Resveratrol as MDR reversion molecule in breast cancer: An overview

Targeting aryl hydrocarbon receptor to prevent cancer in barrier organs

The skin, lung, and gut are important barrier organs that control how the body reacts to environmental stressors such as ultraviolet (UV) radiation, air pollutants, dietary components, and microorganisms. The aryl hydrocarbon receptor (AhR) is a ligand-dependent transcription factor that plays an important role in maintaining homeostasis of barrier organs. AhR was initially discovered as a receptor for environmental chemical carcinogens such as polycyclic aromatic hydrocarbons (PAHs). Activation of AhR pathways by PAHs leads to increased DNA damage and mutations which ultimately lead to carcinogenesis. Ongoing evidence reveals an ever-expanding role of AhR. Recently, AhR has been linked to immune systems by the interaction with the development of natural killer (NK) cells, regulatory T (Treg) cells, and T helper 17 (Th17) cells, as well as the production of immunosuppressive cytokines. However, the role of AhR in carcinogenesis is not as straightforward as we initially thought. Although AhR activation has been shown to promote carcinogenesis in some studies, others suggest that it may act as a tumor suppressor. In this review, we aim to explore the role of AhR in the development of cancer that originates from barrier organs. We also examined the preclinical efficacy data of AhR agonists and antagonists on carcinogenesis to determine whether AhR modulation can be a viable option for cancer chemoprevention.

Enhancing the Bioavailability of Resveratrol: Combine It, Derivatize It, or Encapsulate It?

Overcoming the limited bioavailability and extensive metabolism of effective in vitro drugs remains a challenge that limits the translation of promising drugs into clinical trials. Resveratrol, despite its well-reported therapeutic benefits, is not metabolically stable and thus has not been utilized as an effective clinical drug. This is because it needs to be consumed in large amounts to overcome the burdens of bioavailability and conversion into less effective metabolites. Herein, we summarize the more relevant approaches to modify resveratrol, aiming to increase its biological and therapeutic efficacy. We discuss combination therapies, derivatization, and the use of resveratrol nanoparticles. Interestingly, the combination of resveratrol with established chemotherapeutic drugs has shown promising therapeutic effects on colon cancer (with oxaliplatin), liver cancer (with cisplatin, 5-FU), and gastric cancer (with doxorubicin). On the other hand, derivatizing resveratrol, including hydroxylation, amination, amidation, imidation, methoxylation, prenylation, halogenation, glycosylation, and oligomerization, differentially modifies its bioavailability and could be used for preferential therapeutic outcomes. Moreover, the encapsulation of resveratrol allows its trapping within different forms of shells for targeted therapy. Depending on the nanoparticle used, it can enhance its solubility and absorption, increasing its bioavailability and efficacy. These include polymers, metals, solid lipids, and other nanoparticles that have shown promising preclinical results, adding more "hype" to the research on resveratrol. This review provides a platform to compare the different approaches to allow directed research into better treatment options with resveratrol.

Protective effects of natural compounds against paraquat-induced pulmonary toxicity: the role of the Nrf2/ARE signaling pathway

Paraquat (PQ) is a toxic herbicide to humans. Once absorbed, it accumulates in the lungs. PQ has been well documented that the generation of reactive oxygen species (ROS) is the main mechanism of its toxicity. Oxidative damage of PQ in lungs is represented as generation of cytotoxic and fibrotic mediators, interruption of epithelial and endothelial barriers, and inflammatory cell infiltration. No effective treatment for PQ toxicity is currently available. Several studies have shown that natural compounds (NCs) have the potential to alleviate PQ-induced pulmonary toxicity, due to their antioxidant and anti-inflammatory effects. NCs function as protective agents through stimulation of nuclear factor erythroid 2-related factor 2 (Nrf2)/antioxidant response element (ARE) signaling pathways. Elevation of Nrf2 levels leads to the expression of its downstream enzymes such as SOD, CAT, and HO-1. The hypothesized role of the Nrf2/ARE signaling pathway as the protective mechanism of NCs against PQ-induced pulmonary toxicity is reviewed.

Resveratrol ameliorates ortho- polychlorinated biphenyls' induced toxicity in ovary cells

Polychlorinated biphenyls (PCBs) can induce chronic oxidative stress, inflammation, and cell death, leading to coronary heart disease, endothelial dysfunction, neurotoxicity, cancer, obesity, type 2 diabetes, reproductive dysfunction, etc. The aim of this study was to investigate possible protective effect of resveratrol (2.5-20 μM) in ovarian cells exposed to PCBs. An emphasis was on identifying mechanisms of resveratrol action upon distinct structure of the individual PCB congener-planar dioxin-like PCB 77 and non-planar di-ortho-substituted PCB 153. Multiple toxicity endpoint analysis was performed. Cell viability/proliferation was assessed by Trypan Blue exclusion method, Neutral Red, Kenacid Blue, and MTT bioassays. The level of oxidative stress was measured by fluorescent probes, and flow cytometry was applied to evaluate the mode of cell death. Resveratrol applied alone did not affect cell proliferation and viability in doses up to 20 µM, although significant antioxidative activity was observed. Toxic effects of ortho-PCB 153 (cytotoxicity, oxidative stress, and cell death) were mitigated by resveratrol. On the contrary pre-incubation with resveratrol did not result in cell viability protection when planar PCB 77 was applied. This indicates that resveratrol efficacy may be linked to specific structure of the individual congener, suggesting nutritional modulation of environmental insults caused by ortho-PCBs. We point out the importance of resveratrol dosage considering that synergistic cytotoxic effect with both PCB congeners is observed at concentrations ≥ 10 μM.

Natural compounds regulate the PI3K/Akt/GSK3β pathway in myocardial ischemia-reperfusion injury

The PI3K/Akt/GSK3β pathway is crucial in regulating cardiomyocyte growth and survival. It has been shown that activation of this pathway alleviates the negative impact of ischemia-reperfusion. Glycogen synthase kinase-3 (GSK3β) induces apoptosis through stimulation of transcription factors, and its phosphorylation has been suggested as a new therapeutic target for myocardial ischemia-reperfusion injury (MIRI). GSK3β regulatory role is mediated by the reperfusion injury salvage kinase (RISK) pathway, and its inhibition by Akt activation blocks mitochondrial permeability transition pore (mPTP) opening and enhances myocardial survival. The present article discusses the involvement of the PI3K/Akt/GSK3β pathway in cardioprotective effects of natural products against MIRI.Abbreviations: Akt: protein kinase B; AMPK: AMP-activated protein kinase; ATP: adenosine triphosphate; Bad: bcl2-associated agonist of cell death; Bax: bcl2-associated x protein; Bcl-2: B-cell lymphoma 2; CK-MB: Creatine kinase-MB; CRP: C-reactive-protein; cTnI: cardiac troponin I; EGCG: Epigallocatechin-3-gallate; Enos: endothelial nitric oxide synthase; ER: endoplasmic reticulum; ERK ½: extracellular signal‑regulated protein kinase ½; GSK3β: glycogen synthase kinase-3; GSRd: Ginsenoside Rd; GSH: glutathione; GSSG: glutathione disulfide; HO-1: heme oxygenase-1; HR: hypoxia/reoxygenation; HSYA: Hydroxysafflor Yellow A; ICAM-1: Intercellular Adhesion Molecule 1; IKK-b: IκB kinase; IL: interleukin; IPoC: Ischemic postconditioning; IRI: ischemia-reperfusion injury; JNK: c-Jun N-terminal kinase; Keap1: kelch-like ECH-associated protein- 1; LDH: lactate dehydrogenase; LVEDP: left ventricular end diastolic pressure; LVP: left ventricle pressure; LVSP: left ventricular systolic pressure; MAPK: mitogen-activated protein kinase; MDA: malondialdehyde; MIRI: myocardial ischemia-reperfusion injury; MnSOD: manganese superoxide dismutase; mPTP: mitochondrial permeability transition pore; mtHKII: mitochondria-bound hexokinase II; Nrf-1: nuclear respiratory factor 1; Nrf2: nuclear factor erythroid 2-related factor; NO: nitric oxide; PGC-1α: peroxisome proliferator‑activated receptor γ coactivator‑1α; PI3K: phosphoinositide 3-kinases; RISK: reperfusion injury salvage kinase; ROS: reactive oxygen species; RSV: Resveratrol; SOD: superoxide dismutase; TFAM: transcription factor A mitochondrial; TNF-α: tumor necrosis factor-alpha; VEGF-B: vascular endothelial growth factor B.

