Lutein improves cell viability and reduces Alu RNA accumulation in hydrogen peroxide challenged retinal pigment epithelial cells

Purpose: Dysfunction of the microRNA (miRNA)-processing enzyme DICER1 and Alu RNA accumulation are linked to the pathogenesis of age-related macular degeneration (AMD). This study determined the optimal dose of lutein (LUT) and zeaxanthin (ZEA) to protect human retinal pigment epithelium (RPE) cells against hydrogen peroxide (H₂O₂). The effect of the optimal dose of LUT and ZEA as DICER1 and Alu RNA modulators in cultured human RPE cells challenged with H₂O₂ was investigated.

Materials and methods: ARPE-19 cells were pre-treated with LUT, ZEA, or both for 24?h before 200?μM H₂O₂ challenge. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. DICER1 and Alu RNA were quantified by western blotting and real-time polymerase chain reaction, respectively.

Results: H₂O₂ increased cell Alu RNA expression and decreased cell viability of ARPE-19, but had no significant impact on the DICER1 protein level. LUT, alone and in combination with ZEA pre-treatment, prior to H₂O₂ challenge significantly improved cell viability of ARPE-19 and reduced the level of Alu RNA compared to the negative control.

Conclusions: These results support the use of LUT alone, and in combination with ZEA, in AMD prevention and treatment. This study is also the first to report LUT modulating effects on Alu RNA.     

Provitamin A and vitamin C contents in selected California-grown cantaloupe and honeydew melons and imported melons

Vitamins are essential for human health and are mainly obtained from dietary sources. Cantaloupe and honeydew melons are abundant in provitamin A and vitamin C. California is one of the leading producers of cantaloupe and honeydew melons in the United States. Because melon is a warm-season crop, cantaloupe and honeydew melons are also imported to the United States from other countries to ensure year-around consumption. Nutrient content often varies among different melon varieties as well as among melons grown and harvested from different locations. To provide detailed nutrient information on domestic and imported melons, provitamin A and vitamin C contents of six California-grown and four imported melon varieties were determined by HPLC analysis and compared to the nutrient data published in the USDA nutrient database. Overall, California-grown and imported melons analyzed in the current work have higher vitamin A activity than values reported in the USDA database. Differential accumulation of provitamin A and vitamin C was observed among California-grown and imported melons. In addition, cantaloupe melons accumulate up to 60-fold more β-carotene than honeydew melons.     

Lutein and Age-Related Ocular Disorders in the Older Adult

Abstract

Lutein, a carotenoid found in dark green, leafy vegetables, has been implicated as being protective against the acquired ocular diseases, such as cataracts and age-related macular degeneration. In the eye, lutein may act as an antioxidant and as a blue light filter to protect the underlying tissues from phototoxic damage. Average intakes of lutein in the U.S. are below levels associated with eye disease prevention. Therefore, increased intakes of food sources rich in lutein may be warranted. Age-related factors, such as increased inflammation and body fat, are also related to increased risk of age-related eye disease. The mechanism by which these factors are related to risk may be partially due to adverse effects on lutein status.     

辉瑞液明珠联合托吡卡胺治疗假性近视的临床疗效观察

目的探讨辉瑞液明珠联合托吡卡胺治疗假性近视的科学性及临床应用效果。方法124眼假性近视眼随机分为两组：A组为辉瑞液明珠联合0．5％托吡卡胺治疗组;B组为单用0．5％托吡卡胺治疗组。治疗30d后比较两组视力及视疲劳症状恢复情况,应用矿检验分析两组疗效差异。所有统计数据在SPSS11．0软件包中处理。结果A组治愈45眼,有效12眼,有效率为91．93％;B组治愈22眼,有效10眼,有效率为51．61％。根据x2检验,A组优于B组（P〈0．05,x2=5．68）。结论辉瑞液明珠联合0．5％托吡卡胺治疗组其疗效明显优于单纯应用0．5％托吡卡胺治疗组,其疗效可靠,且在服药期间均未出现任何不良反应,故此法可作为防止假性近视发展成为真性近视的预防性用药。     

