Abstract
Purpose:
Chronic consumption of a high-fat diet induces diabetes, obesity and metabolic syndrome. Meso-Zeaxanthin [MZ] able to protect against chronic and cumulative eye damage and neutralize free radicals produced by oxidative stress. We hypothesized that MZ administration reduces oxidative stress in the retina. We tested this hypothesis in insulin resistance induced by high-fat (HF) diet in rodents.
Methods:
Male Sprague Dawley rats (N=28, age: 8 week, weight: 180 ± 20 g) were housed in a controlled environment with a 12:12-h light-dark cycle at 22°C and provided with rat chow and water ad libitum. All experiments were conducted under the National Institutes of Health's Guidelines for the Care and Use of Laboratory Animals and approved by the Ethics Committee of the Veterinary Control Institute. After acclimation for 2 weeks, the rats were divided into four groups: Twenty eight rats were randomly divided into the following four groups: (1) Control standard diet (C), (2) High Fat Diet (40% of calories as fat, HFD), (3) C+ MZ (100 mg/kg), (4) HFD+ MZ (100 mg/kg) group rats were administered daily as supplement for 12 weeks. Oxidative stress genes and inflammatory responses were analyzed in retinal tissue. Body weight, lipids and glucose were analyzed. The data were analyzed using the GLM procedure of SAS (SAS Institute: SAS User’s Guide:Statistics). The treatments were compared using ANOVA and student's unpaired t test; P < 0.05 was considered statistically significant.
Results:
MZ administration significantly alleviated metabolic health markers and decreased NFkB, VEGF, iNOS, ICAM and improved antioxidant capacity (Nrf2, HO-1) gene proteins in retinal tissues. Thiobarbituric acid reactive substances (TBARS) were reduced in serum and retinal tissue. No gross lesions, no mortality and no adverse events were observed.
Conclusions:
These observations suggest that MZ may be considered as an adjunct therapy to prevent diabetic retinopathy and to improve visual health in chronic conditions.