Resveratrol attenuates the anticancer efficacy of paclitaxel in human breast cancer cells in vitro and in vivo

A novel approach for transforming breast cancer stem cells into endothelial cells

Tumor vascular endothelial cells play a pivotal in the tumor microenvironment, influencing the proliferation, invasion, and metastasis of tumor progression. The present study investigated a novel method for inducing the transformation of breast cancer stem cells into endothelial cells, providing a cellular model investigating anti-angiogenic mechanisms in vitro. The breast cancer cell line MCF-7 was used, and the expression of CD133 was initially detected using flow cytometry. CD133+ breast cancer cells were purified using immunomagnetic bead sorting technology, yielding an MCF-7CD133+ subpopulation. The proliferation ability of these cells was assessed using an MTT assay, while their microsphere formation ability was evaluated using a microsphere formation assay. Post-transformation in an optimized endothelial cell culture medium, expression of endothelial cell markers CD31 and CD105 were detected using flow cytometry. Endothelial cell tube formation assays and DiI-labeled acetylated low-density lipoprotein (DiI-Ac-LDL) assays were employed to analyze the endothelial cell function of the MCF-7CD133+ cells. MDM2/CEN12 gene amplification was detected through fluorescence in situ hybridization (FISH). The MCF-7 breast cancer cell line exhibited 1.7±0.3% trace cells expressing the stem cell surface marker CD133. After anti-CD133 immunomagnetic bead sorting, MCF-7CD133+ and MCF-7CD133- subpopulation cells were obtained, with CD133 expression rates of 85.6±2.8 and 0.18±0.08%, respectively. MTT assay results demonstrated that, after 7 days, the proliferation rate of MCF-7CD133+ cells was significantly higher compared with MCF-7CD133- cells. MCF-7CD133+ subpopulation cells displayed strong stem cell characteristics, growing in suspension in serum-free media and forming tumor cell spheres. In contrast, MCF-7CD133- cells failed to form microspheres. After culturing cells in endothelial cell differentiation and maintenance media, the percentage of MCF-7CD133+ cells before and after endothelial cell culture was 0.3±0.16 and 81.4±8.37% for CD31+ cells and 0.2±0.08 and 83.8±7.24% for CD105+ cells, respectively. Vascular-like structure formation and Ac-LDL phagocytosis with red fluorescence in the tube formation assays confirmed endothelial cell function in the MCF-7CD133+ cells. FISH was used to verify MDM2/CEN12 gene amplification in the induced MCF-7CD133+ cells, indicating tumor cell characteristics. The modified endothelial cell transformation medium effectively induced differentiated tumor stem cells to express vascular endothelial cell markers and exhibit endothelial functions, ideal for in vitro anti-angiogenesis research.

Experimental Studies on the Therapeutic Potential of Vaccinium Berries in Breast Cancer-A Review

Breast cancer (BC) is the largest contributor to cancer deaths in women worldwide. Various parts of plants, including fruits, are known for their therapeutic properties and are used in traditional medicine. Fruit species exhibit anticancer activities due to the presence of bioactive natural compounds such as flavonoids and carotenoids. The Vaccinium spp. are fleshy berry-like drupes and are rich in bioactive compounds, with flavonols, flavanols, chalcones, and phenolic acids as the major groups of compounds. While there is clear evidence linking Vaccinium berries with a decreased risk of BC both in in vivo and in vitro experiments, the exact mechanisms involved in the protective effects of Vaccinium spp. rich extracts on BC cells are not fully understood. Thus, the purpose of this review is to highlight the mechanisms of action involved in the therapeutic potential of Vaccinium berries against BC in experimental models.

Exploring the Antioxidant Potential of Tragia volubilis L.: Mitigating Chemotherapeutic Effects of Doxorubicin on Tumor Cells

Several plants of the genus Tragia L. have shown antibacterial, fungicidal, and antiproliferative activity, among other types of activities; however, most species of the genus have not been investigated. Tragia volubilis L. is native to tropical America and Africa, and although it has been reported as medicinal in the literature, it has not been thoroughly investigated. In this study, the phytochemical screening, isolation, and identification of compounds and the determination of the antioxidant activity of the aqueous extract of Tragia volubilis L. and its partitions were carried out. Ethyl acetate and n-butanol partitions of the extract present high antioxidant activity according to the Antioxidant Activity Index. Due to their activity, these partitions were tested on RKO cells as a representative model, both individually and in combination with Doxorubicin. It was found that the partitions significantly reduced the effect of Doxorubicin, as well as the expression of proteins involved in DNA damage and cell death. While the reduction of the chemotherapeutic effect of Doxorubicin on tumor cells may not be a desired outcome in therapeutic settings, the findings of the study are valuable in revealing the antioxidant potential of Tragia volubilis L. and its partitions. This highlights the importance of carefully regulating the application of antioxidants, especially in the context of cancer chemotherapy.

FooDrugs: a comprehensive food-drug interactions database with text documents and transcriptional data

Food-drug interactions (FDIs) occur when a food item alters the pharmacokinetics or pharmacodynamics of a drug. FDIs can be clinically relevant, as they can hamper or enhance the therapeutic effects of a drug and impact both their efficacy and their safety. However, knowledge of FDIs in clinical practice is limited. This is partially due to the lack of resources focused on FDIs. Here, we describe FooDrugs, a database that centralizes FDI knowledge retrieved from two different approaches: a natural processing language pipeline that extracts potential FDIs from scientific documents and clinical trials and a molecular similarity approach based on the comparison of gene expression alterations caused by foods and drugs. FooDrugs database stores a total of 3 430 062 potential FDIs, with 1 108 429 retrieved from scientific documents and 2 321 633 inferred from molecular data. This resource aims to provide researchers and clinicians with a centralized repository for potential FDI information that is free and easy to use. Database URL:  https://zenodo.org/records/8192515 Database DOI:  https://doi.org/10.5281/zenodo.6638469.

A Novel Resveratrol-Induced Pathway Increases Neuron-Derived Cell Resilience against Oxidative Stress

A promising therapeutic strategy to delay and/or prevent the onset of neurodegenerative diseases (NDs) could be to restore neuroprotective pathways physiologically triggered by neurons against stress injury. Recently, we identified the accumulation of neuroglobin (NGB) in neuronal cells, induced by the 17β-estradiol (E2)/estrogen receptor β (ERβ) axis, as a protective response that increases mitochondria functionality and prevents the activation of apoptosis, increasing neuron resilience against oxidative stress. Here, we would verify if resveratrol (Res), an ERβ ligand, could reactivate NGB accumulation and its protective effects against oxidative stress in neuronal-derived cells (i.e., SH-SY5Y cells). Our results demonstrate that ERβ/NGB is a novel pathway triggered by low Res concentrations that lead to rapid and persistent NGB accumulation in the cytosol and in mitochondria, where the protein contributes to reducing the apoptotic death induced by hydrogen peroxide (H₂O₂). Intriguingly, Res conjugation with gold nanoparticles increases the stilbene efficacy in enhancing neuron resilience against oxidative stress. As a whole, ERβ/NGB axis regulation is a novel mechanism triggered by low concentration of Res to regulate, specifically, the neuronal cell resilience against oxidative stress reducing the triggering of the apoptotic cascade.

Efficacy of resveratrol against breast cancer and hepatocellular carcinoma cell lines

OBJECTIVES

To evaluate the anti-cancer effect of resveratrol on Michigan cancer foundation-7 (MCF-7) and hepatoblastoma cell line (HepG2) cells.

METHODS

The study was carried out at the Department of Botany and Microbiology, Prince Sattam bin Abdulaziz University, Al-kharj, Saudi Arabia, from August 2022 to October 2022. Different concentrations of resveratrol were added to the MCF-7 and HepG2 cell lines. Cell death and proliferation were measured with MTT and Trypan blue exclusion assays. Apoptosis markers were assessed by using a quantitative PCR assay (qPCR).

