Resveratrol, a tumor-suppressive compound from grapes, induces apoptosis via a novel mitochondrial pathway controlled by Bcl-2

Protective Effects of Resveratrol Against Perfluorooctanoic Acid-Induced Testicular and Epididymal Toxicity in Adult Rats Exposed During Their Prepubertal Period

The antioxidant properties of resveratrol (RES) against oxidative toxicity induced by testicular toxicants are well documented. The current study aimed to investigate the probable beneficial role of RES on male reproduction in adult rats following prepubertal exposure to perfluorooctanoic acid (PFOA). Healthy rats of the Wistar strain (23 days old) were allocated into four groups. Rats in group I did not receive any treatment, while rats in groups II, III, and IV received RES, PFOA, and RES + PFOA, respectively, between days 23 and 56 and were monitored for up to 90 days. Exposure to PFOA resulted in a significant reduction in spermiogram parameters, testicular 3β- and 17β-HSD activity levels, and circulatory levels of testosterone. A significant elevation in LPx, PCs, H2O2, and O2-, associated with a concomitant reduction in SOD, CAT, GPx, GR, and GSH, was noticed in the testes, as well as region-specific changes in pro- and antioxidants in the epididymides of exposed rats compared to controls. A significant increase in serum FSH and LH, testicular cholesterol levels, and caspase-3 activity was observed in PFOA-exposed rats compared to controls. Histological analysis revealed that the integrity of the testes was deteriorated in PFOA-exposed rats. Transcriptomic profiling of the testes and epididymides revealed 98 and 611 altered genes, respectively. In the testes, apoptosis and glutathione pathways were disrupted, while in the epididymides, glutathione and bile secretion pathways were altered in PFOA-exposed rats. PFOA exposure resulted in the down-regulation in the testes of 17β-HSD, StAR, nfe2l2, ar, Lhcgr, and mRNA levels, associated with the up-regulation of casp3 mRNA, and down-regulation of alpha 1 adrenoceptor, muscarinic choline receptor 3, and androgen receptor in the epididymides of exposed rats compared to the controls. These events might lead to male infertility in PFOA-exposed rats. In contrast, restoration of selected reproductive variables was observed in RES plus PFOA-exposed rats compared to rats exposed to PFOA alone. Taken together, we postulate that prepubertal exposure to PFOA triggered oxidative damage and altered genes in the testes and epididymides, leading to suppressed male reproductive health in adult rats, while RES, with its steroidogenic, antiapoptotic, and antioxidant effects, restored PFOA-induced fertility potential in rats.

Resveratrol enhances the antiliver cancer effect of cisplatin by targeting the cell membrane protein PLA2

Background

In this study, we aimed to explore the mechanism by which resveratrol promotes cisplatin-induced death of HepG2 cells and to provide a potential strategy for resveratrol in the treatment of cancer.

Methods

HepG2 cells were exposed to a range of drug concentrations for 24 h: resveratrol (2.5 μg/mL [10.95 μM], 5 μg/mL [21.91 μM], 10 μg/mL [43.81 μM], 20 μg/mL [87.62 μM], 40 μg/mL [175.25 μM], and 80 μg/mL [350.50 μM]), cisplatin (0.625 μg/mL [2.08 μM], 1.25 μg/mL [4.17 μM], 2.5 μg/mL [8.33 μM], 4.5 μg/mL [15.00 μM], and 10 μg/mL [33.33 μM]), 24 μg/mL (105.15 μM) resveratrol + 9 μg/mL (30.00 μM) cisplatin, and 12 μg/mL (52.57 μM) resveratrol + 4.5 μg/mL (15.00 μM) cisplatin. The interaction of two drugs was evaluated by coefficient of drug interaction (CDI), which was based on the Pharmacological Additivity model. The MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to detect the effect of different concentrations of drugs on cell viability, while transcriptome sequencing was used to identify pathways associated with higher gene enrichment. Synchrotron radiation FTIR microspectroscopy experiments and data analysis were conducted to obtain detailed spectral information. The second-derivative spectra were calculated using the Savitzky-Golay algorithm. Single-cell infrared spectral absorption matrices were constructed to analyze the spectral characteristics of individual cells. The Euclidean distance between cells was calculated to assess their spectral similarity. The cell-to-cell Euclidean distance was computed to evaluate the spatial relationships between cells. The target protein of resveratrol was verified by performing a Western blot analysis.

Results

After 24 h of treatment with resveratrol, HepG2 cell growth was inhibited in a dose-dependent manner. Resveratrol promotes cisplatin-induced HepG2 cell death through membrane-related pathways. It also significantly changes the membrane components of HepG2 cells. Additionally, resveratrol changes the morphology of the HepG2 cell membrane by decreasing the expression of PLA2G2.

Conclusion

Resveratrol changes the morphology of the HepG2 cell membrane by decreasing the expression of PLA2G2 and promotes cisplatin-induced HepG2 cell death. The combination of cisplatin and resveratrol can play a synergistic therapeutic effect on HepG2 cells.

The effect of resveratrol supplementation on biomarkers of liver health: A systematic review and meta-analysis of randomized controlled trials

This study aimed to evaluate the effect of resveratrol on liver biomarkers in adult participants, using systematic review and meta-analysis of randomized controlled trials. PubMed, Scopus, Web of Science and Cochran Library was searched, up to October 2021. The pooled effects were calculated using a random-effects model and expressed as weighted mean difference and 95% confidence interval. The methodological quality of studies as well as certainty of evidence were assessed by standard tools. Thirty-seven relevant trials were found. Although overall analysis found no significant change, subgroup analysis showed a significant improvement in alanine aminotransferase (ALT; -7.79 U/L) and glutamyl transferase (-6.0 U/L) in patients with liver disorders, and ALT (-2.22 U/L) in younger adults; however, high-dose supplementation (>1,000 mg/day) appeared to increase alkaline phosphatase concentration (+5.07 U/L). ALT also increased in older adults (+2.33 U/L) following resveratrol supplementation. We found resveratrol did not have a significant effect on liver health in the general population. However, resveratrol could be effective in patients with liver disorders. Our findings also suggest that high-dose resveratrol administration and supplementation in older adults should be performed with caution. Further high-quality clinical trials are also needed to firmly establish the clinical efficacy of resveratrol.

Mitochondrial adaptation in cancer drug resistance: prevalence, mechanisms, and management

Drug resistance represents a major obstacle in cancer management, and the mechanisms underlying stress adaptation of cancer cells in response to therapy-induced hostile environment are largely unknown. As the central organelle for cellular energy supply, mitochondria can rapidly undergo dynamic changes and integrate cellular signaling pathways to provide bioenergetic and biosynthetic flexibility for cancer cells, which contributes to multiple aspects of tumor characteristics, including drug resistance. Therefore, targeting mitochondria for cancer therapy and overcoming drug resistance has attracted increasing attention for various types of cancer. Multiple mitochondrial adaptation processes, including mitochondrial dynamics, mitochondrial metabolism, and mitochondrial apoptotic regulatory machinery, have been demonstrated to be potential targets. However, recent increasing insights into mitochondria have revealed the complexity of mitochondrial structure and functions, the elusive functions of mitochondria in tumor biology, and the targeting inaccessibility of mitochondria, which have posed challenges for the clinical application of mitochondrial-based cancer therapeutic strategies. Therefore, discovery of both novel mitochondria-targeting agents and innovative mitochondria-targeting approaches is urgently required. Here, we review the most recent literature to summarize the molecular mechanisms underlying mitochondrial stress adaptation and their intricate connection with cancer drug resistance. In addition, an overview of the emerging strategies to target mitochondria for effectively overcoming chemoresistance is highlighted, with an emphasis on drug repositioning and mitochondrial drug delivery approaches, which may accelerate the application of mitochondria-targeting compounds for cancer therapy.

