Resveratrol as sensitizer in colorectal cancer plasticity

Despite tremendous medical treatment successes, colorectal cancer (CRC) remains a leading cause of cancer deaths worldwide. Chemotherapy as monotherapy can lead to significant side effects and chemoresistance that can be linked to several resistance-activating biological processes, including an increase in inflammation, cellular plasticity, multidrug resistance (MDR), inhibition of the sentinel gene p53, and apoptosis. As a consequence, tumor cells can escape the effectiveness of chemotherapeutic agents. This underscores the need for cross-target therapeutic approaches that are not only pharmacologically safe but also modulate multiple potent signaling pathways and sensitize cancer cells to overcome resistance to standard drugs. In recent years, scientists have been searching for natural compounds that can be used as chemosensitizers in addition to conventional medications for the synergistic treatment of CRC. Resveratrol, a natural polyphenolic phytoalexin found in various fruits and vegetables such as peanuts, berries, and red grapes, is one of the most effective natural chemopreventive agents. Abundant in vitro and in vivo studies have shown that resveratrol, in interaction with standard drugs, is an effective chemosensitizer for CRC cells to chemotherapeutic agents and thus prevents drug resistance by modulating multiple pathways, including transcription factors, epithelial-to-mesenchymal transition-plasticity, proliferation, metastasis, angiogenesis, cell cycle, and apoptosis. The ability of resveratrol to modify multiple subcellular pathways that may suppress cancer cell plasticity and reversal of chemoresistance are critical parameters for understanding its anti-cancer effects. In this review, we focus on the chemosensitizing properties of resveratrol in CRC and, thus, its potential importance as an additive to ongoing treatments.

The Garlic Compound, Diallyl Trisulfide, Attenuates Benzo[a]Pyrene-Induced Precancerous Effect through Its Antioxidant Effect, AhR Inhibition, and Increased DNA Repair in Human Breast Epithelial Cells

Exposure to B[a]P, the most characterized polycyclic aromatic hydrocarbon, significantly increases breast cancer risk. Our lab has previously reported that diallyl trisulfide (DATS), a garlic organosulfur compound (OSC) with chemopreventive and cell cycle arrest properties, reduces lipid peroxides and DNA damage in normal breast epithelial (MCF-10A) cells. In this study, we evaluated the ability of DATS to block the B[a]P-induced initiation of carcinogenesis in MCF-10A cells by examining changes in proliferation, clonogenic formation, reactive oxygen species (ROS) formation, 8-hydroxy-2-deoxyguanosine (8-OHdG) levels, and protein expression of ARNT/HIF-1β, CYP1A1, and DNA POLβ. The study results indicate that B[a]P increased proliferation, clonogenic formation, ROS formation, and 8-OHdG levels, as well as increasing the protein expression of ARNT/HIF-1β and CYP1A1 compared to the control. Conversely, DATS/B[a]P co-treatment (CoTx) inhibited cell proliferation, clonogenic formation, ROS formation, and 8-OHdG levels compared to B[a]P alone. Treatment with DATS significantly inhibited (p < 0.0001) AhR expression, implicated in the development and progression of breast cancer. The CoTx also attenuated all the above-mentioned B[a]P-induced changes in protein expression. At the same time, it increased DNA POLβ protein expression, which indicates increased DNA repair, thus causing a chemopreventive effect. These results provide evidence for the chemopreventive effects of DATS in breast cancer prevention.

Phytocompounds from essential oil of Mentha aquatica L. cv. Lime prevent vemurafenib-promoted skin carcinogenesis via inhibiting HRASQ61L keratinocytes and reprogramming macrophage activities

BACKGROUND

Twenty to thirty percent of patients taking BRAF inhibitors such as vemurafenib (PLX4032) for melanoma develop cutaneous squamous cell carcinomas.

PURPOSE

This study aimed to elucidate the chemopreventive effect of essential oil from Mentha aquatica L. cv. Lime (EO) and its major constituents, limonene and carvone (L + C) that made up 45.68% of the EO, against PLX4032-induced cutaneous side effects.

METHODS

PLX4032 accelerated skin papilloma formation and keratinocyte HRAS mutation in 7,12-dimethylbenz[a]anthracene (DMBA)/12-O-tetradecanoylphorbol-13-acetate (TPA)-induced two-stage skin carcinogenesis mouse model was used to evaluate the in vivo bioefficacy of EO and L + C. The effects and molecular mechanisms of EO and L + C on deregulating mouse PDVHRASQ61L keratinocyte activities were demonstrated using a spectrum of bioactivity assays, western blotting, immunochemistry, and keratinocyte-macrophage co-culture assay.

RESULTS

Treatment with EO suppressed colony formation ability, cell migration, invasion, and induced G2/M cell-cycle arrest and apoptosis in PDVHRASQ61L keratinocytes, and L + C treatment inhibited colony formation, cell migration and invasion of PDV cells. In mouse skin irritated with DMBA/TPA (DT group) or DMBA/TPA with PLX4032 (DTP group), topical application of EO and L + C significantly delayed papilloma appearance and reduced papilloma incidence compared to DT or DTP controls. Histopathology results showed that EO and L + C treatment attenuated K14+ keratinocyte proliferation and paradoxical MAPK activation, and shifted the macrophage population from M2 (CD163+) to M1 (iNOS+) in the mouse skin microenvironment. The conditioned medium of EO or L + C pre-treated PDV keratinocytes promoted M0 macrophages to differentiate from THP-1 cells into M1-like macrophages.

CONCLUSION

This study demonstrates that EO and L + C in combination prevent PLX4032-induced cutaneous side-effects and skin carcinogenesis in mice through reprogramming the macrophage cell population and inhibiting keratinocyte activity. Both mint EO and the natural products L + C can be considered to be effective chemopreventive agents that might be useful in reducing cutaneous lesions in human patients administrated with BRAF inhibitors.

Brassica-derived isothiocyanates as anticancer therapeutic agents and their nanodelivery

The isothiocyanates (ITCs) derived from the precursor glucosinolate molecules present in Brassica vegetables are bioactive organo-sulfur compounds with numerous pharmacologically important properties such as antioxidant, antiinflammatory, antimicrobial, and anticancer. Over the years, ITCs have been the focus of several research investigations associated with cancer treatment. Due to their potent chemo-preventive action, ITCs have been considered to be promising therapeutics for cancer therapy in place of the already existing conventional anticancer drugs. However, their wide spread use at the clinical stage is greatly restricted due to several factors such as low solubility in an aqueous medium, low bioavailability, low stability, and hormetic effect. To overcome these hindrances, nanotechnology can be exploited to develop nano-scale delivery systems that have the potential to enhance stability, and bioavailability and minimize the hermetic effect of ITCs.

Fatty acid modification of casein bioactive peptides nano-assemblies, synthesis, characterization and anticarcinogenic effect

In this study, the nano-assemblies of bovine casein hydrolyzed peptides (HP) modified by fatty acids with various alkyl chain lengths (C8, C10, C12 and C14) were synthesized. The physicochemical properties of HP-C8-HP-C14 nano-assemblies were characterized using spectra, laser particle size analyzer, contact angle meter, scanning electron microscope (SEM) and cryo-transmission electron microscope (Cryo-TEM). HP-C8 and HP-C10 self-assembled into a hollow cube cage with an average size of ~500 nm, and the assembly of HP-C12 showed a flower-shaped morphology with more dispersed behavior, and droplet size was observed as ~20 nm. The in vitro cytotoxicity against human breast cancer cells MCF-7 was tested using CCK-8 assay and flow cytometry analysis. HP-C12 showed the highest cytotoxicity for MCF-7 cells with an inhibition rate of 66.03 % ± 0.35 % with an IC50 value of 7.4 μM among HP-Cn. HP-C8, HP-C10 and HP-C12 significantly affected on the migration, invasion and apoptosis of MCF-7 cells. The apoptosis mechanism may depend on the upregulation of anti-apoptotic protein Bcl-2 as well as pro-apoptotic proteins Bax and caspase-8. The dead MCF-7 cells were analyzed with UHPLC-MS/MS using untargeted metabolomics, revealing key metabolic pathways.

Chemopreventive Effects of Polysaccharides and Flavonoids from Okra Flowers in Azomethane/Dextran Sulfate Sodium-Induced Murine Colitis-Associated Cancer

Okra flowers are a good source of polysaccharides and flavonoids, with biological activities of anti-inflammatory action and modulation of the gut microbiota. Previously, we reported that flavonoid-rich extracts from okra flowers (AFE) presented effective anti-colorectal cancer (CRC) activity in CRC cells as well as xenograft models, but their role in colitis-associated cancer (CAC) is unidentified. In this study, we aimed to evaluate the effects of AFE and APE (polysaccharides extracted from okra flowers) on the CAC symptoms of azoxymethane (AOM)/dextran sodium sulfate (DSS)-intervened mice. The results showed that APE and AFE exert potent efficacy in inhibiting colitis and colorectal tumorigenesis stimulated by AOM/DSS, characterized by decreased colonic shortening, DAI score, and tumor numbers. Compared with the control group, APE/AFE alleviated the microbiota dysbiosis driven by AOM/DSS. In addition, AFE elicited its anticancer activity through regulation of NFκB/IL-6/Stat3, JAK2/Stat3, MAPKs, PI3K/AKT, and Wnt/β-catenin signal transductions in AOM/DSS mice, which was consistent with a vitro model of CT26 cells, while APE treatment exhibited anticancer activity through regulation of Nrf2/IL-6, MAPKs, PI3K/AKT, and Wnt/β-catenin signal transductions in the AOM/DSS mouse model. Collectively, our studies revealed, for the first time, that flavonoids and polysaccharides from okra flowers possess the ability to attenuate colitis and colorectal tumorigenesis, with them having great potential to become promising candidates against CRC.