Resveratrol Analogs and Prodrugs Differently Affect the Survival of Breast Cancer Cells Impairing Estrogen/Estrogen Receptor α/Neuroglobin Pathway

Breast cancer is the first leading tumor in women in terms of incidence worldwide. Seventy percent of cases are estrogen receptor (ER) α-positive. In these malignancies, 17β-estradiol (E2) via ERα increases the levels of neuroglobin (NGB), a compensatory protein that protects cancer cells from stress-induced apoptosis, including chemotherapeutic drug treatment. Our previous data indicate that resveratrol (RSV), a plant-derived polyphenol, prevents E2/ERα-induced NGB accumulation in this cellular context, making E2-dependent breast cancer cells more prone to apoptosis. Unfortunately, RSV is readily metabolized, thus preventing its effectiveness. Here, four different RSV analogs have been developed, and their effect on the ERα/NGB pathway has been compared with RSV conjugated with highly hydrophilic gold nanoparticles as prodrug to evaluate if RSV derivatives maintain the breast cancer cells' susceptibility to the chemotherapeutic drug paclitaxel as the original compound. Results demonstrate that RSV conjugation with gold nanoparticles increases RSV efficacy, with respect to RSV analogues, reducing NGB levels and enhancing the pro-apoptotic action of paclitaxel, even preventing the anti-apoptotic action exerted by E2 treatment on these cells. Overall, RSV conjugation with gold nanoparticles makes this complex a promising agent for medical application in breast cancer treatment.

Resveratrol in breast cancer treatment: from cellular effects to molecular mechanisms of action

Breast cancer (BC) is one of the most common cancers in females and is responsible for the highest cancer-related deaths following lung cancer. The complex tumor microenvironment and the aggressive behavior, heterogenous nature, high proliferation rate, and ability to resist treatment are the most well-known features of BC. Accordingly, it is critical to find an effective therapeutic agent to overcome these deleterious features of BC. Resveratrol (RES) is a polyphenol and can be found in common foods, such as pistachios, peanuts, bilberries, blueberries, and grapes. It has been used as a therapeutic agent for various diseases, such as diabetes, cardiovascular diseases, inflammation, and cancer. The anticancer mechanisms of RES in regard to breast cancer include the inhibition of cell proliferation, and reduction of cell viability, invasion, and metastasis. In addition, the synergistic effects of RES in combination with other chemotherapeutic agents, such as docetaxel, paclitaxel, cisplatin, and/or doxorubicin may contribute to enhancing the anticancer properties of RES on BC cells. Although, it demonstrates promising therapeutic features, the low water solubility of RES limits its use, suggesting the use of delivery systems to improve its bioavailability. Several types of nano drug delivery systems have therefore been introduced as good candidates for RES delivery. Due to RES's promising potential as a chemopreventive and chemotherapeutic agent for BC, this review aims to explore the anticancer mechanisms of RES using the most up to date research and addresses the effects of using nanomaterials as delivery systems to improve the anticancer properties of RES.

Molecular and Cellular Mechanisms of Propolis and Its Polyphenolic Compounds against Cancer

In recent years, interest in natural products such as alternative sources of pharmaceuticals for numerous chronic diseases, including tumors, has been renewed. Propolis, a natural product collected by honeybees, and polyphenolic/flavonoid propolis-related components modulate all steps of the cancer progression process. Anticancer activity of propolis and its compounds relies on various mechanisms: cell-cycle arrest and attenuation of cancer cells proliferation, reduction in the number of cancer stem cells, induction of apoptosis, modulation of oncogene signaling pathways, inhibition of matrix metalloproteinases, prevention of metastasis, anti-angiogenesis, anti-inflammatory effects accompanied by the modulation of the tumor microenvironment (by modifying macrophage activation and polarization), epigenetic regulation, antiviral and bactericidal activities, modulation of gut microbiota, and attenuation of chemotherapy-induced deleterious side effects. Ingredients from propolis also "sensitize" cancer cells to chemotherapeutic agents, likely by blocking the activation of the transcription factor nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB). In this review, we summarize the current knowledge related to the the effects of flavonoids and other polyphenolic compounds from propolis on tumor growth and metastasizing ability, and discuss possible molecular and cellular mechanisms involved in the modulation of inflammatory pathways and cellular processes that affect survival, proliferation, invasion, angiogenesis, and metastasis of the tumor.

HS‑1793 inhibits cell proliferation in lung cancer by interfering with the interaction between p53 and MDM2

The transcription factor or tumor suppressor protein p53 regulates numerous cellular functions, including cell proliferation, invasion, migration, senescence and apoptosis, in various types of cancer. HS-1793 is an analog of resveratrol, which exhibits anti-cancer effects on various types of cancer, including breast, prostate, colon and renal cancer, and multiple myeloma. However, to the best of our knowledge, the role of HS-1793 in lung cancer remains to be examined. The present study aimed to investigate the anti-cancer effect of HS-1793 on lung cancer and to determine its association with p53. The results revealed that HS-1793 reduced cell proliferation in lung cancer and increased p53 stability, thereby elevating the expression levels of the target genes p21 and mouse double minute 2 homolog (MDM2). When the levels of MDM2, a negative regulator of p53, are increased under normal conditions, MDM2 binds and degrades p53; however, HS-1793 inhibited this binding, confirming that p53 protein stability was increased. In conclusion, the findings of the present study provide new evidence that HS-1793 may inhibit lung cancer proliferation by disrupting the p53-MDM2 interaction.

Applications of resveratrol in the treatment of gastrointestinal cancer

Natural product compounds have lately attracted interest in the scientific community as a possible treatment for gastrointestinal (GI) cancer, due to their anti-inflammatory and anticancer properties. There are many preclinical, clinical, and epidemiological studies, suggesting that the consumption of polyphenol compounds, which are abundant in vegetables, grains, fruits, and pulses, may help to prevent various illnesses and disorders from developing, including several GI cancers. The development of GI malignancies follows a well-known path, in which normal gastrointestinal cells acquire abnormalities in their genetic composition, causing the cells to continuously proliferate, and metastasize to other sites, especially the brain and liver. Natural compounds with the ability to affect oncogenic pathways might be possible treatments for GI malignancies, and could easily be tested in clinical trials. Resveratrol is a non-flavonoid polyphenol and a natural stilbene, acting as a phytoestrogen with anti-cancer, cardioprotective, anti-oxidant, and anti-inflammatory properties. Resveratrol has been shown to overcome resistance mechanisms in cancer cells, and when combined with conventional anticancer drugs, could sensitize cancer cells to chemotherapy. Several new resveratrol analogs and nanostructured delivery vehicles with improved anti-GI cancer efficacy, absorption, and pharmacokinetic profiles have already been developed. This present review focuses on the in vitro and in vivo effects of resveratrol on GI cancers, as well as the underlying molecular mechanisms of action.

