Physiologically attainable concentrations of lycopene induce mitochondrial apoptosis in LNCaP human prostate cancer cells

Apoptotic Potential of Glucomoringin Isothiocyanate (GMG-ITC) Isolated from Moringa oleifera Lam Seeds on Human Prostate Cancer Cells (PC-3)

Inhibition of several protein pathways involved in cancer cell regulation is a necessary key in the discovery of cancer chemotherapy. Moringa oleifera Lam is often used in traditional medicine for the treatment of various illnesses. The plant contains glucomoringin isothiocyanate (GMG-ITC) with therapeutic potential against various cancer cells. Therefore, GMG-ITC was evaluated for its cytotoxicity against the PC-3 prostate cancer cell line and its potential to induce apoptosis. GMG-ITC inhibited cell proliferation in the PC-3 cell line with IC50 value 3.5 µg/mL. Morphological changes as a result of GMG-ITC-induced apoptosis showed chromatin condensation, nuclear fragmentation, and membrane blebbing. Additionally, Annexin V assay showed proportion of cells in early and late apoptosis upon exposure to GMG-ITC in a time-dependent manner. Moreover, GMG-ITC induced a time-dependent G2/M phase arrest, with reduction of 39.1% in the PC-3 cell line. GMG-ITC also activates apoptotic genes including caspase, tumor suppressor gene (p53), Akt/MAPK, and Bax of the proapoptotic Bcl family. Early apoptosis proteins (JNK, Bad, Bcl2, and p53) were significantly upregulated upon GMG-ITC treatment. It is concluded that apoptosis induction was observed in PC-3 cells treated with GMG-ITC. These phenomena suggest that GMG-ITC from M. oleifera seeds could be useful as a future cytotoxic agent against prostate cancer.

Lycopene suppresses gastric cancer cell growth without affecting normal gastric epithelial cells

Gastric cancer is one of the leading causes of cancer-related death worldwide. Lycopene, a natural carotenoid, has potent antioxidant activity and anti-cancer effects against several types of cancers. However, the mechanism for the anti-gastric cancer effects of lycopene remains to be fully clarified. Normal gastric epithelial cell line GES-1 and gastric cancer cell line AGS, SGC-7901, Hs746T cells were treated with different concentrations of lycopene and the effects of lycopene were compared. Lycopene specifically suppressed cell growth monitored by Real-Time Cell Analyzer, induced cell cycle arrest and cell apoptosis detected by flow cytometry, and lowered mitochondrial membrane potentials assessed by JC-1 staining of AGS and SGC-7901 cells, while did not affect those of GES-1 cells. Lycopene did not affect the cell growth of Hs746T cells harboring TP53 mutation. Further bioinformatics analysis predicted 57 genes with up-regulated expression levels in gastric cancer and decreased function in cells after lycopene treatment. Quantitative PCR and Western Blot were used to check the critical factors in the cell cycle and apoptosis signaling pathway. Lycopene decreased the high expression levels of CCNE1 and increased the levels of TP53 in AGS and SGC-7901 cells without affecting those in GES-1 cells. In summary, lycopene could effectively suppress gastric cancer cells with CCNE1-amplification, which could be a promising target therapy reagent for gastric cancer.

Fruit Extract of Sechium chinantlense (Lira & F. Chiang) Induces Apoptosis in the Human Cervical Cancer HeLa Cell Line

Sechium edule (Cucurbitaceae) is a commercial species of chayote and is just one of several species in the genus Sechium, whose extracts inhibit proliferation in tumor cell lines. The capacity of the wild species Sechium chinantlense (SCH) as an antitumor agent is unknown, as is the mechanism of action. In the present study, HeLa cervical cancer and HaCaT normal cell lines were treated with SCH and cell proliferation was inhibited in both cell lines in a dose-dependent manner similar to the effect of the antineoplastic agent cisplatin (Cis). Additionally, SCH arrested cell cycle progression but only in HeLa cells and induced apoptosis, as shown by phosphatidylserine translocation and caspase-3 activation, while Cis did so in both cell lines. Exploration of the mechanism of action of SCH in HeLa cells suggests that apoptosis was mediated by the intrinsic signaling pathway since there was no activation of caspase-8, but there was a release of cytochrome-c. These findings suggest that the SCH extract has the potential to selectively kill tumor cells by promoting apoptosis, without harming nontumor cells.

Marine Compounds, Mitochondria, and Malignancy: A Therapeutic Nexus

The marine environment is important yet generally underexplored. It contains new sources of functional constituents that can affect various pathways in food processing, storage, and fortification. Bioactive secondary metabolites produced by marine microorganisms may have significant potential applications for humans. Various components isolated from disparate marine microorganisms, including fungi, microalgae, bacteria, and myxomycetes, showed considerable biological effects, such as anticancer, antioxidant, antiviral, antibacterial, and neuroprotective activities. Growing studies are revealing that potential anticancer effects of marine agents could be achieved through the modulation of several organelles. Mitochondria are known organelles that influence growth, differentiation, and death of cells via influencing the biosynthetic, bioenergetic, and various signaling pathways related to oxidative stress and cellular metabolism. Consequently, mitochondria play an essential role in tumorigenesis and cancer treatments by adapting to alterations in environmental and cellular conditions. The growing interest in marine-derived anticancer agents, combined with the development and progression of novel technology in the extraction and cultures of marine life, led to revelations of new compounds with meaningful pharmacological applications. This is the first critical review on marine-derived anticancer agents that have the potential for targeting mitochondrial function during tumorigenesis. This study aims to provide promising strategies in cancer prevention and treatment.

In Vitro Imaging of Lycopene Delivery to Prostate Cancer Cells

The ability to monitor the uptake and distribution of food nutrients in in vitro cell culture models is key to understanding the efficacy of these nutraceuticals to treat and prevent disease. Lycopene is a carotenoid found in chloroplasts and chromoplasts of tomatoes, providing the familiar red color, and a bioactive that inhibits prostate carcinogenesis. We employed live-cell Raman microscopy to visualize lycopene delivery from tween 80 micelles into PC-3 prostate cancer cells. The tween 80 micelle provides a mimic of natural lipoprotein complexes that deliver lycopene in vivo, overcomes the low aqueous solubility of lycopene and challenges replicating physiological uptake to cells, and provides a stable signal to assess cellular uptake of the nutraceutical formulation. The Raman images indicate subcellular localization of the lycopene within the cells. The lycopene Raman signal is resonantly enhanced at an excitation wavelength of 532 nm, providing a convenient, sensitive, and label-free technique to detect and quantify lycopene uptake in living cells. Analysis of the acquired Raman spectra in the maps determines the concentration of lycopene at each point in the cell. In addition to the expected lycopene Raman signal, Raman scattering from the tween 80 vehicle is also mapped in the cells. The Raman data correlates with scattering features observed in darkfield microscopy images of the cells, which display the cell membrane and other features for reference. Overall, the Raman maps indicate lycopene likely accumulates in lipid membranes of cytoplasmic organelles.