Alsahli M, S. M. Aljohani A, Alhumaydhi FA, Babiker AY, Khan AA, Rahmani AH. Potential Therapeutic Targets of Resveratrol, a Plant Polyphenol, and Its Role in the Therapy of Various Types of Cancer

Cancer is among the most prominent causes of mortality worldwide. Different cancer therapy modes employed, including chemotherapy and radiotherapy, have been reported to be significant in cancer management, but the side effects associated with these treatment strategies are still a health problem. Therefore, alternative anticancer drugs based on medicinal plants or their active compounds have been generating attention because of their less serious side effects. Medicinal plants are an excellent source of phytochemicals that have been recognized to have health-prompting effects through modulating cell signaling pathways. Resveratrol is a well-known polyphenolic molecule with antioxidant, anti-inflammatory, and health-prompting effects among which its anticancer role has been best defined. Additionally, this polyphenol has confirmed its role in cancer management because it activates tumor suppressor genes, suppresses cell proliferation, induces apoptosis, inhibits angiogenesis, and modulates several other cell signaling molecules. The anticancer potential of resveratrol is recognized in numerous in vivo and in vitro studies. Previous experimental data suggested that resveratrol may be valuable in cancer management or improve the efficacy of drugs when given with anticancer drugs. This review emphasizes the potential role of resveratrol as an anticancer drug by modulating numerous cells signaling pathways in different types of cancer.

Alcohol and tobacco use and risk of multiple myeloma: A case-control study

Multiple myeloma (MM) is the second most common hematological cancer and causes significant mortality and morbidity. Knowledge regarding modifiable risk factors for MM remains limited. This analysis of an Australian population-based case-control family study investigates whether smoking or alcohol consumption is associated with risk of MM and related diseases. Incident cases (n = 789) of MM were recruited via cancer registries in Victoria and New South Wales. Controls (n = 1,113) were either family members of cases (n = 696) or controls recruited for a similarly designed study of renal cancers (n = 417). Adjusted odds ratios (OR) and 95% confidence intervals (CI) were estimated using unconditional multivariable logistic regression. Heavy intake (>20 g ethanol/day) of alcohol had a lower risk of MM compared with nondrinkers (OR = 0.68, 95% CI: 0.50-0.93), and there was an inverse dose-response relationship for average daily alcohol intake (OR per 10 g ethanol per day = 0.92, 95% CI: 0.86-0.99); there was no evidence of an interaction with sex. There was no evidence of an association with MM risk for smoking-related exposures (p > 0.18). The associations between smoking and alcohol with MM are similar to those with non-Hodgkin lymphoma. Further research into potential underlying mechanisms is warranted.

The Role of Resveratrol in Liver Disease: A Comprehensive Review from In Vitro to Clinical Trials

Many studies have shown that resveratrol has a lot of therapeutic effects on liver disorders. Its administration can significantly increase the survival rate after liver transplantation, reduce fat deposition and ischemia-induced necrosis and apoptosis in Wistar rats. Resveratrol can provide Liver protection against chemical, cholestatic, and alcohol-mediated damage. It can improve glucose metabolism and lipid profile, reduce liver fibrosis, and steatosis. Additionally, it is capable of altering the fatty acid composition of the liver cells. Resveratrol may be a potential treatment option for the management of non-alcoholic fatty liver disease (NAFLD) due to its anti-inflammatory, antioxidant, and calorie-restricting effects. There are also studies that have evaluated the effect of resveratrol on lipid and liver enzyme profiles among patients with metabolic syndrome (MetS) and related disorders. Based on the extent of liver disease worldwide and the need to find new treatment possibilities, this review critically examines current in vitro and in vivo preclinical studies and human clinical studies related to liver protection.

Anti-tumor effects of Artemisia nilagirica extract on MDA-MB-231 breast cancer cells: deciphering the biochemical and biomechanical properties via TGF-β upregulation

Purpose

Artemisia nilagirica (AN), which is known to have antimicrobial, antioxidant, antiulcer, and anti-asthmatic properties, has been recently shown to have anti-cancer activity. However, the mechanism responsible for the anti-cancer property and its effect on cellular properties and functions are not known.

Material and methods

We have characterized the biochemical and biomechanical properties of MDA-MB-231 cells treated with the methanolic extract from AN.

Results

We show that AN-treatment decreases cell-eccentricity, increases expression of actin and microtubules, and do not affect cell-area. Increased expression of cytoskeletal proteins is known to change the mechanical properties of the cells, which was confirmed using micropipette aspiration and Atomic Force Microscopy. We identified the upregulation of the tumorigenic pathway (TGF-β) leading to activation of Rho-A as the molecular mechanism responsible for actin upregulation. Since the initial stages of TGF-β upregulation are known to suppress tumor growth by activating apoptosis, we hypothesized that the mechanism of cell death due to AN-treatment is through TGF-β activation. We have validated this hypothesis by partially recuing cell death through inhibition of TGF-β using Alk-5.

Conclusion

In summary, our study reveals the mechanism of action of Artemisia nilagirica using a synergy between biochemical and biomechanical techniques.

Differential Effects of Exogenous Resveratrol on the Growth and Energy Metabolism of Zea mays and the Weed Ipomoea grandifolia

An increase in crop competitiveness relative to weed interference has the potential to reduce crop yield losses. In this study, the effects of phytoalexin resveratrol were examined in Zea mays L. (corn) and in the weed species Ipomoea grandifolia (Dammer) O'Donell (morning glory). At a concentration range from 220 to 2200 μM resveratrol exerted a stimulus on Z. mays seedling growth that was more pronounced at low concentrations; in the weed species I. grandifolia, resveratrol exerted inhibitory action on seedling growth in all of the assayed concentration range. In I. grandifolia, resveratrol also inhibited the respiratory activity of the primary roots. In mitochondria isolated from Z. mays roots, resveratrol at concentrations above 440 μM inhibited the respiration coupled to ADP phosphorylation and the activities of NADH-oxidase, succinate-oxidase, and ATPsynthase. These effects were not reproduced in Z. mays grown in the presence of resveratrol as the respiratory activities of the roots were not affected. The finding that the resveratrol exerts beneficial effects on growth of Z. mays seedlings and inhibits the growth of I. grandifolia heightens the potential of resveratrol application for crop protection.

System Prediction and Validation of TCM for Chronic Myeloid Leukemia Treatment from the Perspective of Low-Toxicity Chemotherapy: A Stilbene α-Viniferin Has a Proapoptotic Effect on K562 Cells via the Mitochondrial Pathway

Objective

In traditional Chinese medicine (TCM), chronic myeloid leukemia (CML) has been attributed to “poisoned bone marrow,” which is viewed as a loss of Qi or blood, a deficiency in Yin or Yang that causes a complex imbalance between cell growth and death. Malignant myeloid progenitor cells display excessive growth that is difficult to control without toxicity. More than 60 herbs in TCM have shown efficacy against CML. However, the key molecules and mechanisms involved in the holistic-level characterization, as well as the effective target associations, are still unknown.

Methods

The present study employed a computational approach with filtering potential compounds via admetSAR, systems biology-based functional data prediction, and biochemical and molecular biological validation.