Multidrug Resistance (MDR): A Widespread Phenomenon in Pharmacological Therapies

Multidrug resistance is a leading concern in public health. It describes a complex phenotype whose predominant feature is resistance to a wide range of structurally unrelated cytotoxic compounds, many of which are anticancer agents. Multidrug resistance may be also related to antimicrobial drugs, and is known to be one of the most serious global public health threats of this century. Indeed, this phenomenon has increased both mortality and morbidity as a consequence of treatment failures and its incidence in healthcare costs. The large amounts of antibiotics used in human therapies, as well as for farm animals and even for fishes in aquaculture, resulted in the selection of pathogenic bacteria resistant to multiple drugs. It is not negligible that the ongoing COVID-19 pandemic may further contribute to antimicrobial resistance. In this paper, multidrug resistance and antimicrobial resistance are underlined, focusing on the therapeutic options to overcome these obstacles in drug treatments. Lastly, some recent studies on nanodrug delivery systems have been reviewed since they may represent a significant approach for overcoming resistance.

GSH-responsive poly-resveratrol based nanoparticles for effective drug delivery and reversing multidrug resistance

Cancer poses a serious threat to human health and is the most common cause of human death. Polymer-based nanomedicines are presently used to enhance the treatment effectiveness and decrease the systemic toxicity of chemotherapeutic agents. However, the disadvantage of currently polymeric carriers is without therapy procedure. Herein, for the first time, glutathione (GSH)-responsive polymer (PRES) with anti-cancer effect was synthesized following the condensation–polymerization method using resveratrol (RES) and 3,3′-dithiodipropionic acid. PRES can not only suppress the tumor cells growth but can also self-assemble into nanoparticles (∼93 nm) for delivering antitumor drugs, such as paclitaxel (PTX@PRES NPs). The system could achieve high drug loading (∼7%) and overcome multidrug resistance (MDR). The results from the in vitro studies revealed that the NPs formed of PRES were stable in the systemic circulation, while could be efficiently degraded in tumor cells high GSH environment. Results from cytotoxicity tests confirmed that PTX@PRES NPs could effectively suppress the growth of cancer cells (A549) and drug-resistant cells (A549/PTX). The NPs could also be used to significantly increase the therapeutic efficacy of the drugs in A549/PTX tumor-bearing mice. In vivo investigations also demonstrated that the PRES-based NPs exhibited tumor inhibition effects. In summary, we report that the GSH-responsive polymer synthesized by us exhibited multiple interesting functions and could be used for effective drug delivery. The polymer exhibited good therapeutic effects and could be used to overcome MDR. Thus, the synthesized system can be used to develop a new strategy for treating cancer.

Resveratrol-Loaded TPGS-Resveratrol-Solid Lipid Nanoparticles for Multidrug-Resistant Therapy of Breast Cancer: In Vivo and In Vitro Study

Multidrug resistance (MDR) is a serious problem during cancer therapy. The purpose of the present study was to formulate D-α-Tocopheryl polyethylene glycol 1000 succinate-resveratrol-solid lipid nanoparticles (TPGS-Res-SLNs) to improve its therapeutic efficacy against breast cancer. In this study, the solvent injection method was used to prepare the TPGS-Res-SLNs. It was found that the TPGS-Res-SLNs exhibited zeta potential and drug-loading of -25.6 ± 1.3 mV and 32.4 ± 2.6%, respectively. Therefore, it was evident that the TPGS-Res-SLNs can increase cellular uptake of chemotherapeutic drugs, induce mitochondrial dysfunction, and augment tumor treatment efficiency by inducing apoptosis. Moreover, it was found that SKBR3/PR cells treated with TPGS-Res-SLNs exhibited significant inhibition of cell migration and invasion, as compared with free resveratrol. In addition, results from in vivo SKBR3/PR xenograft tumor models revealed that TPGS-Res-SLNs has better efficacy in promoting apoptosis of tumor cells owing to high therapeutic outcomes on tumors when compared with the efficacy of free resveratrol. In conclusion, the findings of the present study indicate significant potential for use of TPGS-Res-SLNs as an efficient drug delivery vehicle to overcome drug resistance in breast cancer therapy.

Antiproliferative, antimigratory, and prooxidative potential of novel platinum(IV) complexes and resveratrol on breast cancer (MDA-MB-231) and choriocarcinoma (JEG-3) cell lines

Platinum(IV) complexes offer the potential to overcome cisplatin resistance of cancer cells, with possible improved selectivity. Resveratrol, a natural polyphenol with anticancer and antioxidant capacity, could limit the possible side effects of chemotherapeutics on healthy cells. This study investigates the effects of platinum(IV) complexes containing some esters of the ethylenediamine-N,N'-di-S,S-(2,2'-dibenzyl)acetate acid (H₂ -S,S-eddba), and resveratrol on proliferation, migration, and redox balance of breast cancer (MDA-MB-231), choriocarcinoma (JEG-3), and human lung fibroblast (MRC-5) cell line. According to IC₅₀ values, all complexes exhibited a significantly stronger antiproliferative effect on tested cell lines compared to cisplatin. Due to reduced adverse effects on MRC-5 cells, the complex containing ethyl-substituent (10 μM) was selected for further examination with resveratrol (25 μM) cotreatment. Resveratrol enhanced the survival of MRC-5 cells while diminished the viability of both used cancer cell lines when applied combined with selected complex. Furthermore, cotreatment of these two compounds decreased the migratory potential of tested cancer cell lines. The examined platinum(IV) complex was able to induce oxidative stress in all tested cell lines. Resveratrol proved to be efficient in protecting MRC-5 cells from complex-induced oxidative damage, while it significantly amplified antiproliferative, antimigratory, and prooxidative effects of platinum(IV) complex on both examined cancer cell lines. These findings may be valuable in elucidating the mechanism of action of platinum(IV) drugs, which should be further investigated.

The modulation of SIRT1 and SIRT3 by natural compounds as a therapeutic target in doxorubicin-induced cardiotoxicity: A review

Doxorubicin (DOX) is a potent antitumor agent with a broad spectrum of activity; however, irreversible cardiotoxicity resulting from DOX treatment is a major issue that limits its therapeutic use. Sirtuins (SIRTs) play an essential role in several physiological and pathological processes including oxidative stress, apoptosis, and inflammation. It has been reported that SIRT1 and SIRT3 can act as a protective molecular against DOX-induced myocardial injury through targeting numerous signaling pathways. Several natural compounds (NCs), such as resveratrol, sesamin, and berberine, with antioxidative, anti-inflammation, and antiapoptotic effects were evaluated for their potential to suppress the cardiotoxicity induced by DOX via targeting SIRT1 and SIRT3. Numerous NCs exerted their therapeutic effects on DOX-mediated cardiac damage via targeting different signaling pathways, including SIRT1/LKB1/AMPK, SIRT1/PGC-1α, SIRT1/NLRP3, and SIRT3/FoxO. SIRT3 also ameliorates cardiotoxicity by enhancing mitochondrial fusion.

Pro-Oxidant Effect of Resveratrol on Human Breast Cancer MCF-7 Cells is Associated with CK2 Inhibition

Casein kinase 2 (CK2) plays a critical role in the proliferation and apoptosis of cancer cells. Resveratrol is a bioactive compound with anticancer and anti-inflammatory effects. This study investigated the pro-oxidant cytotoxic effects of resveratrol in association with the inhibition of CK2 activity on human breast carcinoma cells MCF-7. We showed that resveratrol and TBB, an inhibitor of CK2, decreased cell viability in a concentration dependent manner with an IC₅₀ value of 238 µM and 106 µM after 24 h, of treatment, respectively. Resveratrol and TBB decreased CK2 activity by 1.6 and 1.4-fold, respectively, and both significantly decreased mitochondrial membrane potential. However, only resveratrol increased reactive oxygen species (ROS) levels by 1.7-fold as opposed to TBB, which did not affect ROS levels. Indeed, incubating MCF-7 cells with the antioxidant polyethylene glycol-catalase (PEG-CAT) preserved cell viability from the cytotoxic effects of resveratrol, but not from TBB toxicity. This effect seemed to be related to PEG-CAT ability to prevent CK2 inhibition induced by resveratrol incubation. In conclusion, this study demonstrated that the cytotoxic effect of resveratrol on MCF-7 cells might be associated with its pro-oxidant action, which inhibited CK2 activity, affecting cell viability and mitochondrial function.

