| Lycopene is an organic compound classified as a tetraterpene and a carotene. Lycopene (from the Neo-Latin Lycopersicon, the name of a former tomato genus) is a bright red carotenoid hydrocarbon found in tomatoes and other red fruits and vegetables.
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InChI=1S/C40H56/c1- 33(2)19-13-23-37(7)27-17-31-39(9)29-15-25-35(5)21-11-12-22-36(6)26-16-30-40(10)32-18-28-38(8)24-14-20-34(3)4/h11-12,15-22,25-32H,13-14,23-24H2,1-10H3/b12-11+,25-15+,26-16+,31-17+,32-18+,35-21+,36-22+,37-27+,38-28+,39-29+,40-30+ |
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| CC(C)=CCC\C(C)=C\C=C\C(C)=C\C=C\C(C)=C\C=C\C=C(C)\C=C\C=C(C)\C=C\C=C(/C)CCC=C(C)C |
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antioxidant
A substance that opposes oxidation or inhibits reactions brought about by dioxygen or peroxides.
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plant metabolite
Any eukaryotic metabolite produced during a metabolic reaction in plants, the kingdom that include flowering plants, conifers and other gymnosperms.
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View more via ChEBI Ontology
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(6E,8E,10E,12E,14E,16E,18E,20E,22E,24E,26E)-2,6,10,14,19,23,27,31-octamethyldotriaconta-2,6,8,10,12,14,16,18,20,22,24,26,30-tridecaene
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ChEBI
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all-trans-lycopene
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UniProt
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all-trans-lycopene
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ChemIDplus
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Lycopene
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KEGG COMPOUND
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LYCOPENE
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PDBeChem
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1730097
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Reaxys Registry Number
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Reaxys
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502-65-8
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CAS Registry Number
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KEGG COMPOUND
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502-65-8
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CAS Registry Number
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ChemIDplus
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Takeshima M, Ono M, Higuchi T, Chen C, Hara T, Nakano S (2014)
Anti-proliferative and apoptosis-inducing activity of lycopene against three subtypes of human breast cancer cell lines.
Cancer science 105, 252-257 [PubMed:24397737]
[show Abstract]
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. | Zaripheh S, Nara TY, Nakamura MT, Erdman JW (2006)
Dietary lycopene downregulates carotenoid 15,15'-monooxygenase and PPAR-gamma in selected rat tissues.
The Journal of nutrition 136, 932-938 [PubMed:16549453]
[show Abstract]
In vitro studies have suggested that lycopene is an efficient substrate for carotenoid 9'10'-monooxygenase II (CMO2) but an inhibitor of carotenoid 15,15'-monooxygenase I (CMO1). The objectives of this study were to clone the rat CMO2 gene, determine whether feeding lycopene for different lengths of time (3-37 d) altered the expression of genes related to carotenoid cleavage [CMO1, CMO2 and peroxisomal proliferator-activated receptor gamma (PPAR-gamma)] or increased the activity of selected phase I and phase II detoxification enzymes in rat tissues. The cloned rat CMO2 gene was 92 and 82% homologous to the mouse and human CMO2 nucleotide sequence, respectively. The relative abundance of CMO1, CMO2, and PPAR-gamma were differentially expressed among rat tissues. CMO1 and PPAR-gamma expression were decreased in the kidney and adrenal with lycopene intake (P < 0.05), whereas CMO2 expression was reduced only in the kidney. Lycopene did not alter hepatic phase I activity, but hepatic quinone reductase activity increased after 3 and 7 d of lycopene feeding (P < 0.05). Lycopene intake decreased a PPAR-gamma target gene, fatty acid binding protein 3 (FABP3), in the kidney and adrenal (P < 0.05). Thus, these data show that although the intake of 0.25 g lycopene/kg diet does not induce hepatic P450 detoxification enzymes, lycopene feeding alters CMO1, PPAR-gamma, and FABP3 mRNA expression in selected rat tissues with a moderate effect on kidney CMO2 expression. These data suggest that lycopene may play an important role in the modulation of beta-carotene, retinoid, and/or lipid metabolism. | Aust O, Stahl W, Sies H, Tronnier H, Heinrich U (2005)
Supplementation with tomato-based products increases lycopene, phytofluene, and phytoene levels in human serum and protects against UV-light-induced erythema.