RESULTS

The resveratrol was shown to suppress the proliferation of MCF-7 and HepG2 cells at dose- and time-dependent. The cytotoxic effect of resveratrol was observed even at 100 μM after 24 hours. In comparison to untreated cells, resveratrol treatment reduced the viability of MCF-7 cells to roughly 57.5% with a half maximal inhibitory concentration (IC50) of 51.18 μM and HepG2 cells to 56.2% with an IC50 of 57.4 μM. Furthermore, in the tested cell lines, resveratrol was able to induce apoptosis mediated by elevated apoptosis markers.

CONCLUSION

Resveratrol appears to be an excellent candidate agent in anticancer therapy in various human cancers.

Cocoa presents cytotoxicity against melanoma cancer cell lines (A-375 e B16-F10) and improves chemotherapy activity by increasing oxidative stress

Melanoma frequently presents a poor chemotherapy response. In this scenario, investigations for new therapies are essential. Thus, cocoa is highlighted in this area since it presents many biological properties. This study investigated the anticarcinogenic activity of cocoa in melanoma cell lines (A-375 and B16-F10). Melanoma and fibroblast (HFF-1) cell lines were exposed to different concentrations of cocoa seeds (30 to 2000 ug/ml) at 24 and 72 h. Cocoa was also associated with paclitaxel IC50. We conducted viability, proliferation, and oxidative stress analyses. Our findings suggested that cocoa isolated, at almost all concentrations tested, was able to reduce viability and proliferation of B16-F10 cells and proliferation of A-375 cells via oxidative stress increasing. Also, cocoa caused no damage in fibroblast cells. Moreover, cocoa increased paclitaxel activity on A-375 by reducing cell proliferation and increasing oxidative stress. Therefore, the results highlight cocoa as a potent selective adjuvant anticancer agent against melanoma. PRACTICAL APPLICATIONS: In conclusion, more studies should be performed to deeply explore this remarkable action of cocoa as a an promising adjuvant to enhance chemotherapy.

The Preventive Effects of Naringin and Naringenin against Paclitaxel-Induced Nephrotoxicity and Cardiotoxicity in Male Wistar Rats

This study assessed the preventive properties of naringin and naringenin on paclitaxel-induced nephrotoxicity and cardiotoxicity in adult male Wistar rats. Intraperitoneal injection of paclitaxel 2 mg/kg body weight, two days/week on the 2nd and 5th days of each week, with or without oral administration of naringin and/or naringenin 10 mg/kg body weight every other day, was continued for six weeks. Treatment of rats with naringin and/or naringenin significantly reversed elevated serum creatinine, urea, and uric acid levels caused by paclitaxel, reflecting improved kidney function. Similarly, heart dysfunction induced by paclitaxel was alleviated after treatment with naringin and/or naringenin, as evidenced by significant decreases in elevated CK-MB and LDH activities. After drug administration, histopathological findings and lesion scores in the kidneys and heart were markedly decreased by naringin and/or naringenin. Moreover, the treatments reversed renal and cardiac lipid peroxidation and the negative impacts on antioxidant defenses via raising GSH, SOD, and GPx. The preventive effects of naringin and naringenin were associated with suppressing oxidative stress and reestablishing antioxidant defenses. A combination of naringin and naringenin was the most efficacious in rescuing organ function and structure.

Eucalyptus oil nanoemulsions against eggs and larvae of Haemonchus contortus

Haemonchus contortus is a highly pathogenic and prevalent helminth that causes many deaths in sheep herds. Anthelmintics are usually employed to overcome this issue; however, they do not guarantee immediate and lasting efficacy because of the occurrence of drug-resistant parasites. Among substances that are used in scientific studies for parasitic control, essential oils are known to have different pharmacological properties. However, they demonstrate instability owing to several factors, and therefore, nanoemulsification is considered an alternative to control the instability and degradability of these compounds. The objective of this study was to evaluate the cytotoxicity of nanoemulsions containing essential oil of Eucalyptus globulus against the blood of healthy sheep and to verify their activity against the parasite H. contortus in sheep. The results presented adequate nanotechnological characteristics (diameter 72 nm, PDI 0.2, zeta -11 mV, and acidic pH) and adequate morphology. Further, the corona effect and cytotoxic profiles of the free oil and nanoemulsion against blood cells from healthy sheep were evaluated. The tests results did not present a toxicity profile. For evaluating efficacy, we observed an important anthelmintic action of the nanoemulsion containing oil in comparison to the free oil; the results demonstrate a potential role of the nanoemulsion in the inhibition of egg hatchability and the development of larvae L1 to L3 (infective stage). Based on these results, we developed an important and potential anthelmintic alternative for the control of the parasite H. contortus.

Role of TRPM2 in brain tumours and potential as a drug target

Ion channels are ubiquitously expressed in almost all living cells, and are the third-largest category of drug targets, following enzymes and receptors. The transient receptor potential melastatin (TRPM) subfamily of ion channels are important to cell function and survival. Studies have shown upregulation of the TRPM family of ion channels in various brain tumours. Gliomas are the most prevalent form of primary malignant brain tumours with no effective treatment; thus, drug development is eagerly needed. TRPM2 is an essential ion channel for cell function and has important roles in oxidative stress and inflammation. In response to oxidative stress, ADP-ribose (ADPR) is produced, and in turn activates TRPM2 by binding to the NUDT9-H domain on the C-terminal. TRPM2 has been implicated in various cancers and is significantly upregulated in brain tumours. This article reviews the current understanding of TRPM2 in the context of brain tumours and overviews the effects of potential drug therapies targeting TRPM2 including hydrogen peroxide (H₂O₂), curcumin, docetaxel and selenium, paclitaxel and resveratrol, and botulinum toxin. It is long withstanding knowledge that gliomas are difficult to treat effectively, therefore investigating TRPM2 as a potential therapeutic target for brain tumours may be of considerable interest in the fields of ion channels and pharmacology.

Antioxidant and cytoprotective effects of avocado oil and extract (Persea americana Mill) against rotenone using monkey kidney epithelial cells (Vero)

Oxidative stress is known to be involved in development of numerous diseases including cardiovascular, respiratory, renal, kidney and cancer. Thus, investigations that mimic oxidative stress in vitro may play an important role to find new strategies to control oxidative stress and subsequent consequences are important. Rotenone, widely used as a pesticide has been used as a model to simulate oxidative stress. However, this chemical was found to produce several diseases. Therefore, the aim of this study was to investigate the antioxidant and cytoprotective effect of avocado (Persea americana Mill) extract and oil in monkey kidney epithelial cells (VERO) exposed to rotenone. VERO cells were exposed to IC₅₀ of rotenone in conjunction with different concentrations of avocado extract and oil (ranging from 1 to 1000 µg/ml), for 24 hr. Subsequently, cell viability and oxidative metabolism were assessed. Data demonstrated that avocado extract and oil in the presence of rotenone increased cellular viability at all tested concentrations compared to cells exposed only to rotenone. In addition, extract and avocado oil exhibited antioxidant action as evidenced by decreased levels of reactive oxygen species (ROS), superoxide ion, and lipid peroxidation, generated by rotenone. Further, avocado extract and oil appeared to be safe, since these compounds did not affect cell viability and or generate oxidative stress. Therefore, avocado appears to display a promising antioxidant potential by decreasing oxidative stress.

Cancer Therapy Challenge: It Is Time to Look in the "St. Patrick's Well" of the Nature

Cancer still remains a leading cause of death despite improvements in diagnosis, drug discovery and therapy approach. Therefore, there is a strong need to improve methodologies as well as to increase the number of approaches available. Natural compounds of different origins (i.e., from fungi, plants, microbes, etc.) represent an interesting approach for fighting cancer. In particular, synergistic strategies may represent an intriguing approach, combining natural compounds with classic chemotherapeutic drugs to increase therapeutic efficacy and lower the required drug concentrations. In this review, we focus primarily on those natural compounds utilized in synergistic approached to treating cancer, with particular attention to those compounds that have gained the most research interest.

