Resveratrol-zinc combination for prostate cancer management

[Effects of zinc and resveratrol as modulators of leptin response in adults with obesity]

INTRODUCTION

fat tissue is an organ with endocrine function, where the hormone leptin (LEP) is identified. This peptide regulates appetite, the immune system, vascular functions and insulin sensitivity. Zinc (Zn) and resveratrol (RES) have potential effects on adipose tissue.

OBJECTIVE

to know if the combined administration of Zn and RES has any effect on blood leptin quantification in obese people.

METHODS

longitudinal experimental study, controlled clinical trial design, randomized, double blind. Randomized formation of four groups: T1 (Zn 50 mg), T2 (control), T3 (RES 500 mg), T4 (Zn 50 mg and RES 500 mg) with a supplementation period of 60 days. Blood samples were taken and glucose (GLU), leptin (LEP) and lipids (HDL, LDL, TGL) were quantified before and after exposure to the study elements.

RESULTS

age 34 (± 7) years. In T-tests, significance in GLU (p = 0.04) and LEP (p = 0.055). By exposure groups: GLU at T1 (p = 0.03) and T2 (p = 0.031); at LEP at T4 (p = 0.024). Lipids by groups: HDL at T3 (p = 0.039) and T4 (p = 0.014). ANOVA, HDL (p = 0.06). Pearson, HDL (p = 0.07) and LDL (p = 0.09).

CONCLUSION

zinc and resveratrol showed promise as agents in modulating leptin and glucose signaling, confirming that they work in a proportional manner and provide benefits for cardiac health, but more exposure time is needed to see if they impact energy balance homeostasis.

Zinc in Prostate Health and Disease: A Mini Review

Introduction-With the high global prevalence of prostate cancer and associated mortalities, it is important to enhance current clinical practices for better prostate cancer outcomes. The current review is towards understanding the value of Zn towards this mission. Method-General information on Zn in biology and multiple aspects of Zn involvement in prostate health and disease were referred to in PubMed. Results-The most influential feature of Zn towards prostate health is its ability to retain sufficient citrate levels for a healthy prostate. Zn deficiencies were recorded in serum, hair, and prostate tissue of men with prostate cancer compared to non-cancer controls. Zn gut absorption, albumin binding, and storage compete with various factors. There are multiple associations of Zn cellular influx and efflux transporters, Zn finger proteins, matrix metalloproteinases, and Zn signaling with prostate cancer outcomes. Such Zn marker variations associated with prostate cancer recorded from biological matrices may improve algorithms for prostate cancer screening, prognosis, and management when coupled with standard clinical practices. Discussion-The influence of Zn in prostatic health and disease is multidimensional, therefore more personalized Zn requirements may be beneficial. Several opportunities exist to utilize and improve understanding of Zn associations with prostate health and disease.

Red Wine and Health: Approaches to Improve the Phenolic Content During Winemaking

There is ample evidence regarding the health benefits of red wine consumption due to its content of phenolic compounds, as an alternative to improve the state of health and prevent various diseases, being the implementation of procedures that allow a greater extraction and stability of phenolic compounds during the elaboration a key aspect. The first part of this review summarizes some studies, mostly at the preclinical level, on the mechanisms by which phenolic compounds act in the human organism, taking advantage of their antioxidant, anti-inflammatory, antitumor, antithrombotic, antiatherogenic, antimicrobial, antiviral, and other activities. Although the migration of grape components into the must/wine occurs during the winemaking process, the application of new technologies may contribute to increasing the content of phenolic compounds in the finished wine. Some of these technologies have been evaluated on an industrial scale, and in some cases, they have been included in the International Code of Oenological Practice by the International Organization of Vine and Wine (OIV). In this sense, the second part of this review deals with the use of these novel technologies that can increase, or at least maintain, the polyphenol content. For example, in the pre-fermentative stage, phenolic extraction can be increased by treating the berries or must with high pressures, pulsed electric fields (PEF), ultrasound (US), e-beam radiation or ozone. At fermentative level, yeasts with high production of pyranoanthocyanins and/or their precursor molecules, low polyphenol absorption, and low anthocyanin-β-glucosidase activity can be used. Whereas, at the post-fermentative level, aging-on-lees (AOL) can contribute to maintaining polyphenol levels, and therefore transmitting health benefits to the consumer.