Carotenoids and Carcinogenesis: Exploring the Antioxidant and Cell Signaling Roles of Carotenoids in the Prevention of Cancer

Carotenoids are lipid soluble pigments found in various fruits and vegetables and are naturally produced in photoautotrophic plants. Various studies have investigated the properties of carotenoids to determine how they are able to mitigate numerous diseases, including cancer. Carotenoids present in human serum, including β-carotene, α-carotene, lycopene, β-cryptoxanthin, zeaxanthin, and lutein have demonstrated the ability to act as anticarcinogenic agents. Prevention of disease is often described to be more effective than treatment; as cancer impacts millions of lives globally, the role of carotenoids in the prevention of oncogenesis for numerous types of cancers have been extensively researched. This review provides an in-depth analysis of the structure and properties of carotenoids, as well as the identified and potential mechanisms by which carotenoids can act as a chemopreventative agent.

Molecular Targets of Natural Compounds with Anti-Cancer Properties

Cancer is the second leading cause of death in humans. Despite rapid developments in diagnostic methods and therapies, metastasis and resistance to administrated drugs are the main obstacles to successful treatment. Therefore, the main challenge should be the diagnosis and design of optimal therapeutic strategies for patients to increase their chances of responding positively to treatment and increase their life expectancy. In many types of cancer, a deregulation of multiple pathways has been found. This includes disturbances in cellular metabolism, cell cycle, apoptosis, angiogenesis, or epigenetic modifications. Additionally, signals received from the microenvironment may significantly contribute to cancer development. Chemical agents obtained from natural sources seem to be very attractive alternatives to synthetic compounds. They can exhibit similar anti-cancer potential, usually with reduced side effects. It was reported that natural compounds obtained from fruits and vegetables, e.g., polyphenols, flavonoids, stilbenes, carotenoids and acetogenins, might be effective against cancer cells in vitro and in vivo. Several published results indicate the activity of natural compounds on protein expression by its influence on transcription factors. They could also be involved in alterations in cellular response, cell signaling and epigenetic modifications. Such natural components could be used in our diet for anti-cancer protection. In this review, the activities of natural compounds, including anti-cancer properties, are described. The influence of natural agents on cancer cell metabolism, proliferation, signal transduction and epigenetic modifications is highlighted.

Multifaceted Effects of Lycopene: A Boulevard to the Multitarget-Based Treatment for Cancer

Lycopene is a pigment belonging to the group of carotenoids and it is among the most carefully studied antioxidants found especially in fruit and vegetables. As a carotenoid, lycopene exerts beneficial effects on human health by protecting lipids, proteins, and DNA from damage by oxidation. Lycopene is a powerful oxygen inactivator in the singlet state. This is suggestive of the fact that lycopene harbors comparatively stronger antioxidant properties over other carotenoids normally present in plasma. Lycopene is also reported to hinder cancer cell proliferation. The uncontrolled, rapid division of cells is a characteristic of the metabolism of cancer cells. Evidently, lycopene causes a delay in the progression of the cell cycle, which explains its antitumor activity. Furthermore, lycopene can block cell transformation by reducing the loss of contact inhibition of cancer cells. This paper collects recent studies of scientific evidence that show the multiple beneficial properties of lycopene, which acts with different molecular and cellular mechanisms.

Investigating into anti-cancer potential of lycopene: Molecular targets

Lycopene, the main pigment of tomatoes, possess the strongest antioxidant activity among carotenoids. Lycopene has unique structure and chemical properties. We searched the literature, via PubMed, Embase, Web of Science and Google database so on to screen citations from inception to Oct 2020 for inclusion in this study. We found that as a common phytochemical, it did not attract much attention in the past few years. However, recent studies have indicated that, in addition to antioxidant activity and the second stage of detoxification, the anticancer of lycopene is also considered to be an important determinant of tumor development including the inhibition of cell proliferation, inhibition of cell cycle progression, induction of apoptosis, inhibition of cell invasion, angiogenesis and metastasis. The effect mechanisms of lycopene are related to the regulation of several signal transduction pathways, such as PI3K/Akt pathway, modulation of insulin-like growth factors system, the suppression of activity of sex steroid hormones, the modification of relevant gene expression, and the alteration of mitochondrial function. These novel findings have suggested that lycopene acts as a promising functional natural pigment, and may be associated with a decreased risk of different types of cancer. This review presents the latest knowledge with respect to its molecular mechanisms and its molecular targets of the inhibitory effects on carcinogenesis.

The colorful world of carotenoids: a profound insight on therapeutics and recent trends in nano delivery systems

The therapeutic effects of carotenoids as dietary supplements to control or even treat some specific diseases including diabetic retinopathy, cardiovascular diseases, bacterial infections, as well as breast, prostate, and skin cancer are discussed in this review and also thoughts on future research for their widespread use are emphasized. From the stability standpoint, carotenoids have low bioavailability and bioaccessibility owing to their poor water solubility, deterioration in the presence of environmental stresses such as oxygen, light, and high heat as well as rapid degradation during digestion. Nanoencapsulation technologies as wall or encapsulation materials have been increasingly used for improving food product functionality. Nanoencapsulation is a versatile process employed for the protection, entrapment, and the delivery of food bioactive products including carotenoids from diverse environmental conditions for extended shelf lives and for providing controlled release. Therefore, we present here, recent (mostly during the last five years) nanoencapsulation methods of carotenoids with various nanocarriers. To us, this review can be considered as the first highlighting not only the potential therapeutic effects of carotenoids on various diseases but also their most effective nanodelivery systems.HighlightsBioactive compounds are of deep interest to improve food properties.Carotenoids (such as β-carotene and xanthophylls) play indispensable roles in maintaining human health and well-being.A substantial research effort has been carried out on developing beneficial nanodelivery systems for various carotenoids.Nanoencapsulation of carotenoids can enhance their functional properties.Stable nanoencapsulated carotenoids could be utilized in food products.

Lutein inhibits breast cancer cell growth by suppressing antioxidant and cell survival signals and induces apoptosis

Reduced risk of breast cancer upon intake of lutein-rich food supplements creates an interest to investigate the molecular mechanism underlying the growth inhibitory potential of lutein in MCF-7 and MDA-MB-231 cells. Lutein purified from Spinacia oleracea was identified by high-performance liquid chromatography and liquid chromatography-mass spectrometry. The cell viability was measured by water-soluble tetrazolium-1 assay. The intracellular reactive oxygen species level was examined by 2',7'-dichlorofluorescein assay. The protein expression of the markers of antioxidant defense, cell survival, and apoptosis was analyzed by western blot analysis. The induction of apoptosis by lutein was measured by 4',6-diamidino-2-phenylindole staining and caspase-3 activity assay. The purified lutein inhibited the viability of MCF-7 and MDA-MB-231 cells. The growth inhibitory effect of lutein was associated with suppressed protein expression of superoxide dismutase-2 and heme oxygenase-1, and its transcription factor nuclear factor erythroid 2-related factor-2. Lutein treatment subsequently blocked the expression of intracellular cell survival proteins, phosphorylated protein kinase B, phosphorylated extracellular-regulated kinase 1/2, and nuclear factor-kB. Suppression of antioxidant defense and cell survival markers by lutein was further linked to apoptosis induction with elevated caspase-3 activity and downregulated expression of Bcl-2 and poly-ADP ribose polymerase. Our results emphasize a significant role of lutein as an effective inhibitor of human breast cancer cell growth that activates cell death partly through the modulation of antioxidant defense response-linked cell survival signaling markers.