Results

We generated 118 bioactive compounds from 11 herbs within four dialectical therapy groups that are most commonly used to treat CML and predicted 141 potential targets. The stilbene resveratrol and its derivatives were found to be highly related to these targets. Among them, α-viniferin was predicted to target Bcl-2, caspase-3, 8, and 9, MAPK14, CDK2, HSP90AA1, and others, reflecting CML therapeutic strategies. In vitro, experimental data showed a nonnecrotic growth limitation of K562 cells caused by α-viniferin was predicted to target Bcl-2, caspase-3, 8, and 9, MAPK14, CDK2, HSP90AA1, and others, reflecting CML therapeutic strategies. μg·mL⁻¹ at 24 h. Finally, we validated the chemotherapeutic effect of α-viniferin was predicted to target Bcl-2, caspase-3, 8, and 9, MAPK14, CDK2, HSP90AA1, and others, reflecting CML therapeutic strategies.

Conclusions

Our work sheds light on the mechanism of the efficacy of the stilbene α-viniferin in TCM for the prevention of CML. This work also predicts and validates targets in the mitochondrial signaling pathway, providing a novel strategy for CML treatment.α-viniferin was predicted to target Bcl-2, caspase-3, 8, and 9, MAPK14, CDK2, HSP90AA1, and others, reflecting CML therapeutic strategies.

Dietary Polyphenols and Mitochondrial Function: Role in Health and Disease

Mitochondria are cytoplasmic double-membraned organelles that are involved in a myriad of key cellular regulatory processes. The loss of mitochondrial function is related to the pathogenesis of several human diseases. Over the last decades, an increasing number of studies have shown that dietary polyphenols can regulate mitochondrial redox status, and in some cases, prevent or delay disease progression. This paper aims to review the role of four dietary polyphenols - resveratrol, curcumin, epigallocatechin-3-gallate nd quercetin - in molecular pathways regulated by mitochondria and their potential impact on human health. Cumulative evidence showed that the aforementioned polyphenols improve mitochondrial functions in different in vitro and in vivo experiments. The mechanisms underlying the polyphenols' beneficial effects include, among others, the attenuation of oxidative stress, the regulation of mitochondrial metabolism and biogenesis and the modulation of cell-death signaling cascades, among other mitochondrial-independent effects. The understanding of the chemicalbiological interactions of dietary polyphenols, namely with mitochondria, may have a huge impact on the treatment of mitochondrial dysfunction-related disorders.

Effects of antioxidants on apoptosis induced by dasatinib and nilotinib in K562 cells

In clinical practice for the treatment of chronic myeloid leukemia, second generation of tyrosine kinase inhibitors such as Nilotinib (NIL) specific and potent inhibitor of the BCR/ABL kinase and Dasatinib (DAS) a inhibitor of BCR/ABL and Src family kinase were developed to clinically overcome imatinib resistance. In this study, we wanted to test the ability of some antioxidants such Resveratrol (RES) or a new recombinant mitochondrial manganese containing superoxide dismutase (rMnSOD) or δ-tocotrienol (δ-TOCO) to interact with DAS and NIL on viability, reactive oxygen species (ROS) production, lipid peroxidation, and apoptosis. To test the possible mechanisms of action of such antioxidants, we utilized N-acetyl-L-cysteine (NAC) a specific inhibitor ROS production or PP1 a specific Src tyrosine kinase inhibitor or BAPTA a specific chelator of intracellular calcium. Our data demonstrated: 1) RES, rMnSOD, δ-TOCO, and NAC, at dose used, significantly reduced the intracellular levels of MDA induced by DAS or NIL; 2) RES, rMnSOD, and δ-TOCO increased the intracellular ROS levels; 3) The increase ROS levels is related to higher levels of oligonucleosomesi induced by DAS and NIL and that NAC significantly reduced this activity. Interestingly, our data showed that apoptotic activity of DAS and NIL have significantly increased the production of oligonucleosomes by triggering excessive ROS generation as well as functionality of SERCA receptors.

The Role of Resveratrol in Cancer Therapy

Natural product compounds have recently attracted significant attention from the scientific community for their potent effects against inflammation-driven diseases, including cancer. A significant amount of research, including preclinical, clinical, and epidemiological studies, has indicated that dietary consumption of polyphenols, found at high levels in cereals, pulses, vegetables, and fruits, may prevent the evolution of an array of diseases, including cancer. Cancer development is a carefully orchestrated progression where normal cells acquires mutations in their genetic makeup, which cause the cells to continuously grow, colonize, and metastasize to other organs such as the liver, lungs, colon, and brain. Compounds that modulate these oncogenic processes can be considered as potential anti-cancer agents that may ultimately make it to clinical application. Resveratrol, a natural stilbene and a non-flavonoid polyphenol, is a phytoestrogen that possesses anti-oxidant, anti-inflammatory, cardioprotective, and anti-cancer properties. It has been reported that resveratrol can reverse multidrug resistance in cancer cells, and, when used in combination with clinically used drugs, it can sensitize cancer cells to standard chemotherapeutic agents. Several novel analogs of resveratrol have been developed with improved anti-cancer activity, bioavailability, and pharmacokinetic profile. The current focus of this review is resveratrol’s in vivo and in vitro effects in a variety of cancers, and intracellular molecular targets modulated by this polyphenol. This is also accompanied by a comprehensive update of the various clinical trials that have demonstrated it to be a promising therapeutic and chemopreventive agent.

Piceatannol induced apoptosis through up-regulation of microRNA-181a in melanoma cells

Background

Melanoma took top position among the lethal cancers and, despite there have been some great attempts made to increase the natural life of patients with metastatic disease, long-lasting and complete remissions are few. Piceatannol, owns the similar function as resveratrol, has been defined as an anti-cancer agent playing important role in inhibition of proliferation, migration and metastasis in various cancer. Thus, we aim to investigate the anti-cancer effect and mechanisms of piceatannol in melanoma cells.

Methods

Melanoma cell lines WM266-4 and A2058 were treated either with or without piceatannol. Cell viability and cell apoptosis were assessed by using MTT and Annexin V/PI assay, respectively. Cells were transfected with specific miRNA using Lipfectamine 2000. miRNA bingding ability to 3'-UTR region within specific gene was assed by firefly luciferase analysis. Gene and protein expression was eveluated by qRT-PCR and western blot analysis, respectively.

Results

Our study showed that piceatannol inhibited WM266-4 and A2058 cells growth and induced apoptosis. Totally, 16 differentially expressed miRNAs were screened out including 8 up-regulated and 8 down-regulated miRNAs. Expression level of miR-181a is significantly higher in piceatannol-treated cells than normal control and is lower in melanoma cancer tissues than its adjacent normal tissues. Bcl-2 is a target gene of miR-181a. Moreover, silencing of miR-181a reverses the decrease of cell viability induced by piceatannol in WM266-4 and A2058 cells. Taken together, present study uncovered the ability of piceatannol to repress melanoma cell growth and clarified the contribution of miR-181a in the anticancer role of piceatannol.

Conclusion

The present study proposes that piceatannol can be taken into account to be a hopeful anticancer agent for melanoma.

Resveratrol induces mitochondria-mediated, caspase-independent apoptosis in murine prostate cancer cells

Found in the skins of red fruits, including grapes, resveratrol (RES) is a polyphenolic compound with cancer chemopreventive activity. Because of this activity, it has gained interest for scientific investigations. RES inhibits tumor growth and progression by targeting mitochondria-dependent or -independent pathways. However, further investigations are needed to explore the underlying mechanisms.