Laser Ablation ICP-MS Analysis of Chemically Different Regions of Rat Prostate Gland with Implanted Cancer Cells

The comparison of tissues analyzed by LA-ICP-MS is challenging in many aspects, both medical and mathematical. The concept of distinguishing regions of interest (ROIs) was proposed in the literature, allowing for data reduction and targeted comparative analysis. ROIs can be drawn before any analysis, by indicating the anatomical parts of tissue, or after the first step of analysis, by using elemental distribution maps and characteristic regions of enrichment in selected elements. A simple method for identifying different regions, without the manual extraction of image fragments, is highly needed in biological experiments, where large groups of individuals (with samples taken from each of them) is very common. In the present study, two ROIs were distinguished: (1) tissue-rich in fat (and tissue-poor in water); and (2) tissue-rich in water (and tissue-poor in fat). ROIs were extracted mathematically, using an algorithm based on the relationship between 13C and 23Na signal intensities. A cut-off point was indicated in the point of the simultaneous decrease in 13C and increase in 23Na signal intensity. Separate analyses of chemically different ROIs allow for targeted comparison, which is a great advantage of laser ablation over liquid introductions to ICP-MS. In the present experiment, tissues were provided from animals with implanted prostate cancer cells as well as supplemented with mineral compounds particularly important both for prostate gland functions (Zn and Se) and neoplastic processes (Ca, Fe, and Cu). One of the goals was to try to determine whether dietary supplementation qualitatively and quantitatively affects the mineral composition of the prostate gland.

Dietary Phytochemicals in Zinc Homeostasis: A Strategy for Prostate Cancer Management

Studies have suggested an important role of the trace element zinc (Zn) in prostate biology and functions. Zn has been shown to exist in very high concentrations in the healthy prostate and is important for several prostatic functions. In prostate cancer (PCa), Zn levels are significantly decreased and inversely correlated with disease progression. Ideally, restoration of adequate Zn levels in premalignant/malignant prostate cells could abort prostate malignancy. However, studies have shown that Zn supplementation is not an efficient way to significantly increase Zn concentrations in PCa. Based on a limited number of investigations, the reason for the lower levels of Zn in PCa is believed to be the dysregulation of Zn transporters (especially ZIP and ZnT family of proteins), metallothioneins (for storing and releasing Zn), and their regulators (e.g., Zn finger transcription factor RREB1). Interestingly, the level of Zn in cells has been shown to be modulated by naturally occurring dietary phytochemicals. In this review, we discussed the effect of selected phytochemicals (quercetin, resveratrol, epigallocatechin-3-gallate and curcumin) on Zn functioning and proposes that Zn in combination with specific dietary phytochemicals may lead to enhanced Zn bioaccumulation in the prostate, and therefore, may inhibit PCa.

Resveratrol-zinc nanoparticles or pterostilbene-zinc: Potential COVID-19 mono and adjuvant therapy

In this manuscript we provide the scientific basis to adopt a novel combination of two widely available nutraceuticals; resveratrol and zinc in management of COVID-19 recommending their administration using a nano-carrier based drug-delivery system. Resveratrol, a well-known antioxidant and anti-inflammatory triphenolic stilbene, is abundant in red grapes, red wine, dark chocolate, and peanut butter. Alternatively, pterostilbene-zinc combination might be also considered without using a nano-carrier. We recommend conducting prompt clinical trials to assess the potential of the suggested combinations as a monotherapy for mild COVID-19 with a potential to prevent its progression to moderate-severe disease for which we recommend their trial as an adjuvant therapy. Furthermore, the suggested combinations might also possess a pharmacotherapeutic potential that exceeds COVID-19 to various inflammatory, immunologic, and oncologic diseases.

