In VitroEffect of Lycopene on Cytokine Production by Human Peripheral Blood Mononuclear Cells

Lycopene alleviates food allergy by modulating the PI3K/AKT pathway in peanut-sensitized BALB/c mice

Food allergies, which lead to life-threatening acute symptoms, are considered an important public health problem. Therefore, it is essential to develop efficient preventive and treatment measures. We developed a crude peanut protein extract (PPE)-induced allergy mouse model to investigate the effects of lycopene on peanut allergy. Mice were divided into four groups: 5 mg/kg lycopene, 20 mg/kg lycopene, no treatment, and control groups. Serum inflammatory factors were detected using enzyme-linked immunosorbent assay. In addition, pathology and immunohistochemistry analyses were used to examine the small intestine of mice. We found that lycopene decreased PPE-specific immunoglobulin E (IgE) and IL-13 levels in the serum, relieved small intestine inflammation, attenuated the production of histamine and mouse mast cell protease-1, and downregulated PI3K and AKT1 expression in the small intestine tissues of mice allergic to peanuts. Our results suggest that lycopene can ameliorate allergy by attenuating the PI3K/AKT pathway and the anaphylactic reactions mediated by PPE-specific IgE.

Beneficial Effects of Olive Oil Enriched with Lycopene on the Plasma Antioxidant and Anti-Inflammatory Profile of Hypercholesterolemic Patients

Olive oil and lycopene are foods that have potent antioxidant activity. The objective was to determine the effects of consumption of olive oil enriched with lycopene on oxidative stress biomarkers in hypercholesterolemic subjects. We examined the effects of oil enriched with lycopene extract daily intake during 1 month on plasma antioxidant capacity, lipids profile (triacylgycerols, total cholesterol, cHDL; cLDL, ox-LDL), biomarkers of oxidative stress, and inflammatory markers related with atherosclerosis risk (C-reactive protein (CRP), IL-6; sDC4L) in subjects hypercholesteremics (cholesterol > 220 mg/dL). In the group consuming olive oil-lycopene, significant increases (p < 0.05) in the levels of plasma lycopene concentration (0.146 ± 0.03 versus 0.202 ± 0.04 (µmol/L)), α-carotene (0.166 ± 0.064 versus 0.238 ± 0.07) and in β-carotene (0.493 ± 0.187 versus 0.713 ± 0.221) were observed. These results are linked with the increases of plasma antioxidants and decreases biomarkers of oxidative stress (carbonyl groups, malondialdehyde and 8-hydroxy-deoxiguanosine) observed in hypercholesterolemic group. In relation to lipid profile, a significant decrease was observed in the levels of ox-LDL (781 ± 302 versus 494 ± 200), remaining unchanged the levels of TG, cholesterol, HDL and LDL-c. Regarding inflammatory biomarkers, the levels of CRP and IL-6 decreased significantly. The positive results obtained in this study support the use of olive oil enriched with lycopene to reduce the risk of coronary disease.

Lycopene from Red Guava (Psidium guajava L.): From Hepatoprotective Effect to Its Use as Promising Self-Emulsifying Drug Delivery System for Anti-Inflammatory and Antioxidant Applications

Lycopene is a carotenoid with potential use in the treatment of chronic illnesses. Here, different formulations of lycopene were studied: lycopene-rich extract from red guava (LEG), purified lycopene from red guava (LPG) and a self-emulsifying drug delivery system loaded with LPG (nanoLPG). The effects of administering orally various doses of LEG to hypercholesterolemic hamsters were evaluated regarding the liver function of the animals. The cytotoxicity of LPG in Vero cells was analyzed by a crystal violet assay and by fluorescence microscopy. In addition, nanoLPG was employed in stability tests. LPG and nanoLPG were tested for their cytotoxic effect on human keratinocytes and antioxidant capacity on cells in an endothelial dysfunction model in an isolated rat aorta. Finally, the effect of different nanoLPG concentrations on the expression of immune-related genes (IL-10, TNF-α, COX-2 and IFN-γ) from peripheral blood mononuclear cells (PBMC) using real-time PCR was also analyzed. Results suggest that LEG, despite not being able to improve blood markers indicative of liver function in hypercholesterolemic hamsters, reduced hepatic degenerative changes. Additionally, LPG did not show cytotoxicity in Vero cells. In relation to nanoLPG, the effects produced by heat stress evaluated by Dynamics Light Scattering (DLS) and visually were loss of color, texture change and phase separation after 15 days without interfering with the droplet size, so the formulation proved to be efficient in stabilizing the encapsulated lycopene. Although LPG and nanoLPG showed moderate toxicity to keratinocytes, which may be related to cell lineage characteristics, both revealed potent antioxidant activity. LPG and nanoLPG showed vasoprotective effects in aortic preparations. The gene expression assay indicates that, although no significant differences were observed in the expression of IL-10 and TNF-α, the PBMCs treated with nanoLPG showed a reduction in transcriptional levels of IFN-γ and an increased expression of COX-2. Thus, the work adds evidence to the safety of the use of lycopene by humans and shows that tested formulations, mainly nanoLPG due to its stability, stand out as promising and biosafe products for the treatment of diseases that have oxidative stress and inflammation in their etiopathology.