Chlorpyrifos pesticide promotes oxidative stress and increases inflammatory states in BV-2 microglial cells: A role in neuroinflammation

The exposure to environmental stressors, such as organophosphate (OP) pesticides, has been associated with the development of neurodegenerative diseases. Chlorpyrifos (CPF) is the worldwide most used OP pesticide and one of the most hazardous pesticides as it can cross the blood-brain barrier. Since studies evaluating the effects of CPF on brain immune cells are scarce, this research investigated the oxidative and inflammatory responses of CPF exposure in murine microglial cells. BV-2 cells were exposed to different concentrations of CPF pesticide (0.3-300 μM). CPF induced activation of microglial cells, confirmed by Iba-1 and CD11b marking, and promoted microglial proliferation and cell cycle arrest at S phase. Moreover, CPF exposure increased oxidative stress production (NO, MDA, and O₂∙), and upregulated pro-inflammatory cytokines (IL-1β and NLRP3) genes expression in BV-2 cells. Overall, data showed that CPF exposure, at the lowest concentrations, acted by promoting pro-oxidative and pro-inflammatory states in microglial cells. These results provide important information on the potential role of microglial activation in CPF-induced neuroinflammation and add to the expanding knowledge on the neurotoxicity of OP.

Nutraceuticals in the Mediterranean Diet: Potential Avenues for Breast Cancer Treatment

The traditional Mediterranean Diet constitutes a food model that refers to the dietary patterns of the population living in countries bordering the Mediterranean Sea in the early 1960s. A huge volume of literature data suggests that the Mediterranean-style diet provides several dietary compounds that have been reported to exert beneficial biological effects against a wide spectrum of chronic illnesses, such as cardiovascular and neurodegenerative diseases and cancer including breast carcinoma. Among bioactive nutrients identified as protective factors for breast cancer, natural polyphenols, retinoids, and polyunsaturated fatty acids (PUFAs) have been reported to possess antioxidant, anti-inflammatory, immunomodulatory and antitumoral properties. The multiple anticancer mechanisms involved include the modulation of molecular events and signaling pathways associated with cell survival, proliferation, differentiation, migration, angiogenesis, antioxidant enzymes and immune responses. This review summarizes the anticancer action of some polyphenols, like resveratrol and epigallocatechin 3-gallate, retinoids and omega-3 PUFAs by highlighting the important hallmarks of cancer in terms of (i) cell cycle growth arrest, (ii) apoptosis, (iii) inflammation and (iv) angiogenesis. The data collected from in vitro and in vivo studies strongly indicate that these natural compounds could be the prospective candidates for the future anticancer therapeutics in breast cancer disease.

In Vitro Evaluation of Antioxidant and Anticancer Activity of Lemongrass (Cymbopogon citratus (D.C.) Stapf)

Cancer is considered a multifactorial disease and its development could be associated with several factors, for example, rotenone exposition. Unfortunately, many cancers are resistant to chemotherapy, as cervical cancer. Regarding this, lemongrass is a remarkable natural product that presents antioxidant and anticancer activities, which could show therapeutic action against rotenone and cervical cancer. Thus, this study aimed to investigate the antioxidant and anticancer action of lemongrass. An in vitro study was conducted using VERO (kidney cells) and SiHa cell lines (cervical cancer cells). VERO cells were exposed to rotenone and lemongrass extract for 24 and 72 h. While SiHa cells were exposed to lemongrass isolated and associated to chemotherapy, 5-fluorouracil, during 24 and 48 h. After, levels of viability, proliferation, and oxidative metabolism were determined. The results showed that lemongrass presents antioxidant activity on VERO cells by increasing cell viability and proliferation and decreasing oxidative stress caused by rotenone. Moreover, lemongrass showed anticancer activity by decreasing cell viability and increasing oxidative stress parameters on SiHa. Besides, lemongrass had no alteration in the chemotherapy activity. Therefore, this study revealed that lemongrass presents antioxidant and anticancer activity since it can protect against the cytotoxicity of rotenone and reduce the cell viability of cervical cancer.

Mechanism underlying resveratrol's attenuation of paclitaxel cytotoxicity in human breast cancer cells: Role of the SIRT1-FOXO1-HER3 signaling pathway

Resveratrol (RES), a dietary phenolic compound, was reported to have cancer chemoprotective and chemotherapeutic effects. Earlier we unexpectedly observed that RES has a growth-enhancing effect in some breast cancer cells and can diminish the susceptibility of MDA-MB-231 and SKBR-3 cells to paclitaxel-induced cell death, but this phenomenon is not observed in MCF-7 cells. The present study seeks to determine the mechanism underlying RES's attenuation of paclitaxel cytotoxicity in cancer cells. It is found that RES reduces the anticancer action of paclitaxel only in the human breast cancer cells that express HER3 protein. Treatment of SKBR-3 cells with RES increases HER3 expression in a dose-dependent manner. The induction of HER3 expression by RES confers resistance of breast cancer cells against paclitaxel cytotoxicity. Furthermore, it is observed that the SIRT1-FOXO1 signaling pathway plays an important role in mediating RES-induced upregulation of HER3 expression. In conclusion, the present study reveals the mechanism for RES-induced resistance against paclitaxel in some human breast cancer cells, and it is suggested that the combined use of RES and paclitaxel is not suitable for treating human breast cancer that expresses HER3 protein.

Resveratrol as an Adjuvant for Normal Tissues Protection and Tumor Sensitization

Cancer is one of the most complicated diseases in present-day medical science. Yearly, several studies suggest various strategies for preventing carcinogenesis. Furthermore, experiments for the treatment of cancer with low side effects are ongoing. Chemotherapy, targeted therapy, radiotherapy and immunotherapy are the most common non-invasive strategies for cancer treatment. One of the most challenging issues encountered with these modalities is low effectiveness, as well as normal tissue toxicity for chemo-radiation therapy. The use of some agents as adjuvants has been suggested to improve tumor responses and also alleviate normal tissue toxicity. Resveratrol, a natural flavonoid, has attracted a lot of attention for the management of both tumor and normal tissue responses to various modalities of cancer therapy. As an antioxidant and anti-inflammatory agent, in vitro and in vivo studies show that it is able to mitigate chemo-radiation toxicity in normal tissues. However, clinical studies to confirm the usage of resveratrol as a chemo-radioprotector are lacking. In addition, it can sensitize various types of cancer cells to both chemotherapy drugs and radiation. In recent years, some clinical studies suggested that resveratrol may have an effect on inducing cancer cell killing. Yet, clinical translation of resveratrol has not yielded desirable results for the combination of resveratrol with radiotherapy, targeted therapy or immunotherapy. In this paper, we review the potential role of resveratrol for preserving normal tissues and sensitization of cancer cells in combination with different cancer treatment modalities.

Diabetes and Cancer: Metabolic Association, Therapeutic Challenges, and the Role of Natural Products

Cancer is considered the second leading cause of death worldwide and in 2018 it was responsible for approximately 9.6 million deaths. Globally, about one in six deaths are caused by cancer. A strong correlation was found between diabetes mellitus and carcinogenesis with the most evident correlation was with type 2 diabetes mellitus (T2DM). Research has proven that elevated blood glucose levels take part in cell proliferation and cancer cell progression. However, limited studies were conducted to evaluate the efficiency of conventional therapies in diabetic cancer patients. In this review, the correlation between cancer and diabetes will be discussed and the mechanisms by which the two diseases interact with each other, as well as the therapeutics challenges in treating patients with diabetes and cancer with possible solutions to overcome these challenges. Natural products targeting both diseases were discussed with detailed mechanisms of action. This review will provide a solid base for researchers and physicians to test natural products as adjuvant alternative therapies to treat cancer in diabetic patients.

