signaling pathways were involved in agrimonolide-induced apoptosis. Cells were exposed to 40 μM of agrimonolide and the level of phospho-ERK/ERK protein was increased to 7.0-fold as compared to the control, and the expression of phospho-p38 protein showed a significant 6.2-fold increase after 24 h incubation, as compared to the control. The employment of protein kinase inhibitors of PD98059 and SB203580, showed the block effects of agrimonolide on the activation of caspase-3 and apoptosis.

Protective Role of Dietary Berries in Cancer

Dietary patterns, including regular consumption of particular foods such as berries as well as bioactive compounds, may confer specific molecular and cellular protection in addition to the overall epidemiologically observed benefits of plant food consumption (lower rates of obesity and chronic disease risk), further enhancing health. Mounting evidence reports a variety of health benefits of berry fruits that are usually attributed to their non-nutritive bioactive compounds, mainly phenolic substances such as flavonoids or anthocyanins. Although it is still unclear which particular constituents are responsible for the extended health benefits, it appears that whole berry consumption generally confers some anti-oxidant and anti-inflammatory protection to humans and animals. With regards to cancer, studies have reported beneficial effects of berries or their constituents including attenuation of inflammation, inhibition of angiogenesis, protection from DNA damage, as well as effects on apoptosis or proliferation rates of malignant cells. Berries extend effects on the proliferation rates of both premalignant and malignant cells. Their effect on premalignant cells is important for their ability to cause premalignant lesions to regress both in animals and in humans. The present review focuses primarily on in vivo and human dietary studies of various berry fruits and discusses whether regular dietary intake of berries can prevent cancer initiation and delay progression in humans or ameliorate patients’ cancer status.

Coumestrol Inhibits Proliferation and Migration of Prostate Cancer Cells by Regulating AKT, ERK1/2, and JNK MAPK Cell Signaling Cascades

Coumestrol is the one of the major phytoestrogens which is abundant in soybeans, legumes, brussel sprouts, and spinach. The beneficial effects of coumestrol are well known in various biological processes including; neuroprotective effects on the nervous system, function of the female reproductive system, anti-bacterial properties, and anti-cancer effects. Although the anti-tumor activity of coumestrol has been demonstrated for ovarian, breast, lung, and cervical cancers, little is known of its effects on prostate cancer. Therefore, in the present study, we investigated the chemotherapeutic effects of coumestrol on two prostate cancer cell lines, PC3 and LNCaP. Our results showed that coumestrol decreased proliferation and migration and induced apoptosis in both PC3 and LNCaP cells. Moreover, effects of coumestrol on cell signaling pathways were investigated and it increased phosphorylation of ERK1/2, JNK, P90RSK, and P53 proteins in a dose- and time-dependent manner whereas phosphorylation of AKT was reduced by coumestrol under the same conditions for culture of PC3 and LNCaP cells. In addition, mitochondrial dysfunction was induced by coumestrol as evidenced by a significant loss of mitochondrial membrane potential. Furthermore, cleavage of caspase-3 and caspase-9, the apoptotic proteins associated with mitochondria, also changed in response to coumestrol. Coumestrol also caused mitochondrial dysfunction resulting in an increase in ROS production in PC3 and LNCaP cells. These results suggest that coumestrol can inhibit progression of prostate cancer and may be a novel chemotherapeutic agent for treatment of prostate cancer via effects mediated via the PI3K/AKT and ERK1/2 and JNK MAPK cell signaling pathways. J. Cell. Physiol. 232: 862-871, 2017. © 2016 Wiley Periodicals, Inc.