Resveratrol attenuates TNBC lung metastasis by down-regulating PD-1 expression on pulmonary T cells and converting macrophages to M1 phenotype in a murine tumor model

Triple-negative breast cancer (TNBC) is an invasive breast cancer with the characteristics of easy to develop distant metastasis. Immune escape is one of the main reasons for TNBC growth and metastasis. Enhancement of T cell-mediated anti-tumor activity may benefit to inhibit tumor metastasis and improve the efficacy of cancer therapy. As a natural bioactive substance, resveratrol shows potential capability to prevent or suppress the development of a variety of cancers through direct or indirect effects, including immunoregulatory effect. However, whether resveratrol might affect lung metastasis of TNBC, and whether the effect of resveratrol might be associated with resveratrol-regulated immune responses in tumor microenvironment is still unknown. In this study, by using an experimental metastatic mouse 4 T1 tumor model, we identified that resveratrol may suppress TNBC lung metastasis by elevating local anti-tumor immunity. Indeed, an increase in the cytotoxic activity of CD8⁺T cells as well as the levels of type 1 cytokine IFN-γ and IL-2 in the lungs of resveratrol-treated tumor bearing mice were observed. The enhanced CD8⁺T cell activity and Th1 immune responses by resveratrol administration might be related to the down-regulated PD-1 expression on pulmonary CD8⁺T cells and CD4⁺T cells. Resveratrol may also convert macrophages to M1 phenotype in the lungs of tumor bearing mice. However, it seems likely resveratrol has no effect on pulmonary myeloid-derived suppressor cell activation. Our results provide an evidence that resveratrol might be a promising candidate agent for adjuvant therapy in the process of TNBC metastasis.

Another look at dietary polyphenols: challenges in cancer prevention and treatment

Cancer is a pathology that impacts in a profound manner people all over the world. The election strategy against cancer often uses chemotherapy and radiotherapy, which more often than not can present many side effects and not always reliable efficacy. By contrast, it is widely known that a diet rich in fruit and vegetables has a protective effect against cancer insurgence and development. Polyphenols are generally believed to be responsible for those beneficial actions, at least partially. In this review, we highlight the metabolic interaction between polyphenols and our metabolism and discuss their potential for anticancer prevention and therapy.

Nanoplatform-based natural products co-delivery system to surmount cancer multidrug-resistant

The emergence of multidrug resistance (MDR) in malignant tumors is the primary reason for invalid chemotherapy. Antitumor drugs are often adversely affected by the MDR of tumor cells. Treatments using conventional drugs, which have specific drug targets, hardly regulate the complex signaling pathway of MDR cells because of the complex formation mechanism of MDR. However, natural products have positive advantages, such as high efficiency, low toxicity, and ability to target multiple mechanism pathways associated with MDR. Natural products, as MDR reversal agents, synergize with chemotherapeutics and enhance the sensitivity of tumor cells to chemotherapeutics, and the co-delivery of natural products and antitumor drugs with nanocarriers maximizes the synergistic effects against MDR in tumor cells. This review summarizes the molecular mechanisms of MDR, the advantages of natural products combined with chemotherapeutics in offsetting complicated MDR mechanisms, and the types and mechanisms of natural products that are potential MDR reversal modulators. Meanwhile, aiming at the low bioavailability of cocktail combined natural products and chemotherapeutic in vivo, the advantages of nanoplatform-based co-delivery system and recent research developments are illustrated on the basis of our previous research. Finally, prospective horizons are analyzed, which are expected to considerably improve the nano-co-delivery of natural products and chemotherapeutic systems for MDR reversal in cancer.

Treatment of lymphomas via regulating the Signal transduction pathways by natural therapeutic approaches: A review

Lymphoma is a heterogeneous group of malignancies, which comprises 4.2 % of all new cancer cases and 3.3 % of all cancer deaths in 2019, globally. The dysregulation of immune system, certain bacterial or viral infections, autoimmune diseases, and immune suppression are associated with a high risk of lymphoma. Although several conventional strategies have improved during the past few decades, but their detrimental impacts remain an obstacle to be resolved. However, natural compounds are considered a good option in the treatment of lymphomas because of their easy accessibility, specific mode of action, high biodegradability, and cost-effectiveness. Vegetables, fruits, and beverages are the primary sources of natural active compounds. The present review investigated the activities of different natural medicinal compounds including curcumin, MK615, resveratrol, bromelain, EGCG, and Annonaceous acetogenins to treat lymphomas. Moreover, in vitro and in vivo studies, classification, risk factors, and diagnosis of lymphoma are also discussed in the present review. The accumulated data proposed that natural compounds regulate the signaling pathways at the level of cell proliferation, apoptosis, and cell cycle to exhibit anti-lymphoma activities both in-vivo and in-vitro studies and suggested that these active compounds could be a good therapeutic option in the treatment of different types of lymphomas.

Resveratrol and its Nanoparticle suppress Doxorubicin/Docetaxel-resistant anaplastic Thyroid Cancer Cells in vitro and in vivo

Background: Docetaxel and doxorubicin combination has been widely used in anaplastic thyroid cancer/ATC treatment but often results in serious adverse effects and drug resistance. Resveratrol effectively inhibits ATC cell proliferation in vitro without affecting the corresponding normal cells, while its in vivo anti-ATC effects especially on the ones with docetaxel/doxorubicin-resistance have not been reported due to its low bioavailability. Nanoparticles with sustained-release and cancer-targeting features may overcome this therapeutic bottleneck. Methods: The resveratrol nanoparticles with sustained-release and IL-13Rα2-targeting capacities (Pep-1-PEG3.5k-PCL4k@Res) were prepared to improve the in vivo resveratrol bioavailability. Human THJ-16T ATC cell line was employed to establish nude mice subcutaneous transplantation model. The tumor-bearing mice were divided into four groups as Group-1, without treatment, Group-2, treated by 30 mg/kg free resveratrol, Group-3, treated by 30 mg/kg Pep-1-PEG3.5k-PCL4k@Res and Group-4, treated by 5 mg/kg docetaxel/5 mg/kg doxorubicin combination. TUNEL staining was used to detect the apoptotic cells in the tumor tissues. Docetaxel/doxorubicin resistant xenografts named as THJ-16T/R were isolated and subjected to 2D and 3D culture. The docetaxel/doxorubicin and resveratrol sensitivities of the original THJ-16T and THJ-16T/R cells were analyzed by multiple methods. Results: Docetaxel/doxorubicin and Pep-1-PEG3.5k-PCL4k@Res but not free resveratrol significantly delayed tumor growth (P < 0.01) and caused extensive apoptosis. The mice in docetaxel/doxorubicin-treated group suffered from weight loss (> 10%) and 2/3 of them died within 3 times of treatment and the chemotherapy was stop to avoid further animal loss. One week after drug withdrawal, the subcutaneous tumors regrew and the tumor volume increased 55.28% within 14 days. The cells isolated from the regrowing tumors (THJ-16T/R) were successfully cultured under 2D and 3D condition and underwent drug treatments. Compared with THJ-16T, the death rate of docetaxel/doxorubicin-treated THJ-16T/R population was lower (39.3% vs 18.0%), which remained almost unchanged in resveratrol-treated group (45.3% vs 49.3%). Conclusion: Resveratrol sustained-release targeting nanoparticles effectively inhibit in vivo ATC growth. Docetaxel/doxorubicin suppresses ATC xenografts but causes obvious side effects and secondary drug resistance that can be overcome by resveratrol.