The present study is focused on examining the role of RES-induced, mitochondria-mediated, caspase-independent apoptosis of prostate cancer cells, namely transgenic adenocarcinoma of mouse prostate (TRAMP) cells. These cells were exposed to RES for various times, and cell killing, cell morphology, mitochondrial membrane potential (Δψm), expression of Bax and Bcl2 proteins, the role of caspase-3, and DNA fragmentation were analyzed.

TRAMP cells exposed to RES showed decreased cell viability, altered cell morphology, and disrupted Δψm, which led to aberrant expression of Bax and Bcl2 proteins. Furthermore, since the caspase-3 inhibitor, z-VAD-fmk (benzyloxycarbonyl-valine-alanine-aspartic acid-fluoromethyl ketone), had no appreciable impact on RES-induced cell killing, the killing was evidently caspase-independent. In addition, RES treatment of TRAMP-C1, TRAMP-C2, and TRAMP-C3 cells caused an appreciable breakage of genomic DNA into low-molecular-weight fragments.

These findings show that, in inhibition of proliferation of TRAMP cells, RES induces mitochondria-mediated, caspase-independent apoptosis. Therefore, RES may be utilized as a therapeutic agent to control the proliferation and growth of cancer cells.

Epigallocatechin-3-gallate inhibits H2O2-induced apoptosis in Mouse Vascular Smooth Muscle Cells via 67kD Laminin Receptor

Epigallocatechin-3-gallate (EGCG) is one of the major polyphenolic compounds present in green tea extracts and has been used as a potential drug for the treatment of numerous diseases. The present study aimed to elucidate the role and mechanism of EGCG in protecting against H₂O₂-induced apoptosis in mouse vascular smooth muscle cells (VSMCs). VSMCs were pretreated with various concentrations of EGCG for 2 hours prior to treatment with H₂O₂. Treatment with H₂O₂ significantly decreased the cell viability and induced apoptosis of VSMCs, which were attenuated by pretreatment with EGCG. In particular, EGCG pretreatment significantly inhibited the H₂O₂-induced upregulation of cleaved forms of caspase-3, caspase-8, and caspase-9, Bax, CathepsinD, and downregulation of Bcl-2. Moreover, the antioxidation effect of EGCG on VSMCs was determined to be associated with the 67kD laminin receptor (67LR). Our results demonstrated that EGCG improved cell viability and protected VSMCs against oxidative stress through both extrinsic and intrinsic pathways, while 67LR is likely to be an active and key receptor of EGCG. These findings provide a novel molecular mechanism of EGCG in inhibiting H₂O₂-induced apoptosis in VSMCs, as well as its function in preventing the development of atherosclerosis.

Cellular and Molecular Targets of Resveratrol on Lymphoma and Leukemia Cells

Resveratrol (RSV) is a well known chemopreventive molecule featuring anti-cancer properties. Our paper describes the main molecular targets of RSV linked to its antiproliferative activity on lymphoma and leukemia experimental models. It discusses further the most recent and most promising among these molecular targets for a translational application.

Expression of mTOR/70S6K signaling pathway in pathological scar fibroblasts and the effects of resveratrol intervention

The aim of the study was to examine the expression of mammalian target of rapamycin (mTOR)/70S6K signaling pathway in pathological scar fibroblasts and the effects of resveratrol (Res) intervention. The mTOR and 70S6K in pathological scar and normal skin fibroblasts were detected by immunofluorescence following treatment with different concentrations of Res. RT-PCR and western blot analysis were used to detect the expression of mTOR and 70S6K mRNA and protein, respectively. Immunofluorescence showed that the expression of 70S6K and mTOR was significantly enhanced in pathological scar fibroblasts, and mainly expressed in the nucleus, but not in normal skin fibroblasts. RT-PCR and western blot analysis showed that after different concentrations of Res treatments, the mTOR and 70S6K mRNA and protein expression significantly (P<0.05) decreased in a dose-dependent manner. In conclusion, the expression of mTOR/70S6K signaling pathway in pathological scar fibroblasts was significantly enhanced. Res can downregulate the expression of mTOR and 70S6K to achieve the inhibition of pathological scar fibroblast proliferation.

Target identification with quantitative activity based protein profiling (ABPP)

As many small bioactive molecules fulfill their functions through interacting with protein targets, the identification of such targets is crucial in understanding their mechanisms of action (MOA) and side effects. With technological advancements in target identification, it has become possible to accurately and comprehensively study the MOA and side effects of small molecules. While small molecules with therapeutic potential were derived solely from nature in the past, the remodeling and synthesis of such molecules have now been made possible. Presently, while some small molecules have seen successful application as drugs, the majority remain undeveloped, requiring further understanding of their MOA and side effects to fully tap into their potential. Given the typical promiscuity of many small molecules and the complexity of the cellular proteome, a high-flux and high-accuracy method is necessary. While affinity chromatography approaches combined with MS have had successes in target identification, limitations associated with nonspecific results remain. To overcome these complications, quantitative chemical proteomics approaches have been developed including metabolic labeling, chemical labeling, and label-free methods. These new approaches are adopted in conjunction with activity-based protein profiling (ABPP), allowing for a rapid process and accurate results. This review will briefly introduce the principles involved in ABPP, then summarize current advances in quantitative chemical proteomics approaches as well as illustrate with examples how ABPP coupled with quantitative chemical proteomics has been used to detect the targets of drugs and other bioactive small molecules including natural products.

Resveratrol-salicylate derivatives as selective DNMT3 inhibitors and anticancer agents

Resveratrol is a natural polyphenol with plethora of biological activities. Resveratrol has previously shown to decrease DNA-methyltransferase (DNMT) enzymes expression and to reactivate silenced tumor suppressor genes. Currently, it seems that no resveratrol analogs have been developed as DNMT inhibitors. Recently, we reported the synthesis of resveratrol-salicylate derivatives and by examining the chemical structure of these analogs, we proposed that these compounds could exhibit DNMT inhibition especially that they resembled NSC 14778, a compound we previously identified as a DNMT inhibitor by virtual screening. Indeed, using in vitro DNMT inhibition assay, some of the resveratrol-salicylate analogs we screened in this work that showed selective inhibition against DNMT3 enzymes which were greater than resveratrol. A molecular docking study revealed key binding interactions with DNMT3A and DNMT3B enzymes. In addition, the most active analog, 10 showed considerable cytotoxicity against three human cancer cells; HT-29, HepG2 and SK-BR-3, which was greater than resveratrol. Further studies are needed to understand the anticancer mechanisms of these derivatives.

Resveratrol Specifically Kills Cancer Cells by a Devastating Increase in the Ca2+ Coupling Between the Greatly Tethered Endoplasmic Reticulum and Mitochondria

Background/Aims

Resveratrol and its derivate piceatannol are known to induce cancer cell-specific cell death. While multiple mechanisms of actions have been described including the inhibition of ATP synthase, changes in mitochondrial membrane potential and ROS levels, the exact mechanisms of cancer specificity of these polyphenols remain unclear. This paper is designed to reveal the molecular basis of the cancer-specific initiation of cell death by resveratrol and piceatannol.

Methods

The two cancer cell lines EA.hy926 and HeLa, and somatic short-term cultured HUVEC were used. Cell viability and caspase 3/7 activity were tested. Mitochondrial, cytosolic and endoplasmic reticulum Ca²⁺ as well as cytosolic and mitochondrial ATP levels were measured using single cell fluorescence microscopy and respective genetically-encoded sensors. Mitochondria-ER junctions were analyzed applying super-resolution SIM and ImageJ-based image analysis.