Enhanced Lycopene Extraction from Tomato Peels by Optimized Mixed-Polarity Solvent Mixtures

Mounting evidence from clinical and epidemiological studies suggests that lycopene, the most abundant carotenoid in tomatoes, may be beneficial in the prevention or treatment of some important diseases. Ripe tomato peels are the richest source of lycopene, but the use of conventional solvent extraction methods without pretreatment of the plant material results in very poor recovery. The reason lies in the localization of lycopene in the plant tissue and the low permeability of the latter to solvent molecules. In this paper, a mixture design procedure was used to formulate solvent mixtures allowing the recovery of lycopene from non-pretreated tomato peels. Two ternary systems were investigated: (a) n-hexane-ethanol-acetone and (b) ethyl lactate-ethanol-acetone. Optimization of the ternary mixture composition led to a recovery of over 90% of the lycopene present in the peels. The high extraction efficiency was explained in terms of lycopene affinity combined with the ability to swell the plant material. A tomato oleoresin with high antioxidant activity and a lycopene content of about 13% (w/w) was also produced. Overall, the results indicate that highly effective solvents for direct recovery of lycopene from tomato peels can be easily prepared by a mixture design approach.

Plant Bioactives and the Prevention of Prostate Cancer: Evidence from Human Studies

Prostate cancer has become the most common form of non-cutaneous (internal) malignancy in men, accounting for 26% of all new male visceral cancer cases in the UK. The aetiology and pathogenesis of prostate cancer are not understood, but given the age-adjusted geographical variations in prostate cancer incidence quoted in epidemiological studies, there is increasing interest in nutrition as a relevant factor. In particular, foods rich in phytochemicals have been proposed to reduce the risk of prostate cancer. Epidemiological studies have reported evidence that plant-based foods including cruciferous vegetables, garlic, tomatoes, pomegranate and green tea are associated with a significant reduction in the progression of prostate cancer. However, while there is well-documented mechanistic evidence at a cellular level of the manner by which individual dietary components may reduce the risk of prostate cancer or its progression, evidence from intervention studies is limited. Moreover, clinical trials investigating the link between the dietary bioactives found in these foods and prostate cancer have reported varied conclusions. Herein, we review the plant bioactives for which there is substantial evidence from epidemiological and human intervention studies. The aim of this review is to provide important insights into how particular plant bioactives (e.g., sulfur-containing compounds, carotenoids and polyphenols) present in commonly consumed food groups may influence the development and progression of prostate cancer.

Lycopene Inhibits Activation of Epidermal Growth Factor Receptor and Expression of Cyclooxygenase-2 in Gastric Cancer Cells

Reactive oxygen species (ROS) contribute to the oncogenic phenotype of cancer cells by acting as signaling molecules for inducing proliferation. ROS are known to activate the epidermal growth factor receptor (EGFR), which causes the activation of the Ras/mitogen-activated protein kinases (MAPKs) pathway. The Ras-dependent pathway promotes the activation of nuclear factor-kappa-light-chain-enhancer of activated B cells (NF-κB), a transcriptional modulator of cyclooxygenase-2 (COX-2) that induces cell proliferation. Lycopene is a potent antioxidant carotenoid and is responsible for the red color of fruits and vegetables. This study aims to investigate whether lycopene inhibits proliferation and induces apoptosis in gastric cancer AGS cells by suppressing the EGFR/Ras/MAPK and NF-κB-COX-2 signaling axis. Lycopene decreased cell viability and increased apoptotic indices (DNA fragmentation, apoptosis inducing factor, cleavage of caspase-3 and caspase-9, Bax/Bcl-2 ratio). Lycopene reduced the level of intracellular and mitochondrial ROS and decreased the activation of the ROS-mediated EGFR/Ras/extracellular signal-regulated kinase (ERK) and p38 MAPK pathways, thus leading to attenuation of the DNA-binding activity of NF-κB p50/p50 and the level of COX-2 gene expression. These results show that lycopene-induced apoptosis and inhibition of proliferation occur via inhibition of ROS-activated EGFR/Ras/ERK and p38 MAPK pathways and NF-κB-mediated COX-2 gene expression in AGS cells. In conclusion, consumption of lycopene-enriched foods could decrease the incidence of gastric cancer.

Lycopene inhibits hepatic stellate cell activation and modulates cellular lipid storage and signaling

Hepatic stellate cells are liver-specific perivascular cells, identified as the major source of collagen in liver fibrosis, following their activation and conversion to myofibroblast-like cells. Lycopene is a carotenoid with biological activities and protective effects described in different pathologies, but little is known about its role in liver protection. We evaluated the influence of lycopene on the cell cycle and lipid metabolism and monitored the possible pathways involved in lycopene inhibition of stellate cell activation. Lycopene induced expression of the lipocyte phenotype, with an accumulation of fat droplets in cytoplasm, with high synthesis and turnover of phospholipids and triglycerides. Cell proliferation analysis showed that lycopene reduced the growth of GRX cells. Lycopene induced an arrest in the G0/G1 phase, followed by a decrease of cells in the G2/M phase, regardless of the concentration of lycopene used. Lycopene modulated relevant signaling pathways related to cholesterol metabolism, cellular proliferation, and lipid metabolism. Also, lycopene treatment increased the expression of RXR-α, RXR-β, and PPARγ, important biomarkers of liver regeneration. These results show that lycopene was able to negatively modulate events related to the activation of hepatic stellate cells through mechanisms that involve changes in expression of cellular lipid metabolism factors, and suggest that this compound might provide a novel pharmacological approach for the prevention and treatment of fibrotic liver diseases.

Comparative Analysis of Lycopene Content from Different Tomato-Based Food Products on the Cellular Activity of Prostate Cancer Cell Lines

Lycopene is more bioavailable in processed tomato products than in raw tomatoes, since arrangement of cis-isomers of lycopene during food processing and storage may increase its biological activity. The aim of the study is evaluate the influence of lycopene content from different tomato-based food products (extract, paste, ketchup and sauce) on cell proliferation, cell cycle, and rate of apoptosis of human prostate cancer cell lines. DU-145 and PC-3 cell lines were treated with lycopene content from different tomato-based food products (500-5000 μg/mL) for 96 h. The data showed a decrease in cell viability in both DU-145 and PC-3 cells after treatment with all lycopene extracts from tomato-based food products. Analysis of cell cycle revealed a decrease in the percentage of prostate cancer cells in G0/G1 and G2/M phases after 96 h of treatment when using lycopene content from tomato paste and tomato extract. However, lycopene extracted from tomato sauce and ketchup promoted a decrease in the percentage of cells in G0/G1 phase and an increase in S and G2/M phases after 96 h of treatment. Lycopene content from all of those tomato-based food products also increased apoptosis in both prostate cancer cell lines. In this regard, lycopene has proved to be a potent inhibitor of cell viability, arrest cell cycle and increase the apoptosis in human prostate cancer cells, suggesting an effect in the balance of human prostate cancer cell lines growth.