Zinc Gluconate Induces Potentially Cancer Chemopreventive Activity in Barrett's Esophagus: A Phase 1 Pilot Study

BACKGROUND

Chemopreventive effects of zinc for esophageal cancer have been well documented in animal models. This prospective study explores if a similar, potentially chemopreventive action can be seen in Barrett's esophagus (BE) in humans.

AIMS

To determine if molecular evidence can be obtained potentially indicating zinc's chemopreventive action in Barrett's metaplasia.

METHODS

Patients with a prior BE diagnosis were placed on oral zinc gluconate (14 days of 26.4 mg zinc BID) or a sodium gluconate placebo, prior to their surveillance endoscopy procedure. Biopsies of Barrett's mucosa were then obtained for miRNA and mRNA microarrays, or protein analyses.

RESULTS

Zinc-induced mRNA changes were observed for a large number of transcripts. These included downregulation of transcripts encoding proinflammatory proteins (IL32, IL1β, IL15, IL7R, IL2R, IL15R, IL3R), upregulation of anti-inflammatory mediators (IL1RA), downregulation of transcripts mediating epithelial-to-mesenchymal transition (EMT) (LIF, MYB, LYN, MTA1, SRC, SNAIL1, and TWIST1), and upregulation of transcripts that oppose EMT (BMP7, MTSS1, TRIB3, GRHL1). miRNA arrays showed significant upregulation of seven miRs with tumor suppressor activity (-125b-5P, -132-3P, -548z, -551a, -504, -518, and -34a-5P). Of proteins analyzed by Western blot, increased expression of the pro-apoptotic protein, BAX, and the tight junctional protein, CLAUDIN-7, along with decreased expression of BCL-2 and VEGF-R2 were noteworthy.

CONCLUSIONS

When these mRNA, miRNA, and protein molecular data are considered collectively, a cancer chemopreventive action by zinc in Barrett's metaplasia may be possible for this precancerous esophageal tissue. These results and the extensive prior animal model studies argue for a future prospective clinical trial for this safe, easily-administered, and inexpensive micronutrient, that could determine if a chemopreventive action truly exists.

Zinc regulates primary ovarian tumor growth and metastasis through the epithelial to mesenchymal transition

BACKGROUND

The trace element zinc plays an indispensable role in human health and diseases including cancer due to its antioxidant properties. While zinc supplements have been used for cancer prevention, zinc is also a risk factor for cancer development. It is still unclear how zinc plays a role in ovarian cancer.

METHODS

To understand how zinc contributes to ovarian tumor growth and metastasis, we examined whether zinc contributes to tumor metastasis by regulating epithelial to mesenchymal transition (EMT) using ovarian cancer cells in vitro. Cell migration and invasion were examined using transwell plates and EMT markers were examined using Western blot. Primary ovarian tumor growth and metastasis were assessed using orthotopic ovarian cancer mouse models in vivo.

RESULTS

Zinc promoted EMT, while TPEN (N, N, N', N'-tetrakis-(2-pyridylmethyl)-ethylenediamine), a membrane-permeable selective zinc chelator, inhibited EMT in a dose dependent manner in ovarian cancer cells. Moreover, zinc promoted ovarian cancer cell migration and invasion, while TPEN inhibited cell migration and invasion. Zinc activated expression of the metal response transcriptional factor-1 (MTF-1), while TPEN inhibited MTF-1 expression in a dose dependent manner. Knockout of MTF-1 inhibited zinc-induced cell migration, invasion and augmented the inhibitory effect of TPEN on cell migration and invasion. Loss of MTF-1 attenuated zinc-induced ERK1/2 and AKT activation and augmented the effect of TPEN in attenuating the ERK1/2 and AKT pathways. TPEN effectively inhibited primary ovarian tumor growth and metastasis in an orthotopic ovarian cancer mouse model by suppressing EMT.