Flavonoids as promising anticancer therapeutics: Contemporary research, nanoantioxidant potential, and future scope

Flavonoids are natural polyphenolic compounds considered safe, pleiotropic, and readily available molecules. It is widely distributed in various food products such as fruits and vegetables and beverages such as green tea, wine, and coca-based products. Many studies have reported the anticancer potential of flavonoids against different types of cancers, including solid tumors. The chemopreventive effect of flavonoids is attributed to various mechanisms, including modulation of autophagy, induction of cell cycle arrest, apoptosis, and antioxidant defense. Despite of significant anticancer activity of flavonoids, their clinical translation is limited due to their poor biopharmaceutical attributes (such as low aqueous solubility, limited permeability across the biological membranes (intestinal and blood-brain barrier), and stability issue in biological systems). A nanoparticulate system is an approach that is widely utilized to improve the biopharmaceutical performance and therapeutic efficacy of phytopharmaceuticals. The present review discusses the significant anticancer potential of promising flavonoids in different cancers and the utilization of nanoparticulate systems to improve their nanoantioxidant activity further to enhance the anticancer activity of loaded promising flavonoids. Although, various plant-derived secondary metabolites including flavonoids have been recommended for treating cancer, further vigilant research is warranted to prove their translational values.

Substances of Natural Origin in Medicine: Plants vs. Cancer

Continuous monitoring of the population's health is the main method of learning about disease prevalence. National and international data draw attention to the persistently high rates of cancer incidence. This necessitates the intensification of efforts aimed at developing new, more effective chemotherapeutic and chemopreventive drugs. Plants represent an invaluable source of natural substances with versatile medicinal properties. Multidirectional activities exhibited by natural substances and their ability to modulate key signaling pathways, mainly related to cancer cell death, make these substances an important research direction. This review summarizes the information regarding plant-derived chemotherapeutic drugs, including their mechanisms of action, with a special focus on selected anti-cancer drugs (paclitaxel, irinotecan) approved in clinical practice. It also presents promising plant-based drug candidates currently being tested in clinical and preclinical trials (betulinic acid, resveratrol, and roburic acid).

Chemopreventive Effect of Cinnamon and Its Bioactive Compounds in a Rat Model of Premalignant Prostate Carcinogenesis

Cinnamon and its bioactive compounds inhibit prostate cancer cell proliferation in vitro. The aim of the current study was to assess the chemopreventive efficacy of cinnamon (CN) and its bioactive compounds in vivo using N-methyl-N-nitrosourea (MNU) and testosterone (T) to induce prostate carcinogenesis in male Wistar/National Institute of Nutrition rats. Cancer-induced (CI) rats (n = 10) developed prostatic hyperplasia and prostatic intraepithelial neoplasia. These histopathologic changes were diminished in CI rats fed for 4 months with diets supplemented with either CN (n = 20) or its bioactive compounds (cinnamaldehyde, n = 10 and procyanidin B2, n = 10). Androgen receptor (AR) expression was lower in the prostates of CI rats than in control, but the AR target gene, probasin, was robustly upregulated. Treatment of CI rats with CN or its bioactive compounds upregulated AR expression but inhibited the expression of the 5-alpha reductase genes (Srd5a1 and Srd5a2) and did not further increase probasin expression, suggesting blunted transcriptional activity of AR due to the limited availability of dihydrotestosterone. MNU+T induced an altered oxidant status in rat prostate, which was reflected by an increase in lipid peroxidation and DNA oxidation. These changes were completely or partially corrected by treatment with CN or the bioactive compounds. CN and its active components increased the activity of the apoptotic enzymes caspase-8 and caspase-3 in the prostates of CI rats. In conclusion, our data demonstrate that CN and its bioactive compounds have inhibitory effects on premalignant prostate lesions induced by MNU + T and, therefore, may be considered for the chemoprevention of prostate cancer.

PREVENTION RELEVANCE

The research work presented in this article demonstrates the chemopreventive efficacy of CN and its bioactive compounds in a rat model of premalignant prostate cancer.

Anticancer Therapeutic Effects of Green Tea Catechins (GTCs) When Integrated with Antioxidant Natural Components

After decades of research and development concerning cancer treatment, cancer is still at large and very much a threat to the global human population. Cancer remedies have been sought from all possible directions, including chemicals, irradiation, nanomaterials, natural compounds, and the like. In this current review, we surveyed the milestones achieved by green tea catechins and what has been accomplished in cancer therapy. Specifically, we have assessed the synergistic anticarcinogenic effects when green tea catechins (GTCs) are combined with other antioxidant-rich natural compounds. Living in an age of inadequacies, combinatorial approaches are gaining momentum, and GTCs have progressed much, yet there are insufficiencies that can be improvised when combined with natural antioxidant compounds. This review highlights that there are not many reports in this specific area and encourages and recommends research attention in this direction. The antioxidant/prooxidant mechanisms of GTCs have also been highlighted. The current scenario and the future of such combinatorial approaches have been addressed, and the lacunae in this aspect have been discussed.

3-Heptylidene-4,6-Dimethoxy-3H-Isobenzofuran-1-One Is Genotoxic, Increases the Frequency of Cell Death, and Potentiates the Effects of Cyclophosphamide and Cisplatin

3-heptylidene-4,6-dimethoxy-3H-isobenzofuran-1-one (Phthalide 1) is the precursor of three resorcinol lipids that have been described as potential chemotherapeutic agents and capable of potentiating the effects of cyclophosphamide. In this study, we evaluated the genotoxic potential, cell-killing potential, and interactions with cyclophosphamide and cisplatin of phthalide 1. Twelve groups were created from 120 mice: Negative Control, cyclophosphamide (100 mg/kg), cisplatin (6 mg/kg), Phthalide 1 (5, 10 and 20 mg/kg), and associations of 1 with cyclophosphamide and 1 with cisplatin. The results demonstrate that 1 increases (p < 0.05) the frequency of chromosomal damage, liver and kidney cell death, and splenic phagocytosis. The association of 1 with cyclophosphamide and cisplatin demonstrated a chemopreventive effect and, therefore, a reduction (p < 0.05) in the frequency of chromosomal damage. However, cell death and splenic phagocytosis did not suffer significant variations. As a result of the above, 1 has potential chemotherapeutic application and may be a candidate for developing a new generation of chemotherapeutics. In addition, it has characteristics to be used as a chemotherapy adjuvant in association with cyclophosphamide and cisplatin since it increases the frequency of cell death induced by chemotherapy. We also reported that the chemopreventive effect of 1, in association with cyclophosphamide and cisplatin, can prevent adverse effects (induction of DNA damage in non-tumor cells) without interfering with the mode of action of chemotherapy drugs and, therefore, without reducing the induction of cell death.

Lycopene as a Potential Bioactive Compound: Chemistry, Extraction, and Anticancer Prospective

Lycopene, a potential bioactive agent, is a non-pro-vitamin A carotenoid recognized as a potent antioxidant. It is extracted from plants like tomatoes, watermelons, red carrots and papayas and has remarkable health benefits. A significant amount of research has been assisted to date to establish the anticancer activity of lycopene. Our review enhances information about the promising anticancer potential of this compound. The biological activity of lycopene has been described in several studies in regard to pancreatic, breast, prostate, liver, gastric, ovarian, kidney, skin, intestine, brain and spinal cord cancers. Lycopene resists cancer by inhibition of apoptosis, induction of cell proliferation, cell invasion, cell cycle development, metastasis and angiogenesis. The mechanisms of anticancer action of lycopene are attributed to the management of certain signal transduction pathways, such as modulation of insulin-like growth factors system, PI3K/Akt pathway, modification of important gene expression, inhibit the activity of sex steroid hormones, and the conversation of mitochondrial behavior. Hence, this review focuses on current knowledge of sources, extraction techniques, and chemistry of lycopene, as well as the prospective mechanisms of action related with its anticancer activity. Also, it summarizes the background information about lycopene and the most current research with consideration to its aspect in treating several types of cancer together with future directions.

Natural Polyphenols for Treatment of Colorectal Cancer

Colorectal cancer (CRC) is a prevalent and serious gastrointestinal malignancy with high mortality and morbidity. Chemoprevention refers to a newly emerged strategy that uses drugs with chemopreventive properties to promote antioxidation, regulate cancer cell cycle, suppress proliferation, and induce cellular apoptosis, so as to improve cancer treatment outcomes. Natural polyphenols are currently recognized as a class of chemopreventive agents that have shown remarkable anticarcinogenic properties. Numerous in vitro and in vivo studies have elucidated the anti-CRC mechanisms of natural polyphenols, such as regulation of various molecular and signaling pathways. Natural polyphenols are also reportedly capable of modulating the gut microbiota and cancer stem cells (CSCs) to suppress tumor formation and progression. Combined use of different natural polyphenols is recommended due to their low bioavailability and instability, and combination treatment can exert synergistical effects, reduce side effects, and avoid drug resistance in CRC treatment. In summary, the application of polyphenols in the chemoprevention and treatment of CRC is promising. Further clinical evaluation of their effectiveness is warranted and anticipated.