Lycopene Inhibits Reactive Oxygen Species-Mediated NF-κB Signaling and Induces Apoptosis in Pancreatic Cancer Cells

Generation of excess quantities of reactive oxygen species (ROS) caused by mitochondrial dysfunction facilitates rapid growth of pancreatic cancer cells. Elevated ROS levels in cancer cells cause an anti-apoptotic effect by activating survival signaling pathways, such as NF-κB and its target gene expression. Lycopene, a carotenoid found in tomatoes and a potent antioxidant, displays a protective effect against pancreatic cancer. The present study was designed to determine if lycopene induces apoptosis of pancreatic cancer PANC-1 cells by decreasing intracellular and mitochondrial ROS levels, and consequently suppressing NF-κB activation and expression of NF-κB target genes including cIAP1, cIAP2, and survivin. The results show that the lycopene decreased intracellular and mitochondrial ROS levels, mitochondrial function (determined by the mitochondrial membrane potential and oxygen consumption rate), NF-κB activity, and expression of NF-κB-dependent survival genes in PANC-1 cells. Lycopene reduced cell viability with increases in active caspase-3 and the Bax to Bcl-2 ratio in PANC-1 cells. These findings suggest that supplementation of lycopene could potentially reduce the incidence of pancreatic cancer.

Lycopene exerts anti-inflammatory effect to inhibit prostate cancer progression

Lycopene is a natural compound that alleviates oxidative stress and inflammation, exerting therapeutic effects in a number of cancers. The aim of this study is to investigate the efficacy of lycopene in inhibiting prostate cancer. Cell viability assays indicated the dose- and time-dependent toxicity of lycopene in prostate cancer cells. Annexin V/propidium iodide double-staining assays revealed the strong apoptotic effects of lycopene. The levels of inflammatory factors, including interleukin-1 (IL1), IL6, IL8, and tumor necrosis factor-α (TNF-α), in lycopene-treated cells were also reduced by lycopene treatment. With the increasing dose of lycopene, the survival of mice bearing prostate cancer xenografts was significantly improved ( P < 0.01), and the tumor burden was significantly reduced ( P < 0.01). Our results indicate that lycopene is a promising chemotherapy drug, which inhibits prostate cancer progression by suppressing the inflammatory response.

Anti/genotoxic, longevity inductive, cytotoxic, and clastogenic-related bioactivities of tomato and lycopene

The aim of this study was to evaluate some biological activities of tomato as well as lycopene and to consider a new nutraceutic value for this fruit regarding to the protection against genetic damage and as a chemopreventive agent. Genotoxicity, DNA-protection against hydrogen peroxide, and lifespan properties of tomato and lycopene were assessed through wing spot test and longevity assay using the Drosophila in vivo model. Additionally, chemopreventive activity was investigated through cytotoxicity, DNA-fragmentation comet and annexin V FITC/PI assays using HL60 in vitro model. Results showed that: (i) tomato and lycopene are not genotoxic and protect against H₂ O₂ -induced damage; (ii) with respect to the lifespan, tomato and lycopene are harmless at the lowest concentration; (iii) tomato is cytotoxic in a dose-dependent manner, but not lycopene; (iv) tomato and lycopene do not induce internucleosomal DNA-fragmentation although they induce significant clastogenic activity at low level in the leukemia cells. To sum up, tomato is a good candidate to be considered as a nutraceutical substance. Furthermore, synergistic action among other components within tomato matrix could be the cause of the health effects observed in this vegetable, which are not fully explained by lycopene. Environ. Mol. Mutagen. 59:427-437, 2018. © 2018 Wiley Periodicals, Inc.

Lycopene Protects Against Spontaneous Ovarian Cancer Formation in Laying Hens

Background

Dietary intake of lycopene has been associated with a reduced risk of ovarian cancer, suggesting its chemopreventive potential against ovarian carcinogenesis. Lycopene's molecular mechanisms of action in ovarian cancer have not been fully understood. Therefore, in the present study, we investigated the effects of lycopene on the ovarian cancer formation using the laying hen model, a biologically relevant animal model of spontaneous ovarian carcinogenesis due to high incidence rates similar to humans.

Methods

In this study, a total of 150 laying hens at age of 102 weeks were randomized into groups of 50: a control group (0 mg of lycopene per kg of diet) and two treatment groups (200 mg or 400 mg of lycopene per kg of diet, or ~26 and 52 mg/d/hen, respectively). At the end of 12 months, blood, ovarian tissues and tumors were collected.

Results

We observed that lycopene supplementation significantly reduced the overall ovarian tumor incidence (P < 0.01) as well as the number and the size of the tumors (P < 0.004 and P < 0.005, respectively). Lycopene also significantly decreased the rate of adenocarcinoma, including serous and mucinous subtypes (P < 0.006). Moreover, we also found that the serum level of oxidative stress marker malondialdehyde was significantly lower in lycopene-fed hens compared to control birds (P < 0.001). Molecular analysis of the ovarian tumors revealed that lycopene reduced the expression of NF-κB while increasing the expression of nuclear factor erythroid 2 and its major target protein, heme oxygenase 1. In addition, lycopene supplementation decreased the expression of STAT3 by inducing the protein inhibitor of activated STAT3 expression in the ovarian tissues.

Conclusions

Taken together, our findings strongly support the potential of lycopene in the chemoprevention of ovarian cancer through antioxidant and anti-inflammatory mechanisms.

The Encapsulation of Lycopene in Nanoliposomes Enhances Its Protective Potential in Methotrexate-Induced Kidney Injury Model

Methotrexate is an antimetabolic drug with a myriad of serious side effects including nephrotoxicity, which presumably occurs due to oxidative tissue damage. Here, we evaluated the potential protective effect of lycopene, a potent antioxidant carotenoid, given in two different pharmaceutical forms in methotrexate-induced kidney damage in rats. Serum biochemical (urea and creatinine) and tissue oxidative damage markers and histopathological kidney changes were evaluated after systemic administration of both lycopene dissolved in corn oil and lycopene encapsulated in nanoliposomes. Similar to previous studies, single dose of methotrexate induced severe functional and morphological alterations of kidneys with cell desquamation, tubular vacuolation, and focal necrosis, which were followed by serum urea and creatinine increase and disturbances of tissue antioxidant status. Application of both forms of lycopene concomitantly with methotrexate ameliorated changes in serum urea and creatinine and oxidative damage markers and markedly reversed structural changes of kidney tissue. Moreover, animals that received lycopene in nanoliposome-encapsulated form showed higher degree of recovery than those treated with free lycopene form. The findings of this study indicate that treatment with nanoliposome-encapsulated lycopene comparing to lycopene in standard vehicle has an advantage as it more efficiently reduces methotrexate-induced kidney dysfunction.

