Lutein bioavailability

Chitchumroonchokchai, C., Schwartz, S.J., and Failla, M.L., Assessment of lutein bioavailability from meals and a supplement using simulated digestion and Caco-2 human intestinal cells, J. Nutr, 134, 2280, 2004. 

Bowen, P.E. Herbst-Espinosa, S.M. Elussain, E.A. Stacewicz-Sapuntzakis, M. Esterification does not impair lutein bioavailability in humans. J. Nutr. 2002, 132 (12), 3668-3673. 

The degree of linkage of a compound may also affect its bioaccessibility in the gut. It is generally admitted that a compound linked with other molecules (e.g., via esterification, glycosylation, etc.) is not absorbed as well as its free form and thus it must be hydrolyzed in the gut in order to be taken up by enterocytes. Due to the presence of hydroxyl or keto groups on their molecules, the xanthophylls (lutein, zeaxanthin, and P-cryptoxanthin) are found in both free and esterified (monoester or diester) forms in nature, but few studies have been conducted to date to assess the bioavailabilities of these esters. 

Chemical properties of carotenoids play an important role in carotenoid micellarization and, therefore, bioavailability. Apolar carotenoids (carotenes) are generally incorporated in the central region, which is highly hydrophobic, of the oil droplets, whereas polar carotenoids (xanthophylls) are localized on the surface, and therefore xanthophylls are more easily micellarized and absorbed than carotenes (Borel and others 1996). van het Hof and others (2000) found in humans that lutein is five times more bioavailable than (3-carotene. 

Xanthophyll esters are common in fruits and vegetables. Few data exist regarding the effect of carotenoid esterification on carotenoid bioavailability. Xanthophyll esters are readily broken in the human intestine (West and Castenmiller 1998 Breithaupt and others 2003 Faulks and Southon 2005). Chitchumroonchokchai and Failla (2006) demonstrated that hydrolysis of zeaxanthin esters increases zeaxanthin bioavailability. Wingerath and others (1995) did not find (3-cryptoxanthin esters in chylomicrons from humans fed with tangerine juice. Herbst and others (1997) demonstrated that lutein diesters are more bioavailable than free lutein. However, the question of whether the free or the esterified form is more bioavailable to humans is still an ongoing discussion. 

Herbst S, Bowen P, Hussain E, Stacewicz-Sapuntzakis M, Damayanti B and Bums J. 1997. Evaluation of the bioavailability of lutein (L) and lutein diesters (LD) in humans. FASEB J 11 A447. 

Roodenburg AJ, Leenen R, van het Hof KH, Weststrate JA and Tijburg LB. 2000. Amount of fat in the diet affects bioavailability of lutein esters but not of alpha-carotene, beta-carotene and vitamin E in humans. Am J Clin Nutr 71 1187-1193. 

Molidrem, K.L., Li, J., Simon, P.W., and Tanumihardjo, S.A. (2004). Lutein and beta-carotene from lutein-containing yellow carrots are bioavailable in humans. Am. J. Clin. Nutrition 80(1) 131-136. 

Matsubara, K., et al. 1995. Improvement of nasal bioavailability of luteinizing hormone-releasing hormone agonist, buserelin, by cyclodextrin derivatives in rats. J Pharm Sci 84 1295. 

The conjugation of vitamin B12 has been shown to increase oral bioavailability of peptides, proteins, and particles.44 46 62,63 Russsell-Jones and coworkers have attempted to exploit RME of vitamin B12 for the enhanced intestinal uptake of macromolecules such as luteinizing hormone—releasing factor (LHRH), granulocyte colony-stimulating factor, erythropoietin, and a-interferon.44,46,63 Also, they demonstrated that surface modification of nanoparticles with vitamin B12 can increase their intestinal uptake.44,62 The extended applications of this unique transport system, however, appear partially hampered by its limited uptake capacity. In human being, the uptake of vitamin B12 is only 1 nmol per intestinal passage. 