Effect of Diacerein on HOTAIR/IL-6/STAT3, Wnt/β-Catenin and TLR-4/NF-κB/TNF-α axes in colon carcinogenesis

Colorectal cancer (CRC) is a common malignancy with high mortality and poor prognosis. Diacerein (DIA) is an anti-inflammatory used for treatment of osteoarthritis. We delineated some underlying molecular mechanisms of DIA's anti-carcinogenic effect in CRC using in vivo and in vitro models. Human Caco-2 cells were treated with DIA followed by MTT and Annexin V assays and CRC was experimentally induced using 1,2-dimethylhydrazine. DIA (50 mg/kg/day, orally) was administrated for 8 weeks. The MTT assay confirmed cytotoxic effect of DIA in vitro and Annexin V confirmed its apoptotic effect. DIA resulted in regression of tumour lesions with reduced colonic TLR4, NF-κB and TNF-α protein levels and down-regulated VEGF expression, confirming anti-angiogenic impact. DIA triggered caspase-3 expression and regulated Wnt/β-Catenin pathway, by apparently interrupting the IL-6/STAT3/ lncRNA HOTAIR axis. In conclusion, DIA disrupted IL-6/STAT3/ lncRNA HOTAIR axis which could offer an effective therapeutic strategy for the management of CRC.

Dietary phytochemicals/nutrients as promising protector of breast cancer development: a comprehensive analysis

Genetic change, particularly epigenetic alteration, is one of the imperative factors for sporadic breast cancer development in the worldwide population of women. The DNA methylation process is essential and natural for human cellular renewal and tissue homeostasis, but its dysregulation contributes to many pathological changes, including breast tumorigenesis. Chemopreventive agents mainly protect the abnormal DNA methylation either by hindering the division of pre-malignant cells or looming the DNA damage, which leads to malignancy. The present review article is about understanding the potential role of dietary phytochemicals in breast cancer prevention. Accordingly, a literature search of the published article until August 2021 has been performed. Further, we have investigated the binding affinity of different phytochemicals isolated from diverse dietary sources against the various oncogenic proteins related to breast cancer initiation to understand the common target(s) in breast cancer prevention mechanisms. Various small phytochemicals, especially dietary phytochemicals including sulforaphane, mahanine, resveratrol, linolenic acid, diallyl sulfide, benzyl/phenethyl isothiocyanate, etc. are being investigated as the chemopreventive agent to manage breast cancer development, and some of them have shown promising outcomes in the cited research. In this present review, we discuss the recent advancement in acceptance of such types of potential dietary phytochemicals as a chemopreventive agent against breast cancer development and their inner lining mechanism. The critical clinical trials and cohort studies have also been considered to understand the progress in contemporary perspectives.

The Chemopreventive Effects of Polyphenols and Coffee, Based upon a DMBA Mouse Model with microRNA and mTOR Gene Expression Biomarkers

Polyphenols are capable of decreasing cancer risk. We examined the chemopreventive effects of a green tea (Camellia sinensis) extract, polyphenol extract (a mixture of blackberry (Rubus fruticosus), blackcurrants (Ribes nigrum), and added resveratrol phytoalexin), Chinese bayberry (Myrica rubra) extract, and a coffee (Coffea arabica) extract on 7,12-dimethylbenz[a]anthracene (DMBA) carcinogen-increased miR-134, miR-132, miR-124-1, miR-9-3, and mTOR gene expressions in the liver, spleen, and kidneys of CBA/Ca mice. The elevation was quenched significantly in the organs, except for miR-132 in the liver of the Chinese bayberry extract-consuming group, and miR-132 in the kidneys of the polyphenol-fed group. In the coffee extract-consuming group, only miR-9-3 and mTOR decreased significantly in the liver; also, miR-134 decreased significantly in the spleen, and, additionally, miR-124-1 decreased significantly in the kidney. Our results are supported by literature data, particularly the DMBA generated ROS-induced inflammatory and proliferative signal transducers, such as TNF, IL1, IL6, and NF-κB; as well as oncogenes, namely RAS and MYC. The examined chemopreventive agents, besides the obvious antioxidant and anti-inflammatory effects, mainly blocked the mentioned DMBA-activated factors and the mitogen-activated protein kinase (MAPK) as well, and, at the same time, induced PTEN as well as SIRT tumor suppressor genes.

Arrabidaea chica chloroform extract modulates estrogen and androgen receptors on luminal breast cancer cells

BACKGROUND

Breast Cancer (BC) is the most common cancer in women worldwide and, although 70% of patients are responsive to selective Estrogen Receptor (ER) modulators such as Tamoxifen (Tam), patients' survival is comprised by resistance to endocrine therapy. Brazilian flora, especially the Amazon biome, is one of the richest global sources of native species with potentially bioactive compounds. Arrabidaea chica is a plant native to the Amazon that has been used in the treatment of different diseases. However, its action on BC remains unclear.

METHODS

Herein the biological effects of the chloroform extract of A. chica (CEAC) were evaluated on BC cells and in in vivo model. After confirmation of CEAC antioxidant capacity, cells were treated with CEAC and Tam, alone and with CEAC+Tam. The cell viability was evaluated by MTT and hormone receptor transcripts levels were assessed (ESR1, ESR2 and AR). Finally, anticarcinogenicity of CEAC was recorded in Drosophila melanogaster through Epithelial Tumor Test (ETT).

RESULTS

The study confirmed the antioxidant activity of CEAC. CEAC was selective for MCF-7, downregulating ESR2 and AR transcripts and upregulating ESR2 expression. The modulatory effects of CEAC on ERs did not differ between cells treated with Tam and with CEAC+Tam. Interestingly, previous treatment with CEAC, followed by treatment with Tam promoted a significant decrease in cell viability. The extract also presented anticarcinogenic effect in in vivo assay.

CONCLUSION

The bioassays on breast tumor cells demonstrated the antiproliferative activity of the extract, which modulated the expression of hormone receptors and sensitized luminal tumor cells to Tam. These results suggest that CEAC could be a complementary treatment for BC.

Microbial enzymes induce colitis by reactivating triclosan in the mouse gastrointestinal tract

Emerging research supports that triclosan (TCS), an antimicrobial agent found in thousands of consumer products, exacerbates colitis and colitis-associated colorectal tumorigenesis in animal models. While the intestinal toxicities of TCS require the presence of gut microbiota, the molecular mechanisms involved have not been defined. Here we show that intestinal commensal microbes mediate metabolic activation of TCS in the colon and drive its gut toxicology. Using a range of in vitro, ex vivo, and in vivo approaches, we identify specific microbial β-glucuronidase (GUS) enzymes involved and pinpoint molecular motifs required to metabolically activate TCS in the gut. Finally, we show that targeted inhibition of bacterial GUS enzymes abolishes the colitis-promoting effects of TCS, supporting an essential role of specific microbial proteins in TCS toxicity. Together, our results define a mechanism by which intestinal microbes contribute to the metabolic activation and gut toxicity of TCS, and highlight the importance of considering the contributions of the gut microbiota in evaluating the toxic potential of environmental chemicals.

Evaluation of the chemopreventive effect of selected medicinal plants extracts via induction of the Nrf2 in a modified model of breast cancer cells: identification of bioactive lead compounds

The cancer chemopreventive potential of various solvent extracts from six medicinal plants was evaluated by their ability to activate the transcription factor Nrf2 using AREc32 cells, which contain a luciferase gene under the control of antioxidant responsive element promoters. Nrf2 regulates the expression of many detoxification enzymes, making it an ideal target for cancer prevention. The present research revealed Zanthoxylum zanthoxyloides extracts as promising sources of cancer chemopreventive compounds. Bioassay-guided isolation of the Z. Zanthoxyloides methanol extract resulted in the isolation of N-methylatanine, N-methylplatydesminecation, sesamin and skimmianine. Among these compounds, skimmianine was identified as the most active compound, causing a 2.8-fold increase in luciferase activity. Skimmianine and other related quinolone alkaloids could represent an appropriate starting scaffold for the development of new chemopreventive cancer drugs.

Lactoferrin Prevents Hepatic Injury and Fibrosis via the Inhibition of NF-κB Signaling in a Rat Non-Alcoholic Steatohepatitis Model

Non-alcoholic steatohepatitis (NASH) can cause liver cirrhosis and hepatocellular carcinoma (HCC), with cases increasing worldwide. To reduce the incidence of liver cirrhosis and HCC, NASH is targeted for the development of treatments, along with viral hepatitis and alcoholic hepatitis. Lactoferrin (LF) has antioxidant, anti-cancer, and anti-inflammatory activities. However, whether LF affects NASH and fibrosis remains unelucidated. We aimed to clarify the chemopreventive effect of LF on NASH progression. We used a NASH model with metabolic syndrome established using connexin 32 (Cx32) dominant negative transgenic (Cx32ΔTg) rats. Cx32ΔTg rats (7 weeks old) were fed a high-fat diet and intraperitoneally injected with dimethylnitrosamine (DMN). Rats were divided into three groups for LF treatment at 0, 100, or 500 mg/kg/day for 17 weeks. Lactoferrin significantly protected steatosis and lobular inflammation in Cx32ΔTg rat livers and attenuated bridging fibrosis or liver cirrhosis induced by DMN. By quantitative RT-PCR, LF significantly down-regulated inflammatory (Tnf-α, Il-6, Il-18, and Il-1β) and fibrosis-related (Tgf-β1, Timp2, and Col1a1) cytokine mRNAs. Phosphorylated nuclear factor (NF)-κB protein decreased in response to LF, while phosphorylated JNK protein was unaffected. These results indicate that LF might act as a chemopreventive agent to prevent hepatic injury, inflammation, and fibrosis in NASH via NF-κB inactivation.