Dendrosomal curcumin nanoformulation modulate apoptosis-related genes and protein expression in hepatocarcinoma cell lines

The side-effects observed in conventional therapies have made them unpromising in curing Hepatocellular carcinoma; therefore, developing novel treatments can be an overwhelming significance. One of such novel agents is curcumin which can induce apoptosis in various cancerous cells, however, its poor solubility is restricted its application. To overcome this issue, this paper employed dendrosomal curcumin (DNC) was employed to in prevent hepatocarcinoma in both RNA and protein levels. Hepatocarcinoma cells, p53 wild-type HepG2 and p53 mutant Huh7, were treated with DNC and investigated for toxicity study using MTT assay. Cell cycle distribution and apoptosis were analyzed using Flow-cytometry and Annexin-V-FLUOS/PI staining. Real-time PCR and Western blot were employed to analyze p53, BAX, Bcl-2, p21 and Noxa in DNC-treated cells. DNC inhibited the growth in the form of time-dependent manner, while the carrier alone was not toxic to the cell. Flow-cytometry data showed the constant concentration of 20μM DNC during the time significantly increases cell population in SubG1 phase. Annexin-V-PI test showed curcumin-induced apoptosis was enhanced in Huh7 as well as HepG2, compared to untreated cells. Followed by treatment, mRNA expression of p21, BAX, and Noxa increased, while the expression of Bcl-2 decreased, and unlike HepG2, Huh7 showed down-regulation of p53. In summary, DNC-treated hepatocellular carcinoma cells undergo apoptosis by changing the expression of genes involved in the apoptosis and proliferation processes. These findings suggest that DNC, as a plant-originated therapeutic agent, could be applied in cancer treatment.

TriCurin, a novel formulation of curcumin, epicatechin gallate, and resveratrol, inhibits the tumorigenicity of human papillomavirus-positive head and neck squamous cell carcinoma

Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent cancer worldwide with about 600,000 new cases diagnosed in the last year. The incidence of human papillomavirus-positive head and neck squamous cell carcinoma (HPV-positive HNSCC) has rapidly increased over the past 30 years prompting the suggestion that an epidemic may be on the horizon. Therefore, there is a clinical need to develop alternate therapeutic strategies to manage the growing number of HPV-positive HNSCC patients. TriCurin is a composition of three food-derived polyphenols in unique stoichiometric proportions consisting of curcumin from the spice turmeric, resveratrol from red grapes, and epicatechin gallate from green tea. Cell viability, clonogenic survival, and tumorsphere formation were inhibited and significant apoptosis was induced by TriCurin in UMSCC47 and UPCI:SCC090 HPV-positive HNSCC cells. Moreover, TriCurin decreased HPV16E6 and HPV16E7 and increased p53 levels. In a pre-clinical animal model of HPV-positive HNSCC, intra-tumoral injection of TriCurin significantly inhibited tumor growth by 85.5% compared to vehicle group (P < 0.05, n = 7). Our results demonstrate that TriCurin is a potent anti-tumor agent for HPV-positive HNSCC. Further development of TriCurin as a novel anti-cancer therapeutic to manage the HPV-positive HNSCC population is warranted.

Polyphenols: Extraction Methods, Antioxidative Action, Bioavailability and Anticarcinogenic Effects

Being secondary plant metabolites, polyphenols represent a large and diverse group of substances abundantly present in a majority of fruits, herbs and vegetables. The current contribution is focused on their bioavailability, antioxidative and anticarcinogenic properties. An overview of extraction methods is also given, with supercritical fluid extraction highlighted as a promising eco-friendly alternative providing exceptional separation and protection from degradation of unstable polyphenols. The protective role of polyphenols against reactive oxygen and nitrogen species, UV light, plant pathogens, parasites and predators results in several beneficial biological activities giving rise to prophylaxis or possibly even to a cure for several prevailing human diseases, especially various cancer types. Omnipresence, specificity of the response and the absence of or low toxicity are crucial advantages of polyphenols as anticancer agents. The main problem represents their low bioavailability and rapid metabolism. One of the promising solutions lies in nanoformulation of polyphenols that prevents their degradation and thus enables significantly higher concentrations to reach the target cells. Another, more practiced, solution is the use of mixtures of various polyphenols that bring synergistic effects, resulting in lowering of the required therapeutic dose and in multitargeted action. The combination of polyphenols with existing drugs and therapies also shows promising results and significantly reduces their toxicity.