Potential Benefits of Lycopene Consumption: Rationale for Using It as an Adjuvant Treatment for Malaria Patients and in Several Diseases

Malaria is a disease that affects thousands of people around the world every year. Its pathogenesis is associated with the production of reactive oxygen and nitrogen species (RONS) and lower levels of micronutrients and antioxidants. Patients under drug treatment have high levels of oxidative stress biomarkers in the body tissues, which limits the use of these drugs. Therefore, several studies have suggested that RONS inhibition may represent an adjuvant therapeutic strategy in the treatment of these patients by increasing the antioxidant capacity of the host. In this sense, supplementation with antioxidant compounds such as zinc, selenium, and vitamins A, C, and E has been suggested as part of the treatment. Among dietary antioxidants, lycopene is the most powerful antioxidant among the main carotenoids. This review aimed to describe the main mechanisms inducing oxidative stress during malaria, highlighting the production of RONS as a defense mechanism against the infection induced by the ischemia-reperfusion syndrome, the metabolism of the parasite, and the metabolism of antimalarial drugs. Furthermore, the effects of lycopene on several diseases in which oxidative stress is implicated as a cause are outlined, providing information about its mechanism of action, and providing an evidence-based justification for its supplementation in malaria.

Lycopene: Sojourn from kitchen to an effective therapy in Alzheimer's disease

Reports on a significant positive correlation between consumption of carotenoid-rich food and prevention of Alzheimer's disease (AD) led to the investigation of carotenoids for the treatment and prevention of AD. More than 1100 types of carotenoids are found naturally, out of which only around 50 are absorbed and metabolized in human body. Lycopene is one of the most commonly ingested members of fat-soluble carotenoid family that gives vegetables and fruits their red, yellow, or orange color. Lycopene has established itself as a promising therapy for AD owing to its neuroprotective activities, including antioxidant, anti-inflammatory, and antiamyloidogenic properties. In this review, we highlight the various in vitro and preclinical studies demonstrating the neuroprotective effect of lycopene. Also, some epidemiological and interventional studies investigating the protective effect of lycopene in AD have been discussed. Diving deeper, we also discuss various significant mechanisms, through which lycopene exerts its remissive effects in AD. Finally, to overcome the issue of poor chemical stability and bioavailability of lycopene, some of the novel delivery systems developed for lycopene have also been briefly highlighted.

An immune-shift induced by lycopene; from an eosinophil-dominant type towards an eosinophil/neutrophil-co-dominant type of airway inflammation