Nanoencapsulation of sulforaphane in broccoli membrane vesicles and their in vitro antiproliferative activity

CONTEXT

The development of nanocarriers of plant origin, such as plant cell membranes, has recently been investigated. Also, plant bioactive compounds as sulforaphane (SFN) from broccoli have recognized antioxidant or anticancer properties.

OBJECTIVE

To investigate the capacity of membrane vesicles from broccoli (BM-vesicles) to encapsulate SFN and their application in the cancer cell line.

MATERIALS AND METHODS

Physicochemical analysis was carried out to characterize BM-vesicles through different approaches: dynamic light scattering, transmission electron microscopy, stopped-flow analysis, and proteomic analysis. They were applied at different concentrations (BM-vesicles at 0.04-0.00315% of protein and SFN at 5, 25, and 100 µM) in SK-MEL-28 cells during 24 h for studying cytotoxicity and gene expression.

RESULTS

The entrapment efficiency was 41%. The anticancer activity tested in cells showed a decrease in proliferation when SFN in BM-vesicles was utilized. Expression patterns when SFN was applied in an encapsulated form showed a reduction of cancer markers and an increase of AQP3. Also, the metabolism of SFN occurred inside of cells, and higher SFN penetrated when it was encapsulated.

DISCUSSION

The results showed that encapsulated SFN was better absorbed by melanoma cells providing metabolism products and a reduction of cancer molecular markers. Also aquaporin, AQP3 was pointed to as an important marker since it appeared to play a key role in homeostasis due to the importance of water transport in biological processes.

CONCLUSION

These results indicate that SFN and SFN encapsulated in BM-vesicles have a high activity for the inhibition of melanocyte development. Therefore, BM-vesicles could serve as nanocarriers for drugs.

Delphinidin and Its Glycosides' War on Cancer: Preclinical Perspectives

Until now, several studies have looked at the issue of anthocyanin and cancer, namely the preventive and inhibitory effects of anthocyanins, as well as the underlying molecular processes. However, no targeted review is available regarding the anticarcinogenic effects of delphinidin and its glycosides on various cancers and their plausible molecular mechanisms. Considerable evidence shows significant anticancer properties of delphinidin-rich preparations and delphinidin alone both in vitro and in vivo. This review covers the in vitro and preclinical implications of delphinidin-mediated cell protection and cancer prevention; thus, we strongly recommend that delphinidin-rich preparations be further investigated as potential functional food, dietary antioxidant supplements, and natural health products targeting specific chronic diseases, including cancer. In addition to in vitro investigations, future research should focus on more animal and human studies to determine the true potential of delphinidin.

Suppression of Transmembrane Tumor Necrosis Factor Alpha Processing by a Specific Antibody Protects Against Colitis-Associated Cancer

Soluble tumor necrosis factor-α (sTNF-α) plays an important role in colitis-associated cancer (CAC); however, little is known about transmembrane TNF-α (tmTNF-α). Here, we observed an increase in sTNF-α mainly in colitis tissues from an azoxymethane/dextran sodium sulfate (DSS)-induced CAC mouse model whereas tmTNF-α levels were chiefly increased on epithelial cells at the tumor stage. The ratio of intracolonic tmTNF-α/sTNF-α was negatively correlated with the levels of pro-inflammatory mediators (IL-1β, IL-6, and NO) and M1 macrophages but positively correlated with the infiltration of myeloid-derived suppressor cells, regulatory T cells, and the level of the anti-inflammatory cytokine IL-10, suggesting an anti-inflammatory effect of tmTNF-α. This effect of tmTNF-α was confirmed again by the induction of resistance to LPS in colonic epithelial cell lines NCM460 and HCoEpiC through the addition of exogenous tmTNF-α or transfection of the tmTNF-α leading sequence that lacks the extracellular segment but retains the intracellular domain of tmTNF-α. A tmTNF-α antibody was used to block tmTNF-α shedding after the first or second round of inflammation induction by DSS drinking to shift the time window of tmTNF-α expression ahead to the inflammation stage. Antibody treatment significantly alleviated inflammation and suppressed subsequent adenoma formation, accompanied by increased apoptosis. An antitumor effect was also observed when the antibody was administered at the malignant phase of CAC. Our results reveal tmTNF-α as a novel molecular marker for malignant transformation in CAC and provide a new insight into blocking the pathological process by targeting tmTNF-α processing.

The chemoprotective effects of IFN-α-2b on rat hepatocarcinogenesis are blocked by vitamin E supplementation

Many cancer patients receive their classical therapies together with vitamin supplements. However, the effectiveness of these strategies is on debate. Here we aimed to evaluate how vitamin E supplementation affects the anticancer effects of interferon (IFN-α) using an early-model of liver cancer development (initiation-promotion, IP). Male Wistar rats subjected to this model were divided as follows: untreated (IP), IP treated with recombinant IFN-α-2b (6.5  ×  105 U/kg), IP treated with vitamin E (50 mg/kg), and IP treated with combination of vitamin E and IFN-α-2b. After treatments rats were fasted and euthanized and plasma and livers were collected. Combined administration of vitamin E and IFN-α-2b induced body weight drop, increased liver apoptosis, and low levels of hepatic lipids. Interestingly, vitamin E and IFN-α-2b combination also induced an increase in altered hepatic foci number, but not in size. It seems that vitamin E acts on its antioxidant capability in order to block the oxidative stress induced by IFN-α-2b, blocking in turn its beneficial effects on preneoplastic livers, leading to harmful final effects. In conclusion, this study shows that vitamin E supplementation in IFN-α-2b-treated rats exerts unwanted effects; and highlights that in spite of being natural, nutritional supplements may not always exert beneficial outcomes when used as complementary therapy for the treatment of cancer.

Biotransformation of the Phenolic Constituents from Licorice and Cytotoxicity Evaluation of Their Metabolites

Biotransformation of four bioactive phenolic constituents from licorice, namely licoisoflavanone (1), glycyrrhisoflavone (2), echinatin (3), and isobavachalcone (4), was performed by the selected fungal strain Aspergillus niger KCCM 60332, leading to the isolation of seventeen metabolites (5-21). Structures of the isolated compounds were determined on the basis of extensive spectroscopic methods, twelve of which (5-7, 10-17 and 19) have been previously undescribed. A series of reactions including hydroxylation, hydrogenation, epoxidation, hydrolysis, reduction, cyclization, and alkylation was observed in the biotransformation process. All compounds were tested for their cytotoxic activities against three different human cancer cell lines including A375P, MCF-7, and HT-29. Compounds 1 and 12 exhibited most considerable cytotoxic activities against all the cell lines investigated, while compounds 2 and 4 were moderately cytotoxic. These findings will contribute to expanding the chemical diversity of phenolic compounds, and compounds 1 and 12 may serve as leads for the development of potential cancer chemopreventive agents.

Inhibitory Effect of Garcinol on Obesity-Exacerbated, Colitis-Mediated Colon Carcinogenesis

SCOPE

Epidemiological studies show a consistent and compelling association between the risk of colorectal cancer development and obesity, but its mechanisms remain poorly understood. Evidence is mounting that colorectal cancer can be prevented by nutritional supplements, such as phytochemicals. Garcinol, a polyisoprenylated benzophenone derivative, is widely present in Garcinia plants. This study investigates the potential role of garcinol supplementation in ameliorating obesity-induced colon cancer development.

METHODS AND RESULTS

An animal model to investigate the effect of high-fat-diet (HFD)-induced obesity on promoting colitis-associated colon cancer (AOM (azoxymethane)/DSS (dextran sodium sulfate)-induced) is designed. The results show that HFD can promote colitis-associated colon cancer as compared to an AOM/DSS group without the intervention of obesity, and supplementing with 0.05% garcinol in the diet can significantly ameliorate obesity-promoted colon carcinogenesis. The results also reveals that the microbiota composition of each group is significantly different and clustered. The most representative genera are Alistipes, Romboutsia, and Ruminococcus. The RNA-sequencing results show that the administration of garcinol can regulate genes and improve obesity-promoting colitis-associated colon carcinogenesis.

CONCLUSION

The study results suggest that garcinol can prevent obesity-promoted colorectal cancer, and these findings provide important niches for the future development of garcinol as functional foods or adjuvant therapeutic agents.

Comparison of the Impact of Xanthohumol and Phenethyl Isothiocyanate and Their Combination on Nrf2 and NF-κB Pathways in HepG2 Cells In Vitro and Tumor Burden In Vivo

Background: Increasing evidence suggests that combinations of phytochemicals are more efficient than single components in the modulation of signaling pathways involved in cancer development. In this study, the impact of phenethyl isothiocyanate (PEITC), indole-3-carbinol (I3C), xanthohumol, (X), and resveratrol (RES) and their combinations on the activation and expression of Nrf2 and NF-κB in human hepatocytes and HCC cells were evaluated. Methods: THLE-2 and HepG2 cells were exposed to single phytochemicals and their combinations for 24 h. The activation of Nrf2 and NF-κB, expression of their target genes, and effect on cells survival were assessed. The tumor burden was evaluated in mice carrying xenografts. Results: All phytochemicals enhanced the activation and expression of Nrf2 and its target genes SOD and NQO1 in HepG2 cells. The increased expression of NQO1 (~90%) was associated with increased ROS generation. X + PEITC downregulated NF-κB activation reducing binding of its active subunits to DNA resulting in diminished COX-2 expression. In contrast to single phytochemicals, X + PEITC induced apoptosis. Moderate reduction of tumor burden in mice carrying xenografts following X and PEITC or their combination was observed. Conclusions: Since Nrf2 is overexpressed in HCC its reduced activation together with diminished level of NF-κB by X + PEITC may be considered as a strategy to support conventional HCC therapy.

