Zeaxanthin attenuates OVA-induced allergic asthma in mice by regulating the p38 MAPK/ß-catenin signaling pathway.

BACKGROUND: Asthma is a heterogeneous and complex chronic airway disease with a high incidence rate, characterized by chronic airway inflammation. Although the anti-inflammatory effect of zeaxanthin has been demonstrated in various disease models, its explicit role in allergic asthma remains elusive. METHODS: An allergic asthma model was established by ovalbumin (OVA) stimulation in BALB/c nude mice. The pathological examination, collagen deposition and expression of α-smooth muscle actin (α-SMA) in lung tissues were determined by hematoxylin and eosin (H&E), MASSON and immunofluorescence staining, respectively. Besides, the effect of zeaxanthin on inflammation and oxidative stress was assessed by the enzyme-linked immunosorbent assay (ELISA) and spectrophotometry measure. Moreover, the underlying mechanism was analyzed by detecting the expression of phosphorylated p38 (p-p38), p38, ß-catenin, p-c-Jun N-terminal kinase (p-JNK) and JNK with western blot assays. RESULTS: The distinct infiltration of inflammatory cells was observed in the OVA-induced asthma mice model with significantly increased concentrations of immunoglobulin E (IgE), interleukin-4 (IL-4), IL-5, IL-13 and eotaxin (p˂0.001), which were prominently reversed by zeaxanthin treatment (p˂0.001). In addition, zeaxanthin treatment decreased the OVA-induced collagen deposition and α-SMA expression. A similar inhibitory effect of zeaxanthin on the oxidative stress was also observed in the OVA-induced asthma mice model, as evidenced by the prominent decrease of malondialdehyde (MDA) concentration and the remarkable increase of superoxide dismutase (SOD), glutathione S transferase (GST) and Glutathione (GSH) concentrations (p˂0.001). Moreover, zeaxanthin introduction markedly reduced the relative expressions of p-p38/p38, ß-catenin and p-JNK/JNK in the OVA-induced asthma mice model (p˂0.001), indicating that zeaxanthin suppressed the p38 mitogen-activated protein kinase (p38 MAPK)/ß-catenin signaling pathway in the OVA-induced asthma mice model. CONCLUSIONS: Zeaxanthin attenuated OVA-induced allergic asthma in mice via modulating the p38 MAPK/ß-catenin signaling pathway.

A Randomized Study of Nutritional Supplementation in Patients with Unilateral Wet Age-Related Macular Degeneration.

The purpose of this study is evaluate the efficacy and safety of medicinal products containing the original Age-Related Eye Disease group (AREDS) formulation at doses approved in Europe (EU, control group; n = 59) with a product that adds DHA, lutein, zeaxanthin, resveratrol and hydroxytyrosol to the formula (intervention group; n = 50). This was a multicenter, randomized, observer-blinded trial conducted in patients aged 50 years or older diagnosed with unilateral exudative Age related Macular Degeneration AMD. At month 12, the intervention did not have a significant differential effect on visual acuity compared with the control group, with an estimated treatment difference in Early Treatment Diabetic Retinopathy Study (ETDRS) of -1.63 (95% CI -0.83 to 4.09; p = 0.192). The intervention exhibited a significant and, in most cases, relevant effect in terms of a reduction in some inflammatory cytokines and a greater improvement in the fatty acid profile and serum lutein and zeaxantin concentration. In patients with unilateral wet AMD, the addition of lutein, zeaxanthin, resveratrol, hydroxytyrosol and DHA to the AREDS EU recommended doses in the short-term did not have a differential effect on visual acuity compared to a standard AREDS EU formula but, in addition to improving the fatty acid profile and increasing carotenoid serum levels, may provide a beneficial effect in improving the proinflammatory and proangiogenic profile of patients with AMD.

Lutein, Zeaxanthin and Meso-zeaxanthin Supplementation Associated with Macular Pigment Optical Density.

The purpose of this study was to evaluate the effects of lutein, zeaxanthin and meso-zeaxanthin on macular pigment optical density (MPOD) in randomized controlled trials (RCTs) among patients with age-related macular degeneration (AMD) and healthy subjects. Medline, Embase, Web of Science and Cochrane Library databases was searched through May 2016. Meta-analysis was conducted to obtain adjusted weighted mean differences (WMD) for intervention-versus-placebo group about the change of MPOD between baseline and terminal point. Pearson correlation analysis was used to determine the relationship between the changes in MPOD and blood xanthophyll carotenoids or baseline MPOD levels. Twenty RCTs involving 938 AMD patients and 826 healthy subjects were identified. Xanthophyll carotenoids supplementation was associated with significant increase in MPOD in AMD patients (WMD, 0.07; 95% CI, 0.03 to 0.11) and healthy subjects (WMD, 0.09; 95% CI, 0.05 to 0.14). Stratified analysis showed a greater increase in MPOD among trials supplemented and combined with meso-zeaxanthin. Additionally, the changes in MPOD were related with baseline MPOD levels (rAMD = -0.43, p = 0.06; rhealthy subjects = -0.71, p < 0.001) and blood xanthophyll carotenoids concentration (rAMD = 0.40, p = 0.07; rhealthy subjects = 0.33, p = 0.05). This meta-analysis revealed that lutein, zeaxanthin and meso-zeaxanthin supplementation improved MPOD both in AMD patients and healthy subjects with a dose-response relationship.

Lutein and Zeaxanthin Isomers in Eye Health and Disease.

Current evidence suggests lutein and its isomers play important roles in ocular development in utero and throughout the life span, in vision performance in young and later adulthood, and in lowering risk for the development of common age-related eye diseases in older age. These xanthophyll (oxygen-containing) carotenoids are found in a wide variety of vegetables and fruits, and they are present in especially high concentrations in leafy green vegetables. Additionally, egg yolks and human milk appear to be bioavailable sources. The prevalence of lutein, zeaxanthin, and meso-zeaxanthin in supplements is increasing. Setting optimal and safe ranges of intake requires additional research, particularly in pregnant and lactating women. Accumulating evidence about variable interindividual response to dietary intake of these carotenoids, based on genetic or metabolic influences, suggests that there may be subgroups that benefit from higher levels of intake and/or alternate strategies to improve lutein and zeaxanthin status.

Lutein and zeaxanthin toxicity with and without brilliant blue in rabbits.

PURPOSE: To evaluate the safety profile of solutions containing lutein and zeaxanthin alone or associated with brilliant blue (BB). METHODS: Twenty-eight New Zealand rabbits were used to evaluate 4 concentrations of the various dye solutions: 0.5% lutein/zeaxanthin; 0.5% lutein/zeaxanthin associated with 0.0125% BB; 0.3% lutein/zeaxanthin associated with 0.025% BB; and 0.25% lutein/zeaxanthin associated with 0.05% BB. The pHs of the dye solutions ranged from 6.5 to 7.2 and the osmolarities from 280 to 320 mOsm/mL. Each rabbit had 0.1 mL of one of the dyeing solutions injected into the vitreous cavity of the right eye, while balanced salt solution (BSS) was injected into the left eye as the control. Scotopic electroretinography responses were recorded in all eyes at different time points. The animals were sacrificed at 1 and 7 days after injection; the eyes were analyzed by light and transmission electron microscopy. RESULTS: No significant (P>0.05) differences were seen in the a- and b-wave amplitudes among groups at any given point in time. Light and electron microscopy findings showed no significant abnormalities either, and were similar to the histological findings after intravitreal BSS injection. CONCLUSIONS: Lutein and zeaxanthin alone or in association with BB showed a good safety profile in this experimental model.