Results

Resveratrol and piceatannol selectively trigger death in cancer but not somatic cells. Hence, these polyphenols strongly enhanced mitochondrial Ca²⁺ uptake in cancer exclusively. Resveratrol and piceatannol predominantly affect mitochondrial but not cytosolic ATP content that yields in a reduced SERCA activity. Decreased SERCA activity and the strongly enriched tethering of the ER and mitochondria in cancer cells result in an enhanced MCU/Letm1-dependent mitochondrial Ca²⁺ uptake upon intracellular Ca²⁺ release exclusively in cancer cells. Accordingly, resveratrol/piceatannol-induced cancer cell death could be prevented by siRNA-mediated knock-down of MCU and Letm1.

Conclusions

Because their greatly enriched ER-mitochondria tethering, cancer cells are highly susceptible for resveratrol/piceatannol-induced reduction of SERCA activity to yield mitochondrial Ca²⁺ overload and subsequent cancer cell death.

Engineering a Piperine Eluting Nanofibrous Patch for Cancer Treatment

The objective of this study was to engineer a biodegradable polymeric system for sustained release of piperine for cancer treatment. We prepared nanofibrous patches of poly(ε-caprolactone) (PCL) and gelatin (GEL) blends of different ratios by electrospinning. The PCL/GEL nanofibers were loaded with up to 30 wt % piperine, a phytochemical derived from black pepper, which is believed to exhibit anticancer, antiarthritis, antibacterial, antioxidant, and anti-inflammatory properties. Scanning electron microscopy revealed that the fiber diameter was in the range of 300-400 nm. Fourier-transform infrared spectroscopy confirmed that the drug was successfully loaded into the nanofiber mats. In vitro release kinetics revealed the sustained release of the drug with 50% release in 3 days from the PCL/GEL (50:50 by weight) blend fibers. The reduced viability and growth of HeLa and MCF-7 cancer cells on the piperine eluting nanofibers demonstrated anticancer activity in vitro. The proliferation of noncancerous cells such as NIH3T3 cells and human mesenchymal stem cells was affected to a markedly lesser extent. Flow cytometry revealed that the released piperine induced the generation of reactive oxygen species (ROS) and cell cycle arrest in the G2/M phase, leading to cell death of cancer cells. The findings of this study suggest that piperine-loaded nanofiber mats could be developed into implantable biodegradable patches for use in postsurgical cancer treatment.

Resveratrol and the mitochondria: From triggering the intrinsic apoptotic pathway to inducing mitochondrial biogenesis, a mechanistic view

BACKGROUND

Mitochondria, the power plants of the cell, are known as a cross-road of different cellular signaling pathways. These cytoplasmic double-membraned organelles play a pivotal role in energy metabolism and regulate calcium flux in the cells. It is well known that mitochondrial dysfunction is associated with different diseases such as neurodegeneration and cancer. A growing body of literature has shown that polyphenolic compounds exert direct effects on mitochondrial ultra-structure and function. Resveratrol is known as one of the most common bioactive constituents of red wine, which improves mitochondrial functions under in vitro and in vivo conditions.

SCOPE OF REVIEW

This paper aims to review the molecular pathways underlying the beneficial effects of resveratrol on mitochondrial structure and functions. In addition, we discuss the chemistry and main sources of resveratrol.

MAJOR CONCLUSIONS

Resveratrol represents the promising effects on mitochondria in different experimental models. However, there are several reports on the detrimental effects elicited by resveratrol on mitochondria.

GENERAL SIGNIFICANCE

An understanding of the chemistry and source of resveratrol, its bioavailability and the promising effects on mitochondria brings a new hope to therapy of mitochondrial dysfunction-related diseases.

Resveratrol-loaded Nanoparticles Induce Antioxidant Activity against Oxidative Stress

Resveratrol acts as a free radical scavenger and a potent antioxidant in the inhibition of numerous reactive oxygen species (ROS). The function of resveratrol and resveratrol-loaded nanoparticles in protecting human lung cancer cells (A549) against hydrogen peroxide was investigated in this study. The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid (ABTS) assay was performed to evaluate the antioxidant properties. Resveratrol had substantially high antioxidant capacity (trolox equivalent antioxidant capacity value) compared to trolox and vitamin E since the concentration of resveratrol was more than 50 μM. Nanoparticles prepared from β-lactoglobulin (β-lg) were successfully developed. The β-lg nanoparticle showed 60 to 146 nm diameter in size with negatively charged surface. Non-cytotoxicity was observed in Caco-2 cells treated with β-lg nanoparticles. Fluorescein isothiocynate-conjugated β-lg nanoparticles were identified into the cell membrane of Caco-2 cells, indicating that nanoparticles can be used as a delivery system. Hydrogen peroxide caused accumulation of ROS in a dose- and time-dependent manner. Resveratrol-loaded nanoparticles restored H₂O₂-induced ROS levels by induction of cellular uptake of resveratrol in A549 cells. Furthermore, resveratrol activated nuclear factor erythroid 2-related factor 2-Kelch ECH associating protein 1 (Nrf2-Keap1) signaling in A549 cells, thereby accumulation of Nrf2 abundance, as demonstrated by western blotting approach. Overall, these results may have implications for improvement of oxidative stress in treatment with nanoparticles as a biodegradable and non-toxic delivery carrier of bioactive compounds.

Resveratrol Induces Glioma Cell Apoptosis through Activation of Tristetraprolin

Tristetraprolin (TTP) is an AU-rich elements (AREs)-binding protein, which regulates the decay of AREs-containing mRNAs such as proto-oncogenes, anti-apoptotic genes and immune regulatory genes. Despite the low expression of TTP in various human cancers, the mechanism involving suppressed expression of TTP is not fully understood. Here, we demonstrate that Resveratrol (3,5,4'-trihydroxystilbene, Res), a naturally occurring compound, induces glioma cell apoptosis through activation of tristetraprolin (TTP). Res increased TTP expression in U87MG human glioma cells. Res-induced TTP destabilized the urokinase plasminogen activator and urokinase plasminogen activator receptor mRNAs by binding to the ARE regions containing the 3' untranslated regions of their mRNAs. Furthermore, TTP induced by Res suppressed cell growth and induced apoptosis in the human glioma cells. Because of its regulation of TTP expression, these findings suggest that the bioactive dietary compound Res can be used as a novel anti-cancer agent for the treatment of human malignant gliomas.

IN-VITRO evidence for the protective properties of the main components of the Mediterranean diet against colorectal cancer: A systematic review

AIM

Epidemiological studies have shown that the incidence and mortality rates of colorectal cancer (CRC) vary over 10-fold worldwide where within Westernized societies lower rates are observed amongst populations living within the Mediterranean basin, suggesting a significant influence of environment and dietary style in CRC carcinogenesis. Interpretation of the data concerning the benefits of mediterranean (MD) diet is difficult in vivo because of the variability of alimentary regimens used, the differing compliance with dietary supplementation and because of the non-uniform duration of patient cohort observation. Therefore, the aim of this review is to evaluate the in-vitro effects on colorectal cancer cell lines.

METHODS

the literature concerning the in-vitro effects of 4 of the principal components symbolizing the MD such as olive oil (polyphenol), red chili (capsaicin), tomato (lycopene) and red grapes (resveratrol) have been systematically reviewed.