Lycopene Extracts from Different Tomato-Based Food Products Induce Apoptosis in Cultured Human Primary Prostate Cancer Cells and Regulate TP53, Bax and Bcl-2 Transcript Expression

Carotenoids are the main tomato components, especially lycopene. Lycopene is more bioavailable in tomato processed products than in raw tomatos, since formation of lycopene cis-isomers during food processing and storage may increase its biological activity. In the current study, we evaluated the influence of lycopene extracts (5 mg / mL) from different tomato-based food products (paste, sauce, extract and ketchup) on cell viability and apoptosis on primary human prostate cancer cells (PCa cels) for 96h. Using MTT assay, we observed a significant decrease on primary PCa cell viability upon treatment with lycopene extracted from either 4 tomato-based food products. Flow cytometeric analysis revealed that lycopene from tomato extract and tomato sauce promoted up to fifty-fold increase on the proportion of apoptotic cells, when compared to the control group. Using real time PCR assay, we found that lycopene promoted an upregulation of TP53 and Bax transcript expression and also downregulation of Bcl-2 expression in PCa cells. In conclusion, our data demostrate that cis-lycopene promoted a significant inhibition on primary PCa cell viability, as well as an increase on their apoptotic rates, evidencing that cis-lycopene contained in tomato sauce and extract cain mainly modulate of primary human prostate cancer cell survival.

Targeting Apoptosis with Dietary Bioactive Agents

Apoptosis, a form of programmed cell death, is a pivotal defense against the occurrence of cancer and is essential to metazoans in maintaining tissue homeostasis. Apoptosis exhibits a distinctive phenotype and involves elimination of potentially deleterious cells. Many diseases have been associated with aberrantly regulated apoptotic cell death, ultimately leading to inhibition of apoptosis and propagation of diseases such as cancer. Elucidation of the critical events associated with carcinogenesis provides the opportunity for dietary intervention to prevent cancer development through induction of apoptosis, Particularly by bioactive agents or functional foods. Diet is a significant environmental factor in the overall cancer process and can exacerbate or interfere with carcinogenesis. Apoptosis occurs primarily through two well-recognized pathways in cells, including the Intrinsic, or mitochondrial-mediated, effector mechanism and the extrinsic, or death receptor-mediated, effector mechanism. In addition to diet's effects on protein expression and function, evidence is also accumulating that a large number of dietary food components can exert effects on the human genome, either directly or indirectly, to modulate gene expression. In fact, many diet-related genes are involved in carcinogenesis as well as apoptosis, and thus are ultimately molecular targets for dietary chemopreventlon. There are multiple steps within pathways in which dietary components can alter gene expression and phenotypes of cells and thus influence cancer outcomes (nutritional transcriptomic effect). Thus, apoptosis is an emerging therapeutic target of bioactive agents of diet. In this review, the process of apoptosis is discussed and the potential mechanistic interaction of bioactive agents, as components of functional foods, is explored within the context of apoptosis.

Mitochondrial β-Carotene 9',10' Oxygenase Modulates Prostate Cancer Growth via NF-κB Inhibition: A Lycopene-Independent Function

Despite numerous inquiries into protective roles of lycopene in prostate cancer prevention or therapy, little is known about mechanisms by which lycopene or its metabolites inhibit prostate cancer. The enzyme β-carotene 9',10'-oxygenase (BCO2), which catalyzes asymmetric cleavage of several carotenoids, is the principal regulator of lycopene metabolism, but the range of BCO2 biological functions is incompletely understood. This study investigated expression and functional roles of BCO2 in human prostate cancer. Expression of the bco2 gene is dramatically decreased in prostate cancer tissue and in a range of prostate cancer cell lines as compared with nonneoplastic prostate tissue and normal prostatic epithelial cells, respectively. Inhibition of DNA methyltransferase activity restored bco2 expression in prostate cancer cell lines tested. Treatment with lycopene or its metabolite, apo-10-lycopenal, also increased bco2 expression and reduced cell proliferation in androgen-sensitive cell lines, but lycopene neither altered bco2 expression nor cell growth in androgen-resistant cells. Notably, restoring bco2 expression in prostate cancer cells inhibited cell proliferation and colony formation, irrespective of lycopene exposure. Exogenous expression of either wild-type BCO2 or a mutant (enzymatically inactive) BCO2 in prostate cancer cells reduced NF-κB activity and decreased NF-κB nuclear translocation and DNA binding. Together, these results indicate epigenetic loss of BCO2 expression is associated with prostate cancer progression. Moreover, these findings describe previously unanticipated functions of BCO2 that are independent of its enzymatic role in lycopene metabolism.

IMPLICATIONS

This study identifies BCO2 as a tumor suppressor in prostate cancer. BCO2-mediated inhibition of NF-κB signaling implies BCO2 status is important in prostate cancer progression. Mol Cancer Res; 14(10); 966-75. ©2016 AACR.

Lycopene acts through inhibition of IκB kinase to suppress NF-κB signaling in human prostate and breast cancer cells

We studied the effect of the potent dietary antioxidant lycopene on multiple points along the nuclear factor kappa B (NF-κB) signaling pathway in prostate and breast cancer cells. Lycopene significantly inhibited prostate and breast cancer cell growth at physiologically relevant concentrations of ≥1.25 μM. Similar concentrations also caused a 30-40 % reduction in inhibitor of kappa B (IκB) phosphorylation in the cells, as determined by western blotting. Furthermore, the same degree of inhibition by lycopene was observed for NF-κB transcriptional activity, as determined by reporter gene assay. Concomitant with this, immunofluorescence staining of lycopene-treated cells showed a significant suppression (≥25 %) of TNF-induced NF-κB p65 subunit nuclear translocation. Further probing of lycopene's effects on upstream elements of the NF-κB pathway showed a 25 % inhibition of both activity of recombinant IκB kinase β (IKKβ) kinase in a cell-free in vitro assay, as well as activity of IKKβ immunoprecipitated from MDA-MB-231 cells treated with lycopene. In conclusion, the anticancer properties of lycopene may occur through inhibition of the NF-κB signaling pathway, beginning at the early stage of cytoplasmic IKK kinase activity, which then leads to reduced NF-κB-responsive gene regulation. Furthermore, these effects in cancer cells were observed at concentrations of lycopene that are relevant and achievable in vivo.

Absorption of Carotenoids and Mechanisms Involved in Their Health-Related Properties

Carotenoids participate in the normal metabolism and function of the human body. They are involved in the prevention of several diseases, especially those related to the inflammation syndrome. Their main mechanisms of action are associated to their potent antioxidant activity and capacity to regulate the expression of specific genes and proteins. Recent findings suggest that carotenoid metabolites may explain several processes where the participation of their parent carotenoids was unclear. The health benefits of carotenoids strongly depend on their absorption and transformation during gastrointestinal digestion. The estimation of the 'bioaccessibility' of carotenoids through in vitro models have made possible the evaluation of the effect of a large number of factors on key stages of carotenoid digestion and intestinal absorption. The bioaccessibility of these compounds allows us to have a clear idea of their potential bioavailability, a term that implicitly involves the biological activity of these compounds.

