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Lutein: A Nutraceutical Nanoconjugate for Human Health
Published in Harishkumar Madhyastha, Durgesh Nandini Chauhan, Nanopharmaceuticals in Regenerative Medicine, 2022
Ishani Bhat, Bangera Sheshappa Mamatha
Lutein is an oxygenated xanthophyll carotenoid consisting of nine conjugated double bonds in a C40 isoprenoid with two ionone rings, each bound to a hydroxyl group (OH) at 3 and 3’ positions, at either end of the isoprenoid (Figure 11.1). Zeaxanthin and meso-zeaxanthin are isomers of lutein and all the three compounds share a common molecular formula C40H56O2. Because the three xanthophyll carotenoids are concentrated in the human eye macula (lutein: 36%, zeaxanthin: 18%, and meso-zeaxanthin: 18%), they are collectively called macular pigments (Bone et al., 1993). The chemical configuration of lutein is not only responsible for manifesting major biological activities such as antioxidant and light-absorbing properties but also defines its polarity and solubility (Woodall et al. 1997). These pigments have their peak absorption at 460 nm, which corresponds to the wavelength of “blue light hazard” (400–500 nm). The incident high-energy, short-wavelength visible blue light causes oxidative stress in the eyes. The MP absorbs 40–90% of blue light, which is incidental to the retina. However, this filtering is Macular Pigment concentration-dependent. Thus, macular pigments function as blue light filtering anti-oxidants to protect the retinal pigment epithelial cells in the eyes from the consequences of light-induced oxidative stress (Krinsky et al. 2003). Henceforth, they are positively associated with preventing age-related macular degeneration.
Carotenoids in Alzheimer’s Disease
Published in Atanu Bhattacharjee, Akula Ramakrishna, Magisetty Obulesu, Phytomedicine and Alzheimer’s Disease, 2020
Adequate intake of xanthophyll carotenoids, such as lutein, zeaxanthin, and meso- zeaxanthin, decreases AD risk (Loef and Walach, 2012; Min and Min, 2014; Feart et al., 2016; Nolan et al., 2018). In addition, lutein and zeaxanthin intake achieved marked cognitive improvements, even in non-AD people (Johnson et al., 2008a; Hammond et al., 2017; Power et al., 2018; Nolan et al., 2018). They were also found to enhance membrane integrity and to contribute to neural efficacy (Bovier and Hammond, 2015; Zamroziewicz et al., 2016; Lindbergh et al., 2017; Nolan et al., 2018). Lutein, zeaxanthin, and meso-zeaxanthin have been found in increased concentrations in the macula (retina), a part of the central nervous system (CNS). They are also found in brain regions such as the hippocampus, cerebellum, and the frontal, temporal, and occipital cortices (Craft et al., 2004; Johnson et al., 2013; Nolan et al., 2018).
Annexes
Published in Claude Leray, Dietary Lipids for Healthy Brain Function, 2017
The following carotenoids are not provitamin A: lutein (Figure 7.5) and zeaxanthin. Lutein is a carotenoid of the xanthophyll group. It is present in some foods of vegetal origin and characterizes the retinal macula. Zeaxanthin is a cis isomer of lutein (both hydroxyl groups in the same plane). Three stereoisomers are present in human serum and in retina, the most abundant being meso-zeaxanthin (3R,3′S-zeaxanthin). Lutein (E161b) and zeaxanthin (E161h) are permitted as food additives.
Factors determining the oral absorption and systemic disposition of zeaxanthin in rats: in vitro, in situ, and in vivo evaluations
Published in Pharmaceutical Biology, 2022
Seong‑Wook Seo, Dong‑Gyun Han, Eugene Choi, Min‑Jeong Seo, Im‑Sook Song, In‑Soo Yoon
Zeaxanthin (β,β‑carotene‑3,3′‑diol) is a yellow‑coloured tetraterpene pigment with a molecular weight of 568.8 Da (Murillo et al. 2019). Zeaxanthin, along with lutein and meso‑zeaxanthin, is highly concentrated in the macula of the retina that is mainly responsible for central and fine‑feature vision (Billsten et al. 2003; Eisenhauer et al. 2017). These three carotenoids (called macular pigments) are efficient absorbers of blue light, protecting against age‑related macular degeneration (AMD), a degenerative disease that may lead to blurred or no vision in the centre of the visual field, owing to their blue light‑filtering and antioxidant activities (Kijlstra et al. 2012; Mares 2016). Dietary intake and plasma levels of these carotenoids have been associated with a lower risk of AMD (Hartmann et al. 2004). Additionally, zeaxanthin acts as a more potent antioxidant than lutein, protecting against oxidative stress in other tissues as well as the eyes (Murillo et al. 2019). Mammals are not able to synthesize zeaxanthin; thus, it must be obtained from dietary sources (Delgado‑Pelayo and Hornero‑Mendez 2012). Zeaxanthin is found in many plants, including green leafy and yellow‑orange vegetables and fruits, such as carrots, corn, orange, paprika, saffron, and wolfberries (goji) (Murillo et al. 2019). It can also be found in animal products, such as egg yolks and cheese (Murillo et al. 2019).
Allyl isothiocyanate attenuates LED light-induced retinal damage in rats: exploration for the potential molecular mechanisms
Published in Cutaneous and Ocular Toxicology, 2021
Cemal Orhan, Hasan Gencoglu, Mehmet Tuzcu, Nurhan Sahin, Ibrahim Hanifi Ozercan, Abhijeet Ashok Morde, Muralidhara Padigaru, Kazim Sahin
LEDs are considered harmful to the retina due to blue-light component and may cause retinal degeneration and risk of developing AMD22,23. LED lights transmit strong energy, create oxidative stress, and activate mitochondria-associated death signalling pathways leading to the death of photoreceptor cells in AMD24. Macular pigments, lutein, zeaxanthin, and meso-zeaxanthin present in the eye are estimated to filter approximately 40% of blue light and protect the retina25,26. Several rodent models have been developed to demonstrate light-induced phototoxic retinal damage and connected mechanisms, including oxidative stress responses27,28. In the current study, we used LED-induced retinal damage in a rat model to explore the protective effect of AITC at 10 and 20 mg/kg body weight doses. We measured serum biochemical parameters and histopathological changes in the retina to rule out any possible adverse effects of AITC in the animals.
Macular pigment optical density after panretinal photocoagulation
Published in Clinical and Experimental Optometry, 2021
Mustafa Doğan, Bünyamin Kutluksaman
The macular pigment, which is one of the important structures of the retina, is located very intensely around the fovea, and its density decreases gradually toward the periphery.10 The human macular pigment consists of isomeric carotenoids containing lutein, zeaxanthin, and meso‐zeaxanthin.10 Lutein and zeaxanthin cannot be synthesised in the human body, whereas meso‐zeaxanthin can be synthesised from lutein in humans.11 Macular pigment resides in photoreceptor axons, inner plexiform layer, retinal pigment epithelium, and outer photoreceptor layers. They protect the retina by its antioxidant effect against high‐energy visible lights and by absorbing blue light that has a destructive impact on the retina.12,13 They also play a role in functional outcomes such as contrast sensitivity and reduction of night glare.14 Recently, literature has suggested that macular pigment optical density (MPOD) can be affected in diabetic retinopathy as well as many conditions.15