International journal for vitamin and nutrition research. Internationale Zeitschrift fur Vitamin- und Ernahrungsforschung. Journal international de vitaminologie et de nutrition 75, 54-60 [PubMed:15830922]
[show Abstract]
Carotenoids are suitable photoprotectants, and beta-carotene supplements are used for protection against ultraviolet (UV) light-induced erythema. Protective effects are also observed when carotenoids are provided with the diet. Here, we investigated the photoprotective effects of synthetic lycopene in comparison with a tomato extract (Lyc-o-Mato) and a drink containing solubilized Lyc-o-Mato (Lyc-o-Guard-Drink). With these different sources, the volunteers ingested similar amounts of lycopene (about 10 mg/day). After 12 weeks of supplementation, significant increases in lycopene serum levels and total skin carotenoids were observed in all groups. Significant increases in the serum levels of phytofluene and phytoene occurred in the Lyc-o-Mato and the Lyc-o-Guard-Drink group. At weeks 0, 4, and 12 an erythema was induced with a solar light simulator. Dorsal skin of each subject was irradiated with 1.25 minimal erythemal dose (MED). Reddening of the skin was evaluated before and 24 hours after irradiation by chromametry and expressed as positive a-values (red/green-axis). delta a-values (difference of a-value before irradiation and after 24 hours) were used as an index of erythema intensity. A decrease in the delta a-value from week 0 to week 12, indicating prevention of erythema formation, was observed in all groups. Compared to week 0, the delta a-value at week 12 was 25% lower in the synthetic lycopene group. The protective effect was more pronounced in the Lyc-o-Mato (38%) and Lyc-o-Guard-Drink (48%) groups. In the two latter groups, phytofluene and phytoene may have contributed to protection. Both of these carotenoids exhibit absorption maxima at wavelengths of UV light. Absorption of UV light protects skin from photodamage and might explain the differences observed between groups. | Hsiao G, Wang Y, Tzu NH, Fong TH, Shen MY, Lin KH, Chou DS, Sheu JR (2005)
Inhibitory effects of lycopene on in vitro platelet activation and in vivo prevention of thrombus formation.
The Journal of laboratory and clinical medicine 146, 216-226 [PubMed:16194683]
[show Abstract]
Lycopene is a natural carotenoid antioxidant that is present in tomatoes and tomato products. The pharmacologic function of lycopene in platelets is not yet understood. Therefore, in this study we sought to systematically examine the effects of lycopene in the prevention of platelet aggregation and thrombus formation. We found that lycopene concentration-dependently (2-12 micromol/L) inhibited platelet aggregation in human platelets stimulated by agonists. Lycopene (6 and 12 micromol/L) inhibited phosphoinositide breakdown in platelets labeled with tritiated inositol, intracellular Ca+2 mobilization in Fura-2 AM-loaded platelets, and thromboxane B2 formation stimulated by collagen. In addition, lycopene (6 and 12 micromol/L) significantly increased the formations of cyclic GMP and nitrate but not cyclic AMP in human platelets. Rapid phosphorylation of a protein of 47,000 Da (P47), a marker of protein kinase C activation, was triggered by PDBu (60 nmol/L). This phosphorylation was markedly inhibited by lycopene (12 micromol/L) in phosphorus-32-labeled platelets. In an in vivo study, thrombus formation was induced by irradiation of mesenteric venules in mice pretreated with fluorescein sodium. Lycopene (5, 10, and 20 mg/kg) significantly prolonged the latency period for the induction of platelet-plug formation in mesenteric venules. These results indicate that the antiplatelet activity of lycopene may involve the following pathways: (1) Lycopene may inhibit the activation of phospholipase C, followed by inhibition of phosphoinositide breakdown and thromboxane B2 formation, thereby leading to inhibition of intracellular Ca+2 mobilization. (2) Lycopene also activated the formations of cyclic GMP/nitrate in human platelets, resulting in the inhibition of platelet aggregation. The results may imply that tomato-based foods are especially beneficial in the prevention of platelet aggregation and thrombosis. | Riso P, Visioli F, Erba D, Testolin G, Porrini M (2004)
Lycopene and vitamin C concentrations increase in plasma and lymphocytes after tomato intake. Effects on cellular antioxidant protection.