RESULTS

Several studies have demonstrated that polyphenols form olive oil, lycopene, resveratrol and capsaicin have multiple anticancer properties affecting several metabolic pathways involved in cancerogenesis, apoptosis, and metastasis in CRC cell lines.

CONCLUSION

This review summarizes some of the most recent data potentially supportive of the use of MD in CRC chemoprevention, analyzing the in vitro effects of individual components of the MD on CRC cell development, progression, metastasis and apoptosis.

Cell death pathway induced by resveratrol-bovine serum albumin nanoparticles in a human ovarian cell line

Resveratrol-bovine serum albumin nanoparticles (RES-BSANP) exhibit chemotherapeutic properties, which trigger apoptosis. The aim of the present study was to investigate the caspase-independent cell death pathway induced by RES-BSANP in human ovarian cancer SKOV3 cells and to analyze its mechanism. Morphological changes were observed by apoptotic body/cell nucleus DNA staining using inverted and fluorescence microscopy. The cell death pathway was determined by phosphatidylserine translocation. Western blot analysis was conducted to detect the activation of apoptosis-inducing factor (AIF), cytochrome c (Cyto c) and B-cell lymphoma 2-associated X protein (Bax). Apoptotic body and nuclear condensation and fragmentation were observed simultaneously following treatment with RES-BSANP. RES-BSANP induced apoptosis in a dose-dependent manner in the human ovarian cancer SKOV3 cells. The translocation of AIF from the mitochondria to the cytoplasm occurred earlier than that of Cyto c. In addition, Bax binding to the mitochondria was required for the release of AIF and Cyto c from the mitochondria. The AIF apoptosis pathway may present an alternative caspase-dependent apoptosis pathway in human ovarian cell death induced by RES-BSANP. Elucidation of this pathway may be critical for the treatment of cancer using high doses of RES-BSANP.

Resveratrol suppresses the proliferation of breast cancer cells by inhibiting fatty acid synthase signaling pathway

In breast cancer cells, overexpression of human epidermal growth factor receptor 2 (HER2) increases the translation of fatty acid synthase (FASN) by altering the activity of PI3K/Akt signaling pathways. Cancer chemotherapy causes major side effects and is not effective enough in slowing down the progression of the disease. Earlier studies showed a role for resveratrol in the inhibition of FASN, but the molecular mechanisms of resveratrol-induced inhibition are not known. In the present study, we examined the novel mechanism of resveratrol on Her2-overexpressed breast cancer cells. The effect of resveratrol on the growth of breast cancer cells was assessed as percent cell viability by cytotoxicity-based MTT assay and the induction of apoptosis was determined by cell-death detection ELISA and flow cytometric analysis of Annexin-V-PI binding. Western immunobloting was used to detect signaling events in human breast cancer (SKBR-3) cells. Data showed that resveratrol-mediated down-regulation of FASN and HER2 genes synergistically induced apoptotic death in SKBR-3 cells. This concurrently caused a prominent up-regulation of PEA3, leads to down-regulation of HER2 genes. Resveratrol also alleviated the PI3K/Akt/mTOR signaling by down-regulation of Akt phosphorylation and up-regulation of PTEN expression. These findings suggest that resveratrol alters the cell cycle progression and induce cell death via FASN inhibition in HER2 positive breast cancer.

Resveratrol inhibits the phosphatidylinositide 3-kinase/protein kinase B/mammalian target of rapamycin signaling pathway in the human chronic myeloid leukemia K562 cell line

Resveratrol inhibits the initiation, promotion and progression of tumors, however, the mechanism by which resveratrol inhibits the proliferation of the human chronic myeloid leukemia K562 cell line remains unclear. The present study was conducted to investigate the effect of resveratrol on the activation of the phosphatidylinositide 3-kinase (PI3K)/protein kinase B (Akt)/mammalian target of rapamycin (mTOR) signaling cascade in K562 cells. Resveratrol showed significant cytotoxic effects and induced apoptosis in K562 cells in a dose- and time-dependent manner. In addition, resveratrol attenuated the phosphorylation of PI3K, Akt and mTOR in the K562 cells. Furthermore, the selected inhibitors of PI3K (LY294002), Akt (SH-6) and mTOR (rapamycin) enhanced the effects of resveratrol in K562 cells. In addition, cyclin D1 levels were found to decrease and the activation of caspase-3 was observed. Resveratrol was also found to significantly attenuate the phosphorylation of the downstream molecules, p70S6K and 4EBP1. These results suggested that the downregulation of the PI3K/Akt/mTOR signaling cascades may be a crucial mediator in the inhibition of proliferation and induction of apoptosis by resveratrol in K562 cells.

The effects of bioactive compounds from plant foods on mitochondrial function: a focus on apoptotic mechanisms

Mitochondria are essential organelles for cellular integrity and functionality maintenance and their imparement is implicated in the development of a wide range of diseases, including metabolic, cardiovascular, degenerative and hyperproliferative pathologies. The identification of different compounds able to interact with mitochondria for therapeutic purposes is currently becoming of primary importance. Indeed, it is well known that foods, particularly those of vegetable origin, present several constituents with beneficial effects on health. This review summarizes and updates the most recent findings concerning the mechanisms through which different dietary compounds from plant foods affect mitochondria functionality in healthy and pathological in vitro and in vivo models, paying particular attention to the pathways involved in mitochondrial biogenesis and apoptosis.

Alcohol consumption has a protective effect against hematological malignancies: a population-based study in Sweden including 420,489 individuals with alcohol use disorders

BACKGROUND

It has been suggested that alcohol consumption is associated with increased risk of a few solid cancers, although studies that examined the association with hematological malignancies have shown inconsistent results. In this study, we examined the risk of hematological malignancies among individuals who had alcohol use disorders (AUDs) in Sweden.

METHODS

Individuals with AUDs were identified from the nationwide Swedish Hospital Discharge Register and Outpatient Register, the Crime Register, and the Prescription Drug Register, and they were linked to the Swedish Cancer Registry to calculate standardized incidence ratios (SIRs) of hematological malignancies, using those Swedes without AUDs as a reference. In addition, we used a quasi-experimental sibling design to investigate the odds ratios among sibling pairs who were discordant with AUDs.

RESULTS

A total of 420,489 individuals were identified with AUDs. After more than 15 million person-years of follow-up, a total of 1755 individuals developed hematological malignancies demonstrating a low risk, i.e., SIR = 0.60 (95% confidence interval = 0.57-0.63). People with AUDs had low risks for developing specific types of malignancies. The lowest risk (0.51) was for leukemia, followed by myeloma (0.52), non-Hodgkin lymphoma (0.65), and Hodgkin disease (0.71). The risk was lower among AUDs identified at an older age. The low risks of hematological malignancies were also noted using sibling analysis.

CONCLUSIONS

Our data suggest that alcohol consumption has a protective effect against hematological malignancies. However, further studies are needed to identity the underlying mechanisms of the protective effect of alcohol consumption against hematological malignancies.

Resveratrol: from basic studies to bedside

Plants produce a remarkable amount of low molecular mass natural products endowed with a large array of pivotal biological activities. Among these molecules, resveratrol (3,5,4'-trihydroxystilbene) has been identified as an important modulator of cell phenotype with a complex and pleiotropic mode of action. Extensive literature regarding its activity, mainly employing cellular models, suggests that this polyphenol controls cell proliferation, induces differentiation, and activates apoptosis and autophagy. The compound also modulates angiogenesis and inflammation. Similarly, studies on implanted cancers and chemical-induced tumors confirm the potential chemotherapeutical interest of the compound. Likewise, several reports clearly demonstrated, in animal models, that the compound might positively affect the development and evolution of chronic diseases including type 2 diabetes, obesity, coronary heart disease, metabolic syndrome, and neurogenerative pathologies. Finally, a number of investigations stated that the toxicity of the molecule is scarce. Despite these promising observations, few clinical trials have yet been performed to evaluate the effectiveness of the molecule both in prevention and treatment of human chronic disease. Preliminary findings therefore suggest the need for more extensive clinical investigations.

