Apo-12'-Lycopenal

Apo-12'-lycopenal, a Lycopene Metabolite, Promotes Adipocyte Differentiation via Peroxisome Proliferator-activated Receptor Gamma Activation.[Pubmed:30449105]

J Agric Food Chem. 2018 Nov 19.

Apo-lycopenals, lycopene metabolites produced by an initial cleavage by beta,beta-carotene-9',10'-oxygenase, exhibit diverse biologically active effects. In this study, we investigated the effect of apo-lycopenals on the activation of nuclear receptors involved in glucose and lipid metabolism. Only apo-12'-lycopenal exhibited selective and dose-dependent transactivation activity for peroxisome proliferator-activated receptor gamma (PPARgamma), whereas neither apo-6'- nor 8'-lycopenals displayed this activity (7.83 +/- 0.66-, 1.32 +/- 0.10-, 1.31 +/- 0.37-fold higher activity relative to control, respectively). Additionally, apo-12'-lycopenal promoted adipocyte differentiation of 3T3-L1 cells and subsequently increased the mRNA levels of PPARgamma (a 2.36 +/- 0.07-fold increase relative to control; p < 0.01) and its target genes, as well as enhanced adiponectin secretion (a 3.25 +/- 0.27-fold increase relative to control; p < 0.01) and insulin-stimulated glucose uptake (1486 +/- 85 pmol/well; p < 0.001) in 3T3-L1 cells. Our results indicated that apo-12'-lycopenal promoted adipocyte differentiation by direct binding and activation of PPARgamma.

beta-Carotene-9',10'-oxygenase status modulates the impact of dietary tomato and lycopene on hepatic nuclear receptor-, stress-, and metabolism-related gene expression in mice.[Pubmed:24553694]

J Nutr. 2014 Apr;144(4):431-9.

Tomato and lycopene (psi,psi-carotene) consumption is hypothesized to protect against nonalcoholic steatohepatitis and hepatocarcinogenesis, processes that may depend upon diet and gene interactions. To investigate the interaction of tomato or lycopene feeding with beta-carotene-9',10'-monooxygenase (Bco2) on hepatic metabolic and signaling pathways, male wild-type (WT) and Bco2(-/-) mice (3-wk-old; n = 36) were fed semi-purified control, 10% tomato powder-containing, or 0.25% lycopene beadlet-containing diets for 3 wk. Serum lycopene concentrations were higher in lycopene- and tomato-fed Bco2(-/-) mice compared with WT (P = 0.03). Tomato- and lycopene-fed mice had detectable hepatic apolipoprotein (apo)-6'-, apo-8'-, and apo-12'-lycopenal concentrations. Hepatic expression of beta-carotene-15,15'-monooxygenase was increased in Bco2(-/-) mice compared with WT (P = 0.02), but not affected by diet. Evaluation of hepatic gene expression by focused quantitative reverse transcriptase-polymerase chain reaction arrays for nuclear receptors and coregulators (84 genes) and stress and metabolism (82 genes) genes indicates that tomato feeding affected 31 genes (>/=1.5-fold, P < 0.05) and lycopene feeding affected 19 genes, 16 of which were affected by both diets. Lycopene down-regulation of 7 nuclear receptors and coregulators, estrogen-related receptor-alpha, histone deacetylase 3, nuclear receptor coactivator 4, RevErbA-beta, glucocorticoid receptor, peroxisome proliferator-activated receptor (PPAR)-alpha, and PPAR-gamma, coactivator 1 beta was dependent upon interaction with Bco2 status. Lycopene and tomato feeding induced gene expression patterns consistent with decreased lipid uptake, decreased cell proliferation and mitosis, down-regulated aryl hydrocarbon receptor signaling, and decreased expression of genes involved in retinoid X receptor heterodimer activation. Tomato feeding also caused expression changes consistent with down-regulation of DNA synthesis and terpenoid metabolism. These data suggest tomato components, particularly lycopene, affect hepatic gene expression, potentially affecting hepatic responses to metabolic, infectious, or chemical stress.

Antimetastatic effects and mechanisms of apo-8'-lycopenal, an enzymatic metabolite of lycopene, against human hepatocarcinoma SK-Hep-1 cells.[Pubmed:22211877]

Nutr Cancer. 2012;64(2):274-85.

Lycopene is primarily metabolized by carotenoid monoxygenase II into apo-8'- and apo-12'-lycopenal in the rat liver. Although lycopene possesses antimetastatic activity in a highly invasive hepatoma SK-Hep-1 cell line, little is known whether its metabolites have a similar effect. In this study, we investigated the antimetastatic effects of apo-8'-lycopenal (1-10 muM) in comparison with lycopene (10 muM) in SK-Hep-1 cells. We found that both apo-8'-lycopenal and lycopene inhibited the invasion and migration of SK-Hep-1 cells, and the effect of apo-8'-lycopenal was stronger than that of lycopene at the same concentration (10 muM). Mechanistically, apo-8'-lycopenal: 1) decreased the activities and protein expression of metalloproteinase-2 (MMP-2) and -9; 2) increased the protein expression of nm23-H1 and the tissue inhibitor of MMP (TIMP)-1 and -2; 3) suppressed protein expression of Rho small GTPases; and 4) inhibited focal adhesion kinase-mediated signaling pathway, such as ERK/p38 and PI3K-Akt axis. Overall, these results demonstrate that apo-8'-lycopenal possesses antimetastatic activity in SK-Hep-1 cells and that this effect is stronger than that of lycopene, suggesting that the antimetastatic effect may be attributed, at least in part, to its metabolites such as apo-8'-lycopenal.