European journal of clinical nutrition 58, 1350-1358 [PubMed:15054415]
[show Abstract]
ObjectiveThis study seeks to verify whether the regular consumption of small amounts of tomato products can protect lymphocyte DNA and lipids from oxidative damage.DesignStandardized dietary intervention.SubjectsTwelve healthy female subjects (mean age 25.2 y).InterventionSubjects were instructed to follow a standardized diet for 1 week, followed by 3 weeks consumption of the same diet enriched with small amounts of different tomato products providing as a mean 8 mg lycopene, 0.5 mg beta-carotene and 11 mg vitamin C per day. Plasma and lymphocyte concentrations of carotenoids, vitamin C and vitamin E were analysed. Ex vivo protection of lymphocyte DNA from oxidative injury produced by iron ions was evaluated by means of the Comet assay, and lipid peroxidation by HPLC analysis of malondialdehyde (MDA).ResultsDietary intervention with tomato products increased lycopene concentration both in plasma (P < 0.001) and lymphocytes (P < 0.01). Vitamin C concentrations increased by approximately 35% in plasma (P < 0.05) and by approximately 230% in lymphocytes (P < 0.005). Vitamin E decreased significantly in plasma (P < 0.0001) but not in lymphocytes. Finally, there was an improved protection from DNA oxidative damage (P < 0.05) with no significant effect on MDA levels.ConclusionsOur results suggest that tomato products are not only good sources of lycopene but also sources of bioavailable vitamin C. A Regular intake of small amounts of tomato products can increase cell protection from DNA damage induced by oxidant species. This effect may originate from the synergism of different antioxidants present in tomatoes. | Hsiao G, Fong TH, Tzu NH, Lin KH, Chou DS, Sheu JR (2004)
A potent antioxidant, lycopene, affords neuroprotection against microglia activation and focal cerebral ischemia in rats.
In vivo (Athens, Greece) 18, 351-356 [PubMed:15341191]
[show Abstract]
We investigated the effects of a potent antioxidant, lycopene, on the free radical-scavenging activity as evaluated by the DPPH test and lipid peroxidation in rat brain homogenates as well as nitric oxide (NO) formation in cultured microglia stimulated by lipopolysaccharide. In addition, we also investigated the therapeutic effect of lycopene in attenuating ischemia/reperfusion brain injury induced by middle cerebral artery (MCA) occlusion in rats. Lycopene (1, 2 and 5 microM) exerted increased DPPH decolorization in the DPPH test, and increased inhibition of iron-catalyzed lipid peroxidation (TBARS formation) in rat brain homogenates in concentration-dependent manners. Furthermore, lycopene (5 and 10 microM) significantly inhibited nitrite production by about 31% and 61% in microglia stimulated by LPS, respectively. Rats which received lycopene at a dosage of 4 mg/kg, but not at 2 mg/kg, showed significant infarct size reductions compared with those which received the solvent control (20% Tween 80). In conclusion, we demonstrate a protective effect of lycopene on ischemic brain injury in vivo. Lycopene, through its antioxidative property, mediates at least a portion of free radical-scavenging activity and inhibits microglia activation, resulting in a reduction in infarct volume in ischemia/reperfusion brain injury. | Ermakov IV, Ermakova MR, Gellermann W, Lademann J (2004)
Noninvasive selective detection of lycopene and beta-carotene in human skin using Raman spectroscopy.
Journal of biomedical optics 9, 332-338 [PubMed:15065899]
[show Abstract]
The predominant long-chain carotenoids found in human skin are lycopene and beta-carotene. They are powerful antioxidants and thought to act as scavengers for free radicals and singlet oxygen formed by normal metabolism as well as excessive exposure of skin to sunlight. The specific importance of the particular representatives of the carotenoid antioxidants regarding skin defense mechanisms is of strong current interest. We demonstrate fast and noninvasive detection of beta-carotene and lycopene concentrations in living human skin using Raman detection of the molecules' carbon-carbon double bond stretch vibrations. Employing excitation with suitable blue and green laser lines, and taking advantage of differing Raman cross sectional profiles for beta-carotene and lycopene, we determine the relative concentration of each carotenoid species. This novel technique permits the quantitative assessment of individual long-chain carotenoid species rather than their composite level in human skin. The obtained results reveal significant differences in the carotenoid composition of the subjects' skin and show that the ratio between beta-carotene and lycopene concentration can vary from 0.5 to 1.6. The technique holds promise as a method for rapid screening of carotenoid compositions in human skin in large populations and should be suitable for clinical studies correlating carotenoid status with risk for cutaneous diseases. | Kravchenko LV, Morozov SV, Beketova NA, Deryagina VP, Avren'eva LI, Tutel'yan VA (2003)
Antioxidant status of rats receiving lycopene in different doses.
Bulletin of experimental biology and medicine 135, 353-357 [PubMed:12910307]
[show Abstract]
Oral treatment with lycopene (per os) in doses of 10 or 50 mg/kg for 2 weeks led to accumulation of lycopene in the liver, liver microsomes, and blood plasma, increased total plasma antioxidant activity, inhibited LPO in the liver, and decreased solubilization of lysosomal enzymes. Lycopene had no effect on ex vivo resistance of liver microsomes to LPO and activities of antioxidant enzymes in the liver. | Michael McClain R, Bausch J (2003)
Summary of safety studies conducted with synthetic lycopene.