Lycopene as the main carotenoid from tomatoes is known to have beneficial effects on various inflammatory diseases. In mice, lycopene ameliorates asthma symptoms and in human asthmatic patients serum lycopene levels are reduced. To further investigate the immunomodulatory effect of lycopene, first, we used a ragweed pollen extract (RWE)-induced asthma model in mice. In a second approach, we established a RWE-induced asthma model in gerbils, because of a more human-like carotenoid absorption in these animals. In RWE-sensitized/RWE-challenged gerbils (C+) following a basal diet, mainly the number of eosinophils in the broncho-alveolar lavage (BAL) significantly increased, comparable to RWE-sensitized/PBS-challenged gerbils (C-). In RWE-sensitized/PBS-challenged gerbils with lycopene-supplementation (L-), an elevated number of mainly neutrophils, in addition to eosinophils, was detected compared to C-, whereas in RWE-sensitized/RWE-challenged animals with lycopene-supplementation (L+), mainly increased neutrophil numbers in BAL were detected compared to C+. Furthermore, using LC-MS, we determined an array of eicosanoids/docosanoids in the lungs and observed that 5-, 8-lipoxygenase (LOX) and cyclooxygenase (COX) pathways were significantly increased after intranasal RWE-challenge in sensitized mice and just by tendency in gerbils. In PBS- and RWE-challenged animals, lycopene-supplementation significantly raised COX-pathway metabolites. In conclusion, we found that lycopene-supplementation resulted in an increased inflammatory influx of neutrophils in combination with increased COX-pathways metabolites. This pro-inflammatory, pro-neutrophil activity induced by lycopene might be an important shift from allergic asthma towards an inflammatory symptomatic asthma type, though with the potential for resolution.

Scientometric and Methodological Analysis of the Recent Literature on the Health-Related Effects of Tomato and Tomato Products

The health benefits of tomato, a vegetable consumed daily in human diets, have received great attention in the scientific community, and a great deal of experiments have tested their utility against several diseases. Herein, we present a scientometric analysis of recent works aimed to estimate the biological effects of tomato, focusing on bibliographic metadata, type of testers, target systems, and methods of analysis. A remarkably variable array of strategies was reported, including testers obtained by standard and special tomatoes, and the use of in vitro and in vivo targets, both healthy and diseased. In vitro, 21 normal and 36 cancer human cell lines derived from 13 different organs were used. The highest cytotoxic effects were reported on cancer blood cells. In vivo, more experiments were carried out with murine than with human systems, addressing healthy individuals, as well as stressed and diseased patients. Multivariate analysis showed that publications in journals indexed in the agriculture category were associated with the use of fresh tomatoes; conversely, medicine and pharmacology journals were associated with the use of purified and formulate testers. Studies conducted in the United States of America preferentially adopted in vivo systems and formulates, combined with blood and tissue analysis. Researchers in Italy, China, India, and Great Britain mostly carried out in vitro research using fresh tomatoes. Gene expression and proteomic analyses were associated with China and India. The emerging scenario evidences the somewhat dichotomic approaches of plant geneticists and agronomists and that of cell biologists and medicine researchers. A higher integration between these two scientific communities would be desirable to foster the assessment of the benefits of tomatoes to human health.

Potential therapeutic applications of phytoconstituents as immunomodulators: Pre-clinical and clinical evidences

Autoimmune and infectious diseases are the major public health issues and have gained great attention in the last few years for the search of new agents with therapeutic benefits on the host immune functions. In recent years, natural products (NPs) have been studied broadly for their multi-targeted activities under pathological conditions. Interestingly, several attempts have been made to outline the immunomodulatory properties of NPs. Research on in-vitro and in-vivo models have shown the immunomodulatory activity of NPs, is due to their antiinflammatory property, induction of phagocytosis and immune cells stimulation activity. Moreover, studies on humans have suggested that phytomedicines reduce inflammation and could provide appropriate benefits either in single form or complex combinations with other agents preventing disease progression, subsequently enhancing the efficacy of treatment to combat multiple malignancies. However, the exact mechanism of immunomodulation is far from clear, warranting more detailed investigations on their effectiveness. Nevertheless, the reduction of inflammatory cascades is considered as a prime protective mechanism in a number of inflammation regulated autoimmune diseases. Altogether, this review will discuss the biological activities of plant-derived secondary metabolites, such as polyphenols, alkaloids, saponins, polysaccharides and so forth, against various diseases and their potential use as an immunomodulatory agent under pathological conditions.