Anti-Angiogenic Therapy: Current Challenges and Future Perspectives

Anti-angiogenic therapy is an old method to fight cancer that aims to abolish the nutrient and oxygen supply to the tumor cells through the decrease of the vascular network and the avoidance of new blood vessels formation. Most of the anti-angiogenic agents approved for cancer treatment rely on targeting vascular endothelial growth factor (VEGF) actions, as VEGF signaling is considered the main angiogenesis promotor. In addition to the control of angiogenesis, these drugs can potentiate immune therapy as VEGF also exhibits immunosuppressive functions. Despite the mechanistic rational that strongly supports the benefit of drugs to stop cancer progression, they revealed to be insufficient in most cases. We hypothesize that the rehabilitation of old drugs that interfere with mechanisms of angiogenesis related to tumor microenvironment might represent a promising strategy. In this review, we deepened research on the molecular mechanisms underlying anti-angiogenic strategies and their failure and went further into the alternative mechanisms that impact angiogenesis. We concluded that the combinatory targeting of alternative effectors of angiogenic pathways might be a putative solution for anti-angiogenic therapies.

Tucumã (Astrocaryum aculeatum) Prevents Oxidative and DNA Damage to Retinal Pigment Epithelium Cells

Eye diseases have a negative impact on the eyesight quality of the world population. The age-related macular degeneration (AMD) draws special attention since it is a chronic disorder characterized by oxidative and inflammatory damage to the retinal epithelial pigment, which triggers progressive vision loss. In the Brazilian Amazon, Astrocaryum aculeatum is an Amazonian fruit (Tucumã) used by riverside communities in traditional medicine to treat a number of ailments. These communities have recently shown to have increased longevity and reduced prevalence of age-related morbidity. Thus, the aim of this research was to chemically characterize and analyze the in vitro antioxidant effect and molecular damage prevention of the Tucumã ethanolic extract in retinal pigment epithelium (RPE) cells in a model for AMD. The extract was chemically characterized by ultra-high-performance liquid chromatography (HPLC) coupled with diode-array detection and mass spectrophotometry (HPLC-DAD-MS). In vitro protocols were performed, and the cytopreventive effect of Tucumã on RPE cells exposed to high concentrations of superoxide anion, an oxidant and genotoxic molecule, as well as the effect of Tucumã extract on oxidative and molecular makers were assessed. Biochemical and flow cytometry analyses were conducted in these protocols. The extract presents high concentrations of caffeic acid, gallic acid, catechin, luteolin, quercetin, and rutin. Treatment did not show cytotoxic effects in cells treated only with extract at 50 μg/mL. In fact, it improved cell viability and was able to prevent necrosis and apoptosis, and oxidative and molecular damage was significantly reduced. In summary, Tucumã is an important Amazon fruit, which seems to contribute significantly to improve human health conditions, as our findings suggest that its extract has a relevant chemical matrix rich in antioxidant molecules, and its consumption could improve eye health and contribute to prevention against oxidative stress through cytoprevention, reactive oxygen species reduction, and maintenance of DNA integrity in retinal pigment epithelium (RPE) cells.

Resveratrol induces PD-L1 expression through snail-driven activation of Wnt pathway in lung cancer cells

Purpose

Recent clinical trials with agents targeting immune checkpoint pathway have emerged as an important therapeutic approach for a broad range of cancer types. Resveratrol has been shown to possess cancer preventive and therapeutic effects and has potential to be chemotherapeutic agent/adjuvant. Here, we assessed the effect of resveratrol on immune checkpoint pathways.

Methods

The expression patterns of Wnt components and PD-L1 were examined by Western blot, Chromatin immunoprecipitation (ChIP) was used for analysis of DNA–protein interaction, the promoter activity was determined by luciferase reporter assay, apoptosis was analyzed by flow cytometry and the ability of the resveratrol to modulate T cell function was assessed in a co-culture system.

Results

Although the dose-, and cell-type dependent effects of resveratrol on PD-L1 expression have been reported, we show here that resveratrol dose-dependently upregulates PD-L1 expression at the range of pharmacologic-achievable concentrations in lung cancer cells and that is essential for suppression of T-cell-mediated immune response. We also found that Wnt pathway is critical for mediating resveratrol-induced PD-L1 upregulation. Mechanistically, resveratrol activates SirT1 deacetylase to deacetylate and stabilize transcriptional factor Snail. Snail in turn inhibits transcription of Axin2, which leads in disassembly of destruction complex and enhanced binding of β-catenin/TCF to PD-L1 promoter.

Conclusion

We conclude that resveratrol is capable to suppress anti-tumor immunity by controlling mainly PD-L1 expression. This finding will extend the understanding of resveratrol in regulation of tumor immunity and is relevant to the debate on resveratrol supplements for lung cancer patients.

Resveratrol enhances the sensitivity of FL118 in triple-negative breast cancer cell lines via suppressing epithelial to mesenchymal transition

We aimed to investigate whether resveratrol (RSV) could sensitize human triple-negative breast cancer (TNBC) cells to FL118-induced cell death, epithelial to mesenchymal transition (EMT), invasion, and migration. The effects of sequential administration of RSV and FL118 on MDA-MB-436 and MDA-MB-468 cells were evaluated in terms of cell viability, cytotoxicity, apoptosis, cell cycle distribution, active caspase-3/7 levels, migration and invasion. Furthermore, mRNA and protein levels of EMT associated genes and proteins were also evaluated. Sequential administration of RSV and FL118 inhibited the cell viability in both TNBC cell lines. Meanwhile sequential administration of RSV and FL118 also dramatically reduced the migratory and invasive capabilities, it also reversed the EMT process in both TNBC cells. Moreover, sequential administration of RSV and FL118 led to a significant increase of apoptotic cells, as well as active Caspase-3/7 levels. Sequential administration of RSV and FL118 caused TNBC cells accumulating in the G1 phase, and markedly suppressed the mRNA and protein levels of N-cadherin, β-catenin, Vimentin, Snail, and Slug, and also significantly downregulated mRNA levels of Fibronectin, Twist1, Twist2, Zeb1, and Zeb2 genes, while enhanced the mRNA and protein levels of E-cadherin genes. RSV sensitized TNBC cells to FL118 via facilitating apoptosis, migration, invasion, and EMT and enhancing intracellular entrapment of FL118. Thus, our results suggest that since RSV enhanced the in vitro anticancer activity of FL118 in BC, it may be a potential therapeutic agent in advanced BC.

Cellular Mechanisms Triggered by the Cotreatment of Resveratrol and Doxorubicin in Breast Cancer: A Translational In Vitro-In Silico Model

Doxorubicin (Doxo) is the most effective chemotherapeutic agent for the treatment of breast cancer. However, resistance to Doxo is common. Adjuvant compounds capable of modulating mechanisms involved in Doxo resistance may potentiate the effectiveness of the drug. Resveratrol (Rsv) has been tested as an adjuvant in mammary malignancies. However, the cellular and molecular mechanisms underlying the effects of cotreatment with Doxo and Rsv in breast cancer are poorly understood. Here, we combined in vitro and in silico analysis to characterize these mechanisms. In vitro, we employed a clinically relevant experimental design consisting of acute (24 h) treatment followed by 15 days of analysis. Acute Rsv potentiated the long-lasting effect of Doxo through the induction of apoptosis and senescence. Cells that survived to the cotreatment triggered high levels of autophagy. Autophagy inhibition during its peak of activation but not concomitant with Doxo+Rsv increased the long-term toxicity of the cotreatment. To uncover key proteins potentially associated with in vitro effects, an in silico multistep strategy was implemented. Chemical-protein networks were predicted based on constitutive gene expression of MCF7 cells and interatomic data from breast cancer. Topological analysis, KM survival analysis, and a quantitative model based on the connectivity between apoptosis, senescence, and autophagy were performed. We found seven putative genes predicted to be modulated by Rsv in the context of Doxo treatment: CCND1, CDH1, ESR1, HSP90AA1, MAPK3, PTPN11, and RPS6KB1. Six out of these seven genes have been experimentally proven to be modulated by Rsv in cancer cells, with 4 of the 6 genes in MCF7 cells. In conclusion, acute Rsv potentiated the long-term toxicity of Doxo in breast cancer potentially through the modulation of genes and mechanisms involved in Doxo resistance. Rational autophagy inhibition potentiated the effects of Rsv+Doxo, a strategy that should be further tested in animal models.