Regulatory toxicology and pharmacology : RTP 37, 274-285 [PubMed:12726756]
[show Abstract]
Lycopene belongs to the group of natural carotenoids, which are found in many fruits and vegetables, but predominantly in tomatoes and tomato-based products. This manuscript summarizes the safety of synthetic lycopene as a water-dispersible beadlet formulation containing antioxidants and includes acute and subchronic safety studies, reproductive studies, genotoxicity studies, metabolic studies, and exploratory studies on the hepatic uptake of lycopene. Lycopene has a low order of acute toxicity and no significant toxicity has been observed in rats treated with lycopene beadlet formulations in the diet at doses of up to 500 mg/kg bw/day for 14 weeks or 1000 mg/kg bw/day for 4 weeks. No teratogenic effects were noted in a rat two-generation study (1000 ppm in the diet) or in a teratology study in rats with 1000 mg/kg bw/day lycopene as beadlet formulations. Lycopene accumulates in hepatocytes and to a lesser extent in spleen. In short-term studies with synthetic lycopene, as a beadlet formulation, and natural source lycopene, as tomato concentrate, the accumulation of lycopene in the liver and the presence of pigment deposits in the hepatocytes were similar and neither was associated with any histopathological changes. The pigment deposits in hepatocytes are no longer present after approximately 13 weeks of depletion, demonstrating reversibility for this effect. Unformulated pure crystalline lycopene and lycopene as a 10% beadlet formulation are not genotoxic as determined in a comprehensive battery of tests, however, improperly stored, unformulated crystalline lycopene can degrade to mutagenic products if exposed to light and air. Lycopene is commercially available only in formulated forms, containing antioxidants, which prevent the degradation of lycopene and other excipients that provide for water dispersibility. In the animal studies, there is a large margin of safety based on the repeated dose safety and reproductive/teratology studies in rodents. In humans, there is a very long history of use with respect to dietary exposure, and even in the case of very high exposures from dietary sources, there is no indication of any significant adverse effects. | Walfisch Y, Walfisch S, Agbaria R, Levy J, Sharoni Y (2003)
Lycopene in serum, skin and adipose tissues after tomato-oleoresin supplementation in patients undergoing haemorrhoidectomy or peri-anal fistulotomy.
The British journal of nutrition 90, 759-766 [PubMed:13129444]
[show Abstract]
Lycopene, the main carotenoid found in tomatoes and tomato-based products, has been reported to be protective against several types of cancer. Assessment of changes in plasma concentration of carotenoids following ingestion of lycopene-rich food sources does not necessarily predict changes in lycopene concentration or distribution of its isomers in other body tissues. Our aim was to determine the relationship between concentrations of lycopene and other tomato carotenoids in human serum and body tissues after tomato-oleoresin supplementation. Tomato lycopene oleoresin (30 mg/d) or a placebo was administered for 1 to 7 weeks to seventy-five volunteers undergoing elective haemorrhoidectomy or peri-anal fistulotomy. Carotenoid concentration and isomer distribution in blood and in the surgically removed skin and adipose tissues was measured by HPLC. The serum concentration of lycopene increased after supplementation from 0.26 (SD 0.12) to 0.52 (SD 0.25) micromol/l (n 35; P<0.0001). In the placebo group (n 40), lycopene serum concentration did not change significantly. Serum lycopene concentration after treatment was 2.2-fold greater in the lycopene group than in the placebo group, a slightly higher ratio than that found in skin and adipose tissue (1.6- and 1.4-fold higher than the placebo, respectively). A significant correlation between serum and tissue concentrations was found for both beta-carotene and lycopene in the placebo group, whereas in the lycopene-supplemented group the correlation between serum and tissues remained the same for beta-carotene but for lycopene was weak. Lycopene supplementation did not significantly change the proportion of all-trans v. cis isomers in the serum and tissues, despite the fact that more than 90 % of the supplemented lycopene was in the all-trans form. These results show that tomato-oleoresin supplementation increases lycopene concentrations in serum and in adipose tissue and skin. The ability to increase lycopene levels in tissues is one of the prerequisites for using it as a food supplement with health benefits. | Alien CM, Smith AM, Clinton SK, Schwartz SJ (2002)
Tomato consumption increases lycopene isomer concentrations in breast milk and plasma of lactating women.