Lycopene and apo-12'-lycopenal reduce cell proliferation and alter cell cycle progression in human prostate cancer cells.[Pubmed:21207319]

Nutr Cancer. 2011;63(2):256-63.

Lycopene is associated with a reduced risk of prostate cancer. However, lycopene may not be wholly responsible for the effects seen in vivo or in cell culture systems. Apo-lycopenals or other lycopene metabolites, whether produced by cleavage enzymes within the body or consumed with tomato products, can be found in tissues at concentrations equivalent to physiological retinoid concentrations. Therefore, it is plausible that lycopenoids, like retinoids, are bioactive within tissues. Androgen-independent DU145 prostate cancer cells were treated with lycopene, apo-8'-lycopenal, or apo-12'-lycopenal. DU145 cell proliferation was significantly reduced by supra-physiological levels of lycopene and apo-12'-lycopenal, in part, through alteration of the normal cell cycle. Levels of the gap junction protein, connexin 43, were unaltered by lycopene or apo-lycopenal treatment while cell apoptosis rates significantly decreased. We further confirmed that connexin 43 protein levels were unaltered by lycopene treatment in mouse embryonic fibroblasts, or in Dunning R3327-H rat prostate tumor. The present data indicate that lycopene and apo-12'-lycopenal reduce the proliferation of prostate cancer cells, in part, by inhibiting normal cell cycle progression.

Lycopene epoxides and apo-lycopenals formed by chemical reactions and autoxidation in model systems and processed foods.[Pubmed:20492100]

J Food Sci. 2009 Nov-Dec;74(9):C674-82.

To gain a better understanding of the reactions and the underlying mechanisms of the oxidative degradation of lycopene, the products formed by epoxidation with m-chloroperbenzoic acid (MCPBA), oxidative cleavage with KMnO(4), and autoxidation in low-moisture and aqueous model systems, under light exposure, at ambient temperature were identified. The presence of oxidation products was also verified in processed products (tomato juice, tomato paste, tomato puree, guava juice, "goiabada"). A total of 8 lycopene epoxides and a cyclolycopene diol were formed by the reaction of lycopene with MCPBA and 6 apo-lycopenals were produced with KMnO(4). Some of these oxidation products were not detected in the model systems and in the foods analyzed, but the acid-catalyzed rearrangement product 2,6-cyclolycopene-1,5-diol and apo-12'-lycopenal were found in all model and food systems and lycopene-1,2-epoxide and 2,6-cyclolycopene-1,5-epoxide were found in the model systems and in all but 1 ("goiabada") of the 5 foods analyzed. Other epoxides and apo-lycopenals were found in some systems. The inability to detect an intermediate product could be due to a fast turn over. Increased Z-isomerization was also observed and Z-isomers of the oxidation products were detected.

Apo-8'-lycopenal and apo-12'-lycopenal are metabolic products of lycopene in rat liver.[Pubmed:16702320]

J Nutr. 2006 Jun;136(6):1552-7.

The health benefits of lycopene as an anticarcinogenic compound have been widely studied but little is known about the metabolic products of lycopene produced in vivo. We investigated lycopene metabolites in the liver of F344 male rats that had been prefed a lycopene-containing diet (0.25 g lycopene/kg diet). After 30 d of feeding, they were given a single oral dose of 14C-labeled lycopene (421.8 kBq). The metabolic products of both nonradioactive and 14C-labeled lycopene in rat liver were extracted and separated using HPLC and analyzed by UV/VIS spectrometry, online radioactive detection, and off-line and in-line positive ion electrospray ionization MS. Among a number of metabolite products formed, we identified apo-8'-lycopenal (lambdamax = 473 nm and m/z = 417). The putative compound, apo-12'-lycopenal, was detected but no apo-10'-lycopenal was present. A number of other very polar, short-chain and/or short chromophore compounds with UV/VIS absorption <300 nm were present but were not characterized. These data show that lycopene is cleaved in vivo by rats at different positions to produce apo-12'-lycopenal, and other unidentified metabolites in addition to apo-8'-lycopenal. Apo-8'-lycopenal and the putative apo-12'-lycopenal are identified as lycopene metabolites in rat liver in vivo.

Formation of cleavage products by autoxidation of lycopene.[Pubmed:11269700]

Lipids. 2001 Feb;36(2):191-9.

The cleavage products formed by autoxidation of lycopene were evaluated in order to elucidate possible oxidation products of lycopene in biological tissues. Lycopene solubilized at 50 microM in toluene, aqueous Tween 40, or liposomal suspension was oxidized by incubating at 37 degrees C for 72 h. Among a number of oxidation products formed, eight products in the carbonyl compound fraction were identified as 3,7,11 -trimethyl-2,4,6,10-dodecatetraen-1-al, 6,10,14-trimethyl-3,5,7,9,13-pentadecapentaen-2-one, acycloretinal, apo-14'-lycopenal, apo-12'-lycopenal, apo-10'-lycopenal, apo-8'-lycopenal, and apo-6'-lycopenal. These correspond to a series of products formed by cleavage in the respective 11 conjugated double bonds of lycopene. The maximal formation of acycloretinal was 135 nM in toluene, 49 nM in aqueous Tween 40, and 64 nM in liposomal suspension. Acycloretinoic acid was also formed by autoxidation of lycopene, although its formation was lower in the aqueous media than in toluene. The pig liver homogenate had the ability to convert acycloretinal to acycloretinoic acid, comparable to the conversion of all-transretinal to all-trans-retinoic acid. These results suggest that lycopene might be cleaved to a series of apolycopenals and short-chain carbonyl compounds under the oxidative conditions in biological tissues and that acycloretinal is further enzymatically converted to acycloretinoic acid.