CONCLUSION

zinc contributes to ovarian tumor metastasis by promoting EMT through a MTF-1 dependent pathway. Zinc depletion by TPEN may be a novel approach for ovarian cancer therapy by inhibiting EMT and attenuating the ERK1/2 and AKT pathways.

Zinc Deficiency in Men Over 50 and Its Implications in Prostate Disorders

Research has been consistently showing the role of zinc (Zn) in prostate function. In this article, we review the current literature on the anatomy and main functions of the prostate, highlighting the role of zinc. In particular, we will review the etiology of benign prostate enlargement (BPH), its prevalence in men over 50, the likelihood of BPH becoming prostate cancer (PCa), and explain the relationship of zinc and apoptosis in the prostate cells and the implications for BPH and PCa. We present a model that explains how endogenous factors provoke excretion of zinc or limit zinc absorption, and how exogenous factors like nutrition and drugs regularly used in men over 50 can significantly decrease zinc status and thereby increase the risk of BPH. Finally, we explain how Zn amino acid (AA) complexes may be capable of avoiding antagonists and inhibitors of zinc absorption, thereby increasing the bioavailability of zinc for the necessary biological processes in the prostate.

Advances of Zinc Signaling Studies in Prostate Cancer

Prostate cancer (PCa) is one of the most common cancers and the second leading cause of cancer-related death among men worldwide. Despite progresses in early diagnosis and therapeutic strategies, prognosis for patients with advanced PCa remains poor. Noteworthily, a unique feature of healthy prostate is its highest level of zinc content among all soft tissues in the human body, which dramatically decreases during prostate tumorigenesis. To date, several reviews have suggested antitumor activities of zinc and its potential as a therapeutic strategy of PCa. However, an overview about the role of zinc and its signaling in PCa is needed. Here, we review literature related to the content, biological function, compounds and clinical application of zinc in PCa. We first summarize zinc content in prostate tissue and sera of PCa patients with their clinical relevance. We then elaborate biological functions of zinc signaling in PCa on three main aspects, including cell proliferation, death and tumor metastasis. Finally, we discuss clinical applications of zinc-containing compounds and proteins involved in PCa signaling pathways. Based on currently available studies, we conclude that zinc plays a tumor suppressive role and can serve as a biomarker in PCa diagnosis and therapies.

Zinc chelator TPEN induces pancreatic cancer cell death through causing oxidative stress and inhibiting cell autophagy

The essential trace element zinc (Zn) is widely required in cellular functions, and abnormal Zn homeostasis causes a variety of health problems including immunodeficiency and sensory dysfunctions. Previous studies had shown that Zn availability was also important for tumor growth and progression. The aim of the present study was to investigate the potential mechanisms of N,N,N,N-Tetrakis(2-pyridylmethyl)-ethylenediamine (TPEN) (a membrane permeable zinc chelator) induced pancreatic cancer cell death. The text of inductively coupled plasma-mass spectrometry (ICP-MS) showed in human pancreatic cancer samples that the zinc content in cancer was higher than that in adjacent tissues. The pancreatic cancer cell lines Panc-1, 8988T, BxPc-3, and L3.6 were used in this study. Our results indicated that TPEN markedly induced cell death, via increasing reactive oxygen species (ROS) and restraining autophagy. Our data also indicated that TPEN-stimulated mitochondrial metabolism produced much ROS. Meanwhile, TPEN reduced the levels of glutathione (GSH) and triggered ROS outbreak, which were the main causes of cell death. In addition, cell autophagy was significantly depressed in Panc-1 cells treated by TPEN, which was due to the ability of disrupting lysosomal by TPEN. Thus, we thought zinc depletion by TPEN was a potential therapeutic strategy for pancreatic cancer.