Polymer micelle-based combination therapy of paclitaxel and resveratrol with enhanced and selective antitumor activity

mPEG-b-PLA polymer micelles for sequential delivery of resveratrol and paclitaxel to achieve enhanced and selective anticancer activity.

Resveratrol as a pan-HDAC inhibitor alters the acetylation status of histone [corrected] proteins in human-derived hepatoblastoma cells

The polyphenolic alcohol resveratrol has demonstrated promising activities for the prevention and treatment of cancer. Different modes of action have been described for resveratrol including the activation of sirtuins, which represent the class III histone deacetylases (HDACs). However, little is known about the activity of resveratrol on the classical HDACs of class I, II and IV, although these classes are involved in cancer development or progression and inhibitors of HDACs (HDACi) are currently under investigation as promising novel anticancer drugs. We could show by in silico docking studies that resveratrol has the chemical structure to inhibit the activity of different human HDAC enzymes. In vitro analyses of overall HDAC inhibition and a detailed HDAC profiling showed that resveratrol inhibited all eleven human HDACs of class I, II and IV in a dose-dependent manner. Transferring this molecular mechanism into cancer therapy strategies, resveratrol treatment was analyzed on solid tumor cell lines. Despite the fact that hepatocellular carcinoma (HCC) is known to be particularly resistant against conventional chemotherapeutics, treatment of HCC with established HDACi already has shown promising results. Testing of resveratrol on hepatoma cell lines HepG2, Hep3B and HuH7 revealed a dose-dependent antiproliferative effect on all cell lines. Interestingly, only for HepG2 cells a specific inhibition of HDACs and in turn a histone hyperacetylation caused by resveratrol was detected. Additional testing of human blood samples demonstrated a HDACi activity by resveratrol ex vivo. Concluding toxicity studies showed that primary human hepatocytes tolerated resveratrol, whereas in vivo chicken embryotoxicity assays demonstrated severe toxicity at high concentrations. Taken together, this novel pan-HDACi activity opens up a new perspective of resveratrol for cancer therapy alone or in combination with other chemotherapeutics. Moreover, resveratrol may serve as a lead structure for chemical optimization of bioavailability, pharmacology or HDAC inhibition.

Inhibition of JAK2/STAT3 signalling induces colorectal cancer cell apoptosis via mitochondrial pathway

Abnormalities in the JAK2/STAT3 pathway are involved in the pathogenesis of colorectal cancer (CRC), including apoptosis. However, the exact mechanism by which dysregulated JAK2/STAT3 signalling contributes to the apoptosis has not been clarified. To investigate the role of both JAK2 and STAT3 in the mechanism underlying CRC apoptosis, we inhibited JAK2 with AG490 and depleted STAT3 with a small interfering RNA. Our data showed that inhibition of JAK2/STAT3 signalling induced CRC cellular apoptosis via modulating the Bcl-2 gene family, promoting the loss of mitochondrial transmembrane potential (Δψm) and the increase of reactive oxygen species. In addition, our results demonstrated that the translocation of cytochrome c (Cyt c), caspase activation and cleavage of poly (ADP-ribose) polymerase (PARP) were present in apoptotic CRC cells after down-regulation of JAK2/STAT3 signalling. Moreover, inhibition of JAK2/STAT3 signalling suppressed CRC xenograft tumour growth. We found that JAK2/STAT3 target genes were decreased; meanwhile caspase cascade was activated in xenograft tumours. Our findings illustrated the biological significance of JAK2/STAT3 signalling in CRC apoptosis, and provided novel evidence that inhibition of JAK2/STAT3 induced apoptosis via the mitochondrial apoptotic pathway. Therefore, JAK2/STAT3 signalling may be a potential target for therapy of CRC.

VDAC1: from structure to cancer therapy

Here, we review current evidence pointing to the function of VDAC1 in cell life and death, and highlight these functions in relation to cancer. Found at the outer mitochondrial membrane, VDAC1 assumes a crucial position in the cell, controlling the metabolic cross-talk between mitochondria and the rest of the cell. Moreover, its location at the boundary between the mitochondria and the cytosol enables VDAC1 to interact with proteins that mediate and regulate the integration of mitochondrial functions with other cellular activities. As a metabolite transporter, VDAC1 contributes to the metabolic phenotype of cancer cells. This is reflected by VDAC1 over-expression in many cancer types, and by inhibition of tumor development upon silencing VDAC1 expression. Along with regulating cellular energy production and metabolism, VDAC1 is also a key protein in mitochondria-mediated apoptosis, participating in the release of apoptotic proteins and interacting with anti-apoptotic proteins. The involvement of VDAC1 in the release of apoptotic proteins located in the inter-membranal space is discussed, as is VDAC1 oligomerization as an important step in apoptosis induction. VDAC also serves as an anchor point for mitochondria-interacting proteins, some of which are also highly expressed in many cancers, such as hexokinase (HK), Bcl2, and Bcl-xL. By binding to VDAC, HK provides both metabolic benefit and apoptosis-suppressive capacity that offers the cell a proliferative advantage and increases its resistance to chemotherapy. VDAC1-based peptides that bind specifically to HK, Bcl2, or Bcl-xL abolished the cell’s abilities to bypass the apoptotic pathway. Moreover, these peptides promote cell death in a panel of genetically characterized cell lines derived from different human cancers. These and other functions point to VDAC1 as a rational target for the development of a new generation of therapeutics.

Beneficial effects of polyphenols on cardiovascular disease

In recent years, numerous studies have demonstrated the health benefits of polyphenols, and special attention has been paid to their beneficial effects against cardiovascular disease, the leading cause of death in the world today. Polyphenols present vasodilator effects and are able to improve lipid profiles and attenuate the oxidation of low density lipoproteins. In addition, they present clear anti-inflammatory effects and can modulate apoptotic processes in the vascular endothelium. It has been suggested that most of these effects are a consequence of the antioxidant properties of polyphenols, but this idea is not completely accepted, and many other mechanisms have been proposed recently to explain the health effects of these compounds. In fact, different signaling pathways have been linked to polyphenols. This review brings together some recent studies which establish the beneficial properties of polyphenols for cardiovascular disease and analyzes the mechanisms involved in these properties.

Resveratrol induces gastric cancer cell apoptosis via reactive oxygen species, but independent of sirtuin1

The currently available chemotherapeutic regimens against gastric cancer are not very effective, leading to high recurrence and poor survival. Resveratrol is a naturally occurring polyphenol with potent apoptosis-inducing activity. However, the mechanism underlying its actions remains unknown. In the present study, human gastric adenocarcinoma SGC7901 cells were treated with resveratrol (0, 25, 50, 100 and 200 μmol/L) for 48 h, and cellular apoptosis DNA damage were determined. In certain experiments, cells were incubated with superoxide dismutase (100 U/mL), catalase (300 U/mL) or sirtinol (10 μmol/L) to determine the role of reactive oxygen species (ROS) and sirtuin1 in resveratrol-induced cellular apoptosis. Treatment with resveratrol (50-200 μmol/L) for 48 h significantly induced apoptosis and DNA damage in human gastric cancer SGC7901 cells. This was due to the increased generation of ROS following resveratrol treatment because incubation of cells with superoxide dismutase (100 U/mL) or catalase (300 U/mL) attenuated resveratrol-induced cellular apoptosis. Interestingly, treatment with resveratrol (25-200 μmol/L) did not affect the level and activity of sirtuin1, whereas the sirtuin1 inhibitor sirtinol (10 μmol/L) significantly reduced sirtuin1 activity. Furthermore, treatment with sirtinol (10 μmol/L) did not have any effect on apoptosis induced by resveratrol. These data provide evidence that resveratrol induces apoptosis via ROS, but independent of sirtuin1, in the human gastric cancer cell line SGC7901.