Journal of the American Dietetic Association 102, 1257-1262 [PubMed:12792623]
[show Abstract]
ObjectiveTo compare plasma and milk lycopene concentrations and the changes in lycopene isomer patterns in lactating women before and after a 3-day dietary intervention with fresh or processed tomato products.DesignRandomized prospective trial.Subjects24 lactating women, 4 to 12 weeks postpartum, aged 22 to 39 years.InterventionSubjects initially consumed a low-lycopene diet for 7 days (washout period) and then were randomly assigned to one of 3 dietary groups (n=8 per group) without any other sources of lycopene: control (low-lycopene), fresh tomatoes, or processed tomato sauce. Subjects in each of the tomato groups consumed approximately 50 mg total lycopene over 3 days.Outcome measuresBefore and after dietary intervention, plasma and breast milk samples were obtained for high-performance liquid chromotography analysis of lycopene and its geometric isomers (all-trans, 5-cis, all other cis, and total lycopene).Statistical analysisDescriptive statistics, analysis of variance to test for differences among intervention groups, and Spearman's correlation coefficients to test for blood-milk relationships.ResultsPlasma total lycopene and lycopene isomer concentrations increased in the fresh and processed tomato group but not in the low-lycopene control group during the study. Milk total and cis- and trans-lycopene concentrations (unadjusted for fat) increased in the processed tomato group but did not change in the fresh tomato group. In the control group, milk total and trans-lycopene decreased. Milk total lycopene concentrations were not significantly different from baseline in any group when adjusted for fat content of milk.ApplicationsThe results of this study indicate that consumption of a "standard size portion" of tomato products increases plasma and milk lycopene concentrations in lactating women and, therefore, could increase the lycopene status of nursing infants. For dietary recommendations during lactation, the results suggest that consumption of tomato sauce increases milk lycopene concentrations more effectively than consumption of fresh tomatoes. | Stahl W, Sies H (2002)
Carotenoids and protection against solar UV radiation.
Skin pharmacology and applied skin physiology 15, 291-296 [PubMed:12239422]
[show Abstract]
Upon exposure to UV light photooxidative reactions are initiated which are damaging to biomolecules and affect the integrity of cells and tissues. Photooxidative damage plays a role in pathological processes and is involved in the development of disorders affecting the skin. When skin is exposed to UV light, erythema is observed as an initial reaction. Carotenoids like beta-carotene or lycopene are efficient antioxidants scavenging singlet molecular oxygen and peroxyl radicals generated in during photooxidation. When beta-carotene was applied as such or in combination with alpha-tocopherol for 12 weeks, erythema formation induced with a solar light simulator was diminished from week 8 on. Similar effects were also achieved with a diet rich in lycopene. Ingestion of tomato paste corresponding to a dose of 16 mg lycopene/ day over 10 weeks led to increases in serum levels of lycopene and total carotenoids in skin. At week 10, erythema formation was significantly lower in the group that ingested the tomato paste as compared to the control group. No significant difference was found at week 4 of treatment. Thus, protection against UV light-induced erythema can be achieved by ingestion of a commonly consumed dietary source of lycopene. Such protective effects of carotenoids were also demonstrated in cell culture. The in-vitro data indicate that there is an optimal level of protection for each carotenoid. | Neuman I, Nahum H, Ben-Amotz A (2000)
Reduction of exercise-induced asthma oxidative stress by lycopene, a natural antioxidant.
Allergy 55, 1184-1189 [PubMed:11117277]
[show Abstract]
BackgroundLycopene has previously been shown to have high antioxidative activity. In view of the controversy regarding the beneficial effect of antioxidants on asthma, the acute effects of lycopene (LYC-O-MATO) on airway hyperreactivity were assessed in patients with exercise-induced asthma (EIA).MethodsTwenty patients with EIA participated in our study to verify the antioxidative effects. The test was based on the following sequence: measurement of baseline pulmonary function, 7-min exercise session on a motorized treadmill, 8-min rest and again measurement of pulmonary function, 1-week, oral, randomly administered, double-blind supplementation of placebo or 30 mg/day of lycopene (LYC-O-MATO), measurement of pulmonary function at rest, 7-min exercise session, and 8-min rest and again measurement of pulmonary function. A 4-week washout interval was allowed between each protocol.ResultsAll patients given placebo showed significant postexercise reduction of more than 15% in their forced expiratory volume in 1 s (FEV1). After receiving a daily dose of 30 mg of lycopene for 1 week, 11 (55%) patients were significantly protected against EIA. Serum analyses of the patients by high-pressure liquid chromatography detected in the lycopene-supplemented patients an elevated level of lycopene compared to the placebo group, with no change in retinol, tocopherols, or in the other carotenoids.ConclusionsOur results indicate that a daily dose of lycopene exerts a protective effect against EIA in some patients, most probably through an in vivo antioxidative effect. | Stahl W, von Laar J, Martin HD, Emmerich T, Sies H (2000)
Stimulation of gap junctional communication: comparison of acyclo-retinoic acid and lycopene.