Understanding the complicated relationship between antioxidants and carcinogenesis

Reactive oxygen species (ROS) are generated as by-product of cellular respiration and also due to the exposure of various xenobiotics, whereas mitochondrial electron transport chain is considered as the main source of ROS generation. The sequential addition to molecular oxygen gives rise to various forms of ROS like superoxide anion, peroxide, hydroxyl radical, hydroxyl ion, and so forth. However, the uncontrolled level of ROS generation and accumulation alters the body homeostasis. Excessive generation of ROS leads to oxidative stress and various kinds of diseases including cancer. To counteract ROS, enzymatic and nonenzymatic antioxidants' armory is available in our body. Apart from endogenous antioxidants, we are also consuming various exogenous antioxidants. Antioxidants protect us from ROS-mediated damages and inhibit ROS-induced carcinogenesis. Recent studies have revealed that antioxidants could also act as tumor-promoting agents. Various anticancer drugs are used to kill the cancer cells through the generation of oxidative stress in them, but the cancer cells can counteract the effect with the help of various endogenous as well as exogenous antioxidants. Our review will summarize the multifaceted relationship between antioxidants and carcinogenesis, and it will help to create new directions in antioxidant-based chemotherapy.

SPR064, a pro-drug of paclitaxel, has anti-tumorigenic effects in endometrial cancer cell lines and mouse models

Paclitaxel is one of the most effective and widely used agents in treating a variety of cancers, including endometrial cancer. Because of its poor solubility in water, the current intravenous pharmaceutical paclitaxel is formulated in Cremophor EL and dehydrated in ethanol in equal volumes. Cremophor EL is capable of causing complement activation, which can trigger an immediate hypersensitivity reaction. SPR064 is a pro-drug of paclitaxel which has a much higher solubility as compared to the parent drug; hence, SPR064 can be conveniently formulated in non-cremapor based medium, reducing the risk of cremaphor-related hypersensitivity reactions. The pharmacokinetics and solubility of SPR064 were evaluated in rats. The anti-tumorigenic potential of SPR064 was compared to paclitaxel in endometrial cancer cell lines and a genetically engineered mouse model (Lkb^fl/flp53^fl/fl ) of endometrial cancer. Overall, SPR064 exhibited improved solubility and better exposure to drug in rats when compared to paclitaxel. SPR064 and paclitaxel inhibited cell proliferation, induced apoptosis, enhanced cellular stress and caused cell cycle G1 arrest in endometrial cancer cell lines, with similar potency. Both SPR064 and paclitaxel reduced tumor weight in the Lkb^fl/flp53^fl/fl mouse model under obese and lean conditions compared to their respective controls. Immunohistochemical staining demonstrated that SPR064 and paclitaxel significantly reduced the expression of Ki-67 and BCL-xL in the endometrial tumors of both obese and lean mice. In summary, SPR064 has anti-tumorigenic effects that are equivalent to paclitaxel in endometrial cancer cell lines and a genetically engineered mouse model of endometrial cancer. Thus, SPR064 may be a promising therapy for endometrial cancer without the significant risk of hypersensitivity reactions seen with paclitaxel.

Vaticanol C, a phytoalexin, induces apoptosis of leukemia and cancer cells by modulating expression of multiple sphingolipid metabolic enzymes

Resveratrol (RSV) has recently attracted keen interest because of its pleiotropic effects. It exerts a wide range of health-promoting effects. In addition to health-promoting effects, RSV possesses anti-carcinogenic activity. However, a non-physiological concentration is needed to achieve an anti-cancer effect, and its in vivo bioavailability is low. Therefore, the clinical application of phytochemicals requires alternative candidates that induce the desired effects at a lower concentration and with increased bioavailability. We previously reported a low IC₅₀ of vaticanol C (VTC), an RSV tetramer, among 12 RSV derivatives (Ito T. et al, 2003). However, the precise mechanism involved remains to be determined. Here, we screened an in-house chemical library bearing RSV building blocks ranging from dimers to octamers for cytotoxic effects in several leukemia and cancer cell lines and their anti-cancer drug-resistant sublines. Among the compounds, VTC exhibited the highest cytotoxicity, which was partially inhibited by a caspase 3 inhibitor, Z-VAD-FMK. VTC decreased the expression of sphingosine kinase 1, sphingosine kinase 2 and glucosylceramide synthase by transcriptional or post-transcriptional mechanisms, and increased cellular ceramides/dihydroceramides and decreased sphingosine 1-phosphate (S1P). VTC-induced sphingolipid rheostat modulation (the ratio of ceramide/S1P) is thought to be involved in cellular apoptosis. Indeed, exogenous S1P addition modulated VTC cytotoxicity significantly. A combination of SPHK1, SPHK2, and GCS chemical inhibitors induced sphingolipid rheostat modulation, cell growth suppression, and cytotoxicity similar to that of VTC. These results suggest the involvement of sphingolipid metabolism in VTC-induced cytotoxicity, and indicate VTC is a promising prototype for translational research.

Chemopreventive efficacy of stampidine in a murine breast cancer model

Background: The purpose of the present study was to examine the chemopreventive effect of stampidine, an aryl phosphate derivative of stavudine, in side by side comparison with the standard anti-breast cancer drug paclitaxel in the well-established 7,12-dimethylbenz(a)anthracene (DMBA)-induced murine breast cancer model.Methods: Groups of 20 female mice were challenged with the DMBA. DMBA-challenged mice were assigned to various chemoprevention treatments, including stampidine, paclitaxel, and stampidine plus paclitaxel according to the same treatment schedules for 25 weeks.Results: Stampidine resulted in substantially reduced numbers of tumors, tumor weight as well as tumor size in DMBA-treated mice. Stampidine was as effective as paclitaxel in the model and their combination exhibited greater chemopreventive activity, as measured by reduced tumor incidence and improved tumor-free survival as well as overall survival of DMBA-treated mice. The length of time for the initial tumor to appear in DMBA-challenged mice treated with stampidine was longer than that of mice treated DMBA-challenged control mice. Tumors from mice treated with stampidine or stampidine plus paclitaxel displayed unique changes of a signature protein cassette comprised BRCA1, p21, Bax, and Bcl-2.Conclusion: Stampidine has potent chemopreventive activity and is as effective as the standard chemotherapy drug paclitaxel in the chemical carcinogenesis.

Astrocaryum aculeatum fruit improves inflammation and redox balance in phytohemagglutinin-stimulated macrophages

ETHNOPHARMACOLOGICAL RELEVANCE

The fruit of Astrocaryum aculeatum G.Mey. (tucumã) is highly consumed by riverside communities in the Amazonian region. These communities have recently been shown to have increased longevity and reduced prevalence of age-related morbidity. Tucumã, which is locally used in their diet and traditional medicine may contribute to these features.

AIM OF THE STUDY

To investigate the anti-inflammatory and antioxidant properties of A. aculeatum extract against phytohemagglutinin-induced inflammation in cell cultures.

MATERIALS AND METHODS

Cell viability and cytotoxicity assays, gene expression of interleukins IL-1β, IL-6, IL-10, levels of reactive oxygen species (ROS), nitric oxide (NO) and thiols were employed, as well as the activities of antioxidant enzymes in RAW 264.7 cells stimulated with phytohemagglutinin to mimic inflammation.

RESULTS

The extract of A. aculeatum fruit inhibited macrophage proliferation (P < 0.05), arrested the cell cycle in G0/G1 phase (P < 0.001), increased antioxidant defenses (P < 0.01), reduced oxidative stress (P < 0.01), and modulated genes related to the inflammatory response (P < 0.001).

CONCLUSION

Our results demonstrate that A. aculeatum fruit has anti-inflammatory and antioxidant capacities. These beneficial effects of tucumã on cells are also likely to be seen in vivo, thereby suggesting that its extract is a suitable therapeutic adjuvant in the prevention or treatment of inflammatory diseases.