Dietary phytochemicals and cancer prevention: Nrf2 signaling, epigenetics, and cell death mechanisms in blocking cancer initiation and progression

Reactive metabolites from carcinogens and oxidative stress can drive genetic mutations, genomic instability, neoplastic transformation, and ultimately carcinogenesis. Numerous dietary phytochemicals in vegetables/fruits have been shown to possess cancer chemopreventive effects in both preclinical animal models and human epidemiological studies. These phytochemicals could prevent the initiation of carcinogenesis via either direct scavenging of reactive oxygen species/reactive nitrogen species (ROS/RNS) or, more importantly, the induction of cellular defense detoxifying/antioxidant enzymes. These defense enzymes mediated by Nrf2-antioxidative stress and anti-inflammatory signaling pathways can contribute to cellular protection against ROS/RNS and reactive metabolites of carcinogens. In addition, these compounds would kill initiated/transformed cancer cells in vitro and in in vivo xenografts via diverse anti-cancer mechanisms. These mechanisms include the activation of signaling kinases (e.g., JNK), caspases and the mitochondria damage/cytochrome c pathways. Phytochemicals may also have anti-cancer effects by inhibiting the IKK/NF-κB pathway, inhibiting STAT3, and causing cell cycle arrest. In addition, other mechanisms may include epigenetic alterations (e.g., inhibition of HDACs, miRNAs, and the modification of the CpG methylation of cancer-related genes). In this review, we will discuss: the current advances in the study of Nrf2 signaling; Nrf2-deficient tumor mouse models; the epigenetic control of Nrf2 in tumorigenesis and chemoprevention; Nrf2-mediated cancer chemoprevention by naturally occurring dietary phytochemicals; and the mutation or hyper-expression of the Nrf2-Keap1 signaling pathway in advanced tumor cells. The future development of dietary phytochemicals for chemoprevention must integrate in vitro signaling mechanisms, relevant biomarkers of human diseases, and combinations of different phytochemicals and/or non-toxic therapeutic drugs, including NSAIDs.

Resveratrol induces apoptosis associated with mitochondrial dysfunction in bladder carcinoma cells

OBJECTIVE

Resveratrol shows chemopreventive activity in a variety of human cancers by targeting mitochondria and triggering apoptosis. The purpose of this study was to investigate the antitumor action of resveratrol in bladder cancer and its underlying mechanism.

METHODS

Using two different bladder cell lines, BTT739 and T24, the cytotoxicity of resveratrol were determined by MTT assay. The apoptosis induced by resveratrol was assayed by transferase dUTP nick end labeling staining. To show whether the mitochondrial dysfunction involved in the effects of resveratrol, mitochondrial function was detected by mitochondrial membrane potential, reactive oxygen species production and adenosine 5'-triphosphate content. In addition, the markers of apoptosis in the intrinsic mitochondrial-dependent pathway were analyzed by the release of cytochrome c and the activities of caspase-9 and caspase-3.

RESULTS

Resveratrol effectively decreased cell viability and induced apoptosis in a concentration- and time-dependent manner. In addition, resveratrol significantly disrupted the mitochondrial membrane potential in both intact cells and isolated mitochondria. Resveratrol also increased reactive oxygen species production and reduced adenosine 5'-triphosphate concentrations. Western blot analysis showed that resveratrol provoked the release of cytochrome c from mitochondria to the cytosol. Furthermore, resveratrol significantly promoted the activation of caspase-9 and caspase-3.

CONCLUSIONS

These findings suggest that resveratrol efficiently triggers apoptosis in bladder cancer cells through the intrinsic mitochondrial-dependent pathway, which is associated with mitochondrial dysfunction. Resveratrol might have great pharmacological promise in the treatment of bladder cancer.

Mitochondrial remodeling in cancer metabolism and survival: potential for new therapies

Mitochondria are semi-autonomous organelles that play essential roles in cellular metabolism and programmed cell death pathways. Genomic, functional and structural mitochondrial alterations have been associated with cancer. Some of those alterations may provide a selective advantage to cells, allowing them to survive and grow under stresses created by oncogenesis. Due to the specific alterations that occur in cancer cell mitochondria, these organelles may provide promising targets for cancer therapy. The development of drugs that specifically target metabolic and mitochondrial alterations in tumor cells has become a matter of interest in recent years, with several molecules undergoing clinical trials. This review focuses on the most relevant mitochondrial alterations found in tumor cells, their contribution to cancer progression and survival, and potential usefulness for stratification and therapy.

STAT5 isoforms regulate colorectal cancer cell apoptosis via reduction of mitochondrial membrane potential and generation of reactive oxygen species

Although the two isoforms of signal transducer and activator of transcription 5 (STAT5) protein, STAT5a and STAT5b, have 94% sequence identity, they are encoded by different genes. Previous studies have been unable to define clearly the roles of the STAT5 genes in colorectal cancer (CRC). To investigate the role of STAT5 isoforms in CRC oncogenesis, immunohistochemical staining was performed. Colorectal adenocarcinomas showed higher expression of STAT5a/5b than normal colonic mucosa (P < 0.05), and STAT5b expression was significantly higher than that of STAT5a in colorectal adenocarcinoma tissue (P < 0.05). Furthermore, STAT5b expression was significantly associated with TNM stage. To delineate the roles of STAT5a/5b in CRC carcinogenesis, we studied CRC cells depleted of each isoform by treating the cells with small interfering RNA. Both STAT5a and STAT5b were found to be involved in cell growth, cell cycle progression, and apoptosis of CRC cells, and exerted their effects via the regulation of downstream targets of the STAT genes. However, STAT5b influenced CRC cell apoptosis more than STAT5a (P < 0.05), reducing mitochondrial membrane potential and generating reactive oxygen species. In conclusion, both isoforms of STAT5 are involved in the growth and cell cycle progression of CRC cells, STAT5b could play a more important role than STAT5a in the clinicopathological characteristics of CRC and CRC cell apoptosis.

Mitochondrial therapeutics for cardioprotection

Mitochondria represent approximately one-third of the mass of the heart and play a critical role in maintaining cellular function-however, they are also a potent source of free radicals and pro-apoptotic factors. As such, maintaining mitochondrial homeostasis is essential to cell survival. As the dominant source of ATP, continuous quality control is mandatory to ensure their ongoing optimal function. Mitochondrial quality control is accomplished by the dynamic interplay of fusion, fission, autophagy, and mitochondrial biogenesis. This review examines these processes in the heart and considers their role in the context of ischemia-reperfusion injury. Interventions that modulate mitochondrial turnover, including pharmacologic agents, exercise, and caloric restriction are discussed as a means to improve mitochondrial quality control, ameliorate cardiovascular dysfunction, and enhance longevity.