Anti-Cancer and Electrochemical Properties of Thiogenistein-New Biologically Active Compound

Pharmacological and nutraceutical effects of isoflavones, which include genistein (GE), are attributed to their antioxidant activity protecting cells against carcinogenesis. The knowledge of the oxidation mechanisms of an active substance is crucial to determine its pharmacological properties. The aim of the present work was to explain complex oxidation processes that have been simulated during voltammetric experiments for our new thiolated genistein analog (TGE) that formed the self-assembled monolayer (SAM) on the gold electrode. The thiol linker assured a strong interaction of sulfur nucleophiles with the gold surface. The research comprised of the study of TGE oxidative properties, IR-ATR, and MALDI-TOF measurements of SAM before and after electrochemical oxidation. TGE has been shown to be electrochemically active. It undergoes one irreversible oxidation reaction and one quasi-reversible oxidation reaction in PBS buffer at pH 7.4. The oxidation of TGE results in electroactive products composed likely from TGE conjugates (e.g., trimers) as part of polymer. The electroactive centers of TGE and its oxidation mechanism were discussed using IR supported by quantum chemical and molecular mechanics calculations. Preliminary in-vitro studies indicate that TGE exhibits higher cytotoxic activity towards DU145 human prostate cancer cells and is safer for normal prostate epithelial cells (PNT2) than genistein itself.

Genistein: An Integrative Overview of Its Mode of Action, Pharmacological Properties, and Health Benefits

Genistein is an isoflavone first isolated from the brooming plant Dyer's Genista tinctoria L. and is widely distributed in the Fabaceae family. As an isoflavone, mammalian genistein exerts estrogen-like functions. Several biological effects of genistein have been reported in preclinical studies, such as the antioxidant, anti-inflammatory, antibacterial, and antiviral activities, the effects of angiogenesis and estrogen, and the pharmacological activities on diabetes and lipid metabolism. The purpose of this review is to provide up-to-date evidence of preclinical pharmacological activities with mechanisms of action, bioavailability, and clinical evidence of genistein. The literature was researched using the most important keyword "genistein" from the PubMed, Science, and Google Scholar databases, and the taxonomy was validated using The Plant List. Data were also collected from specialized books and other online resources. The main positive effects of genistein refer to the protection against cardiovascular diseases and to the decrease of the incidence of some types of cancer, especially breast cancer. Although the mechanism of protection against cancer involves several aspects of genistein metabolism, the researchers attribute this effect to the similarity between the structure of soy genistein and that of estrogen. This structural similarity allows genistein to displace estrogen from cellular receptors, thus blocking their hormonal activity. The pharmacological activities resulting from the experimental studies of this review support the traditional uses of genistein, but in the future, further investigations are needed on the efficacy, safety, and use of nanotechnologies to increase bioavailability and therapeutic efficacy.

Styrax camporum, a typical species of the Brazilian cerrado, attenuates DNA damage, preneoplastic lesions and oxidative stress in experimental rat colon carcinogenesis

Styrax camporum Pohl, a typical species from the Brazilian cerrado, commonly known as "benjoeiro", is used to treat gastroduodenal diseases. In previous studies carried out by our research group, hydroalcoholic extract of S. camporum stems (SCHE) exhibited antigenotoxic and antiproliferative effects. For a comparative analysis of the chemopreventive effect of SCHE, the aim of this study was to investigate the influence of SCHE against carcinogen 1,2-dimethylhydrazine (DMH)-induced DNA damage and pre-neoplastic lesions in Wistar rat colon. Animals were treated orally with SCHE at 250, 500 or 1000 mg/kg body weight in conjunction with a subcutaneous injection of DMH. DNA damage was assessed using the comet assay while tpre-neoplastic lesions by aberrant crypt foci (ACF) assay. The following hepatic oxidative stress markers were determined including activities of catalase (CAT) and glutathione S-transferase (GST) as well as levels of reduced glutathione (GSH) and malondialdehyde (MDA). Treatment with SCHE was not genotoxic or carcinogenic at the highest dose tested (1000 mg/kg b.w.). The extract effectively inhibited DNA damage and pre-neoplastic lesions induced by DMH administration at all concentrations tested. Measurement of CAT, and GST activities and levels of GSH showed that SCHE did not reduce oxidative processes. In contrast, treatment with SCHE (1000 mg/kg b.w.) decreased liver MDA levels. Taken together, these findings suggested the chemopreventive effect attributed to SCHE in colon carcinogenesis, may be related to its capacity to inhibit DNA damage as well as an antioxidant action associated with its chemical constituents egonol and homoegonol.

Sulforaphane inhibits PRMT5 and MEP50 function to suppress the mesothelioma cancer cell phenotype

Mesothelioma is a highly aggressive cancer of the mesothelial lining that is caused by exposure to asbestos. Surgical resection followed by chemotherapy is the current treatment strategy, but this is marginally successful and leads to drug-resistant disease. We are interested in factors that maintain the aggressive mesothelioma cancer phenotype as therapy targets. Protein arginine methyltransferase 5 (PRMT5) functions in concert with the methylosome protein 50 (MEP50) cofactor to catalyze symmetric dimethylation of key arginine resides in histones 3 and 4 which modifies the chromatin environment to alter tumor suppressor and oncogene expression and enhance cancer cell survival. Our studies show that PRMT5 or MEP50 loss reduces H4R3me2s formation and that this is associated with reduced cancer cell spheroid formation, invasion, and migration. Treatment with sulforaphane (SFN), a diet-derived anticancer agent, reduces PRMT5/MEP50 level and H4R3me2s formation and suppresses the cancer phenotype. We further show that SFN treatment reduces PRMT5 and MEP50 levels and that this reduction is required for SFN suppression of the cancer phenotype. SFN treatment also reduces tumor formation which is associated with reduced PRMT5/MEP50 expression and activity. These findings suggest that SFN may be a useful mesothelioma treatment agent that operates, at least in part, via suppression of PRMT5/MEP50 function.

DNA methylome, transcriptome, and prostate cancer prevention by phenethyl isothiocyanate in TRAMP mice

Epigenetics/epigenomics has been shown to be involved in carcinogenesis. However, how the epigenome would be altered in the transgenic adenocarcinoma of the mouse prostate (TRAMP) cancer model and the effect of cancer chemopreventive phytochemical phenethyl isothiocyanate (PEITC) on the epigenome in TRAMP mice are not known. PEITC has been reported to reduce the risk of many cancers including prostate cancer (PCa). In this study, male TRAMP mice were fed a control diet or diet containing 0.05% PEITC from 8 weeks to 16 weeks. The tumor incidence was reduced in the PEITC diet (0/6) as compared with the control diet (6/7). RNA-sequencing (RNA-seq) analyses on nontumor and tumor prostatic tissues revealed several pathways like cell cycle/Cdc42 signaling, inflammation, and cancer-related signaling, were activated in prostate tissues of TRAMP mice but were reversed or attenuated in TRAMP mice fed with PEITC diet. DNA CpG methyl-seq analyses showed that global methylation patterns of prostate samples from TRAMP mice were hugely different from those of wild-type mice. Dietary PEITC partially reversed the global methylation changes during prostatic carcinogenesis. Integration of RNA-seq and DNA methyl-seq analyses identified a list of genes, including Adgrb1 and Ebf4, with an inverse regulatory relationship between their RNA expression and CpG methylation. In summary, our current study demonstrates that alteration of the global epigenome in TRAMP prostate tumor and PEITC administration suppresses PCa carcinogenesis, impacts global CpG epigenome and transcriptome, and attenuates carcinogenic pathways like cell cycle arrest and inflammation. These results may provide insights and epigenetic markers/targets for PCa prevention and treatment in human PCa patients.

Heterogeneity of Colorectal Cancer Progression: Molecular Gas and Brakes

The review begins with molecular genetics, which hit the field unveiling the involvement of oncogenes and tumor suppressor genes in the pathogenesis of colorectal cancer (CRC) and uncovering genetic predispositions. Then the notion of molecular phenotypes with different clinical behaviors was introduced and translated in the clinical arena, paving the way to next-generation sequencing that captured previously unrecognized heterogeneity. Among other molecular regulators of CRC progression, the extent of host immune response within the tumor micro-environment has a critical position. Translational sciences deeply investigated the field, accelerating the pace toward clinical transition, due to its strong association with outcomes. While the perturbation of gut homeostasis occurring in inflammatory bowel diseases can fuel carcinogenesis, micronutrients like vitamin D and calcium can act as brakes, and we discuss underlying molecular mechanisms. Among the components of gut microbiota, Fusobacterium nucleatum is over-represented in CRC, and may worsen patient outcome. However, any translational knowledge tracing the multifaceted evolution of CRC should be interpreted according to the prognostic and predictive frame of the TNM-staging system in a perspective of clinical actionability. Eventually, we examine challenges and promises of pharmacological interventions aimed to restrain disease progression at different disease stages.