Dietary flavonoid fisetin increases abundance of high-molecular-mass hyaluronan conferring resistance to prostate oncogenesis

We and others have shown previously that fisetin, a plant flavonoid, has therapeutic potential against many cancer types. Here, we examined the probable mechanism of its action in prostate cancer (PCa) using a global metabolomics approach. HPLC-ESI-MS analysis of tumor xenografts from fisetin-treated animals identified several metabolic targets with hyaluronan (HA) as the most affected. Efficacy of fisetin on HA was then evaluated in vitro and also in vivo in the transgenic TRAMP mouse model of PCa. Size exclusion chromatography-multiangle laser light scattering (SEC-MALS) was performed to analyze the molar mass (Mw) distribution of HA. Fisetin treatment downregulated intracellular and secreted HA levels both in vitro and in vivo Fisetin inhibited HA synthesis and degradation enzymes, which led to cessation of HA synthesis and also repressed the degradation of the available high-molecular-mass (HMM)-HA. SEC-MALS analysis of intact HA fragment size revealed that cells and animals have more abundance of HMM-HA and less of low-molecular-mass (LMM)-HA upon fisetin treatment. Elevated HA levels have been shown to be associated with disease progression in certain cancer types. Biological responses triggered by HA mainly depend on the HA polymer length where HMM-HA represses mitogenic signaling and has anti-inflammatory properties whereas LMM-HA promotes proliferation and inflammation. Similarly, Mw analysis of secreted HA fragment size revealed less HMM-HA is secreted that allowed more HMM-HA to be retained within the cells and tissues. Our findings establish that fisetin is an effective, non-toxic, potent HA synthesis inhibitor, which increases abundance of antiangiogenic HMM-HA and could be used for the management of PCa.

Dietary flavonoid fisetin for cancer prevention and treatment

Cancer remains a major public health concern and a significant cause of death worldwide. Identification of bioactive molecules that have the potential to inhibit carcinogenesis continues to garner interest among the scientific community. In particular, flavonoids from dietary sources are the most sought after because of their safety, cost-effectiveness, and feasibility of oral administration. Emerging data have provided newer insights into understanding the molecular mechanisms that are essential to identify novel mechanism-based strategies for cancer prevention and treatment. Dietary flavonoid fisetin (3,3',4',7-tetrahydroxyflavone) found in many fruits and vegetables has been shown in preclinical studies to inhibit cancer growth through alteration of cell cycle, inducing apoptosis, angiogenesis, invasion, and metastasis without causing any toxicity to normal cells. Although data from in-vitro and in-vivo studies look convincing, well-designed clinical trials in humans are needed to conclusively determine the efficacy across various cancers. This review highlights the chemopreventive and therapeutic effects, molecular targets, and mechanisms that contribute to the observed anticancer activity of fisetin against various cancers.

Dietary total antioxidant capacity is associated with plasmatic antioxidant capacity, nutrient intake and lipid and DNA damage in healthy women

Dietary total antioxidant capacity (DTAC) seems to be associated with reducing risk of diseases. However, data about the influence of the DTAC on oxidative stress parameters are scarce. The aim of this study was to estimate the DTAC and its influence on plasma total antioxidant capacity (PTAC), and damage to lipids, proteins and DNA in healthy women. It was found a positive correlation between DTAC and PTAC in young and healthy subjects, where presumably the endogenous defenses are fully functional. DTAC and PTAC were positively correlated with the intake of known antioxidants, including vitamin C and polyphenols. The DTAC exhibited a negative correlation with lipid oxidative damage, while PTAC showed a negative correlation with DNA damage. This data contributes to better understanding of the recommended dietary antioxidant intake for promoting health.