Role of Reactive Oxygen Species in Cancer Progression: Molecular Mechanisms and Recent Advancements

Reactive oxygen species (ROS) play a pivotal role in biological processes and continuous ROS production in normal cells is controlled by the appropriate regulation between the silver lining of low and high ROS concentration mediated effects. Interestingly, ROS also dynamically influences the tumor microenvironment and is known to initiate cancer angiogenesis, metastasis, and survival at different concentrations. At moderate concentration, ROS activates the cancer cell survival signaling cascade involving mitogen-activated protein kinase/extracellular signal-regulated protein kinases 1/2 (MAPK/ERK1/2), p38, c-Jun N-terminal kinase (JNK), and phosphoinositide-3-kinase/ protein kinase B (PI3K/Akt), which in turn activate the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), matrix metalloproteinases (MMPs), and vascular endothelial growth factor (VEGF). At high concentrations, ROS can cause cancer cell apoptosis. Hence, it critically depends upon the ROS levels, to either augment tumorigenesis or lead to apoptosis. The major issue is targeting the dual actions of ROS effectively with respect to the concentration bias, which needs to be monitored carefully to impede tumor angiogenesis and metastasis for ROS to serve as potential therapeutic targets exogenously/endogenously. Overall, additional research is required to comprehend the potential of ROS as an effective anti-tumor modality and therapeutic target for treating malignancies.

Immunomodulatory effect of mancozeb, chlorothalonil, and thiophanate methyl pesticides on macrophage cells

Mancozeb (MZ), chlorothalonil (CT), and thiophanate methyl (TM) are pesticides commonly used in agriculture due to their efficacy, low acute toxicity to mammals, and short environmental persistence. Although the toxic effects of these pesticides have been previously reported, studies regarding their influence on the immune system are limited. As such, this study focused on the immunomodulatory effect of MZ, CT, and TM pesticides on macrophage cells. RAW 264.7 cells were exposed to a range of concentrations (0.1-100 μg/mL) of these pesticides. CT exposure promoted an increase in reactive oxygen species (ROS) and nitric oxide (NO) levels. The MTT and ds-DNA assay results demonstrated that MZ, CT, and TM exposure induced macrophage proliferation. Moreover, MZ, CT, and TM promoted cell cycle arrest at S phase, strongly suggesting macrophage proliferation. The levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IFN-γ) and caspases (caspase 1, 3, and 8) in macrophages exposed to MZ, CT, and TM pesticides increased, whereas the anti-inflammatory cytokine levels decreased. These results suggest that MZ, CT, and TM exert an immunomodulatory effect on the immune system, inducing macrophage activation and enhancing the inflammatory response.

Targeting Reactive Oxygen Species in Cancer via Chinese Herbal Medicine

Recently, reactive oxygen species (ROS), a class of highly bioactive molecules, have been extensively studied in cancers. Cancer cells typically exhibit higher levels of basal ROS than normal cells, primarily due to their increased metabolism, oncogene activation, and mitochondrial dysfunction. This moderate increase in ROS levels facilitates cancer initiation, development, and progression; however, excessive ROS concentrations can lead to various types of cell death. Therefore, therapeutic strategies that either increase intracellular ROS to toxic levels or, conversely, decrease the levels of ROS may be effective in treating cancers via ROS regulation. Chinese herbal medicine (CHM) is a major type of natural medicine and has greatly contributed to human health. CHMs have been increasingly used for adjuvant clinical treatment of tumors. Although their mechanism of action is unclear, CHMs can execute a variety of anticancer effects by regulating intracellular ROS. In this review, we summarize the dual roles of ROS in cancers, present a comprehensive analysis of and update the role of CHM—especially its active compounds and ingredients—in the prevention and treatment of cancers via ROS regulation and emphasize precautions and strategies for the use of CHM in future research and clinical trials.

Comparison of the Hepatoprotective Effects of the Three Main Stilbenes from Mulberry Twigs

The purpose of this study was to compare the hepatoprotective effects of Oxy (oxyresveratrol), Res (resveratrol), and MulA (mulberroside A) (80 mg/kg body weight/d, i.g.) on acute liver injury (ALI) induced by lipopolysaccharide (LPS)/d-galactosamine (d-GalN) in mice. After 7 h of LPS (50 μg/kg body weight, i.p.) and d-GalN (500 mg/kg body weight, i.p.) exposure, the activities of serum transaminases and antioxidant enzymes were determined. The expressions of the Kelch-like ECH-associated protein 1 (Keap1)-nuclear factor erythroid 2-related factor 2 (Nrf2) signal pathway, the nuclear factor-kappa B (NF-κB) signal pathway, and the mitogen-activated protein kinase (MAPK) signal pathway related proteins were evaluated by Western blot assays. Histopathological analysis was performed by hematoxylin-eosin (H&E) staining on the separated livers of mice. The results showed that treatment with Oxy, Res, and MulA could significantly decreases the levels of alanine transaminase (ALT) and aspartate transaminase (AST) ( P < 0.01). MulA was the most effective ingredient among the three, and the ALT and AST levels were reduced at 90.3 ± 1.3% and 93.9 ± 1.1% compared with the LPS/D-GalN treated group ( P < 0.01). Meanwhile, the stilbenes curbed the expression of inflammatory factors, NF-κB pathway activation, and MAPKs phosphorylation and upregulated antioxidant enzymes, Nrf2, NAD (P) H:quinone oxidoreductase (NQO1), and heme oxygenase-1 (HO-1) expression levels. Stilbenes might protect the ALI caused by LPS/d-GalN through inhibiting the negative effectiveness of oxidation stress and inflammation. The protective performance of MulA was better than those of Oxy and Res, and we hypothesize that it might be due to the mediation of the specific metabolic pathway of the MulA in vivo. All of these results implied that stilbenes in mulberry twigs might be promising as natural additives.

Guarana improves behavior and inflammatory alterations triggered by methylmercury exposure: an in vivo fruit fly and in vitro neural cells study

Methylmercury (MeHg) is a well-known environmental pollutant associated with neurological and developmental deficits in animals and humans. However, epidemiological data showed that people living in the Amazon region although exposed to MeHg do not present these effects probably due to the protective effect of certain foods. We hypothesized here if guarana, a highly caffeinated fruit and consumed on a daily basis by Amazon people, could have some protective effect against MeHg toxicity using two complementary approaches. To assess locomotor impairment and sleep disruption, we used fruit fly (Drosophila melanogaster) model, and to evaluate neuroinflammation, we used human SH-SY5Y neural cells by measuring inflammatory cytokines levels. Results showed that guarana had a protective effect on the locomotor activity of male fruit flies reducing the excessive sleepiness caused by MeHg and increasing daily activity. Also, guarana increased the viability of flies and attenuated neural cells mortality. In addition, guarana reduced all pro-inflammatory cytokines levels increased by MeHg, along with caspase-1, caspase -3, caspase-8, and 8-dOHG levels, whereas increased the anti-inflammatory (IL-10) cytokine levels, which was decreased by MeHg. Our study provides new insights on the protective effects of guarana on the viability, locomotor activity, sleep, and activity patterns in vivo and the in vitro neuronal anti-inflammatory effect against MeHg toxicity.

Role of Hedgehog Signaling in Breast Cancer: Pathogenesis and Therapeutics

Breast cancer (BC) is the leading cause of cancer-related mortality in women, only followed by lung cancer. Given the importance of BC in public health, it is essential to identify biomarkers to predict prognosis, predetermine drug resistance and provide treatment guidelines that include personalized targeted therapies. The Hedgehog (Hh) signaling pathway plays an essential role in embryonic development, tissue regeneration, and stem cell renewal. Several lines of evidence endorse the important role of canonical and non-canonical Hh signaling in BC. In this comprehensive review we discuss the role of Hh signaling in breast development and homeostasis and its contribution to tumorigenesis and progression of different subtypes of BC. We also examine the efficacy of agents targeting different components of the Hh pathway both in preclinical models and in clinical trials. The contribution of the Hh pathway in BC tumorigenesis and progression, its prognostic role, and its value as a therapeutic target vary according to the molecular, clinical, and histopathological characteristics of the BC patients. The evidence presented here highlights the relevance of the Hh signaling in BC, and suggest that this pathway is key for BC progression and metastasis.