An Overview of the Chemical Characteristics, Bioactivity and Achievements Regarding the Therapeutic Usage of Acetogenins from Annona cherimola Mill

Annona cherimola Mill., or the custard apple, is one of the species belonging to the Annonaceae family, is widely used in traditional medicine, and has been reported to be a valuable source of bioactive compounds. A unique class of secondary metabolites derived from this family are Annonaceous acetogenins, lipophilic polyketides considered to be amongst the most potent antitumor compounds. This review provides an overview of the chemical diversity, isolation procedures, bioactivity, modes of application and synthetic derivatives of acetogenins from A. cherimola Mill.

3,3'-Diindolylmethane Suppresses the Growth of Hepatocellular Carcinoma by Regulating Its Invasion, Migration, and ER Stress-Mediated Mitochondrial Apoptosis

Hepatocellular carcinoma (HCC) is the leading cause of cancer-related death worldwide with limited treatment options. Biomarker-based active phenolic flavonoids isolated from medicinal plants might shed some light on potential therapeutics for treating HCC. 3,3′-diindolylmethane (DIM) is a unique biologically active dimer of indole-3-carbinol (I3C), a phytochemical compound derived from Brassica species of cruciferous vegetables—such as broccoli, kale, cabbage, and cauliflower. It has anti-cancer effects on various cancers such as breast cancer, prostate cancer, endometrial cancer, and colon cancer. However, the molecular mechanism of DIM involved in reducing cancer risk and/or enhancing therapy remains unknown. The aim of the present study was to evaluate anti-cancer and therapeutic effects of DIM in human hepatoma cell lines Hep3B and HuhCell proliferation was measured with MTT and trypan blue colony formation assays. Migration, invasion, and apoptosis were measured with Transwell assays and flow cytometry analyses. Reactive oxygen species (ROS) intensity and the loss in mitochondrial membrane potential of Hep3B and Huh7 cells were determined using dihydroethidium (DHE) staining and tetramethylrhodamine ethyl ester dye. Results showed that DIM significantly suppressed HCC cell growth, proliferation, migration, and invasion in a concentration-dependent manner. Furthermore, DIM treatment activated caspase-dependent apoptotic pathway and suppressed epithelial–mesenchymal transition (EMT) via ER stress and unfolded protein response (UPR). Taken together, our results suggest that DIM is a potential anticancer drug for HCC therapy by targeting ER-stress/UPR.

The effects of flavonoids, green tea polyphenols and coffee on DMBA induced LINE-1 DNA hypomethylation

The intake of carcinogenic and chemopreventive compounds are important nutritional factors related to the development of malignant tumorous diseases. Repetitive long interspersed element-1 (LINE-1) DNA methylation pattern plays a key role in both carcinogenesis and chemoprevention. In our present in vivo animal model, we examined LINE-1 DNA methylation pattern as potential biomarker in the liver, spleen and kidney of mice consuming green tea (Camellia sinensis) extract (catechins 80%), a chinese bayberry (Morella rubra) extract (myricetin 80%), a flavonoid extract (with added resveratrol) and coffee (Coffee arabica) extract. In the organs examined, carcinogen 7,12-dimethylbenz(a)anthracene (DMBA)-induced hypomethylation was prevented by all test materials except chinese bayberry extract in the kidneys. Moreover, the flavonoid extract caused significant hypermethylation in the liver compared to untreated controls and to other test materials. The tested chemopreventive substances have antioxidant, anti-inflammatory properties and regulate molecular biological signaling pathways. They increase glutathione levels, induce antioxidant enzymes, which decrease free radical damage caused by DMBA, and ultimately, they are able to increase the activity of DNA methyltransferase enzymes. Furthermore, flavonoids in the liver may inhibit the procarcinogen to carcinogen activation of DMBA through the inhibition of CYP1A1 enzyme. At the same time, paradoxically, myricetin can act as a prooxidant as a result of free radical damage, which can explain that it did not prevent hypomethylation in the kidneys. Our results demonstrated that LINE-1 DNA methylation pattern is a useful potential biomarker for detecting and monitoring carcinogenic and chemopreventive effects of dietary compounds.

Svalbamides A and B, Pyrrolidinone-Bearing Lipodipeptides from Arctic Paenibacillus sp

Two new secondary metabolites, svalbamides A (1) and B (2), were isolated from a culture extract of Paenibacillus sp. SVB7 that was isolated from surface sediment from a core (HH17-1085) taken in the Svalbard archipelago in the Arctic Ocean. The combinational analysis of HR-MS and NMR spectroscopic data revealed the structures of 1 and 2 as being lipopeptides bearing 3-amino-2-pyrrolidinone, d-valine, and 3-hydroxy-8-methyldecanoic acid. The absolute configurations of the amino acid residues in svalbamides A and B were determined using the advanced Marfey's method, in which the hydrolysates of 1 and 2 were derivatized with l- and d- forms of 1-fluoro-2,4-dinitrophenyl-5-alanine amide (FDAA). The absolute configurations of 1 and 2 were completely assigned by deducing the stereochemistry of 3-hydroxy-8-methyldecanoic acid based on DP4 calculations. Svalbamides A and B induced quinone reductase activity in Hepa1c1c7 murine hepatoma cells, indicating that they represent chemotypes with a potential for functioning as chemopreventive agents.

Tacrolimus inhibits oral carcinogenesis through cell cycle control

Tacrolimus (TAC, FK506) is a major calcineurin inhibitor and has been commonly used in treatments of patients with organ transplants and immune diseases. Moreover, tacrolimus is recommended by the treatment guidelines for oral potentially malignant disorders (OPMDs) such as oral lichen planus (OLP). However, whether tacrolimus increases the risk of cancer remains controversial. We observed that in a 4-Nitroquinoline N-oxide (4NQO)-induced oral carcinogenesis model, tacrolimus treatment was associated with a significantly lower ratio of cancer formation (52.94% vs. 90%) and a lower proportion of Ki67 and proliferation cell nuclear antigen (PCNA) -positive cells in lesion areas (P < 0.001). Liver, kidney, and lung functions of rats and the tumor immune microenvironment of the tongue were not affected. These observations suggest that tacrolimus blocked oral carcinogenesis through epithelial cell proliferation inhibition, independent of its immunosuppressive effects. As a processing factor, tacrolimus decreased tumor formation and cell proliferation in different stages of oral squamous cell carcinoma (OSCC) progression in vivo and in vitro. Furthermore, we investigated effects on the cell cycle and expression of related proteins. Tacrolimus induced G1/S phase arrest and significantly downregulated the expression of cyclinD1, cyclinE1, and c-Myc. These results suggest that tacrolimus induces G1/S phase arrest via inhibition of cyclinD1, cyclinE1, and c-Myc expression and retards oral cell carcinogenesis in vitro and in vivo. Thus, application of tacrolimus is a safe therapeutic strategy for treating OPMDs.

Nutritional Value and Preventive Role of Nigella sativa L. and Its Main Component Thymoquinone in Cancer: An Evidenced-Based Review of Preclinical and Clinical Studies

In recent times, scientific attention has been paid to different foods and their bioactive components for the ability to inhibit the onset and progress of different types of cancer. Nigella sativa extract, powder and seed oil and its main components, thymoquinone and α-hederin, have showed potent anticancer and chemosensitizing effects against various types of cancer, such as liver, colon, breast, renal, cervical, lung, ovarian, pancreatic, prostate and skin tumors, through the modulation of various molecular signaling pathways. Herein, the purpose of this review was to highlight the anticancer activity of Nigella sativa and it constitutes, focusing on different in vitro, in vivo and clinical studies and projects, in order to underline their antiproliferative, proapoptotic, cytotoxic and antimetastatic effects. Particular attention has been also given to the synergistic effect of Nigella sativa and it constitutes with chemotherapeutic drugs, and to the synthesized analogs of thymoquinone that seem to enhance the chemo-sensitizing potential. This review could be a useful step towards new research on N. sativa and cancer, to include this plant in the dietary treatments in support to conventional therapies, for the best achievement of therapeutic goals.

Chemomodulatory effect of neferine on DMBA-induced squamous cell carcinogenesis: Biochemical and molecular approach

BACKGROUND

Neferine (NEF) is nontoxic, bisbenzylisoquinoline alkaloid is derived from the seed embryo of lotus, a familiar medicinal plant. Although several mechanisms have been planned, an evident antitumor action pathway of NEF on the oral tumor is still not known. In the current study, we aimed at investigating the protecting effect of NEF against experimental oral carcinoma and clarify its possible mechanism through the induction of apoptosis, proliferation, and inflammatory signaling pathways.

METHODS

The experimental hamsters were divided into four groups (I-IV) containing six hamsters each. The group I was control group, group II and III hamsters treated with 7,12-dimethylbenz(a)anthracene (DMBA) (0.5%) alone, thrice in a week for 10 weeks, and group III and IV hamsters received oral supplementation of NEF at a concentration of 15 mg/kg bw. All the hamsters were sacrificed after 16 weeks.