The Effect of Lycopene Preexposure on UV-B-Irradiated Human Keratinocytes

Lycopene has been reported as the antioxidant most quickly depleted in skin upon UV irradiation, and thus it might play a protective role. Our goal was to investigate the effects of preexposure to lycopene on UV-B-irradiated skin cells. Cells were exposed for 24 h to 10 M lycopene, and subsequently irradiated and left to recover for another 24 h period. Thereafter, several parameters were analyzed by FCM and

RT-PCR

genotoxicity/clastogenicity by assessing the cell cycle distribution; apoptosis by performing the Annexin-V assay and analyzing gene expression of apoptosis biomarkers; and oxidative stress by ROS quantification. Lycopene did not significantly affect the profile of apoptotic, necrotic and viable cells in nonirradiated cells neither showed cytostatic effects. However, irradiated cells previously treated with lycopene showed an increase in both dead and viable subpopulations compared to nonexposed irradiated cells. In irradiated cells, lycopene preexposure resulted in overexpression of BAX gene compared to nonexposed irradiated cells. This was accompanied by a cell cycle delay at S-phase transition and consequent decrease of cells in G0/G1 phase. Thus, lycopene seems to play a corrective role in irradiated cells depending on the level of photodamage. Thus, our findings may have implications for the management of skin cancer.

How Phytochemicals Prevent Chemical Carcinogens and/or Suppress Tumor Growth?

Phytochemicals are a powerful group of chemicals that are derived from natural resource, especially with plants origin. They have shown to exhibit chemoprevention and chemotherapeutic effects not only in cell lines and in animal models of cancer but also some of them are in the clinical trial phase I and II. Despite numerous reports of these phytochemical effects on cancer, an overview of the mechanisms of their action and their effects on various cellular and molecular functions important in the inhibition of cancer progression has been lacking. In this review, we attempt to catalogue various studies to examine the effect of phytochemicals in cancer initiation, promotion, signaling, and epigenetic changes. Because of the numerous studies in these topics, we only pointed out to some examples in each section.

Torularhodin, isolated from Sporidiobolus pararoseus, inhibits human prostate cancer LNCaP and PC-3 cell growth through Bcl-2/Bax mediated apoptosis and AR down-regulation

Torularhodin is one of the principal carotenoids inSporidiobolus pararoseusand has a similar structure to that of lycopene.

Tomato and tomato byproducts. Human health benefits of lycopene and its application to meat products: a review

During recent decades, the food industry, consumers, and regulatory authorities have developed a significant interest in functional foods because of their potential benefits for human health over and above their basic nutritional value. Tomato is the second most important vegetable crop in the world. The amount of the related wastes is estimated at up to 50,000 tons per year, representing a serious disposal problem with a consequent negative impact on the environment. Tomato byproducts contain a great variety of biologically active substances, principally lycopene, which have been demonstrated by in vitro and in vivo studies to possess antioxidant, hypolipidemic, and anticarcinogenic activities. The aim of this review is to present an overview of the functional and physiological properties of the principal bioactive compound present in tomato and tomato byproducts, lycopene, its addition to meat, and meat products.

Effect of lycopene isolated from Chlorella marina on proliferation and apoptosis in human prostate cancer cell line PC-3

Even though the role of lycopene from tomato (trans form) in controlling prostate cancer was reported, lycopene (cis and trans 60:40) isolated from green algae Chlorella marina was not reported so far. The present study aimed to assess the anti-proliferative and apoptotic effect of lycopene from a new source and to compare the activity with available trans lycopene by using androgen-independent human prostate cancer cell lines. Exposure of PC-3 and DU-145 cell lines to algal lycopene (AL) at a dose of 20 and 50 μM significantly inhibited the growth and colony formation, and the percentage of inhibition was higher than tomatal lycopene (TL)-treated groups. The stability of AL in cell culture medium was high, when compared to TL under standard cell culture conditions. The level of lycopene was not detected in PC-3 cell lines cultured in medium lacking lycopene. Staining cells with acridine orange and ethidium bromide, the PC-3 control cells showed largely non-fragmented intact nucleoid. Stronger apoptosis signal was induced with higher concentrations (50 μM) of algal lycopene. Increased DNA damage was observed in AL- and TL-treated cells which appear as comet during single-cell gel electrophoresis. Flow cytometry results revealed that AL caused PC-3 cells to accumulate in the G0/G1 phase and to undergo apoptosis. The effect was higher in AL groups than TL-treated groups. Algal lycopene showed very significant anti-proliferative and apoptotic effect in human prostate cancer cell lines. Therefore, algal lycopene from C.marina would be recommended for the treatment of prostate cancer.

Low expression of ERK signaling pathway affecting proliferation, cell cycle arrest and apoptosis of human gastric HGC-27 cells line

This study was carried out for the first time to examine the potential role and the underlying mechanisms of Lycopene in the gastric cancer HGC-27 cells. HGC-27 cells were seeded onto heat-sterilized coverslips in six-well plates and exposed to Lycopene (5, 10, 20, 30 and 40 μmol/L) for periods of 72 h at 37 °C. Results showed that Lycopene (5, 10, 20, 30 and 40 μmol/L) dose-dependently increased NBT positive rate and decreased lactate dehydrogenase activity in HGC-27 cells. In addition, Lycopene (5, 10, 20, 30 and 40 μmol/L) inhibited proliferation and induced G0-G1 phase cell cycle arrest in HGC-27 cells. Western blot and FQRT-PCR analysis showed that Lycopene decreased pERK and extracellular signal-regulated kinase (ERK) protein and mRNA expression in a dose-dependent manner. These findings demonstrate that Lycopene inhibited gastric cancer HGC-27 cells growth and stimulated its apoptosis via the suppressing ERK signaling pathway.

Anti-proliferative and apoptosis-inducing activity of lycopene against three subtypes of human breast cancer cell lines

Although lycopene, a major carotenoid component of tomatoes, has been suggested to attenuate the risk of breast cancer, the underlying preventive mechanism remains to be determined. Moreover, it is not known whether there are any differences in lycopene activity among different subtypes of human breast cancer cells. Using ER/PR positive MCF-7, HER2-positive SK-BR-3 and triple-negative MDA-MB-468 cell lines, we investigated the cellular and molecular mechanism of the anticancer activity of lycopene. Lycopene treatment for 168 consecutive hours exhibited a time-dependent and dose-dependent anti-proliferative activity against these cell lines by arresting the cell cycle at the G₀/G₁ phase at physiologically achievable concentrations found in human plasma. The greatest growth inhibition was observed in MDA-MB-468 where the sub-G₀/G₁ apoptotic population was significantly increased, with demonstrable cleavage of PARP. Lycopene induced strong and sustained activation of the ERK1/2, with concomitant cyclin D1 suppression and p21 upregulation in these three cell lines. In triple negative cells, lycopene inhibited the phosphorylation of Akt and its downstream molecule mTOR, followed by subsequent upregulation of proapoptotic Bax without affecting anti-apoptotic Bcl-xL. Taken together, these data indicate that the predominant anticancer activity of lycopene in MDA-MB-468 cells suggests a potential role of lycopene for the prevention of triple negative breast cancer.

