Modulatory Effect of Carotenoid Supplement Constituting Lutein and Zeaxanthin (10:1) on Anti-oxidant Enzymes and Macular Pigments Level in Rats

BACKGROUND: Human eye is constantly exposed to different wavelengths and intensities of light. Oxidative stress results in distinct changes to retinal organs and tissues. Macular pigments (lutein and zeaxanthin), present in the central macular region, provide protection from photodamages by absorption of high energy blue light and also by virtue of their anti-oxidant activity. Ocular phototoxicity is thus prevented by our efficient anti-oxidant system, in both young and old. One of the best commercial sources of pure lutein and zeaxanthin is Marigold flowers. OBJECTIVE: In the present study, oil-soluble dietary carotenoid supplement constituting lutein and zeaxanthin in the ratio of 10:1 was evaluated for its modulatory effect on anti-oxidant enzymes and macular pigments in the serum and macula of the Swiss albino rats. MATERIALS AND METHODS: Male Swiss albino rats were treated with carotenoid supplement constituting lutein and trans-Zeaxanthin (10:1) at two different doses daily, under standard experimental conditions for 42 days. End of the treatment, serum and macula were collected and used for measurement of lutein and zeaxanthin levels along with anti-oxidant parameters. STATISTICAL ANALYSIS USED: Statistical differences were assessed by analysis of variance (ANOVA) followed by Dunnet's test. P < 0.05 was considered statistically significant. All the results were expressed as mean ± standard deviation. RESULTS: The supplement exhibited significant elevation of anti-oxidant enzyme levels in treated animals in dose-dependent manner. Concomitantly, the total anti-oxidant capacity has also been found to show similar increment at the end of the study period. This study revealed significant expression of the two macular pigments investigated. CONCLUSIONS: Our study, therefore, provides a strong claim for the anti-oxidant effect of the oil-soluble dietary carotenoid supplement, and thus substantiates its use in the prevention of phototoxic damage to the eye on long-term supplementation. SUMMARY: Apart from its ornamental value, Marigold (Tagetes erecta L.) flowers are well known as an herbal remedy due to its antimicrobial, anti-inflammatory, and anti-oxidant activities. Epidemiological studies have implicated prolonged exposure to ultraviolet radiations & blue light and in turn oxidative stress in the pathogenesis of the majority of the eye diseases, since childhood. Studies have shown that with age a number of changes occur predisposing the retinal various organs and tissues to oxidative stress. These changes manifest in decreased levels in plasma of Vitamin C, Vitamin E, glutathione, Retinal Pigment Epithelium (RPE), Catalase (CAT), Super Oxide Dismutase (SOD), Thiobarbituric Acid Reactive Substance (TBARS), and total anti-oxidant capacity (TAC). Age- and diet-related loss of Lutein and Zeaxanthin enhance phototoxic damage to the eye, and thus supplementation of these carotenoids becomes vital for maintaining optimal eye health. In the present study, XanMax(®) 2002 oil, a supplement constituting lutein and trans-Zeaxanthin, extracted from the flowers of T. erecta, was evaluated for its modulatory effect on anti-oxidant enzymes and macular pigments in the serum and macula of the Swiss albino rats. XanMax(®) 2002 oil exhibited significant elevation of anti-oxidant enzyme levels in treated animals in dose-dependent manner. Concomitantly, the TAC has also been found to show similar increment at the end of the study period. This study revealed significant expression of the two macular pigments investigated. Abbreviations used: AMD: Age related Macular Diseases; RPE: Retinal Pigment Epithelium; CAT: Catalase; SOD: Super Oxide Dismutase; TAC: Total Antioxidant Capacity; ROS: Reactive Oxygen Species; LC-MS: Liquid chromatography-mass spectrometry; p.o.: Per Orally; CMC Carboxymethyl cellulose.