RESULTS

Our results revealed that DMBA treated hamsters exhibited 100% oral tumor cell formation with high-tumor incidence (TI), tumor number (TN), tumor volume (TV), decreased levels of antioxidants, increased status of lipid peroxidation (LPO), and modulated the activities of liver marker agents as well as NF-kB, cell proliferation (PCNA), and p53 proteins. NEF supplementation in DMBA treated hamsters, resulted in delayed lesion synthesis, and brought back the levels of the biochemical parameters. In addition, immunostaining of NF-kB, PCNA, and p53 showed that they were inhibited by NEF.

CONCLUSION

Thus, NEF might be considered a better chemopreventive drug in an experimental model of home-based primary care (HBPC). More research is necessary to study other pathways implicated in oral carcinomas and their modulation by NEF.

Vitexin prevents colitis-associated carcinogenesis in mice through regulating macrophage polarization

BACKGROUND

Patients with inflammatory bowel disease are at increased risks of developing ulcerative colitis-associated colorectal cancer (CAC). Vitexin can suppress the proliferation of colorectal carcinoma cells in vitro orin vivo. However, different from colorectal carcinoma, CAC is more consistent with the transformation from inflammation to cancer in clinical chronic IBD patients. Therefore, we aim to investigated that vitexin whether possess benefic effects on CAC mice.

PURPOSE

We aimed to determine the beneficial effects of vitexin on CAC mice and reveal its underlying mechanism.

METHODS

The mouse CAC model was induced by Azoxymethane and dextran sodium sulfate (AOM/DSS) and CAC mice were treated with vitexin. At the end of this study, inflammatory cytokines of IL-1β, IL-6, TNF-α, IL-10 as well as nitric oxide (NO) were detected by kits after long-term treatment of vitexin. Pathological changes and macrophage polarization were determined by H&E and immunofluorescence in adjacent noncancerous tissue and carcinomatous tissue respectively of CAC mice.

RESULTS

Our results showed that oral administration of vitexin could significantly improve the clinical signs and symptoms of chronic colitis, relieve colon damage, regulate colonic inflammatory cytokines, as well as suppress tumor incidence and tumor burden. Interesting, vitexin caused a significant increase in serum level of NO and a higher content of NO in tumor tissue. In addition, vitexin significantly decreased M1 phenotype macrophages in the adjacent noncancerous tissue, while markedly up-regulated M1 macrophage polarization in the tumor tissue in the colon of CAC mice.

CONCLUSION

Vitexin can attenuate chronic colitis-associated carcinogenesis induced by AOM/DSS in mice and its protective effects are partly associated with its alternations in macrophage polarization in the inflammatory and tumor microenvironment .

Role of the global gut microbial community in the development of colitis-associated cancer in a murine model

The gut microbiota has been implicated in the development of colitis-associated cancer (CAC). We investigated how the gut microbiota affects the development of CAC when the composition of the microbial community is altered by the administration of various antibiotics in a murine model. C57BL/6 mice were given intraperitoneal injection of 12.5 mg/kg azoxymethane (AOM), followed by two rounds of 2.0 % dextran sodium sulfate (DSS) exposure. Antibiotics, including ampicillin, neomycin, metronidazole, and/or vancomycin, were administered 14 days prior to AOM injection until the end of the experiment. High-throughput sequencing of mice feces was conducted to evaluate alterations of the gut microbiota. Tumorigenesis and inflammation were most markedly suppressed in the mice treated with an antibiotic cocktail therapy consisting of ampicillin, neomycin, metronidazole, and vancomycin. Individual antibiotic treatments had different effects on tumorigenesis and inflammation. Metronidazole attenuated both tumorigenesis and inflammation. Neomycin suppressed tumorigenesis but did not alleviate inflammation. Ampicillin and vancomycin did not significantly attenuate either tumorigenesis or inflammation. Antimicrobial therapy differentially altered the diversity and composition of the gut microbiota depending on antibiotic type. The phyla Proteobacteria and Tenericutes were positively correlated with tumor burden. Colon tumorigenesis was attenuated through various antibiotics in the AOM/DSS-induced CAC model. Individual antibiotics differentially altered the gut microbial composition and showed different effects on tumor suppression; however, the degree of tumor suppression was less pronounced than that relative to the antibiotic cocktail therapy, suggesting that the global gut microbial community plays an important role in the development of CAC.

Thymoquinone loaded calcium alginate and polyvinyl alcohol carrier inhibits the 7,12-dimethylbenz[a]anthracene-induced hamster oral cancer via the down-regulation of PI3K/AKT/mTOR signaling pathways

Oral cancer is a multifactorial cancer that affects millions of peoples worldwide. The current exploration aimed to evaluate the mechanisms that thymoquinone nanoencapsulated carrier and its effects on 7,12-Dimethylbenz[a]anthracene (DMBA) stimulated hamster buccal pouch cancer in Syrian hamster model. Nanocarrier was characterized by SEM, TEM, FTIR analysis. The incidence of tumor, and biochemicals makers was studied through standard methods. The mRNA expression level of inflammatory markers NF-κBp50, NF-κBp65, and PI3K/AKT/mTOR markers in the buccal tissues of control and experimental animals were investigated through RT-PCR analysis. In thymoquinone (TQ) loaded calcium alginate and polyvinyl alcohol carrier (TQ/Ca-alg-PVA) no squamous cell carcinogenesis developed and others moderate dysplasia revealed differentiated form of hyperplasia and keratosis. In biochemical analyses with DMBA + TQ/Ca-alg-PVA (20 mg/kg bw) orally administered hamsters showed restored the antioxidants, detoxification, xenobiotic metabolising enzymes in DMBA induced plasma and oral tissues of hamsters. Further, mRNA expression level of NF-κBp50/p65 and PI3K/AKT/mTOR were upregulated in the DMBA alone painted hamster. In contrast, these expressions were down regulated in orally TQ/Ca-alg-PVA treated experimental animals. This ability more eligible to deregulate the inflammatory and PI3K/AKT/mTOR signaling pathway that proved it suppresses anti-invasion/metastasis activity during hamster buccal pouch carcinogenesis. From this study, we recommended that TQ/Ca-alg-PVA has documented as effective chemopreventive agents, in further many molecular machineries need to study.

Lycopene sensitizes the cervical cancer cells to cisplatin via targeting nuclear factor- kappa B (NF-κB) pathway

Background/aim

Lycopene is associated with anticancer effects in various tumor types. However, the exact underlying mechanisms of action of lycopene in human cervical cancer remain to be determined. This study aimed to determine anticancer efficacy and mechanism of lycopene in human cervical carcinoma (HeLa) cells.

Materials and methods

HeLa cells were treated with cisplatin (1 μM) alone, lycopene (10 μM) alone, and in combination for 72 h. The cell viability of HeLa cells was assessed via MTS assay. Western blot was used to analyze the expression levels of the nuclear factor-kappa B (NF-κB), B-cell-associated X protein (Bax), nuclear factor erythroid 2-related factor (Nrf2), and B-cell lymphoma 2 (Bcl-2).

Results

We found that lycopene acts as a synergistic agent with cisplatin in preventing the growth of HeLa cells. The rates of HeLa cells’ viability were 65.6% and 71.1% with lycopene and cisplatin treatment alone compared to the control group, respectively (P < 0.001). The inhibitory effect of cisplatin was enhanced with lycopene addition by declining the cell viability to 37.4% (P < 0.0001). Lycopene treatment significantly increased Bax expression (P < 0.0001) and decreased Bcl-2 expression (P < 0.0001) in HeLa cells. Furthermore, lycopene markedly activated the Nrf2 expression (P < 0.001) and suppressed the NF-κB signaling pathway (P < 0.0001).

Conclusion

Lycopene increases the sensitization of cervical cancer cells to cisplatin via inhibition of cell viability, up-regulation of Bax expression, and down-regulation of Bcl-2 expression. Furthermore, the anticancer effect of lycopene might be also associated with suppression of NF-κB-mediated inflammatory responses, and modulation of Nrf2-mediated oxidative stress. The results of the present study suggest that lycopene and concurrent cisplatin chemotherapy might have a role in improving the treatment of cervical cancer.

Anticancer and antimicrobial potential of enterocin 12a from Enterococcus faecium

BACKGROUND

Increase in the number of infections caused by Gram-negative bacteria in neutropenic cancer patients has prompted the search for novel therapeutic agents having dual anticancer and antimicrobial properties. Bacteriocins are cationic proteins of prokaryotic origin that have emerged as one of the most promising alternative antimicrobial agents with applications as food preservatives and therapeutic agents. Apart from their antimicrobial activities, bacteriocins are also being explored for their anticancer potential.

RESULTS

In this study, a broad-spectrum, cell membrane-permeabilizing enterocin with a molecular weight of 65 kDa was purified and characterized from the culture supernatant of vaginal Enterococcus faecium 12a. Enterocin 12a inhibited multidrug-resistant strains of various Gram-negative pathogens such as Salmonella enterica, Shigella flexneri, Vibrio cholerae, Escherichia coli and Gram-positive, Listeria monocytogenes, but had no activities against different strains of gut lactobacilli. The mass spectrometric analysis showed that the enterocin 12a shared partial homology with 4Fe-4S domain-containing redox protein of E. faecalis R712. Further, enterocin 12a selectively inhibited the proliferation of various human cancer cell lines in a dose-dependent manner but not that of normal human peripheral blood mononuclear cells. Enterocin 12a-treated cancer cells showed apoptosis-like morphological changes.

CONCLUSION

Enterocin 12a is a novel bacteriocin that has anticancer properties against human cell lines and negligible activity towards non-malignant cells. Therefore, it should be further evaluated for its anticancer potential in animal models.