Identification of immune-related genes in gill cells of Japanese eels (Anguilla japonica) in adaptation to water salinity changes

The changes in ambient salinity influence ion and water homeostasis, hormones secretion, and immune response in fish gills. The physiological functions of hormones and ion transporters in the regulation of gill-osmoregulation have been widely studied, however the modulation of immune response under salinity changes is not determined. Using transcriptome sequencing, we obtained a comprehensive profile of osmo-responsive genes in gill cells of Japanese eel (Anguilla japonica). Herein, we applied bioinformatics analysis to identify the immune-related genes that were significantly higher expressed in gill pavement cells (PVCs) and mitochondrial-rich cells (MRCs) in freshwater (FW) than seawater (SW) adapted fish. We validated the data using the real-time qPCR, which showed a high correlation between the RNA-seq and real-time qPCR data. In addition, the immunohistochemistry results confirmed the changes of the expression of selected immune-related genes, including C-reactive protein (CRP) in PVCs, toll-like receptor 2 (TLR2) in MRCs and interleukin-1 receptor type 2 (IL-1R2) in both PVCs and MRCs. Collectively our results demonstrated that those immune-related genes respond to salinity changes, and might trigger related special signaling pathways and network. This study provides new insights into the impacts of ambient salinity changes on adaptive immune response in fish gill cells.

trans-Lycopene from tomato juice attenuates inflammatory biomarkers in human plasma samples: An intervention trial

SCOPE

The effect of carotenoids from tomato juice (TJ) on inflammatory biomarkers was evaluated by performing a 4-week dose-response nutritional trial in a population at high cardiovascular risk.

METHODS AND RESULTS

An open, prospective, randomized, cross-over, and controlled clinical trial was carried out with 28 volunteers (mean age 69.7 ± 3.1 years; mean BMI 31.5 ± 3.6 kg/m² ) at high cardiovascular risk, which were assigned to consume daily for 4 weeks in random order: 200 mL (LD) or 400 mL (HD) of TJ, or water as a control (C), with a 21-day wash-out period between each intervention. Blood samples were collected at baseline (B) and after each intervention. Endpoints included significant changes in plasmatic carotenoids, and adhesion molecules ICAM-1, and VCAM-1, as well as a tendency to decrease the chemokine IL-8. Compared to C, concentration of ICAM-1, and VCAM-1 were significantly lower (p ˂ 0.001), after each TJ intervention. Decreases were correlated remarkably with the trans-lycopene, while the other carotenoids present in TJ have presented a minor association or no association with changes in these molecules.

CONCLUSION

trans-Lycopene from TJ may attenuate the risk of cardiovascular disease by reducing the concentration of important inflammatory molecules related to atherosclerosis.

Carotenoids: biochemistry, pharmacology and treatment

Carotenoids and retinoids have several similar biological activities such as antioxidant properties, the inhibition of malignant tumour growth and the induction of apoptosis. Supplementation with carotenoids can affect cell growth and modulate gene expression and immune responses. Epidemiological studies have shown a correlation between a high carotenoid intake in the diet with a reduced risk of breast, cervical, ovarian, colorectal cancers, and cardiovascular and eye diseases. Cancer chemoprevention by dietary carotenoids involves several mechanisms, including effects on gap junctional intercellular communication, growth factor signalling, cell cycle progression, differentiation-related proteins, retinoid-like receptors, antioxidant response element, nuclear receptors, AP-1 transcriptional complex, the Wnt/β-catenin pathway and inflammatory cytokines. Moreover, carotenoids can stimulate the proliferation of B- and T-lymphocytes, the activity of macrophages and cytotoxic T-cells, effector T-cell function and the production of cytokines. Recently, the beneficial effects of carotenoid-rich vegetables and fruits in health and in decreasing the risk of certain diseases has been attributed to the major carotenoids, β-carotene, lycopene, lutein, zeaxanthin, crocin (/crocetin) and curcumin, due to their antioxidant effects. It is thought that carotenoids act in a time- and dose-dependent manner. In this review, we briefly describe the biological and immunological activities of the main carotenoids used for the treatment of various diseases and their possible mechanisms of action.

LINKED ARTICLES

This article is part of a themed section on Principles of Pharmacological Research of Nutraceuticals. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v174.11/issuetoc.

Anti-inflammatory effect of lycopene in SW480 human colorectal cancer cells

BACKGROUND/OBJECTIVES

Although the antioxidative effects of lycopene are generally known, the molecular mechanisms underlying the anti-inflammatory properties of lycopene are not fully elucidated. This study aimed to examine the role and mechanism of lycopene as an inhibitor of inflammation.