Direct Conjugation of Resveratrol on Hydrophilic Gold Nanoparticles: Structural and Cytotoxic Studies for Biomedical Applications

Strongly hydrophilic gold nanoparticles (AuNPs), functionalized with citrate and L-cysteine, were synthetized and used as Resveratrol (RSV) vehicle to improve its bioavailability. Two different conjugation procedures were investigated: the first by adding RSV during AuNPs synthesis (1) and the second by adding RSV after AuNPs synthesis (2). The two different conjugated systems, namely AuNPs@RSV1 and AuNPs@RSV2 respectively, showed good loading efficiency (η%): η1 = 80 ± 5% for AuNPs@RSV1 and η2 = 20 ± 3% for AuNPs@RSV2. Both conjugated systems were investigated by means of Dynamic Light Scattering (DLS), confirming hydrophilic behavior and nanodimension (<2RH> 1 = 45 ± 12 nm and <2RH> 2 = 170 ± 30 nm). Fourier Transform Infrared Spectroscopy (FT-IR), Synchrotron Radiation induced X-Ray Photoelectron Spectroscopy (SR-XPS) and Near Edge X-ray Absorption Fine Structure (NEXAFS) techniques were applied to deeply understand the hooking mode of RSV on AuNPs surface in the two differently conjugated systems. Moreover, the biocompatibility of AuNPs and AuNPs@RSV1 was evaluated in the concentration range 1.0-45.5 µg/mL by assessing their effect on breast cancer cell vitality. The obtained data confirmed that, at the concentration used, AuNPs do not induce cell death, whereas AuNPs@RSV1 maintains the same anticancer effects as the unconjugated RSV.

Bioactive Compounds and Metabolites from Grapes and Red Wine in Breast Cancer Chemoprevention and Therapy

Phytochemicals and their metabolites are not considered essential nutrients in humans, although an increasing number of well-conducted studies are linking their higher intake with a lower incidence of non-communicable diseases, including cancer. This review summarizes the current findings concerning the molecular mechanisms of bioactive compounds from grapes and red wine and their metabolites on breast cancer—the most commonly occurring cancer in women—chemoprevention and treatment. Flavonoid compounds like flavonols, monomeric catechins, proanthocyanidins, anthocyanins, anthocyanidins and non-flavonoid phenolic compounds, such as resveratrol, as well as their metabolites, are discussed with respect to structure and metabolism/bioavailability. In addition, a broad discussion regarding in vitro, in vivo and clinical trials about the chemoprevention and therapy using these molecules is presented.

Siva‑1 regulates multidrug resistance of gastric cancer by targeting MDR1 and MRP1 via the NF‑κB pathway

Siva-1 is a well-known anti-apoptosis protein that serves a role in multiple types of cancer cells. However, whether Siva-1 affects multidrug resistance via the NF-κB pathway in gastric cancer is currently unknown. The present study aimed to determine the possible involvement of Siva-1 in gastric cancer anticancer drug resistance in vitro. A vincristine (VCR)-resistant KATO III/VCR gastric cancer cell line with stable Siva-1 overexpression was established. The protein expression levels of Siva-1, NF-κB, multidrug resistance 1 (MDR1) and multidrug resistance protein 1 (MRP1) were detected via western blotting. The effect of Siva-1 overexpression on anticancer drug resistance was assessed by measuring the 50% inhibitory concentration of KATO III/VCR cells to VCR, 5-fluorouracil and doxorubicin. The rate of doxorubicin efflux and apoptosis were detected by flow cytometry. Additionally, colony formation, wound healing and Transwell assays were used to detect the proliferation, migration and invasion of cells, respectively. The results of the current study revealed that the Siva-1-overexpressed KATO III/VCR gastric cancer cells exhibited a significantly decreased sensitivity to VCR, 5-fluorouracil and doxorubicin. The results of flow cytometry revealed that the percentage of apoptotic cells decreased following overexpression of Siva-1. The colony formation assay demonstrated that cell growth and proliferation were significantly promoted by Siva-1 overexpression. Additionally, Siva-1 overexpression increased the migration and invasion of KATO III/VCR cells in vitro. Western blot analysis determined that Siva-1 overexpression increased NF-κB, MDR1 and MRP1 levels. The current study demonstrated that overexpression of Siva-1, which functions as a regulator of MDR1 and MRP1 gene expression in gastric cancer cells via promotion of NF-κB expression, inhibited the sensitivity of gastric cancer cells to certain chemotherapies. These data provided novel insight into the molecular mechanisms of gastric cancer, and may be of significance for the clinical diagnosis and therapy of patients with gastric cancer.

Phytochemicals: Potential Lead Molecules for MDR Reversal

Multidrug resistance (MDR) is one of the main impediments in the treatment of cancers. MDR cancer cells are resistant to multiple anticancer drugs. One of the major mechanisms of MDR is the efflux of anticancer drugs by ABC transporters. Increased activity and overexpression of these transporters are important causes of drug efflux and, therefore, resistance to cancer chemotherapy. Overcoming MDR is a fundamental prerequisite for developing an efficient treatment of cancer. To date, various types of ABC transporter inhibitors have been employed but no effective anticancer drug is available at present, which can completely overcome MDR. Phytochemicals can reverse MDR in cancer cells via affecting the expression or activity of ABC transporters, and also through exerting synergistic interactions with anticancer drugs by addressing additional molecular targets. We have listed numerous phytochemicals which can affect the expression and activity of ABC transporters in MDR cancer cell lines. Phytochemicals in the groups of flavonoids, alkaloids, terpenes, carotenoids, stilbenoids, lignans, polyketides, and curcuminoids have been examined for MDR-reversing activity. The use of MDR-reversing phytochemicals with low toxicity to human in combination with effective anticancer agents may result in successful treatment of chemotherapy-resistant cancer. In this review, we summarize and discuss published evidence for natural products with MDR modulation abilities.

Biotransformation of dietary phytoestrogens by gut microbes: A review on bidirectional interaction between phytoestrogen metabolism and gut microbiota

Phytoestrogens are a class of plant produced polyphenolic compounds with diphenolic structure, which is similar to 17β-estradiol. These phytoestrogens preferentially bind to estrogen receptors, however, with weak affinity. Recently, many studies have found that these phytoestrogens can be transformed by gut microbiota through novel enzymatic reactions into metabolites with altered bioactivity. Recent studies have also implied that these metabolites could possibly modulate the host gut ecosystem, gene expression, metabolism and the immune system. Thus, isolating gut microbes capable of biotransforming phytoestrogens and characterizing the novel enzymatic reactions involved are principal to understand the mechanisms of beneficial effects brought by gut microbiota and their metabolism on phytoestrogens, and to provide the theoretical knowledge for the development of functional probiotics. In the present review, we summarized works on gut microbial biotransformation of phytoestrogens, including daidzin (isoflavone), phenylnaringenin (prenylflavonoid), lignans, resveratrol (stilbene) and ellagitannins. We mainly focus on gut bacterial isolation, metabolic pathway characterization, and the bidirectional interaction of phytoestrogens with gut microbes to illustrate the novel metabolic capability of gut microbiota and the methods used in these studies.