Differential Response of Two Human Breast Cancer Cell Lines to the Phenolic Extract from Flaxseed Oil

Many studies have evidenced that the phenolic components from flaxseed (FS) oil have potential health benefits. The effect of the phenolic extract from FS oil has been evaluated on two human breast cancer cell lines, MCF7 and MDA-MB231, and on the human non-cancerous breast cell line, MCF10A, by SRB assay, cellular death, cell cycle, cell signaling, lipid peroxidation and expression of some key genes. We have evidenced that the extract shows anti-proliferative activity on MCF7 cells by inducing cellular apoptosis, increase of the percentage of cells in G0/G1 phase and of lipid peroxidation, activation of the H2AX signaling pathway, and upregulation of a six gene signature. On the other hand, on the MDA-MB2131 cells we verified only an anti-proliferative activity, a weak lipid peroxidation, the activation of the PI3K signaling pathway and an up-regulation of four genes. Overall these data suggest that the extract has both cytotoxic and pro-oxidant effects only on MCF7 cells, and can act as a metabolic probe, inducing differences in the gene expression. For this purpose, we have performed an interactomic analysis, highlighting the existing associations. From this approach, we show that the phenotypic difference between the two cell lines can be explained through their differential response to the phenolic extract.

MicroRNA-410-5p as a potential serum biomarker for the diagnosis of prostate cancer

Background

Prostate cancer (PCa) remains to be a diagnostic challenge due to its variable presentation and the lack of reliable diagnosis tool. MicroRNAs (miRNAs) regulate gene in extensive range of pathophysiologic processes. Plasma miRNAs are ideal biomarkers in heart failure, diabetes and other disease. However, using circulating miRNAs as biomarkers for the diagnosis of PCa is still unknown.

Methods

149 PCa patients, 57 healthy controls, and 121 non-cancer patients (benign prostatic hyperplasia and other urinary diseases) were enrolled in this study. The reverse transcription of miRNA and SYBR-Green-based double standards curve miRNA quantitative polymerase chain reactions (qPCR) were used to evaluate the dysregulated miR-410-5p. Receiver operator characteristic (ROC) curve analysis was used to evaluate the diagnostic accuracy of miR-410-5p identified as the alternative biomarker.

Results

Circulating miRNA-410-5p (miR-410-5p) level was significantly higher in the PCa patients than in healthy controls or non-cancer patients. ROC curve analysis showed that plasma miR-410-5p was a specific diagnostic biomarker of PCa with an area under curve(AUC) of 0.8097 (95 % confidence interval, 0.7371–0.8823; P < 0.001).

Conclusions

The serum miR-410-5p level is a potential biomarker for the diagnosis of PCa.

The bounty of nature for changing the cancer landscape

The landscape of cancer has changed considerably in past several years, due mainly to aggressive screening, accumulation of data from basic and epidemiological studies, and the advances in translational research. Natural anticancer agents have always been a part and parcel of cancer research. The initial focus on natural anticancer agents was in context of their cancer chemopreventive properties but their ability to selectively target oncogenic signaling pathways has also been recognized. In light of the rapid advancements in our understanding of the role of microRNAs, cancer stem cells, and epigenetic events in cancer initiation and progression, a number of natural anticancer agents are showing promise in vitro, in vivo as well as in preclinical studies. Moreover, parent structures of natural agents are being extensively modified with the hope of improving efficacy, specificity, and bioavailability. In this article, we focus on two natural agents, 3,3'-diindolylmethane and garcinol, along with 3,4-difluorobenzo curcumin, a synthetic analog of natural agent curcumin. We showcase how these anticancer agents are changing cancer landscape by modulating novel microRNAs, epigenetic factors, and cancer stem cell markers. These activities are relevant and being appreciated for overcoming drug resistance and inhibition of metastases, the two overarching clinical challenges in modern medicine.

Polyphenolic carbosilane dendrimers as anticancer agents against prostate cancer

Polyphenolic carbosilane dendrimers improved the antioxidant and anticancer properties of free vanillin.