The signaling effects of ATP on melanoma-like skin cancer

Melanoma is a type of skin cancer originated by the malignant transformation of melanocytes. Increasing incidence and mortality require efforts focused on studies and research about this cancer. Its microenvironment is rich in extracellular ATP, but there are no studies evaluating the ectonucleotidases and ATP effects on tumor-derived melanoma cells with known amounts of ATP. This way, the objective of this work was to evaluate the purinergic signaling in the pathophysiology of in vivo melanoma and the in vitro effects of ATP signaling. We found increased and effective extracellular ATP hydrolysis in platelets and a significant decrease of extracellular ATP levels and adenosine hydrolysis. In addition, we cultured PBMCs of melanoma patients and used ATP salt with specific concentrations to evaluate its signaling effects. The enzymatic activity analysis revealed that even with higher ATP doses cells metabolize adenine nucleotides less efficiently, and present low ATP, ADP and AMP hydrolytic activity in CM compared to CT cells. In summary, we showed for the first time important data about the purinergic signaling in the pathophysiology of melanoma and ATP signaling exercising immunosuppressive effects. Therefore, as already shown for other tumors, the purinergic signaling should be considered a potential target for melanoma management and treatment and could offer novel therapeutic prospects.

Resveratrol Enhances Apoptotic and Oxidant Effects of Paclitaxel through TRPM2 Channel Activation in DBTRG Glioblastoma Cells

Numerous studies have reported a strong association between increased production of reactive oxygen species (ROS) and the pathobiology of several diseases, and cancer in particular. Therefore, manipulation of cellular oxidative stress levels represents an important therapeutic target. Recently, resveratrol (RESV), a naturally occurring phytochemical, has been shown to sensitize several cell lines to the anticancer effects of other chemotherapeutic agents, including paclitaxel (PAX). However, the molecular mechanisms of action of RESV through oxidative sensitive TRPM2 channel activation remain unclear. The aim of this study was to evaluate the effect of combination therapy of RESV and PAX on activation of TRPM2 in DBTRG glioblastoma cells. DBTRG cells were divided into four treatment groups: control, RESV (50 μM), PAX (50 μM), and PAX + RESV for 24 hours. Our data shows that markers for apoptosis, mitochondrial membrane depolarization and mitochondrial function, intracellular steady-state ROS levels, caspase 3 activity, TRPM2 current density, and Ca²⁺ florescence intensity were significantly increased in DBTRG cells following treatment with PAX and RESV, respectively, although cell viability was also decreased by these treatments. These biochemical markers were further increased to favor the anticancer effects of PAX in DBTRG cells in combination with RESV. The PAX and RESV-mediated increase in current density and Ca²⁺ florescence intensity was decreased with a TRPM2 blocker. This suggests that for this combination therapy to have a substantial effect on apoptosis and cell viability, the TRPM2 channel must be stimulated.

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.

The "Yin and Yang" of Natural Compounds in Anticancer Therapy of Triple-Negative Breast Cancers

Among the different types of breast cancers, triple-negative breast cancers (TNBCs) are highly aggressive, do not respond to conventional hormonal/human epidermal growth factor receptor 2 (HER2)-targeted interventions due to the lack of the respective receptor targets, have chances of early recurrence, metastasize, tend to be more invasive in nature, and develop drug resistance. The global burden of TNBCs is increasing regardless of the number of cytotoxic drugs being introduced into the market each year as they have only moderate efficacy and/or unforeseen side effects. Therefore, the demand for more efficient therapeutic interventions, with reduced side effects, for the treatment of TNBCs is rising. While some plant metabolites/derivatives actually induce the risk of cancers, many plant-derived active principles have gained attention as efficient anticancer agents against TNBCs, with fewer adverse side effects. Here we discuss the possible oncogenic molecular pathways in TNBCs and how the purified plant-derived natural compounds specifically target and modulate the genes and/or proteins involved in these aberrant pathways to exhibit their anticancer potential. We have linked the anticancer potential of plant-derived natural compounds (luteolin, chalcones, piperine, deguelin, quercetin, rutin, fisetin, curcumin, resveratrol, and others) to their ability to target multiple dysregulated signaling pathways (such as the Wnt/β-catenin, Notch, NF-κB, PI3K/Akt/mammalian target of rapamycin (mTOR), mitogen-activated protein kinase (MAPK) and Hedgehog) leading to suppression of cell growth, proliferation, migration, inflammation, angiogenesis, epithelial-mesenchymal transition (EMT) and metastasis, and activation of apoptosis in TNBCs. Plant-derived compounds in combination with classical chemotherapeutic agents were more efficient in the treatment of TNBCs, possibly with lesser side effects.

Combination of resveratrol and 5-flurouracil enhanced anti-telomerase activity and apoptosis by inhibiting STAT3 and Akt signaling pathways in human colorectal cancer cells

Colorectal cancer is one of the leading causes for mortalities worldwide. The most common cause of colorectal cancer mortality is hepatic metastasis. There has been a limited advancement in the targeted-therapies for metastatic colorectal cancer. Conventional chemotherapeutic agent 5-fluorouracil has been used for various cancer treatments including colorectal cancer. Development of drug resistance and severe toxicity are major hurdles for its use in clinical setting. Resveratrol is a natural polyphenolic compound which has protective effects against aging-related diseases. In this study, we have tested whether combined treatments of resveratrol and 5-FU enhanced inhibitory effects against colorectal cancer cell growth. We herein showed that resveratrol and 5-FU combination treatments caused the anti-cancer activities by simultaneously inhibiting STAT3 and Akt signaling pathways. Resveratrol treatment induced S-phase specific cell cycle arrest, and when combined with 5-FU, it showed further increase in colorectal cancer cell apoptosis. Combined treatments of resveratrol and 5-FU inhibited epithelial-mesenchymal transition. Notably, resveratrol showed anti-inflammatory effects by downregulating inflammatory biomarkers, pSTAT3 and pNFκB. Resveratrol and 5-FU treatments inhibited STAT3 phosphorylation and its binding to the promoter region of human telomerase reverse transcriptase (hTERT). Our data provide the first evidence that resveratrol can enhance anti-telomeric and pro-apoptotic potentials of 5-FU in colorectal cancer, hence lead to re-sensitization to chemotherapy.

MitoVitE, a mitochondria-targeted antioxidant, limits paclitaxel-induced oxidative stress and mitochondrial damage in vitro, and paclitaxel-induced mechanical hypersensitivity in a rat pain model

BACKGROUND

Neuropathic pain is a common side-effect of chemotherapy. Although precise mechanisms are unclear, oxidative stress and mitochondrial damage are involved. We investigated whether the mitochondria targeted antioxidant, MitoVitE, provided better protection against paclitaxel-induced mitochondrial damage in rat dorsal root ganglion (DRG) cells, than a non-targeted form of vitamin E, Trolox. We also determined whether MitoVitE, compared with duloxetine, could limit paclitaxel-induced mechanical hypersensitivity in rats.

METHODS

Mitochondrial function was measured in DRG cells exposed to paclitaxel with and without MitoVitE or Trolox. The effect of MitoVitE or Trolox on paclitaxel-induced cell killing in cancer cell lines was also determined. Rats received a cumulative dose of 8 mg kg^-1 paclitaxel plus either MitoVitE (2 mg^-1 kg day^-1), duloxetine (10 mg kg^-1 day^-1) or vehicle control daily. Mechanical hind paw withdrawal thresholds were measured every two days.