Reversal Effect of ALK Inhibitor NVP-TAE684 on ABCG2-Overexpressing Cancer Cells

Failure of cancer chemotherapy is mostly due to multidrug resistance (MDR). Overcoming MDR mediated by overexpression of ATP binding cassette (ABC) transporters in cancer cells remains a big challenge. In this study, we explore whether NVP-TAE684, a novel ALK inhibitor which has the potential to inhibit the function of ABC transport, could reverse ABC transporter-mediated MDR. MTT assay was carried out to determine cell viability and reversal effect of NVP-TAE684 in parental and drug resistant cells. Drug accumulation and efflux assay was performed to examine the effect of NVP-TAE684 on the cellular accumulation and efflux of chemotherapeutic drugs. The ATPase activity of ABCG2 transporter in the presence or absence of NVP-TAE684 was conducted to determine the impact of NVP-TAE684 on ATP hydrolysis. Western blot analysis and immunofluorescence assay were used to investigate protein molecules related to MDR. In addition, the interaction between NVP-TAE684 and ABCG2 transporter was investigated via in silico analysis. MTT assay showed that NVP-TAE684 significantly decreased MDR caused byABCG2-, but not ABCC1-transporter. Drug accumulation and efflux tests indicated that the effect of NVP-TAE684 in decreasing MDR was due to the inhibition of efflux function of ABCG2 transporter. However, NVP-TAE684 did not alter the expression or change the subcellular localization of ABCG2 protein. Furthermore, ATPase activity analysis indicated that NVP-TAE684 could stimulate ABCG2 ATPase activity. Molecular in silico analysis showed that NVP-TAE684 interacts with the substrate binding sites of the ABCG2 transporter. Taken together, our study indicates that NVP-TAE684 could reduce the resistance of MDR cells to chemotherapeutic agents, which provides a promising strategy to overcome MDR.

Quantitative Analysis of Proteome in Non-functional Pituitary Adenomas: Clinical Relevance and Potential Benefits for the Patients

Background: Non-functional pituitary adenoma (NFPA) is a common tumor that occurs in the pituitary gland, and generally without any symptoms at its early stage and without clinical elevation of hormones, which is commonly diagnosed when it grows up to compress its surrounding tissues and organs. Currently, the pathogenesis of NFPA has not been clarified yet. It is necessary to investigate molecular alterations in NFPA, and identify reliable biomarkers and drug therapeutic targets for effective treatments. Methods: Tandem mass tags (TMT)-based quantitative proteomics was used to identify and quantify proteins in NFPAs. GO and KEGG enrichment analyses were used to analyze the identified proteins. Differentially expressed genes (DEGs) between NFPA and control tissues were obtained from GEO datasets. These two sets of protein and gene data were analyzed to obtain overlapped molecules (genes; proteins), followed by further GO and KEGG pathway analyses of these overlapped molecules, and molecular network analysis to obtain the hub molecules with Cytoscape. Two hub molecules (SRC and AKT1) were verified with Western blotting. Results: Totally 6076 proteins in NFPA tissues were identified, and 3598 DEGs between NFPA and control tissues were identified from GEO database. Overlapping analysis of 6076 proteins and 3598 DEGs obtained 1088 overlapped molecules (DEGs; proteins). KEGG pathway analysis of 6076 proteins obtained 114 statistically significant pathways, including endocytosis, and spliceosome signaling pathways. KEGG pathway analysis of 1088 overlapped molecules obtained 52 statistically significant pathways, including focal adhesion, cGMP-PKG pathway, and platelet activation signaling pathways. These pathways play important roles in cell energy supply, adhesion, and maintenance of the tumor microenvironment. According to the association degree in Cytoscape, ten hub molecules (DEGs; proteins) were identified, including GAPDH, ALB, ACACA, SRC, ENO2, CALM1, POTEE, HSPA8, DECR1, and AKT1. Western-blotting analysis confirmed the upregulated expressions of SRC and PTMScan experiment confirmed the increased levels of pAKT1, in NFPAs compared to controls. Conclusions: This study established the large-scale quantitative protein profiling of NFPA tissue proteome. It offers a basis for subsequent in-depth proteomics analysis of NFPAs, and insight into the molecular mechanism of NFPAs. It also provided the basic data to discover reliable biomarkers and therapeutic targets for NFPA patients.

Evaluation of anti-tumour properties of two depsidones - Unguinol and Aspergillusidone D - in triple-negative MDA-MB-231 breast tumour cells

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Unguinol and Aspergillusidone D inhibit cell viability at low μM concentrations.

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These depsidones increase the amount of apoptotic cells in the MDA-MB-231 cell line.

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Unguinol causes cell cycle arrest of MDA-MB-231 cells in the G2/M-phase.

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Apoptosis and cell cycle arrest were seen at clinically high concentrations (>60 μM).

There is an ongoing search for new compounds to lower the mortality and recurrence of breast cancer, especially triple-negative breast cancer. Naturally occurring depsidones, extracted from the fungus Aspergillus, are known for their wide range of biological activities such as cytotoxicity, aromatase inhibition, radical scavenging, and antioxidant properties. Research showed the potential of depsidones as a treatment option for hormone receptor-positive breast cancer treatment, yet its effects on hormone receptor-negative breast cancer are still unkown.

This study, therefore, investigated the potential of two depsidones (Unguinol and Aspergillusidone D) to induce apoptosis, cell cycle arrest and cytotoxicity, and reduce cell proliferation in the triple-negative MDA-MB-231 breast cancer cell line. Results were compared with the effects of the cytostatic drug doxorubicin, antimitotic agent colchicine and endogenous hormones 17β-estradiol, testosterone and dihydrotestosterone.

The cytostatic drugs and hormones affected the MDA-MB-231 cell line comparable to other studies, showing the usefulness of this model to study the effects of depsidones on a triple-negative breast cancer cell line. At sub μM levels, Unguinol and Aspergillusidone D did not influence cell proliferation, while cell viability was reduced at concentrations higher than 50 μM. Both depsidones induced apoptosis, albeit not statistically significantly. In addition, Unguinol induced cell cycle arrest in MDA-MB-231 cells at 100 μM.

Our research shows the potential of two depsidones to reduce triple-negative breast cancer cell survival. Therefore, this group of compounds may be promising in the search for new cancer treatments, especially when looking at similar depsidones.

Contribution of Resveratrol in the Development of Novel Urease Inhibitors: Synthesis, Biological Evaluation and Molecular Docking Studies

Aims and Objective:

A new library of resveratrol derivatives was designed and synthesized in excellent yield via two-step reaction utilizing Vilsmeier reaction as the first step and subsequent addition of substituted aromatic amine in the second step.

Methods:

Synthesized compounds were investigated for their antioxidant as well as for in vitro inhibition activity against jack bean urease enzyme. Compounds R3b and R4 with IC50 value 18.85±0.15 and 21.60±0.19µM against urease enzyme and 6.01±0.07 and 7.52±0.14µM in vitro- DPPH free radical scavenging activity have emerged as most active molecules from the selected library. Molecular simulation studies were also carried out for determining the interaction detail of newly synthesized compounds within a protein pocket.

Results and Conclusion:

Newly synthesized compounds were found to possess better docking score (-5.941 to -6.894) and binding energy (-46.854 to -56.455) as compared to the parent resveratrol (-5.45 and -20.155) which revealed that the newly synthesized compounds bind in a better way as compared to the parent molecule

An Efficient Synthesis of Deoxyrhapontigenin-3-O-β-D-glucuronide, a Brain-targeted Derivative of Dietary Resveratrol, and its Precursor 4'-O-Me-Resveratrol

Bioactive dietary polyphenols have health benefits against a variety of disorders, but some benefits of polyphenols may be not directly related to them, but rather to their metabolites. Recently, we have identified the brain-available phenol glucuronide metabolite deoxyrhapontigenin-3-O-β-D-glucuronide (5) in perfused rat brains following sub-acute treatment with the stilbene resveratrol (1). However, the role of such a metabolite in the neuroprotective activity of resveratrol (1) is not understood, in part due to the non-commercial availability of 5 for performing biological evaluation in animal models of Alzheimer's disease or other neurological disorders. Here, we describe a concise chemical synthesis of deoxyrhapontigenin-3-O-β-D-glucuronide (5) and its precursor, 4-O-Me-resveratrol (2), accomplished in 4 and 6 steps with 74% and 21% overall yields, respectively, starting from commercially available 3,5-dihydroxybenzaldehyde. Pivotal reactions employed in the synthesis include the palladium-catalyzed C-C coupling between 3,5-di-tert-butyldiphenylsilyloxystyrene and p-iodoanisole in the presence of tributylamine and the acid-catalysed glucuronidation between the trichloroacetimidate-activated glucuronic acid and 4-O-Me-resveratrol.