Archives of biochemistry and biophysics 373, 271-274 [PubMed:10620348]
[show Abstract]
Carotenoids and retinoids stimulate gap junctional communication (GJC), thought to be related to cancer-preventive properties. Lycopene, a nonprovitamin A carotenoid and its possible oxidation product, acyclo-retinoic acid, were tested for their effect on GJC, on stabilization of connexin43 mRNA, and on the transactivation of the RAR-beta2-promoter in vitro. In human fetal skin fibroblasts, GJC was stimulated by lycopene and acyclo-retinoic acid. Lycopene was effective at a concentration of 0.1 microM, whereas higher amounts of acyclo-retinoic acid (1 microM) were needed for comparable stimulation. Stabilizing effects of acyclo-retinoic acid on the mRNA of connexin43 via elements located in the 3'-UTR were weak. In comparison to retinoic acid (0.1 microM), considerably higher concentrations of the acyclo analog (50 microM) were required for similar effects; lycopene (0.1 microM) was not active in this system. Likewise, unphysiologically high levels of acyclo-retinoic acid (50 microM) were necessary to transactivate the RAR-beta2 promoter. The data demonstrate that acyclo-retinoic acid is much less active than retinoic acid with respect to GJC and retinoid-related signaling. Therefore, we conclude that lycopene affects GJC independent of the formation of acyclo-retinoic acid. | Arab L, Steck S (2000)
Lycopene and cardiovascular disease.
The American journal of clinical nutrition 71, 1691S-5S; discussion 1696S-7S [PubMed:10837319]
[show Abstract]
Considerable evidence suggests that lycopene, a carotenoid without provitamin A activity found in high concentrations in a small set of plant foods, has significant antioxidant potential in vitro and may play a role in preventing prostate cancer and cardiovascular disease in humans. Tomato products, including ketchup, tomato juice, and pizza sauce, are the richest sources of lycopene in the US diet, accounting for >80% of the total lycopene intake of Americans. Unlike other carotenoids, lycopene is not consistently lower among smokers than among nonsmokers, suggesting that any possible preventive activity is not as an antioxidant. Instead, lycopene may have a cholesterol synthesis-inhibiting effect and may enhance LDL degradation. Available evidence suggests that intimal wall thickness and risk of myocardial infarction are reduced in persons with higher adipose tissue concentrations of lycopene. The question of whether lycopene helps to prevent cardiovascular disease can only be answered by a trial specifically evaluating its effectiveness in this area. | Porrini M, Riso P (2000)
Lymphocyte lycopene concentration and DNA protection from oxidative damage is increased in women after a short period of tomato consumption.
The Journal of nutrition 130, 189-192 [PubMed:10720168]
[show Abstract]
Several epidemiologic studies have suggested a role of tomato products in protecting against cancer and chronic diseases. In nine adult women, we evaluated whether the consumption of 25 g tomato puree (containing 7 mg lycopene and 0.3 mg beta-carotene) for 14 consecutive days increased plasma and lymphocyte carotenoid concentration and whether this was related to an improvement in lymphocyte resistance to an oxidative stress (500 micromol/L hydrogen peroxide for 5 min). Before and after the period of tomato intake, carotenoid concentrations were analyzed by HPLC and lymphocyte resistance to oxidative stress by the Comet assay, which detects DNA strand breaks. Intake of tomato puree increased plasma (P <0.001) and lymphocyte (P<0.005) lycopene concentration and reduced lymphocyte DNA damage by approximately 50% (P<0.0001). Beta-carotene concentration increased in plasma (P<0.05) but not in lymphocytes after tomato puree consumption. An inverse relationship was found between plasma lycopene concentration (r = -0.82, P<0.0001) and lymphocyte lycopene concentration (r = -0.62, P<0.01) and the oxidative DNA damage. In conclusion, small amounts of tomato puree added to the diet over a short period can increase carotenoid concentrations and the resistance of lymphocytes to oxidative stress. | Yeh S, Hu M (2000)
Antioxidant and pro-oxidant effects of lycopene in comparison with beta-carotene on oxidant-induced damage in Hs68 cells.