Chemoprevention of Breast Cancer by Dietary Polyphenols

The review will discuss in detail the effects of polyphenols on breast cancer, including both the advantages and disadvantages of the applications of these natural compounds. First, we focus on the characterization of the main classes of polyphenols and then on in vitro and in vivo experiments carried out in breast cancer models. Since the therapeutic effects of the administration of a single type of polyphenol might be limited because of the reduced bioavailability of these drugs, investigations on combination of several polyphenols or polyphenols with conventional therapy will also be discussed. In addition, we present recent data focusing on clinical trials with polyphenols and new approaches with nanoparticles in breast cancer. Besides the clinical and translational findings this review systematically summarizes our current knowledge about the molecular mechanisms of anti-cancer effects of polyphenols, which are related to apoptosis, cell cycle regulation, plasma membrane receptors, signaling pathways and epigenetic mechanisms. At the same time the effects of polyphenols on primary tumor, metastasis and angiogenesis in breast cancer are discussed. The increasing enthusiasm regarding the combination of polyphenols and conventional therapy in breast cancer might lead to additional efforts to motivate further research in this field.

Assessing the Protective Activity of a Recently Discovered Phenolic Compound against Oxidative Stress Using Computational Chemistry

The protection exerted by 3,5-dihydroxy-4-methoxybenzyl alcohol (DHMBA), a phenolic compound recently isolated from the Pacific oyster, against oxidative stress (OS) is investigated using the density functional theory. Our results indicate that DHMBA is an outstanding peroxyl radical scavenger, being about 15 times and 4 orders of magnitude better than Trolox for that purpose in lipid and aqueous media, respectively. It was also found to react faster with HOO(•) than other known antioxidants such as resveratrol and ascorbic acid. DHMBA is also predicted to be able to sequester Cu(II) ions, consequently inhibiting the OS induced by Cu(II)-ascorbate mixtures and downgrading the (•)OH production via the Haber-Weiss reaction. However, it is proposed that DHMBA is more efficient as a primary antioxidant (free radical scavenger), than as a secondary antioxidant (metal ion chelator). In addition, it was found that DHMBA can be efficiently regenerated in aqueous solution, at physiological pH. Such regeneration is expected to contribute to increase the antioxidant protection exerted by DHMBA. These results suggest that probably synthetic routes for this compound should be pursued, because albeit its abundance in nature is rather low, its antioxidant activity is exceptional.

Gallic acid, a phenolic compound, exerts anti-angiogenic effects via the PTEN/AKT/HIF-1α/VEGF signaling pathway in ovarian cancer cells

Gallic acid (GA), a polyphenol, is widely found in numerous fruits and vegetables, particularly in hickory nuts. In the present study, we found that gallic acid, a natural phenolic compound isolated from fruits and vegetables, had a more potent growth inhibitory effect on two ovarian cancer cell lines, OVCAR-3 and A2780/CP70, than the effect on a normal ovarian cell line, IOSE-364. These results demonstrated that GA selectively inhibits the growth of cancer cells. Gene expression was examined by ELISA and western blot analysis, and gene pathways were examined by luciferase assay. It was found that GA inhibited VEGF secretion and suppressed in vitro angiogenesis in a concentration-dependent manner. GA downregulated AKT phosphorylation as well as HIF-1α expression but promoted PTEN expression. The luciferase assay results suggest that the PTEN/AKT/HIF-1α pathway accounts for the inhibitory effect of GA on VEGF expression and in vitro angiogenesis. These findings provide strong support for the high potential of GA in the prevention and therapy of ovarian cancer.

