Lycopene absorption

Moussa, M. et al. (2008). Lycopene absorption in human intestinal cells and in mice involves scavenger receptor class B type I but not Nienmann-Pick Cl-like 1. J. Nutr. 138 1432-1436. 

All-trans lycopene is rapidly isomerized to an equilibrium mixture with its cis isomers both in cell culture medium (Liu et al. 2006) and in vivo in prostate tissue (Clinton et al. 1996, van Breemen et al. 2002). The cis isomers of lycopene are absorbed better than the all -trans isomers when fed to humans (Unlu et al. 2007). The 5 -cis isomer predominates in plasma (Gustin et al. 2004). Since lycopene absorption by prostate cells might be due to facilitated diffusion (Liu et al. 2006), it is likely that the cis isomers of lycopene form a significant proportion of intracellular lycopene in the experiments that are reviewed later. 

Handelman et al., 1996). Alcohol consumption was also shown to alter serum lycopene levels (Brady et al., 1997). Other factors that influence the bioavailability of lycopene are its release from the food matrix due to processing, presence of dietary lipids, and heat-induced isomerization from the all-trans to cis conformation. They all enhance lycopene absorption into the body. Ingestion of cooked tomato juice in oil medium increased serum lycopene levels threefold whereas consumption of an equal amount of unprocessed juice did not have any effect (Stahl and Sies, 1992). 

FIG. 10 Lycopene absorption kinetics in prostate cancer patients and controls. CaP, cancer patients TJ, tomato juice Bkf, breakfast. (Lycopene, tomatoes and health New Perspectives 2000. Reprinted from Lycopene and the prevention of chronic diseases. Major findings from five international conferences. 2002. A.V. Rao, D. Heber, eds., p. 24. By permission of Caledonian Science Press.)... 

The presence of other carotenoids can affect the absorption of carotenoids into intestinal mucosal cells, since carotenoids can compete for absorption or facilitate the absorption of another. Data on carotenoid interactions are not clear. Human studies show that /3-carotene decreases lutein absorption, while lutein has either no effect or a lowering effect on /3-carotene absorption. Although not confirmed in humans, the inhibitory effect of lutein on /3-carotene absorption might be partly attributed to the inhibition of the /3-carotene cleavage enzyme by lutein shown in rats. Beta-carotene also seemed to lower absorption of canthaxanthin, whereas canthaxanthin did not inhibit /3-carotene absorption. Studies showed that /3-carotene increased lycopene absorption, although lycopene had no effect on /3-carotene. Alpha-carotene and cryptoxanthin show high serum responses to dietary intake compared to lutein. In addition, cis isomers of lycopene seem to be more bioavailable than the -trans, and selective intestinal absorption of a)X-trans /3-carotene occurs, as well as conversion of the 9-cis isomer to sW-trans /3-carotene. It is clear, then, that selective absorption of carotenoids takes place into the intestinal mucosal cell. 

Many organic compounds such as lycopene are colored because their HOMO-LUMO energy gap is small enough that appears m the visible range of the spec trum All that is required for a compound to be colored however is that it possess some absorption m the visible range It often happens that a compound will have its k m the UV region but that the peak is broad and extends into the visible Absorption of the blue to violet components of visible light occurs and the compound appears yellow... 

Lycopene is a bright red pigment that colors several ripe fruits, vegetables, and flowers. Tomato and tomato products are the main dietary sources of this carotenoid, although it is also found in watermelons, guavas, pink grapefruits, and in small quantities in at least 40 plants. - The absorption of lycopene in the human gut is increased by heat treatment, probably because the breakdown of the plant cells makes the pigment more accessible. ... 

As has been pointed out earlier in this chapter, the dietary consumption and historical medicinal use of carotenoids has been well documented. In the modern age, in addition to crocin, 3.7, and norbixin, 3.8, several carotenoids have become extremely important commercially. These include, in particular, astaxanthin, 3.6 (fish, swine, and poultry feed, and recently human nutritional supplements) lutein, 3.4, and zeaxanthin, 3.3 (animal feed and poultry egg production, human nutritional supplements) and lycopene, 3.2 (human nutritional supplements). The inherent lipophilicity of these compounds has limited their potential applications as hydrophilic additives without significant formulation efforts in the diet, the lipid content of the meal increases the absorption of these nutrients, however, parenteral administration to potentially effective therapeutic levels requires separate formulation that is sometimes ineffective or toxic (Lockwood et al. 2003). 

FIGURE 12.4 Lycopene photodegradation in 0.02 M Triton X-100 aqueous solutions illuminated with a 150 W (> 380 nm) filament lamp. Inset evolution of the difference absorption spectrum (AA). 

Reboul et al., 2007a,b). As mentioned earlier the competitive uptake occurs also in the presence of a mixture of carotenoids where absorption of lutein is inhibited by [1-carotene but not by lycopene (Reboul et al., 2005). This indicates that the presence of a mixture of different lipophilic substrates can strongly influence the uptake of certain carotenoids. It has also been demonstrated that cultured Caco-2 cells secrete (3-carotene, preferentially within micelles rich in long fatty acids (Yonekura et al., 2006), suggesting that carotenoids can be stored in the cell or secreted depending on the absence or presence of appropriate carotenoid acceptors. 

M. E. O Neill and D. I. Thumham, Intestinal absorption of beta-carotene, lycopene and lutein in men and women following a standard meal Response curves in the triacylglycerol-rich lipoprotein fraction, Br. J. Nutr. 79 (1998) 149-159. 

Liu, A, N Pajkovic, Y Pang, D Zhu, B Calamini, AL Mesecar, and RB van Breemen. 2006. Absorption and subcellular localization of lycopene in human prostate cancer cells. Mol Cancer Ther 5(11) 2879-2885. 

In systems where several carotenoids are involved, the absorption of each carotenoid is governed by interactions among them carotenoids compete for absorption (Furr and Clark 1997). For example, (3-carotene supplementation reduced absorption of dietary lutein and lycopene in humans (Micozzi and others 1992). Tyssandier and others (2002) found that the absorption of dietary lycopene was reduced when a portion of spinach or pills of lutein were additionally administered to the volunteers. Similarly, the absorption of dietary lutein was reduced by consumption of tomato puree or lycopene pills (Tyssandier and others 2002). Furusho and others (2000) demonstrated that liver retinol accumulation in Wistar rats was significantly reduced when a fixed amount of (3-carotene was replaced by a mixture of (3- and a-carotene, suggesting that each one of these carotenoids mutually inhibits the utilization of the other. The proportion of (3-and a-carotene in the mixture used in that study (Furusho and others 2000) simulated that of carrots. 

Porrini M, Riso P and Testolin G. 1998. Absorption of lycopene from single or daily portions of raw and processed tomato. Br J Nutr 80(4) 353-361. 

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