METHODS/MATERIALS

Lipopolysaccharide (LPS)-stimulated SW 480 human colorectal cancer cells were treated with 0, 10, 20, and 30 µM lycopene. The MTT assay was performed to determine the effects of lycopene on cell proliferation. Western blotting was performed to observe the expression of inflammation-related proteins, including nuclear factor-kappa B (NF-κB), inhibitor kappa B (IκB), mitogen-activated protein kinase (MAPK), extracellular signal-related kinase (ERK), c-jun NH2-terminal kinase (JNK), and p38 (p38 MAP kinase). Real-time polymerase chain reaction was performed to investigate the mRNA expression of tumor necrosis factor α (TNF-α), interleukin-1 beta (IL-1β), interleukin-6 (IL-6), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). Concentrations of nitric oxide (NO) and prostaglandin E₂ (PGE₂) were determined via enzyme-linked immunosorbent assays.

RESULTS

In cells treated with lycopene and LPS, the mRNA expression of TNF-α, IL-1β, IL-6, iNOS, and COX-2 were decreased significantly in a dose-dependent manner (P < 0.05). The concentrations of PGE₂ and NO decreased according to the lycopene concentration (P < 0.05). The protein expressions of NF-κB and JNK were decreased significantly according to lycopene concertation (P < 0.05).

CONCLUSIONS

Lycopene restrains NF-κB and JNK activation, which causes inflammation, and suppresses the expression of TNF-α, IL-1β, IL-6, COX-2, and iNOS in SW480 human colorectal cancer cells.

Tomato Aqueous Extract Modulates the Inflammatory Profile of Immune Cells and Endothelial Cells

Nutrients transiently or chronically modulate functional and biochemical characteristics of cells and tissues both in vivo and in vitro. The influence of tomato aqueous extract (TAE) on the in vitro inflammatory response of activated human peripheral blood leukocytes (PBLs) and macrophages was investigated. Its effect on endothelial dysfunction (ED) was analyzed in human umbilical vein endothelial cells (HUVECs). Murine macrophages (RAW264.7 cells), PBLs and HUVECs were incubated with TAE. They were activated with LPS or TNF-α in order to induce inflammatory processes and ED, respectively. Inflammatory mediators and adhesion molecules were measured by immune assay-based multiplex analysis. Gene expression was quantified by RT-PCR. TAE altered the production of interleukins (IL-1β, IL-6, IL-10, IL-12) and chemokines (CCL2/MCP-1, CCL3/MIP-1α, CCL5/RANTES, CXCL8/IL-8, CXCL10/IP-10) in PBLs. TAE reduced ED-associated expression of adhesion molecules (ICAM-1, VCAM-1) in endothelial cell. In macrophages, the production of nitric oxide, PGE2, cytokines and ILs (TNF-α, IL-1β, IL-6, IL-12), which reflects chronic inflammatory processes, was reduced. Adenosine was identified as the main bioactive of TAE. Thus, TAE had cell-specific and context-dependent effects. We infer from these in vitro data, that during acute inflammation TAE enhances cellular alertness and therefore the sensing of disturbed immune homeostasis in the vascular-endothelial compartment. Conversely, it blunts inflammatory mediators in macrophages during chronic inflammation. A novel concept of immune regulation by this extract is proposed.

Tomato extract and the carotenoids lycopene and lutein improve endothelial function and attenuate inflammatory NF-κB signaling in endothelial cells

OBJECTIVES

In our previous research the antihypertensive properties of lycopene-containing tomato oleoresin have been revealed. The present study was aimed to assess if oleoresin interferes in the inflammatory signalling in endothelial cells, imitating reduction of inflammatory processes in the vessel wall and in this way to propose the mechanism for the reduction of blood pressure by oleoresin.

METHODS AND RESULTS

A wide number of functional and inflammatory markers were investigated in two cultured endothelial cell models [EA.hy926 and human umbilical vein endothelial cell (HUVEC)], exposed to oleoresin and carotenoids lycopene and lutein. All the carotenoids significantly improved basic endothelial function as measured by increased nitric oxide and decreased endothelin (ET-1) release. They were effective in attenuation of inflammatory nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signalling: decrease of tumour necrosis factor-alpha (TNF-α)-induced leukocytes adhesion, expression of adhesion molecules inter-cellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and nuclear translocation of NF-κB components as well as some revert of inhibitor of kappa B (IκB) ubiquitination. In addition, the carotenoids were able to inhibit NF-κB activation in transfected endothelial cells. When combined with lutein, oleoresin exerted synergistic effect on preclusion of leukocytes adhesion.