A Brief Overview from the Physiological and Detrimental Roles of Zinc Homeostasis via Zinc Transporters in the Heart

Zinc (mostly as free/labile Zn²⁺) is an essential structural constituent of many proteins, including enzymes in cellular signaling pathways via functioning as an important signaling molecule in mammalian cells. In cardiomyocytes at resting condition, intracellular labile Zn²⁺ concentration ([Zn²⁺]_i) is in the nanomolar range, whereas it can increase dramatically under pathological conditions, including hyperglycemia, but the mechanisms that affect its subcellular redistribution is not clear. Therefore, overall, very little is known about the precise mechanisms controlling the intracellular distribution of labile Zn²⁺, particularly via Zn²⁺ transporters during cardiac function under both physiological and pathophysiological conditions. Literature data demonstrated that [Zn²⁺]_i homeostasis in mammalian cells is primarily coordinated by Zn²⁺ transporters classified as ZnTs (SLC30A) and ZIPs (SLC39A). To identify the molecular mechanisms of diverse functions of labile Zn²⁺ in the heart, the recent studies focused on the discovery of subcellular localization of these Zn²⁺ transporters in parallel to the discovery of novel physiological functions of [Zn²⁺]_i in cardiomyocytes. The present review summarizes the current understanding of the role of [Zn²⁺]_i changes in cardiomyocytes under pathological conditions, and under high [Zn²⁺]_i and how Zn²⁺ transporters are important for its subcellular redistribution. The emerging importance and the promise of some Zn²⁺ transporters for targeted cardiac therapy against pathological stimuli are also provided. Taken together, the review clearly outlines cellular control of cytosolic Zn²⁺ signaling by Zn²⁺ transporters, the role of Zn²⁺ transporters in heart function under hyperglycemia, the role of Zn²⁺ under increased oxidative stress and ER stress, and their roles in cancer are discussed.

A Therapeutic Connection between Dietary Phytochemicals and ATP Synthase

For centuries, phytochemicals have been used to prevent and cure multiple health ailments. Phytochemicals have been reported to have antioxidant, antidiabetic, antitussive, antiparasitic, anticancer, and antimicrobial properties. Generally, the therapeutic use of phy-tochemicals is based on tradition or word of mouth with few evidence-based studies. Moreo-ver, molecular level interactions or molecular targets for the majority of phytochemicals are unknown. In recent years, antibiotic resistance by microbes has become a major healthcare concern. As such, the use of phytochemicals with antimicrobial properties has become perti-nent. Natural compounds from plants, vegetables, herbs, and spices with strong antimicrobial properties present an excellent opportunity for preventing and combating antibiotic resistant microbial infections. ATP synthase is the fundamental means of cellular energy. Inhibition of ATP synthase may deprive cells of required energy leading to cell death, and a variety of die-tary phytochemicals are known to inhibit ATP synthase. Structural modifications of phyto-chemicals have been shown to increase the inhibitory potency and extent of inhibition. Site-directed mutagenic analysis has elucidated the binding site(s) for some phytochemicals on ATP synthase. Amino acid variations in and around the phytochemical binding sites can re-sult in selective binding and inhibition of microbial ATP synthase. In this review, the therapeu-tic connection between dietary phytochemicals and ATP synthase is summarized based on the inhibition of ATP synthase by dietary phytochemicals. Research suggests selective target-ing of ATP synthase is a valuable alternative molecular level approach to combat antibiotic resistant microbial infections.