Low prostate concentration of lycopene is associated with development of prostate cancer in patients with high-grade prostatic intraepithelial neoplasia

Prostate cancer (PC) is a frequent male malignancy and represents the second most diagnosed cancer in men. Since pre-cancerous lesions, i.e., the high-grade prostatic intraepithelial neoplasia (HGPIN), can be detected years before progression to PC, early diagnosis and chemoprevention are targeted strategies to reduce PC rates. Animal studies have shown that lycopene, a carotenoid contained in tomatoes, is a promising candidate for the chemoprevention of PC. However, its efficacy in humans remains controversial. The present study aimed to investigate the relevance of plasma and prostate concentration of lycopene after a lycopene-enriched diet in patients diagnosed with HGPIN. Thirty-two patients diagnosed with HGPIN were administered a lycopene-enriched diet (20–25 mg/day of lycopene; through 30 g/day of triple concentrated tomato paste) for 6 months. A 6-month follow-up prostate biopsy assessed progression to PC. Patients were classified into three groups according to the histopathological features of the 6-month follow-up biopsy results: prostatitis; HGPIN and PC. PSA and plasma lycopene levels were measured before and after the dietary lycopene supplementation. Prostatic lycopene concentration was only assessed after the supplementation diet. Only prostatic lycopene concentration showed significant differences between the three groups (p = 0.03). Prostatic lycopene concentration below a 1 ng/mg threshold was associated with PC at 6-month follow-up biopsy (p = 0.003). We observed no overall benefits from a 6-month lycopene supplementation, as the rate of HGPIN progression to PC in our population (9/32, 28%) was similar to rates reported in the literature. Baseline PSA levels also showed no significant changes after a lycopene-enriched diet. Our findings point to prostatic lycopene concentration as a promising biomarker of PC. Further prospective longitudinal studies are needed to assess the prognostic role of prostatic lycopene in PC.

Carotenoid intake and esophageal cancer risk: a meta-analysis

This meta-analysis was conducted to evaluate the association between intake of carotenoids and risk of esophageal cancer. A systematic search using PubMed, Cochrane Library, Web of Science, Scopus, CNKI, and CBM (updated to 6 May 2012) identified ten articles meeting the inclusion criteria with 1,958 cases of esophageal cancer and 4,529 controls. Higher intake of beta-carotene, alpha-carotene, lycopene, beta-cryptoxanthin, lutein, and zeaxanthin reduced esophageal cancer risk with pooled ORs of 0.58 (95% CI 0.44, 0.77), 0.81 (95% CI 0.70, 0.94), 0.75 (95% CI 0.64, 0.86), 0.80 (95% CI 0.66, 0.97), and 0.71 (95% CI 0.59, 0.87), respectively. In subgroup analyses, beta-carotene showed protective effects against esophageal adenocarcinoma in studies located in Europe and North America. Alpha-carotene, lycopene, and beta-cryptoxanthin showed protection against esophageal squamous cell cancer. This meta-analysis suggested that higher intake of carotenoids (beta-carotene, alpha- carotene, lycopene, beta-cryptoxanthin, lutein, and zeaxanthin) is associated with lower risk of esophageal cancer. Further research with large-sample studies need to be conducted to better clarify the potentially protective mechanisms of carotenoid associations risk of different types of esophageal cancer.

Multiple molecular and cellular mechanisms of action of lycopene in cancer inhibition

Epidemiological studies suggest that including fruits, vegetables, and whole grains in regular dietary intake might prevent and reverse cellular carcinogenesis, reducing the incidence of primary tumours. Bioactive components present in food can simultaneously modulate more than one carcinogenic process, including cancer metabolism, hormonal balance, transcriptional activity, cell-cycle control, apoptosis, inflammation, angiogenesis and metastasis. Some studies have shown an inverse correlation between a diet rich in fruits, vegetables, and carotenoids and a low incidence of different types of cancer. Lycopene, the predominant carotenoid found in tomatoes, exhibits a high antioxidant capacity and has been shown to prevent cancer, as evidenced by clinical trials and studies in cell culture and animal models. In vitro studies have shown that lycopene treatment can selectively arrest cell growth and induce apoptosis in cancer cells without affecting normal cells. In vivo studies have revealed that lycopene treatment inhibits tumour growth in the liver, lung, prostate, breast, and colon. Clinical studies have shown that lycopene protects against prostate cancer. One of the main challenges in cancer prevention is the integration of new molecular findings into clinical practice. Thus, the identification of molecular biomarkers associated with lycopene levels is essential for improving our understanding of the mechanisms underlying its antineoplastic activity.

The potential role of lycopene for the prevention and therapy of prostate cancer: from molecular mechanisms to clinical evidence

Lycopene is a phytochemical that belongs to a group of pigments known as carotenoids. It is red, lipophilic and naturally occurring in many fruits and vegetables, with tomatoes and tomato-based products containing the highest concentrations of bioavailable lycopene. Several epidemiological studies have linked increased lycopene consumption with decreased prostate cancer risk. These findings are supported by in vitro and in vivo experiments showing that lycopene not only enhances the antioxidant response of prostate cells, but that it is even able to inhibit proliferation, induce apoptosis and decrease the metastatic capacity of prostate cancer cells. However, there is still no clearly proven clinical evidence supporting the use of lycopene in the prevention or treatment of prostate cancer, due to the only limited number of published randomized clinical trials and the varying quality of existing studies. The scope of this article is to discuss the potential impact of lycopene on prostate cancer by giving an overview about its molecular mechanisms and clinical effects.

Prostate cancer chemoprevention in men of African descent: current state of the art and opportunities for future research

Prostate cancer is the most frequently diagnosed malignancy in men. However, African American/Black men are 60 % more likely to be diagnosed with and 2.4 times more likely to die from prostate cancer, compared to Non-Hispanic White men. Despite the increased burden of this malignancy, no evidence-based recommendation regarding prostate cancer screening exists for the high-risk population. Moreover, in addition to screening and detection, African American men may constitute a prime population for chemoprevention. Early detection and chemoprevention may thus represent an integral part of prostate cancer control in this population. Importantly, recent research has elucidated biological differences in the prostate tumors of African American compared to European American men. The latter may enable a more favorable response in African American men to specific chemopreventive agents that target relevant signal transduction pathways. Based on this evolving evidence, the aims of this review are threefold. First, we aim to summarize the biological differences that were reported in the prostate tumors of African American and European American men. Second, we will review the single- and multi-target chemopreventive agents placing specific emphasis on the pathways implicated in prostate carcinogenesis. And lastly, we will discuss the most promising nutraceutical chemopreventive compounds. Our review underscores the promise of chemoprevention in prostate cancer control, as well as provides justification for further investment in this filed to ultimately reduce prostate cancer morbidity and mortality in this high-risk population of African American men.

Adverse effects in broiler chickens fed a high lycopene concentration supplemented diet