CONCLUSIONS

Prevention of over-expression of adhesion molecules through inhibition of NF-κB signalling may be one of the main mechanisms driving carotenoids to attenuate inflammatory leukocyte adhesion to endothelium. This is the first profound study on the mechanisms involved in the positive action of natural tomato products in endothelial cells.

Lycopene induces retinoic acid receptor transcriptional activation in mice

SCOPE

Lycopene is a lipophilic carotenoid and provides the red colour to tomatoes and tomato product. Various studies indicated that lycopene and tomatoes/tomato products are able to positively influence various diseases associated with a chronic inflammation. The mechanism of action of lycopene to elicit these effects is partly unknown. A possible mechanism is that biological metabolites of lycopene may activate nuclear hormone receptors in mammalian cells. The aim of this study was to investigate the potential of orally administered lycopene and all-trans retinoic acid (ATRA) for the induction of the retinoic acid receptor (RAR) in a transgenic retinoic acid response-element (RARE)-reporter mouse system.

METHODS AND RESULTS

Orally administered lycopene (100 mg/kg bw in beadlets, n = 6) and ATRA as an endogenous RAR ligand (50 mg/kg bw, n = 6) for the induction of the retinoic acid receptor in male mice using a transgenic RARE-reporter mouse system.

CONCLUSION

Lycopene treatments induced RARE-mediated cell signalling indicated by quantified bioimaging, increased luciferase activity and up-regulated the retinoid target genes in selected organs of the mice. We conclude that lycopene can induce RAR-transcriptional activation in mice and lycopene might be a precursor of still non-identified biologically active metabolites.

Lycopene inhibits lymphocyte proliferation through mechanisms dependent on early cell activation

SCOPE

Epidemiological evidence suggests that lycopene is potentially cardio-protective. Recruitment and activation of T cells in the arterial wall is a critical process during atherogenesis, but the effects of lycopene on T-cell response remain to be elucidated. We aimed to determine whether lycopene could modulate T-cell function and activity.

METHODS AND RESULTS

Peripheral blood mononuclear cells from 16 healthy adults were cultured in the presence of lycopene-enriched liposomes (0-2.9 μg lycopene/mL) with or without mitogens. Cell cycle as well as the expression of CD69 (marker of early cell activation), CD25 (IL-2 receptor), and CD11a (late activation marker) were measured in T cells, T-helper cells, and T-cytotoxic cells by flow cytometry. IL-2 secretion and cell proliferation were determined by ELISA and [³H]-thymidine incorporation, respectively. Lycopene significantly inhibited lymphocyte proliferation (up to 40%) in activated cells. Lycopene also significantly inhibited CD69 expression (by up to 12%) as well as IL-2 secretion (by up to 29%). However, CD25 and CD11a expression as well as the cell-cycle profile were unaffected by lycopene.

CONCLUSION

Lycopene influences lymphocyte proliferation through its effects on processes involved in early cellular activation, providing one possible mechanism to explain the beneficial effects of tomato-rich diets against cardiovascular disease.

Lycopene inhibits NF-kB-mediated IL-8 expression and changes redox and PPARγ signalling in cigarette smoke-stimulated macrophages