Analysis of Zinc-Exporters Expression in Prostate Cancer

Maintaining optimal intracellular zinc (Zn) concentration is crucial for critical cellular functions. Depleted Zn has been associated with prostate cancer (PCa) progression. Solute carrier family 30 (SLC30A) proteins maintain cytoplasmic Zn balance by exporting Zn out to the extracellular space or by sequestering cytoplasmic Zn into intracellular compartments. In this study, we determined the involvement of Zn-exporters, SLC30A 1-10 in PCa, in the context of racial health disparity in human PCa samples obtained from European-American (EA) and African-American (AA) populations. We also analyzed the levels of Zn-exporters in a panel of PCa cells derived from EA and AA populations. We further explored the expression profile of Zn-exporters in PCa using Oncomine database. Zn-exporters were found to be differentially expressed at the mRNA level, with a significant upregulation of SLC30A1, SLC30A9 and SLC30A10, and downregulation of SLC30A5 and SLC30A6 in PCa, compared to benign prostate. Moreover, Ingenuity Pathway analysis revealed several interactions of Zn-exporters with certain tumor suppressor and promoter proteins known to be modulated in PCa. Our study provides an insight regarding Zn-exporters in PCa, which may open new avenues for future studies aimed at enhancing the levels of Zn by modulating Zn-transporters via pharmacological means.

ZnCl2 sustains the adriamycin-induced cell death inhibited by high glucose

Hyperglycemia, the condition of high blood glucose, is typical of diabetes and obesity and represents a significant clinical problem. The relationship between hyperglycemia and cancer risk has been established by several studies. Moreover, hyperglycemia has been shown to reduce cancer cell response to therapies, conferring resistance to drug-induced cell death. Therefore, counteracting the negative effects of hyperglycemia may positively improve the cancer cell death induced by chemotherapies. Recent studies showed that zinc supplementation may have beneficial effects on glycemic control. Here we aimed at evaluating whether ZnCl2 could counteract the high-glucose (HG) effects and consequently restore the drug-induced cancer cell death. At the molecular level we found that the HG-induced expression of genes known to be involved in chemoresistance (such as HIF-1α, GLUT1, and HK2 glycolytic genes, as well as NF-κB activity) was reduced by ZnCl2 treatment. In agreement, the adryamicin (ADR)-induced apoptotic cancer cell death was significantly impaired by HG and efficiently re-established by ZnCl2 cotreatment. Mechanistically, the ADR-induced c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) phosphorylation, inhibited by HG, was efficiently restored by ZnCl2. The JNK involvement in apoptotic cell death was assessed by the use of JNK dominant-negative expression vector that indeed impaired the ZnCl2 ability to restore drug-induced cell death in HG condition. Altogether, these findings indicate that ZnCl2 supplementation efficiently restored the drug-induced cancer cell death, inhibited by HG, by both sustaining JNK activation and counteracting the glycolytic pathway.

Comparative study of serum zinc concentrations in benign and malignant prostate disease: A Systematic Review and Meta-Analysis

Many studies have investigated the relationship between serum zinc concentration and prostatic disease, but have shown inconsistent results. Hence, we performed a systematic literature review and meta-analysis to assess the correlation between serum zinc concentration and prostate disease. Systematic literature searches were conducted with PubMed, EMBASE, Science Direct/Elsevier, MEDLINE, CNKI and the Cochrane Library up to June 2015 for studies that involved the relationship between serum zinc concentration and prostate disease. Fourteen studies were identified from the databases. Our results illustrated that the serum zinc concentrations in prostate cancer patients were significantly lower than those in Benign prostatic hyperplasia (BPH) patients and normal controls (SMD (95% CI), −0.94 [−1.57, −0.32]; −1.18 [−1.90, −0.45]). However, the serum zinc concentrations in BPH patients were significantly higher than those in normal controls (SMD (95% CI) 1.77 [0.15, 3.39]). The present study showed that different levels of serum zinc concentrations are correlated with different prostatic disease. Serum zinc concentration may be used as a tool for the diagnosis and screening of prostate disease. But, further studies with well-designed larger sample studies are needed in this field to further clarify the correlation between serum zinc concentration and prostate disease.