Anti-cancer effects of polyphenols via targeting p53 signaling pathway: updates and future directions

The anticancer effects of polyphenols are ascribed to several signaling pathways including the tumor suppressor gene tumor protein 53 (p53). Expression of endogenous p53 is silent in various types of cancers. A number of polyphenols from a wide variety of dietary sources could upregulate p53 expression in several cancer cell lines through distinct mechanisms of action. The aim of this review is to focus the significance of p53 signaling pathways and to provide molecular intuitions of dietary polyphenols in chemoprevention by monitoring p53 expression that have a prominent role in tumor suppression.

The effect of medicinal plants on multiple drug resistance through autophagy: A review of in vitro studies

Multiple drug resistance (MDR) often occurs after prolonged chemotherapy, leading to refractory tumor and cancer recurrence. Autophagy as a primarily process during starvation or stress has a bipolar nature in cancer. It can cause MDR to become more difficult or make resistant cancer cells more susceptible to chemotherapeutic agents. A number of natural products have been introduced to drug discovery for many years. Some of these compounds have been shown to reverse drug resistance by different regulatory mechanisms. In this review, the focus is on the role of medicinal plants in the MDR phenomenon, primarily through the autophagy process.

Resveratrol and Its Effects on the Vascular System

Resveratrol, the phenolic substance isolated initially from Veratrum grandiflorum and richly present in grapes, wine, peanuts, soy, and berries, has been attracting attention of scientists and medical doctors for many decades. Herein, we review its effects on the vascular system. Studies utilizing cell cultures and pre-clinical models showed that resveratrol alleviates oxidative stress and inflammation. Furthermore, resveratrol suppresses vascular smooth muscle cell proliferation, promotes autophagy, and has been investigated in the context of vascular senescence. Pre-clinical models unambiguously demonstrated numerous vasculoprotective effects of resveratrol. In clinical trials, resveratrol moderately diminished systolic blood pressure in hypertensive patients, as well as blood glucose in patients with diabetes mellitus. Yet, open questions remain, as exemplified by a recent report which states that the intake of resveratrol might blunt certain positive effects of exercise in older persons, and further research addressing the framework for long-term use of resveratrol as a food supplement, will stay in demand.

Development of a novel drug targeting delivery system for cervical cancer therapy

'Targeting peptides' have demonstrated their value in diagnostic imaging and therapy and novel peptide probes specific to cervical cancer were developed. In the M13KE phage dodecapeptide (12-mer) peptide library, the phage clone S7 showed the best binding to the cancer cells as confirmed by immunofluorescence and flow cytometry assays, and was selected for continued studies. Its binding peptide, CSP3, was synthesized from the sequence of S7's 12-mer at the N-terminus of the minor coat protein pIII of this M13KE phage vector. The peptide's binding was analyzed by the same assays used for S7. It was also assessed using competitive inhibition and binding to a tissue chip. The results demonstrated that the CSP3 peptide bound to cervical carcinoma cells with high sensitivity and specificity. The positive results indicated that the peptide CSP3, conjugated with nanomaterials and chemotherapeutics, may be developed as a targeting vehicle for therapeutic drug delivery against cervical cancer, especially cervical cancer with multiple drug resistance. For this aim, we prepared a CSP3 conjugated liposome drug delivery system containing doxorubicin (DOX) and microRNA101 (miR101) expression plasmids (CSP3-Lipo-DOX-miR101), and the primary result showed that the system demonstrated significantly enhanced cytotoxicity to SiHa cells and DOX resistant SiHa cells, SiHa/ADR. Our results showed that CSP3 is a cervical cancer targeting 12aa peptide with high specificity and sensitivity, and the CSP3 conjugated drug delivery system, CSP3-Lipo-DOX-miR101 has promising potential for development as an efficient drug system for the therapy of cervical cancer.

Bioactivity of dietary polyphenols: The role of metabolites

A polyphenol-rich diet protects against chronic pathologies by modulating numerous physiological processes, such as cellular redox potential, enzymatic activity, cell proliferation and signaling transduction pathways. However, polyphenols have a low oral bioavailability mainly due to an extensive biotransformation mediated by phase I and phase II reactions in enterocytes and liver but also by gut microbiota. Despite low oral bioavailability, most polyphenols proved significant biological effects which brought into attention the low bioavailability/high bioactivity paradox. In recent years, polyphenol metabolites have attracted great interest as many of them showed similar or higher intrinsic biological effects in comparison to the parent compounds. There is a huge body of literature reporting on the biological functions of polyphenol metabolites generated by phase I and phase II metabolic reactions and gut microbiota-mediated biotransformation. In this respect, the review highlights the pharmacokinetic fate of the major dietary polyphenols (resveratrol, curcumin, quercetin, rutin, genistein, daidzein, ellagitannins, proanthocyanidins) in order to further address the efficacy of biometabolites as compared to parent molecules. The present work strongly supports the contribution of metabolites to the health benefits of polyphenols, thus offering a better perspective in understanding the role played by dietary polyphenols in human health.

Potentiation of paclitaxel effect by resveratrol in human breast cancer cells by counteracting the 17β-estradiol/estrogen receptor α/neuroglobin pathway

Neuroglobin (NGB), an antiapoptotic protein upregulated by 17β-estradiol (E2), is part of E2/estrogen receptor α (ERα) pathway pointed to preserve cancer cell survival in presence of microenvironmental stressors including chemotherapeutic drugs. Here, the possibility that resveratrol (Res), an anticancer plant polyphenol, could increase the susceptibility of breast cancer cells to paclitaxel (Pacl) by affecting E2/ERα/NGB pathway has been evaluated. In MCF-7 and T47D (ERα-positive), but not in MDA-MB 231 (ERα-negative) nor in SK-N-BE (ERα and ERβ positive), Res decreases NGB levels interfering with E2/ERα-induced NGB upregulation and with E2-induced ERα and protein kinase B phosphorylation. Although Res treatment does not reduce cell viability by itself, this compound potentiates Pacl proapoptotic effects. Notably, the increase of NGB levels by NGB expression vector transfection prevents Pacl or Res/Pacl effects. Taken together, these findings indicate a new Res-based mechanism that acts on tumor cells impairing the E2/ERα/NGB signaling pathways and increasing cancer cell susceptibility to chemotherapeutic agent.

Resveratrol enhances the chemotherapeutic response and reverses the stemness induced by gemcitabine in pancreatic cancer cells via targeting SREBP1

OBJECTIVES

Gemcitabine is a standard treatment for advanced pancreatic cancer patients but can cause chemoresistance during treatment. The chemoresistant cells have features of cancer stem cells (CSCs). Resveratrol has been reported to overcome the resistance induced by gemcitabine. However, the mechanism by which resveratrol enhances chemosensitivity remains elusive. Here, we explored the mechanism by which resveratrol enhanced chemosensitivity and the role of sterol regulatory element binding protein 1 (SREBP1) in gemcitabine-induced stemness.

MATERIALS AND METHODS

The pancreatic cancer cell lines MiaPaCa-2 and Panc-1 were treated under different conditions. Methyl thiazolyl tetrazolium and colony formation assays were performed to evaluate effects on proliferation. Flow cytometry was conducted to detect apoptosis. Oil red O staining was performed to examine lipid synthesis. The sphere formation assay was applied to investigate the stemness of cancer cells. Immunohistochemistry was performed on tumour tissue obtained from treated KPC mice.