Pozzo, L., Tarantola, M., Biasibetti, E., Capucchio, M. T., Pagella, M., Mellia, E., Bergagna, S., Gennero, M. S., Strazzullo, G. and Schiavone, A. 2013. Adverse effects in broiler chickens fed a high lycopene concentration supplemented diet. Can. J. Anim. Sci. 93: 231–241. The present investigation was designed to assess the effects of the administration of a high dietary lycopene dose to broiler chickens on growth and slaughter performances, haemato–biochemical parameters, antioxidant enzymes, histological lesions and lycopene accumulation in the tissues. Thirty-six 1-d-old male Hubbard broiler chicks were examined and divided randomly into two groups (three replicates for each dietary treatment): the Control group, which received a basal diet, and the Lycopene group, which received the basal diet supplemented with 500 mg lycopene kg−1diet. The experimental period lasted 35 d and growth performance was recorded on a weekly basis. At the end of the experiment (day 35), blood samples (n=12) were collected from the femoral vein. Erythrocyte and leukocyte numbers were assessed and the heterophil-to-lymphocyte ratio was determined. The alpha-1-acid glycoprotein, lysozyme, total protein and the electrophoretic patterns were evaluated in serum samples. Nine chickens per group were slaughtered to measure the carcass yields and the weight of the liver, spleen, bursa of Fabricius and thymus. Spleen, liver, and bursa of Fabricius samples were collected for histological examination and fixed in 10% neutral buffered formalin. The lycopene concentration, thiobarbituric acid reactive substances (TBARS) and chemical composition were assayed in breast meat and thigh samples. The TBARS, glutathione content, catalase and superoxide dismutase activity were measured in liver and kidney samples. The high lycopene concentration supplemented diet did not affect the birds’ growth, slaughter performance or antioxidant enzymes in the breast meat, thigh meat, liver and kidney samples. The concentrations of lycopene in the breast and thigh of the lycopene-supplemented group were 0.10±0.05 mg kg−1and 0.42±0.35 mg kg−1, respectively, while no lycopene was found in the Control group. Spleen and bursa of Fabricius of birds fed a diet supplemented with a high level of lycopene showed weight decrease (P<0.05) and degenerative lesions (P<0.05). Moreover, lycopene supplementation reduced the serum protein concentration, albumin, alpha and the gamma globulin serum concentration (P<0.05).

Update on in vitro cytotoxicity assays for drug development

BACKGROUND

in vitro cytotoxicity testing provides a crucial means of ranking compounds for consideration in drug discovery. The choice of using a particular viability or cytotoxicity assay technology may be influenced by specific research goals.

OBJECTIVE

Although the high-throughput screening (HTS) utility is typically dependent upon sensitivity and scalability, it is also impacted by signal robustness and resiliency to assay interferences. Further consideration should be given to data quality, ease-of-use, reagent stability, and matters of cost-effectiveness.

METHODS

Here we focus on three main classes of assays that are at present the most popular, useful, and practical for HTS drug discovery efforts. These methods measure: i) viability by metabolism reductase activities; ii) viability by bioluminescent ATP assays; or iii) cytotoxicity by enzymes 'released' into culture medium. Multi-parametric technologies are also briefly discussed.

RESULTS/CONCLUSION

Each of these methods has its relative merits and detractions; however multi-parametric methods using both viability and cytotoxicity markers may mitigate the inherent shortcomings of single parameter measures.

Lycopene inhibits angiogenesis both in vitro and in vivo by inhibiting MMP-2/uPA system through VEGFR2-mediated PI3K-Akt and ERK/p38 signaling pathways

SCOPE

Limited in vitro data show that lycopene may be anti-angiogenic but with unclear mechanisms. Here, we employed ex vivo and in vivo assays to substantiate the anti-angiogenic action of lycopene and determined its molecular mechanisms in human umbilical vein endothelial cells (HUVECs).

METHODS AND RESULTS

The anti-angiogenic activity of lycopene was confirmed by ex vivo rat aortic ring and in vivo chorioallantoic membrane assays. Furthermore, the in vivo matrigel plug assay in mice demonstrated that lycopene implanted s.c. at the highest dose used (400 μg/plug) completely inhibited the formation of vascular endothelial cells induced by vascular endothelial growth factor (VEGF). As expected, lycopene inhibited tube formation, invasion, and migration in HUVECs, and such actions were accompanied by reduced activities of matrix metalloproteinase-2, urokinase-type plasminogen activator, and protein expression of Rac1, and by enhancing protein expression of tissue inhibitors of metalloproteinase-2 and plasminogen activator inhibitor-1. Moreover, lycopene attenuated VEGF receptor-2 (VEGFR2)-mediated phosphorylation of extracellular signal-regulated kinase (ERK), p38, and Akt as well as protein expression of PI3K.

CONCLUSION

Our data demonstrate the anti-angiogenic effect of lycopene both in vitro and in vivo. The anti-angiogenic activity of lycopene may involve inhibition of MMP-2/uPA system through VEGFR2-mediated PI3K-Akt and ERK/p38 signaling pathways.

Effect of lycopene on cell viability and cell cycle progression in human cancer cell lines

BACKGROUND

Lycopene, a major carotenoid component of tomato, has a potential anticancer activity in many types of cancer. Epidemiological and clinical trials rarely provide evidence for mechanisms of the compound's action, and studies on its effect on cancer of different cell origins are now being done. The aim of the present study was to determine the effect of lycopene on cell cycle and cell viability in eight human cancer cell lines.

METHODS

Human cell lines were treated with lycopene (1-5 μM) for 48 and 96 h. Cell viability was monitored using the method of MTT. The cell cycle was analyzed by flow cytometry, and apoptotic cells were identified by terminal deoxynucleotidyl transferase-mediated dUTP nick labeling (TUNEL) and by DAPI.

RESULTS

Our data showed a significant decrease in the number of viable cells in three cancer cells lines (HT-29, T84 and MCF-7) after 48 h treatment with lycopene, and changes in the fraction of cells retained in different cell cycle phases. Lycopene promoted also cell cycle arrest followed by decreased cell viability in majority of cell lines after 96 h, as compared to controls. Furthermore, an increase in apoptosis was observed in four cell lines (T-84, HT-29, MCF-7 and DU145) when cells were treated with lycopene.

CONCLUSIONS

Our findings show the capacity of lycopene to inhibit cell proliferation, arrest cell cycle in different phases and increase apoptosis, mainly in breast, colon and prostate lines after 96 h. These observations suggest that lycopene may alter cell cycle regulatory proteins depending on the type of cancer and the dose of lycopene administration. Taken together, these data indicated that the antiproliferative effect of lycopene was cellular type, time and dose-dependent.

Apo-8'-lycopenal induces expression of HO-1 and NQO-1 via the ERK/p38-Nrf2-ARE pathway in human HepG2 cells

Lycopene and its metabolite apo-10'-lycopenoic acid have been shown to induce phase II detoxifying/antioxidant enzymes through activation of the nuclear factor erythroid-derived 2-like 2 (Nrf2)-antioxidant response element (ARE) transcription system. However, little is known about whether apo-8'-lyocpenal, one of the main metabolites of lycopene in rat livers, in lycopene-containing food, and in human plasma, has similar effects. This study investigated the effect of apo-8'-lycopenal on Nrf2-ARE system-mediated heme oxygenase 1 (HO-1) and NAD(P)H:quinine oxidoreductase 1 (NQO-1) expression in human HepG2 cells. It was found that apo-8'-lycopenal (1-10 μM) significantly increased nuclear Nrf2 accumulation, ARE-luciferase activity, Nrf2-ARE binding activity, chymotrypsin-like activity, and downstream HO-1 and NQO-1 expression, but decreased cytosolic Kelch-like ECH-associated protein 1 (Keap1) expression. Results also revealed that the ERK/p38-Nrf2 pathway is involved in activation of HO-1 and NQO-1 expression by apo-8'-lycopenal using Nrf2 siRNA and ERK/p38 specific inhibitors. In addition, the activation time of lycopene on nuclear Nrf2 accumulation is slower than that of apo-8'-lycopenal, suggesting that the chemopreventive effects of lycopene may be partially attributed to its metabolites.