RESULTS

Paclitaxel caused loss of membrane potential in DRG cells. At 100 µM paclitaxel median [range] change was 61[44-78]%, P < 0.0001, which was ameliorated by MitoVitE (86[62-104]%) but not Trolox (46[46-57]%). Similarly, loss of metabolic activity and glutathione induced by paclitaxel (both P < 0.0001) were reduced by MitoVitE but not Trolox. Cytotoxicity of paclitaxel was not affected by co-exposure of ovarian cancer cells to either MitoVitE or Trolox, but was slightly reduced against breast cancer cells, in the presence of Trolox. Mean (SD) areas under the curve of withdrawal thresholds at 6 h after injection in rats given paclitaxel + control, or + MitoVitE (P < 0.0001) or + duloxetine (P < 0.0001) were 110 (5), 145 (10) and 156 (13) respectively.

CONCLUSIONS

Paclitaxel affected mitochondrial function and glutathione in DRG cells, which was abrogated by MitoVitE but not Trolox, without decreasing cancer cell cytotoxicity. In rats, paclitaxel-induced mechanical hypersensitivity was ameliorated by MitoVitE treatment to an extent similar to duloxetine. These data confirm mitochondria as a mechanistic target for paclitaxel-induced damage and suggest mitochondria targeted antioxidants as future therapeutic strategies.

LFM-A13, a potent inhibitor of polo-like kinase, inhibits breast carcinogenesis by suppressing proliferation activity and inducing apoptosis in breast tumors of mice

The goals of the present study were to define the anticancer activity of LFM-A13 (α-cyano-β-hydroxy-β-methyl-N-(2,5-dibromophenyl)-propenamide), a potent inhibitor of Polo-like kinase (PLK), in a mouse mammary cancer model induced by 7,12-dimethylbenz(a)anthracene (DMBA) in vivo and explore its anticancer mechanism(s). We also examined whether the inhibition of PLK by LFM-A13 would improve the efficiency of paclitaxel in breast cancer growth in vivo. To do this, female BALB/c mice received 1 mg of DMBA once a week for 6 weeks with oral gavage. LFM-A13 (50 mg/kg body weight) was administered intraperitoneally with DMBA administration and continued for 25 weeks. We found that LFM-A13, paclitaxel, and their combination have a significant effect on the DMBA-induced breast tumor incidence, mean tumor numbers, average tumor weight, and size. At the molecular level, the administration of LFM-A13 hindered mammary gland carcinoma development by regulating the expression of PLK1, cell cycle-regulating proteins cyclin D1, cyclin dependent kinase-4 (CDK-4), and the CDK inhibitor, p21. Moreover, LFM-A13 treatment upregulated the levels of IκB, the pro-apoptotic proteins Bax, and caspase-3, and down-regulated p53 and the antiapoptotic protein Bcl-2 in mammary tumors. The combination of LFM-A13 with paclitaxel was found to be more effective compared with either agent alone. Collectively, these results suggest that LFM-A13 has an anti-proliferative activity against breast cancer in vivo and that LFM-A13 and paclitaxel combination could be a strategy for the treatment of breast cancer.

Tea tree oil presents in vitro antitumor activity on breast cancer cells without cytotoxic effects on fibroblasts and on peripheral blood mononuclear cells

The purpose of this study was to investigate some possible mechanisms underlying the in vitro antitumor activity of tea tree oil (TTO) on human and mouse breast cancer cells (MCF-7 and 4T1, respectively) and its cytotoxicity on fibroblasts (HFF-1) and on peripheral blood mononuclear cells (PBMCs). TTO High-Resolution Gas Chromatography (HRGC) showed seventeen main constituents, such as Terpinen-4-ol, γ-Terpinene, and α-Terpinene. High TTO concentrations (≥ 600 μg/mL) showed a remarkable antitumor activity, decreasing cell viability and cell proliferation of MCF-7 and 4T1 cells. TTO at 300 μg/mL increased the number of MCF-7 cells in the early stages of apoptosis and increased the BAX/BCL-2 genes ratio. TTO, mainly at 300 μg/mL, decreased cell growth and arrested MCF-7 cells in the S phase of the cell cycle. Lower antitumor concentrations (≤300 μg/mL) evaluated in MCF-7 and 4T1 cells were not cytotoxic to PBMCs and HFF-1. Also, TTO (300 μg/mL) was able to induce cell proliferation in fibroblasts after 72 h, indicating non-cytotoxic effect in these cells. TTO exhibited in vitro antitumor effect on MCF-7 and 4T1 cells by decreasing cell viability and modulating apoptotic pathways and cell cycle arrestment of MCF-7 cells. In this sense, our study provides new perspectives on the potential use of TTO for the development of new alternative therapies to treat topically locally advanced breast cancer (LABC).

Modulation by hydroxytyrosol of oxidative stress and antitumor activities of paclitaxel in breast cancer

PURPOSE

The main objective of this study was to test the therapeutic potential of hydroxytyrosol and its combination with paclitaxel in breast cancer on oxidative stress status.

METHODS

Impact on proliferation rates of different chemotherapy administration patterns was assayed in MCF-7 and MDA-MB-231 breast cancer cell lines. Breast tumor-bearing rats were randomly assigned to Control, Hydroxytyrosol, Paclitaxel and Paclitaxel plus hydroxytyrosol groups, for 6 weeks. Tumor volume, cell proliferation and several systemic oxidative stress parameters were measured. Anti-proliferative activity in vitro experiments was correlated with in vivo experiments.

RESULTS

Combination group did significantly reduce tumor volume when compared with paclitaxel alone. Additionally, the combination improved the antioxidant status without compromising the antitumor activity of standard chemotherapy.

CONCLUSION

These findings reveal for the first time that hydroxytyrosol is an active partner in combined therapies with paclitaxel against breast cancer. Combination with hydroxytyrosol would also ensure a less oxidative impact of chemotherapeutic drugs that could potentially improve patient wellness.

Administration of antioxidants in cancer: debate of the decade

Several randomized clinical trials have divulged that administration of antioxidants during chemotherapy decreases the effectiveness of treatment. Hence, the characteristic feature of this article is extensive assessment of putative benefits and potential risks of natural and synthetic antioxidant supplementation, administered with chemotherapy, based upon the available preclinical and clinical data. After analyzing mixed results, it was concluded that current FDA guidelines should be followed before supplementing antioxidants during cytotoxic treatment. Nevertheless, contradictory experimental animal models opposing human clinical trials discourage the concurrent administration of antioxidants ostensibly owing to the possibility of tumor protection and reduced survival.

A chemical compound based on methylxanthine-polyphenols lowers nitric oxide levels and increases post-thaw human sperm viability

We produced a new chemical compound based on methylxanthines and polyphenols (CCMP) present in the chemical matrix of guaraná (Paullinia cupana), a seed extract with antioxidant properties. After supplementation with the standard extract of resveratrol, a well documented antioxidant found in other plant sources, we investigated whether this resveratrol-enriched compound could improve sperm viability and modulate differentially reactive oxygen species (ROS) and nitric oxide (NO) levels in thawed sperm. Sperm samples obtained from healthy young donors were treated with different concentrations of guaraná extract (0.1, 1, 5 or 10 mg/ml) and cells were frozen at -80°C for 24 h. In addition, the potential protective effects of guaraná treatment on sperm treated with pro-oxidant compound (200 µM hydrogen peroxide, H2O2) were assessed. Samples were also exposed to three concentrations of CCMP before being frozen in liquid nitrogen (-196°C) or in an ultrafreezer (-80°C) for 24 h, and both pre-freezing and post-thaw measurements of viability and oxidative stress were performed. Guaraná supplementation at 10 mg/ml significantly increased post-thaw viability and decreased oxidative metabolism of the sperm. Moreover, selected concentrations of CCMP improved viability and oxidative metabolism in sperm samples pre-freezing. Furthermore, CCMP showed cryoprotective activity by increasing viability and decreasing oxidative stress in post-thaw samples. In summary, these findings suggested that CCMP supplementation acts as a cryoprotectant to modulate ROS and NO levels in thawed sperm. CCMP could be used to enhance sperm quality and reproductive success.