The absorption and bioavailability of both lutein and zeaxanthin were studied and their epimeric isomers were found in human serum. Much evidence shows that a high intake of carotenoids in fruits and vegetables might be associated with a reduction in the risk of lung cancer, and in particular that a-carotene rather than -carotene may be associated with that reduced risk. 

AMS has been used for many years to study the pharmacokinetics of (3-carotene, as has been reviewed by van Lieshout et al. (2003). Recent studies have been performed on the absorption of (3-carotene and metabolism to vitamin A (Dueker et ah, 2000 Hickenbottom et ah, 2002a) and other metabolites (Ho et ah, 2007) in humans. AMS has also been used to monitor the kinetics of lutein metabolism (Moura et ah, 2005) and lycopene bioavailability and metabolism (Ross et ah, 2011) in humans. 

No carotenoids were detected in tissues of animals sacrificed after 6 weeks. However, as shown in Table 10.4, after 24 weeks, nearly all carotenoids (lutein, zeaxanthin, lycopene, y-carotene, -carotene, a-carotene, P-carotene, phytofluene, phytoene) were bioavailable in colon and liver of the animals that received MCM. A typical HPLC profile of carotenoids in a pooled extract from mouse liver is shown in Figure 10.2. The major carotenoids in brain were lycopene, lutein, and P-carotene. Carotene predominated in the breast tissues, while lutein, lycopene, y-carotene, and a-carotene were detected in low concentrations. Carotenoids were not detected in tissues of the mice on WD without MCM. 

Khachik, R, Steck, A., and Pfander, H., Bioavailability, metabolism, and possible mechanism of chemoprevention by lutein and lycopene in humans, in Food Factors for Cancer Prevention, Ohigashi, H., Osawa, T., Terao, J., Watanabe, S., Yoshikawa, T., Eds., Springer-Verlag, Tokyo, 1997, p. 542. 

This luteinizing hormone-releasing hormone has been used in the treatment of endometriosis and hormone-dependent tumors. Modes of administration have included injections, nasal sprays and subcutaneous implantations. One study, conducted in pigs, demonstrated the value of glycodeoxycholate (a penetration enhancer) in improving the bioavailability of buserelin by up to five-fold after buccal delivery. ... 

Lycopene is the major carotenoid pigment found in tomatoes, along with lesser amounts of a-, P-, y-, and -carotene, phytoene, phytofluene, neurosporene, and lutein (Trombly and Porter, 1953 Kargl et al., 1960). The basic physicochemical information on lycopene is fairly well established and is outlined in Table 4.1. Lycopene is dispersible in edible oils and soluble in apolar organic solvents. In aqueous systems, lycopene tends to aggregate and to precipitate as crystals this behavior is suspected to inhibit the bioavailability of lycopene in humans (Zumbrunn et al., 1985). In fresh tomatoes, the crystalline form of lycopene is responsible for the typical bright red of the ripe fruits. 

Tenover JS, Matsumoto AM, Plymate SR, Bremner WJ. The effects of aging in normal men on bioavail-able testosterone and luteinizing hormone secretion Response to clomiphene citrate. J Clin Endocrinol Metab 1987 65 1118-26. 

Pharmacology Progesterone is the major natural progestin. Rationale for synthetics is t oral bioavailability and t feedback inhibition of gonadotropins, especially luteinizing hormone (LH). 

Castenmiller, J.J. et al.. The food matrix of spinach is a limiting factor in determining the bioavailability of beta-carotene and to a lesser extent of lutein in humans, J. Nutr., 129, 349, 1999. 

Shanmugam, S., Baskaran, R., Balakrishnan, P., Thapa, P., Yong, C.S., Yoo, B.K., 2011. Solid self-nanoemulsifying drug delivery system (S-SNEDDS) containing phosphatidylcholine for enhanced bioavailability of highly lipophilic bioactive carotenoid lutein. Eur. J. Pharm. Biopharm. 79, 250—257. 

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