Oncopreventive effects of theanine and theobromine on dimethylhydrazine-induced colon cancer model

Theanine and theobromine are abundantly present in tea and cocoa, respectively. This study was performed to assess the chemopreventive effects of these phytochemicals, alone or together, on dimethylhydrazine (DMH)-induced colon cancer. Thirty male Wistar rats were divided into five groups and subcutaneously injected with saline (negative control group) or 30 mg/kg DMH (the other groups) two times/week for 12 weeks. The negative and positive control animals were orally treated with drinking water, and the other groups were gavaged with theanine (400 mg/kg), theobromine (100 mg/kg), or their mixture for two weeks before and throughout the injection period. At the end of the study, the morphological and histopathological features, Ki-67 proliferation marker, and the expression of Akt/mTOR, JAK2/STAT3, MAPK/ERK, and TGF-β/Smad pathways were investigated. Theanine and theobromine, alone or together, reduced the number of cancerous and precancerous lesions, the volume of tumors, the Ki-67 immunostaining, and the expression of Akt/mTOR and JAK2/STAT3 oncogenic pathways. The simultaneous treatment was more effective in the down-regulation of Akt and mTOR compared to either theanine or theobromine alone. Theobromine administration also caused more inhibitory effects on the Ki-67 and Akt/mTOR expression than theanine. Besides, all dietary interventions increased the mRNA and protein expression of Smad2. In conclusion, theanine and theobromine, alone and in combination, inhibited tumorigenesis through down-regulation of the Akt/mTOR and JAK2/STAT3 pathways and an increment of the Smad2 tumor suppressor. The inhibition of the Akt/mTOR pathway was more pronounced by simultaneous treatment.

Brain Training and Sulforaphane Intake Interventions Separately Improve Cognitive Performance in Healthy Older Adults, Whereas a Combination of These Interventions Does Not Have More Beneficial Effects: Evidence from a Randomized Controlled Trial

Background: Earlier studies have demonstrated that a single-domain intervention, such as a brain-training (BT) game alone and a sulforaphane (SFN) intake, positively affects cognition. This study examined whether a combined BT and SFN intake intervention has beneficial effects on cognitive function in older adults. Methods: In a 12-week double-blinded randomized control trial, 144 older adults were randomly assigned to one of four groups: BT with SFN (BT-S), BT with placebo (BT-P), active control game (AT) with SFN (AT-S), and active control game with placebo (AT-P). We used Brain Age in BT and Tetris in AT. Participants were asked to play BT or AT for 15 min a day for 12 weeks while taking a supplement (SFN or placebo). We measured several cognitive functions before and after the intervention period. Results: The BT (BT-S and BT-P) groups showed more improvement in processing speed than the active control groups (AT-S and AT-P). The SFN intake (BT-S and AT-S) groups recorded significant improvements in processing speed and working memory performance unlike the placebo intake groups (BT-P and AT-P). However, we did not find any evidence of the combined intervention’s beneficial effects on cognition. Discussion: We discussed a mechanism to improve cognitive functions in the BT and SFN alone interventions.

Effects of 6,8-Diprenylgenistein on VEGF-A-Induced Lymphangiogenesis and Lymph Node Metastasis in an Oral Cancer Sentinel Lymph Node Animal Model

BACKGROUND

The major determining factor of prognosis of oral squamous cell carcinoma is cervical lymph node metastasis. 6,8-Diprenylgenistein (6,8-DG), an isoflavonoid isolated from Cudrania tricuspidata has been reported to have anti-microbial and anti-obesity activities. However, its effects on lymphangiogenesis and lymph node metastasis in oral cancer have not yet been reported.

METHODS

To investigate the in vitro inhibitory effects of 6,8-DG on VEGF-A-induced lymphangiogenesis, we performed the proliferation, tube formation, and migration assay using human lymphatic microvascular endothelial cells (HLMECs). RT-PCR, Western blot, immunoprecipitation, ELISA and co-immunoprecipitation assays were used to investigate the expression levels of proteins, and mechanism of 6,8-DG. The in vivo inhibitory effects of 6,8-DG were investigated using an oral cancer sentinel lymph node (OCSLN) animal model.

RESULTS

6,8-DG inhibited the proliferation, migration and tube formation of rhVEGF-A treated HLMECs. In addition, the in vivo lymphatic vessel formation stimulated by rhVEGF-A was significantly reduced by 6,8-DG. 6,8-DG inhibited the expression of VEGF-A rather than other lymphangiogenic factors in CoCl₂-treated SCCVII cells. 6,8-DG inhibited the expression and activation of VEGFR-2 stimulated by rhVEGF-A in HLMECs. Also, 6,8-DG inhibited the activation of the lymphangiogenesis-related downstream signaling factors such as FAK, PI3K, AKT, p38, and ERK in rhVEGF-A-treated HLMECs. Additionally, 6,8-DG inhibited the expression of the hypoxia-inducible factor (HIF-1α), which is involved in the expression of VEGF-A in CoCl₂-treated SCCVII cells, and 6,8-DG inhibited VEGF-A signaling via interruption of the binding of VEGF-A and VEGFR-2 in HLMECs. In the VEGF-A-induced OCSLN animal model, we confirmed that 6,8-DG suppressed tumor-induced lymphangiogenesis and SLN metastasis.

CONCLUSION

These data suggest that 6,8-DG inhibits VEGF-A-induced lymphangiogenesis and lymph node metastasis in vitro and in vivo. Furthermore, the inhibitory effects of 6,8-DG are probably mediated by inhibition of VEGF-A expression in cancer cells and suppression of the VEGF-A/VEGFR-2 signaling pathway in HLMEC. Thus, 6,8-DG could be novel and valuable therapeutic agents for metastasis prevention and treatment of oral cancer.

Melatonin in Wine and Beer: Beneficial Effects

Melatonin is a hormone secreted in the pineal gland with several functions, especially regulation of circadian sleep cycle and the biological processes related to it. This review evaluates the bioavailability of melatonin and resulting metabolites, the presence of melatonin in wine and beer and factors that influence it, and finally the different benefits related to treatment with melatonin. When administered orally, melatonin is mainly absorbed in the rectum and the ileum; it has a half-life of about 0.45–1 h and is extensively inactivated in the liver by phase 2 enzymes. Melatonin (MEL) concentration varies from picograms to ng/mL in fermented beverages such as wine and beer, depending on the fermentation process. These low quantities, within a dietary intake, are enough to reach significant plasma concentrations of melatonin, and are thus able to exert beneficial effects. Melatonin has demonstrated antioxidant, anticarcinogenic, immunomodulatory and neuroprotective actions. These benefits are related to its free radical scavenging properties as well and the direct interaction with melatonin receptors, which are involved in complex intracellular signaling pathways, including inhibition of angiogenesis and cell proliferation, among others. In the present review, the current evidence on the effects of melatonin on different pathophysiological conditions is also discussed.

In Silico Drug-designing Studies on Sulforaphane Analogues: Pharmacophore Mapping, Molecular Docking and QSAR Modeling

AIMS

In the presented work we successfully discovered several novel NQO1 inducers using the computational approaches.

BACKGROUND

The phytochemical sulforaphane (SFN) is a potent inducer of carcinogen detoxication enzymes like NAD(P)H:quinone oxidoreductase 1 (NQO1) through the Kelch-like erythroid cellderived protein with CNC homology[ECH]-associated protein 1 (Keap1)-[NF-E2]-related factor 2 (Nrf2) signaling pathway.

OBJECTIVE

In this paper, we report the first QSAR and pharmacophore modeling study of sulforaphane analogues as NQO1 inducers. The pharmacophore model and understanding the relationships between the structures and activities of the known inducers will give useful information on the structural basis for NQO1 enzymatic activity and lead optimization for future rational design of new sulforaphane analogues as potent NQO1 inducers.

METHODS

In this study, a combination of QSAR modeling, pharmacophore generation, virtual screening and molecular docking was performed on a series of sulforaphane analogues as NQO1 inducers.

RESULTS

In deriving the QSAR model, the stepwise multiple linear regression established a reliable model with the training set (N: 43, R: 0.971, RMSE: 0.216) and test set (N: 14, R: 0.870, RMSE: 0.324, Q2: 0.80) molecules. The best ligand-based pharmacophore model comprised two hydrophobic (HY), one ring aromatic (RA) and three hydrogen bond acceptor (HBA) sites. The model was validated by a testing set and the decoys set, Güner-Henry (GH) scoring methods, etc. The enrichment of model was assessed by the sensitivity (0.92) and specificity (0.95). Moreover, the values of enrichment factor (EF) and the area under the receiver operating characteristics curve (AUC) were 12 and 0.94, respectively. This well-validated model was applied to screen two Asinex libraries for the novel NQO1 inducers. The hits were subsequently subjected to molecular docking after being filtering by Lipinski's, MDDR-like, and Veber rules as well as evaluating their interaction with three major drugmetabolizing P450 enzymes, CYP2C9, CYP2D6 and CYP3A4. Ultimately, 12 hits filtered by molecular docking were subjected to validated QSAR model for calculating their inducer potencies and were introduced as potential NQO1 inducers for further investing action.

CONCLUSION

Conclusively, the validated QSAR model was applied on the hits to calculate their inducer potencies and these 12 hits were introduced as potential NQO1 inducers for further investigations.