The Journal of nutritional biochemistry 11, 548-554 [PubMed:11137891]
[show Abstract]
Lycopene has become a focal point in recent research following clinical trials that suggest that beta-carotene may promote lung cancer in smokers. Because lycopene only differs from beta-carotene in lacking the beta-ionone structure, and beta-carotene is known to have pro-oxidant activity in vitro, we sought to determine whether lycopene might also have pro-oxidant activity in vitro in comparison with beta-carotene. Human foreskin fibroblasts (Hs68 cells) were first enriched with 10 and 20 µM lycopene or beta-carotene for 1 hr followed by incubation with various oxidants. Lipid peroxidation was measured as thiobarbituric acid-reactive substances (TBARS) released into the medium and DNA damage was measured as formation of comet and 8-hydroxy-2'-deoxyguanosine. The results showed that lycopene at 20 µM significantly decreased levels of TBARS induced by ferric nitrilotriacetate (Fe/NTA) but enhanced levels of TBARS induced by a lipid-soluble radical generator (2,2'-azobis[2,4-dimethylvaleronitrile]; AMVN). Both the antioxidant and pro-oxidant effects of lycopene tended to be dose-dependent. beta-Carotene at 20 µM did not significantly decrease TBARS induced by Fe/NTA but significantly increased TBARS induced by AMVN. Lipid peroxidation induced by a water-soluble radical generator 2,2'-azobis(2-amidinopropane)dihydrochloride was not significantly affected by either lycopene or beta-carotene. Neither lycopene nor beta-carotene affected DNA damage or changes in cell morphology induced by any of the three oxidants tested. The present study in Hs68 cells demonstrates that lycopene can be either an antioxidant or a pro-oxidant depending on the oxidants used, and that lycopene and beta-carotene behave similarly under the in vitro oxidative conditions. Although it is unclear whether lycopene may have pro-oxidant activity in vivo, our results caution that it may be premature to undertake clinical trials with lycopene. | Sengupta A, Das S (1999)
The anti-carcinogenic role of lycopene, abundantly present in tomato.
European journal of cancer prevention : the official journal of the European Cancer Prevention Organisation (ECP) 8, 325-330 [PubMed:10493308]
[show Abstract]
Among the many carotenoids present in nature, lycopene has been of special interest and has received attention in recent times due to its suggestive association in reducing risk for cancer at many sites including breast, prostate and pancreas. Several studies have attempted to determine the bioactive levels of this carotenoid in human tissues and the influence of plant food and cancer on carotenoid levels. Experimental studies have also implicated the protective role of lycopene during carcinogenesis. These observations should justify further exploration and evaluation of the biological function of lycopene alone or in combination with other chemical compounds present in tomato fruit for their use in cancer prevention. | Böhm V, Bitsch R (1999)
Intestinal absorption of lycopene from different matrices and interactions to other carotenoids, the lipid status, and the antioxidant capacity of human plasma.
European journal of nutrition 38, 118-125 [PubMed:10443333]
[show Abstract]
BackgroundThe bioavailability of carotenoids has been investigated in animal studies as well as in human studies, so far mostly for beta-carotene. Only few results exist for lycopene. In recent studies, lycopene was significantly better available from processed tomatoes compared to raw tomatoes, when using daily intakes between 16.5 mg and 75 mg lycopene.Aim of the studyIn a comparative study the availability of a low oral lycopene dosage of 5 mg/d from different food matrices versus soft gel capsules containing tomato oleoresin was assessed. In addition to the plasma carotenoid content, the effect of lycopene ingestion on other plasma carotenoids, the lipid status parameters, and the antioxidant activity was estimated.MethodsTwenty-two female adults (20-27 y) were randomized in three groups and were advised to minimize their carotenoid intake for two weeks. After this initial period, two groups received a portion of tomatoes or tomato juice adjusted to a lycopene dose of 5 mg/d, the third group ingested the same dose comprised in soft gel capsules containing tomato oleoresin. During the test period of 6 weeks, the participants continued reducing the intake of carotenoids from food. Fasting blood samples were withdrawn prior to the study, before supplementation started, and then weekly while supplemented. Seven-day dietary records were prepared before the study started and after one week of supplementation. Carotenoids were analyzed by reversed phase HPLC with diode array detection. Dietary records were evaluated using the computer software EBIS 2.1. The plasma total cholesterol, HDL cholesterol, and triglycerides were determined enzymatically. In addition, the antioxidant activity of plasma was estimated by using the TEAC and the TRAP assays.ResultsThe basal levels of lycopene in plasma were comparable for all groups (0.2-0.3 mumol/l) and decreased significantly during the two weeks of depletion to approximately 50% of the basal values. Other plasma carotenoids such as beta-carotene and beta-cryptoxanthin decreased significantly, too, whereas lutein and zeaxanthin remained unchanged. After supplementation with tomato oleoresin capsules or tomato juice, the plasma lycopene increased significantly, while it remained unchanged during intake of tomatoes. Normal dietary habits were practised of all volunteers before and during the study except vitamin C whose intake was significantly lower during the study period, because the probands were recommended to reduce the intake of fruits and vegetables. Lycopene supplementation did not affect the lipid status parameters of the three groups. After ingestion of lycopene the antioxidant activity of the plasma was not altered. Mean TEAC values were estimated to 0.33 +/- 0.05 mmol/l and TRAP values to 1.0 +/- 0.1 mmol/l and showed no significant differences in all groups during the whole study period.ConclusionsThe bioavailability of lycopene varied significantly depending on the administered matrix. Lycopene from tomato oleoresin capsules and tomato juice (processed tomatoes) was better absorbed from the intestine than lycopene from raw tomatoes. The daily intake of 5 mg lycopene, an intake comparable to the usual daily carotenoid intake, did not affect cholesterol and triglycerides in plasma or its antioxidant capacity. | Gerster H (1997)
The potential role of lycopene for human health.
