TY  - JOUR
A1  - Schweigert, Florian J.
A1  - Reimann, J.
T1  - Micronutrients and their Relevance for the Eye - Function of Lutein, Zeaxanthin and Omega-3 Fatty Acids
JF  - Klinische Monatsblätter für Augenheilkunde
N2  - Micronutrients play an important role in function and health maintenance for the eye. Especially lutein, zeaxanthin and omega-3 fatty acids perform remarkable functions: lutein together with zeaxanthin forms the macular pigment, these carotenoids filter out the damaging blue light component from the sunlight as well as the ultraviolet light which leads to improved contrast sensitivity and less problems with screen glare. Furthermore, the macular pigment has antioxidant and anti-inflammatory effects. The omega-3 fatty acids also possess anti-inflammatory effects and, when converted into neuroprotectin, they protect against oxidative induced apoptosis in the retina. They are also responsible for the fluidity and supply to the photoreceptor membrane. These properties are important for the prevention and treatment of degenerative eye diseases like age-related macular degeneration. However, older people are often not sufficiently supplied of micronutrients in their diet. Because the supply of nutrients can hardly be achieved by dietary change, the additional intake in the form of food supplements is useful in this age group. Scientific studies have shown the positive effects of supplementation with micronutrients such as lutein/zeaxanthin, vitamin C, vitamin E, zinc and omega-3 fatty acids, docosahexaenoic acid and eicosapentaenoic acid (DHA and EPA). Currently available nutritional products are based in part on the ingredients of the ARED study (Age Related Eye Disease Study). According to more recent studies formulations containing lutein and omega-3 fatty acids in physiologically meaningful doses without additional beta-carotene should be preferred. 10 to 20 mg of lutein and zeaxanthin represent a safe daily dose Regarding to the context above, beta-carotene in high doses plays a minor role to the eye and is especially critical for the health of smokers. This paper summarises the functions of the presented micronutrients in the eye and can assist ophthalmologists in advising their patients.
KW  - AMD
KW  - lutein
KW  - omega-3 fatty acids
KW  - macular pigment density
KW  - micronutrients
KW  - dosage recommendation
Y1  - 2011
U6  - https://doi.org/10.1055/s-0029-1245527
SN  - 0023-2165
VL  - 228
IS  - 6
SP  - 537
EP  - 543
PB  - Thieme
CY  - Stuttgart
ER  - 
TY  - JOUR
A1  - Frede, Katja
A1  - Ebert, Franziska
A1  - Kipp, Anna Patricia
A1  - Schwerdtle, Tanja
A1  - Baldermann, Susanne
T1  - Lutein Activates the Transcription Factor Nrf2 in Human Retinal Pigment Epithelial Cells
JF  - Journal of agricultural and food chemistry : a publication of the American Chemical Society
N2  - The degeneration of the retinal pigment epithelium caused by oxidative damage is a stage of development in age related macular degeneration (AMD). The carotenoid lutein is a major macular pigment that may reduce the incidence and progression of AMD, but the underlying mechanism is currently not fully understood. Carotenoids are known to be direct antioxidants. However, carotenoids can also activate cellular pathways resulting in indirect antioxidant effects. Here, we investigate the influence of lutein on the activation of nuclear factor erythroid 2-related factor 2 (Nrf2) target genes in human retinal pigment epithelial cells (ARPE-19 cells) using lutein-loaded Tween40 micelles. The micelles were identified as a suitable delivery system since they were nontoxic in APRE-19 cells up to 0.04% Tween40 and led to a cellular lutein accumulation of 62 mu M +/- 14 mu M after 24 h. Lutein significantly enhanced Nrf2 translocation to the nucleus 1.5 +/- 0.4-fold compared to that of unloaded micelles after 4 h. Furthermore, lutein treatment for 24 h significantly increased the transcripts of NAD(P)H:quinone oxidoreductase 1 (NQO1) by 1.7 +/- 0.1-fold, glutamate-cysteine ligase regulatory subunit (GCLm) by 1.4 +/- 0.1-fold, and heme oxygenase-1 (HO-1) by 1.8 +/- 0.3-fold. Moreover, we observed a significant enhancement of NQO1 activity by 1.2 +/- 0.1-fold. Collectively, this study indicates that lutein not only serves as a direct antioxidant but also activates Nrf 2 in ARPE-19 cells.
KW  - lutein
KW  - Nif2
KW  - ARPE-19 cells
KW  - AMD
KW  - Tween40 micelles
Y1  - 2017
U6  - https://doi.org/10.1021/acs.jafc.7b01929
SN  - 0021-8561
SN  - 1520-5118
VL  - 65
SP  - 5944
EP  - 5952
PB  - American Chemical Society
CY  - Washington
ER  -