RESULTS

Resveratrol enhanced the sensitivity of gemcitabine and inhibited lipid synthesis via SREBP1. Knockdown of SREBP1 limited the sphere formation ability and suppressed the expression of CSC markers. Furthermore, suppression of SREBP1 induced by resveratrol reversed the gemcitabine-induced stemness. These results were validated in a KPC mouse model.

CONCLUSIONS

Our data provide evidence that resveratrol reverses the stemness induced by gemcitabine by targeting SREBP1 both in vitro and in vivo. Thus, resveratrol can be an effective chemotherapy sensitizer, and SREBP1 may be a rational therapeutic target.

Resveratrol: A Double-Edged Sword in Health Benefits

Resveratrol (3,5,4'-trihydroxy-trans-stilbene) belongs to polyphenols' stilbenoids group, possessing two phenol rings linked to each other by an ethylene bridge. This natural polyphenol has been detected in more than 70 plant species, especially in grapes' skin and seeds, and was found in discrete amounts in red wines and various human foods. It is a phytoalexin that acts against pathogens, including bacteria and fungi. As a natural food ingredient, numerous studies have demonstrated that resveratrol possesses a very high antioxidant potential. Resveratrol also exhibit antitumor activity, and is considered a potential candidate for prevention and treatment of several types of cancer. Indeed, resveratrol anticancer properties have been confirmed by many in vitro and in vivo studies, which shows that resveratrol is able to inhibit all carcinogenesis stages (e.g., initiation, promotion and progression). Even more, other bioactive effects, namely as anti-inflammatory, anticarcinogenic, cardioprotective, vasorelaxant, phytoestrogenic and neuroprotective have also been reported. Nonetheless, resveratrol application is still being a major challenge for pharmaceutical industry, due to its poor solubility and bioavailability, as well as adverse effects. In this sense, this review summarized current data on resveratrol pharmacological effects.

Mechanistic evaluation of phytochemicals in breast cancer remedy: current understanding and future perspectives

Breast cancer is one of the most commonly diagnosed cancers around the globe and accounts for a large proportion of fatalities in women. Despite the advancement in therapeutic and diagnostic procedures, breast cancer still represents a major challenge. Current anti-breast cancer approaches include surgical removal, radiotherapy, hormonal therapy and the use of various chemotherapeutic drugs. However, drug resistance, associated serious adverse effects, metastasis and recurrence complications still need to be resolved which demand safe and alternative strategies. In this scenario, phytochemicals have recently gained huge attention due to their safety profile and cost-effectiveness. These phytochemicals modulate various genes, gene products and signalling pathways, thereby inhibiting breast cancer cell proliferation, invasion, angiogenesis and metastasis and inducing apoptosis. Moreover, they also target breast cancer stem cells and overcome drug resistance problems in breast carcinomas. Phytochemicals as adjuvants with chemotherapeutic drugs have greatly enhanced their therapeutic efficacy. This review focuses on the recently recognized molecular mechanisms underlying breast cancer chemoprevention with the use of phytochemicals such as curcumin, resveratrol, silibinin, genistein, epigallocatechin gallate, secoisolariciresinol, thymoquinone, kaempferol, quercetin, parthenolide, sulforaphane, ginsenosides, naringenin, isoliquiritigenin, luteolin, benzyl isothiocyanate, α-mangostin, 3,3'-diindolylmethane, pterostilbene, vinca alkaloids and apigenin.

Mitochondria-targeted delivery of doxorubicin to enhance antitumor activity with HER-2 peptide-mediated multifunctional pH-sensitive DQAsomes

Introduction

Multidrug resistance (MDR) of breast cancer is the major challenge to successful chemotherapy while mitochondria-targeting therapy was a promising strategy to overcome MDR.

Materials and methods

In this study, HER-2 peptide-PEG₂₀₀₀-Schiff base-cholesterol (HPSC) derivate was synthesized successfully and incorporated it on the surface of the doxorubicin (DOX)-loaded dequalinium (DQA) chloride vesicle (HPS-DQAsomes) to treat drug-resistant breast cancer. Evaluations were performed using human breast cancer cell and DOX-resistant breast cancer cell lines (MCF-7 and MCF-7/ADR).

Results

The particle size of HPS-DQAsomes was ~110 nm with spherical shape. In vitro cytotoxicity assay indicated that HPS-DQAsomes could increase the cytotoxicity against MCF-7/ADR cell line. Cellular uptake and mitochondria-targeting assay demonstrated that HPS-DQAsomes could target delivering therapeutical agent to mitochondria and inducing mitochondria-driven apoptosis process. In vivo antitumor assay suggested that HPS-DQAsomes could reach favorable antitumor activity due to both tumor targetability and sub-organelles’ targetability. Histological assay also indicated that HPS-DQAsomes showed a strong apoptosis-inducing effect. No obvious systematic toxicity of HPS-DQAsomes could be observed.

Conclusion

In summary, multifunctional HPS-DQAsomes provide a novel and versatile approach for overcoming MDR via mitochondrial pathway in cancer treatment.

Resveratrol inhibits human leiomyoma cell proliferation via crosstalk between integrin αvβ3 and IGF-1R

Leiomyomas (myomas) are the most common benign smooth muscle cell tumor of the myometrium. Resveratrol, a stilbene, has been used as an anti-inflammatory and antitumor agent. In the current study, we investigated the inhibitory effect of resveratrol on the proliferation of primary human myoma cell cultures. Resveratrol arrested cell proliferation via integrin αvβ3. It also inhibited integrin αvβ3 expression and protein accumulation. Concurrently, constitutive AKT phosphorylation in myoma cells was inhibited by resveratrol. Expressions of proapoptotic genes, such as cyclooxygenase (COX)-2, p21 and CDKN2, were induced by resveratrol in myoma cells. On the other hand, expressions of proliferative (anti-apoptotic) genes were either inhibited, as in BCL2, or unchanged, as in cyclin D1 and proliferating cell nuclear antigen (PCNA). The accumulation of insulin-like growth factor (IGF)-1 receptor (IGF-1R) was inhibited by resveratrol in primary myoma cells. IGF-1-induced cell proliferation was inhibited by co-incubation with resveratrol. Therefore, growth modulation of myoma cells occurs via mechanisms dependent on cross-talk between integrin αvβ3 and IGF-1R. Our findings suggest that resveratrol can be considered an alternative therapeutic agent for myomas.

Endothelial growth factor receptor-targeted and reactive oxygen species-responsive lung cancer therapy by docetaxel and resveratrol encapsulated lipid-polymer hybrid nanoparticles

Special targeted therapy like endothelial growth factor receptor (EGFR) targeted therapy is available for the treatment of advanced non-small cell lung cancer (NSCLC). Biodegradable core-shell lipid-polymer hybrid nanoparticles (LPNs) can combine the beneficial properties of lipid and polymeric NPs for controlled drug delivery. In the present study, epidermal growth factor (EGF) conjugated LPNs were fabricated to co-deliver docetaxel (DTX) and resveratrol (RSV). In vitro and in vivo studies demonstrated that EGF DTX/RSV LPNs have significant synergistic effects, best tumor inhibition ability and the lowest systemic toxicity. The results indicate that EGF DTX/RSV LPNs may be a promising strategy for treatment of NSCLC.

The polypharmacology of natural products

The once-popular approach of using natural products as a prime source for medicinal chemistry and drug discovery has waned considerably in the past two decades due to the advent of high-throughput screening of small molecule mega libraries. However, the growing appreciation of network pharmacology as the next drug-discovery paradigm suggests that natural products and their unique polypharmacology offer significant advantages for finding novel therapeutics particularly for the treatment of complex and multifactorial diseases. Drug discovery process is awaiting the revitalization of interest in natural products and their derivatives. The current challenge is how to decipher this natural chemical diversity.