Essential Metals Zinc, Selenium, and Strontium Protect against Chromosome Damage Caused by Polycyclic Aromatic Hydrocarbons Exposure

Essential metals play important roles in maintaining cellular homeostasis, but the effects of their interaction with the environmental pollutants are still not very well-known in human subjects. The aim of this study was to evaluate the roles of essential metals and their interactions with polycyclic aromatic hydrocarbons (PAHs) on chromosome damage, an early carcinogenic event. A total of 1245 male workers were included in this study and the levels of 11 urinary essential metals, 12 urinary PAH metabolites, plasma concentrations of benzo[a]pyrene-r-7,t-8,t-9,c-10-tetrahydotetrol-albumin (BPDE-Alb) adducts, and lymphocyte micronucleus (MN) frequencies were monitored. We found that zinc (Zn), selenium (Se), and strontium (Sr) have significant inverse dose-response relationships with MN frequencies (all P < 0.05). Furthermore, the protective roles of Zn, Se, and Sr were mainly shown among subjects with high levels of BPDE-Alb adducts. Significant effect modification of BPDE-Alb adducts on the associations of Zn, Se, and Sr with MN frequencies was observed (all Pinteraction < 0.05). Our study showed evidence that Zn, Se, and Sr play protective roles in reducing chromosome damage, and these effects can be modified by PAH exposure levels. These findings add potential evidence for the preventive effects of Zn, Se, and Sr against carcinogenesis in human subjects.

Thymoquinone Inhibits Escherichia coli ATP Synthase and Cell Growth

We examined the thymoquinone induced inhibition of purified F1 or membrane bound F1FO E. coli ATP synthase. Both purified F1 and membrane bound F1FO were completely inhibited by thymoquinone with no residual ATPase activity. The process of inhibition was fully reversible and identical in both membrane bound F1Fo and purified F1 preparations. Moreover, thymoquinone induced inhibition of ATP synthase expressing wild-type E. coli cell growth and non-inhibition of ATPase gene deleted null control cells demonstrates that ATP synthase is a molecular target for thymoquinone. This also links the beneficial dietary based antimicrobial and anticancer effects of thymoquinone to its inhibitory action on ATP synthase.

Dietary polyphenols in prevention and treatment of prostate cancer

Prostate cancer is the most prevalent disease affecting males in many Western countries, with an estimated 29,480 deaths in 2014 in the US alone. Incidence rates for prostate cancer deaths have been decreasing since the early 1990s in men of all races/ethnicities, though they remain about 60% higher in African Americans than in any other group. The relationship between dietary polyphenols and the prevention of prostate cancer has been examined previously. Although results are sometimes inconsistent and variable, there is a general agreement that polyphenols hold great promise for the future management of prostate cancer. Various dietary components, including polyphenols, have been shown to possess anti-cancer properties. Generally considered as non-toxic, dietary polyphenols act as key modulators of signaling pathways and are therefore considered ideal chemopreventive agents. Besides possessing various anti-tumor properties, dietary polyphenols also contribute to epigenetic changes associated with the fate of cancer cells and have emerged as potential drugs for therapeutic intervention. Polyphenols have also been shown to affect post-translational modifications and microRNA expressions. This article provides a systematic review of the health benefits of selected dietary polyphenols in prostate cancer, especially focusing on the subclasses of polyphenols, which have a great effect on disease prevention and treatment.

Resveratrol and cancer: Challenges for clinical translation

Significant work has been done towards identifying the health-beneficial effects of the grape antioxidant resveratrol in a variety of bioassay- and disease- models, with much research being focused on its possible application to cancer management. Despite the large number of preclinical studies dealing with different aspects of the biological effects of resveratrol, its translation to clinics is far from reality due to a variety of challenges. In this review, we discuss the issues and questions associated with resveratrol becoming an effective in vivo anticancer drug, from basic metabolic issues to the problems faced by incomplete understanding of the mechanism(s) of action in the body. We also explore efforts taken by researchers, both public and private, to contend with some of these issues. By examining the published data and previous clinical trials, we have attempted to identify the problems and issues that hinder the clinical translation of resveratrol for cancer management. This article is part of a Special Issue entitled: Resveratrol: Challenges in translating pre-clinical findings to improved patient outcomes.