Journal of the American College of Nutrition 16, 109-126 [PubMed:9100211]
[show Abstract]
Lycopene is one of the major carotenoids in Western diets and is found almost exclusively in tomatoes and tomato products. It accounts for about 50% of carotenoids in human serum. Among the common dietary carotenoids lycopene has the highest singlet oxygen quenching capacity in vitro. Other outstanding features are its high concentration in testes, adrenal gland and prostate. In contrast to other carotenoids its serum values are not regularly reduced by smoking or alcohol consumption but by increasing age. Remarkable inverse relationships between lycopene intake or serum values and risk have been observed in particular for cancers of the prostate, pancreas and to a certain extent of the stomach. In some of the studies lycopene was the only carotenoid associated with risk reduction. Its role in cancer risk reduction still needs to be clarified. Patients with HIV infection, inflammatory diseases and hyperlipidemia with and without lipid lowering treatment may have depleted lycopene serum concentrations. Before embarking on large-scale human trials the distribution of lycopene and its biological functions need to be further evaluated. | Ribaya-Mercado JD, Garmyn M, Gilchrest BA, Russell RM (1995)
Skin lycopene is destroyed preferentially over beta-carotene during ultraviolet irradiation in humans.
The Journal of nutrition 125, 1854-1859 [PubMed:7616301]
[show Abstract]
This placebo-controlled study examined in healthy women the effects of ingestion of a single large dose of beta-carotene (120 mg) on the concentrations of beta-carotene and lycopene in plasma and skin, and the effects of UV light exposure on the concentrations of beta-carotene and lycopene in the skin. Ingestion of beta-carotene increased plasma beta-carotene concentration by 127%, from 0.26 +/- 0.06 (mean +/- SEM) to 0.59 +/- 0.07 mumol/L after 1 d, and the level remained elevated at 0.54 +/- 0.11 mumol/L after 5 d. beta-Carotene in skin, analyzed after 6 d, increased by 23%, from 1.41 +/- 0.74 to 1.74 +/- 0.72 nmol/g. beta-Carotene ingestion had no effect on the lycopene concentrations of plasma (0.37 +/- 0.11 mumol/L) or skin (1.60 +/- 0.62 nmol/g). A single exposure of a small area of one volar forearm to a dose of solar-simulated light (three times the individually determined minimal erythema dose) resulted in 31 to 46% reductions in skin lycopene concentration compared with an adjacent non-exposed area. The same UV dose did not result in significant changes in skin beta-carotene concentration. We conclude that a single 120-mg dose of beta-carotene increases plasma and skin beta-carotene concentrations and has no effect on plasma and skin lycopene concentrations. The amounts of lycopene in plasma and skin are comparable to or even greater than those of beta-carotene. When skin is subjected to UV light stress, more skin lycopene is destroyed compared with beta-carotene, suggesting a role of lycopene in mitigating oxidative damage in tissues. | Stahl W, Schwarz W, Sundquist AR, Sies H (1992)
cis-trans isomers of lycopene and beta-carotene in human serum and tissues.
Archives of biochemistry and biophysics 294, 173-177 [PubMed:1550343]
[show Abstract]
Since cis or trans isomers of carotenoids may have different biological reactivities, the isomeric composition of lycopene and beta-carotene was measured in serum and seven human tissues. In addition to all-trans lycopene, at least three cis-isomers (9-, 13-, and 15-cis) were present, accounting for more than 50% of total lycopene. 13- and 15-cis-beta-carotene, however, were present at only 5% of the all-trans isomer. In addition, 9-cis-beta-carotene was present in tissue samples but not in serum. There were interindividual differences in carotenoid levels of the different tissue types, but liver, adrenal gland, and testes always contained significantly higher amounts of the carotenoids than kidney, ovary, and fat; carotenoids in brain stem tissue were below the detection limit. beta-Carotene was the major carotenoid in liver, adrenal gland, kidney, ovary, and fat, whereas lycopene was the predominant carotenoid in testes. |
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