Chemoprevention of cancer: current evidence and future prospects

Cancer chemoprevention refers to the use of agents for the inhibition, delay, or reversal of carcinogenesis before invasion. In the present review, agents examined in the context of cancer chemoprevention are classified in four major categories—hormonal, medications, diet-related agents, and vaccines—and the main representatives of each category are presented. Although there are serious constraints in the documentation of effectiveness of chemopreventive agents, mainly stemming from the long latency of the condition they are addressing and the frequent lack of intermediate biomarkers, there is little disagreement about the role of aspirin, whereas a diet rich in vegetables and fruits appears to convey more protection than individual micronutrients. Among categories of cancer chemopreventive agents, hormonal ones and vaccines might hold more promise for the future. Also, the identification of individuals who would benefit most from chemopreventive interventions on the basis of their genetic profiles could open new prospects for cancer chemoprevention.

A new class of hybrid anticancer agents inspired by the synergistic effects of curcumin and genistein: Design, synthesis, and anti-proliferative evaluation

Inspired by the synergistic effects of dietary natural products with different scaffolds on the inhibition of cancer cell proliferation, incorporation of central (1E,4E)-1,4-penta-dien-3-one linker (an optimal substitute for the central metabolically unstable diketone linker of curcumin), 1-alkyl-1H-imidazol-2-yl (a promising bioisostere of terminal aryl group in curcumin), and chromone (the common pharmacophore in genistein and quercetin) into one chemical entity resulted in ten new hybrid molecules, 3-((1E,4E)-5-(1-alkyl-1H-imidazol-2-yl)-3-oxopenta-1,4-dien-1-yl)-4H-chromen-4-ones. They were synthesized through a three-step transformation using acid-catalyzed aldol condensation as key step. The WST-1 cell proliferation assay showed that they have greater anti-proliferative potency than curcumin, quercetin, and genistein on both androgen-dependent and androgen-independent human prostate cancer cells.

[Effect of Chemical Prevention Drugs-based MicroRNAs and Their Target Genes on Tumor Inhibition]

Chemopreventive drugs including natural chemopreventive drugs and synthetic chemopreventive drugs, it not only can prevent cancer, can also play a role in tumor treatment. MicroRNAs (miRNAs) is a kind of short chains of non-coding RNA, regulating the expression of many genes through the way of degradation of mRNA or inhibitting mRNA translation. In recent years, more and more studies have shown that chemopreventive drugs through influence the expression of miRNAs and their target genes play a role in the prevention and treatment in a variety of tumors, and chemopreventive drugs on the experimental study of miRNAs and their target genes in tumor have demonstrated a good safety and efficacy. Effect on chemopreventive drugs-based microRNAs and their target genes into cancer cells will be expected as a new starting point for cancer research. The thesis expounds and analyzes between the natural chemopreventive drugs and synthetic chemopreventive drugs and miRNAs and their target genes in tumor research progress.

In vitro and in vivo antitumoral effects of combinations of polyphenols, or polyphenols and anticancer drugs: perspectives on cancer treatment

Carcinogenesis is a multistep process triggered by genetic alterations that activate different signal transduction pathways and cause the progressive transformation of a normal cell into a cancer cell. Polyphenols, compounds ubiquitously expressed in plants, have anti-inflammatory, antimicrobial, antiviral, anticancer, and immunomodulatory properties, all of which are beneficial to human health. Due to their ability to modulate the activity of multiple targets involved in carcinogenesis through direct interaction or modulation of gene expression, polyphenols can be employed to inhibit the growth of cancer cells. However, the main problem related to the use of polyphenols as anticancer agents is their poor bioavailability, which might hinder the in vivo effects of the single compound. In fact, polyphenols have a poor absorption and biodistribution, but also a fast metabolism and excretion in the human body. The poor bioavailability of a polyphenol will affect the effective dose delivered to cancer cells. One way to counteract this drawback could be combination treatment with different polyphenols or with polyphenols and other anti-cancer drugs, which can lead to more effective antitumor effects than treatment using only one of the compounds. This report reviews current knowledge on the anticancer effects of combinations of polyphenols or polyphenols and anticancer drugs, with a focus on their ability to modulate multiple signaling transduction pathways involved in cancer.