Increasing evidence suggests that lycopene, the major carotenoid present in tomato, may be preventive against smoke-induced cell damage. However, the mechanisms of such a prevention are still unclear. The aim of this study was to investigate the role of lycopene on the production of the pro-inflammatory cytokine IL-8 induced by cigarette smoke and the possible mechanisms implicated. Therefore, human THP-1 macrophages were exposed to cigarette smoke extract (CSE), alone and following a 6-h pre-treatment with lycopene (0.5–2 µM). CSE enhanced IL-8 production in a time- and a dose-dependent manner. Lycopene pre-treatment resulted in a significant inhibition of CSE-induced IL-8 expression at both mRNA and protein levels. NF-kB controlled the transcription of IL-8 induced by CSE, since PDTC prevented such a production. Lycopene suppressed CSE-induced NF-kB DNA binding, NF-kB/p65 nuclear translocation and phosphorylation of IKKα and IkBα. Such an inhibition was accompanied by a decrease in CSE-induced ROS production and NOX-4 expression. Lycopene further inhibited CSE-induced phosphorylation of the redox-sensitive ERK1/2, JNK and p38 MAPKs. Moreover, the carotenoid increased PPARγ levels which, in turn, enhanced PTEN expression and decreased pAKT levels in CSE-exposed cells. Such effects were abolished by the PPARγ inhibitor GW9662. Taken together, our data indicate that lycopene prevented CSE-induced IL-8 production through a mechanism involving an inactivation of NF-kB. NF-kB inactivation was accompanied by an inhibition of redox signalling and an activation of PPARγ signalling. The ability of lycopene in inhibiting IL-8 production, NF-kB/p65 nuclear translocation, and redox signalling and in increasing PPARγ expression was also found in isolated rat alveolar macrophages exposed to CSE. These findings provide novel data on new molecular mechanisms by which lycopene regulates cigarette smoke-driven inflammation in human macrophages.

Carotenoids modulate cytokine production in Peyer's patch cells ex vivo

This study investigated the effects of carotenoid and capsaicin constituents of Capsicum on intestinal immune responses in mice. Peyer's patch (PP) cells were isolated from mice orally administered with capsaicin, or one of three carotenoids (beta-carotene, beta-cryptoxanthin, or lycopene), at 5 mg/kg/day for 7 consecutive days. Collagenase-separated PP cells were then cultured in the presence or absence of concanavalin A (Con A). PP cells from mice treated with capsaicin, beta-carotene, or beta-cryptoxanthin all showed significantly enhanced interleukin (IL)-2 and interferon (IFN)-gamma production when costimulated with 5 microg/mL Con A, with capsaicin having the greatest effect (approximately two times greater than in normal mice). No increase in the production of IL-2 or IL-4 was observed when PP cells from mice were cultured without Con A. We further tested the combined efficacy of carotenoids and capsaicin on intestinal T-cell cytokine production. Oral administration of capsaicin with beta-carotene, both at 5 mg/kg/day for 7 days, increased IFN-gamma and IL-2 production in cultured PP cells costimulated with Con A. In contrast, oral administration of beta-cryptoxanthin counteracted the stimulatory effect of capsaicin treatment on T-helper cytokine production. Flow cytometric analysis revealed that the population of IFN-gamma(+) and IL-4(+) cells in PPs from mice administered capsaicin and/or carotenoids did not change, which suggested that the effects of carotenoids and capsaicin on cytokine production were not due to changes in the lymphoid population in PPs. These results indicate that carotenoids and capsaicin, which are common components of foods such as Capsicum, mutually modulate T-cell immune responses to exogenous or endogenous inducers such as antigens in PPs, without changing the lymphoid population. Carotenoids modulate the potentiality of cytokine production in T cells or indirectly activate T cells but have no triggering effect such as Con A.

On the combined effect of statins and lycopene on cytokine production by human peripheral blood cells

Since both statins and lycopene exert immunomodulatory activities following incubation with human peripheral blood mononuclear cells (PBMC), the present work was designed to examine whether they may induce a synergistic or antagonistic effect on cytokine production while applied together. Peripheral blood mononuclear cells isolated from 15 healthy subjects were incubated for 24 h as follows: (1) without and with 0.125 or 0.25 microM lycopene, (2) without and with 10 or 50 mM pravastatin or simvastatin, and (3) with lycopene and with one of the statins together at the respective doses. The production of the following cytokines was assessed: interleukin (IL)-1beta, IL-1ra, IL-2, and IL-10, as well as tumor necrosis factor alpha (TNFalpha) and interferon gamma (IFNgamma). The results showed that lycopene and simvastatin applied together reduced TNFalpha and IFNgamma secretion, and abolished the increased production of the proinflammatory cytokine IL-1gamma caused by incubation with simvastatin only, an observation suggesting that simultaneous administration of both substances may reduce inflammatory responses.