Lutein prevents cataract development and progression in diabetic rats

Background  Diabetes mellitus is a heterogeneous metabolic disorder characterized by hyperglycemia. It is often associated with complications, such as cataracts. Cataract, characterized by cloudiness or opacity of the eye lens, is the leading cause of blindness worldwide. Methods  The present study investigated the effect of lutein, alone or combined with insulin on the progression of eye lens opacities in streptozotocin-diabetic rats for a period of 12 weeks. Tissue markers of oxidative stress were also determined at the end of the experiment. Results  Herein we demonstrate that lutein treatment prevents the development and progression of cataracts (0 eyes with mature cataract, and ten out of 16 eyes with clear lenses in the lutein-treated diabetic animals group, vs. seven and three eyes in the non-treated diabetic group, respectively). Lipid peroxidation is significantly increased in diabetic lens (up to three-fold); lutein and insulin, alone or in combination, are able to prevent this alteration. Only insulin and lutein together could prevent the diabetes-induced decrease of glutathione content. Conclusions  The combined treatment with lutein and insulin is useful in preventing the development of cataracts in streptozotocin-induced diabetic rats, supporting its utility in diabetes management, especially when a tight metabolic control is difficult to achieve.     

Lutein,zeaxanthin, and meso-zeaxanthin: The basic and clinical science underlying carotenoid-based nutritional interventions against ocular disease

The human macula uniquely concentrates three carotenoids: lutein, zeaxanthin, and meso-zeaxanthin. Lutein and zeaxanthin must be obtained from dietary sources such as green leafy vegetables and orange and yellow fruits and vegetables, while meso-zeaxanthin is rarely found in diet and is believed to be formed at the macula by metabolic transformations of ingested carotenoids. Epidemiological studies and large-scale clinical trials such as AREDS2 have brought attention to the potential ocular health and functional benefits of these three xanthophyll carotenoids consumed through the diet or supplements, but the basic science and clinical research underlying recommendations for nutritional interventions against age-related macular degeneration and other eye diseases are underappreciated by clinicians and vision researchers alike. In this review article, we first examine the chemistry, biochemistry, biophysics, and physiology of these yellow pigments that are specifically concentrated in the macula lutea through the means of high-affinity binding proteins and specialized transport and metabolic proteins where they play important roles as short-wavelength (blue) light-absorbers and localized, efficient antioxidants in a region at high risk for light-induced oxidative stress. Next, we turn to clinical evidence supporting functional benefits of these carotenoids in normal eyes and for their potential protective actions against ocular disease from infancy to old age.     

Effect of micellar lipids, dietary fiber and β-carotene on lutein bioavailability in aged rats with lutein deficiency

Objective

To determine the effect of various dietary components on the intestinal uptake of lutein in aged rats.

Methods

This study determined the time-course (2, 4, 6, 8 h) plasma and tissue responses of a pharmacologic dose of lutein (200 μM) solubilized in mixed micelles with fat (3%, soybean oil), phosphatidylcholine (PC; 3 mM), lysophosphatidylcholine (lysoPC; 3 mM), dietary fiber (pectin, 1.25%), β-carotene (200 μM), or micelles with no dietary components (control) in aged rats with lutein deficiency.

Results

No lutein was detected in the plasma of rats at 0 h indicating the deficiency. After gavages of lutein, the mean percent area under the curve (picomoles per milliliter per 8 h) of plasma lutein in the fat (91.4), PC (218.0), and lysoPC (94.1) groups were higher (P > 0.05), whereas its level in the dietary fiber and β-carotene groups was lower than the control group. The liver and eye lutein levels of the PC (95.4, 38.67%) and fat (18.2, 143%) groups were significantly higher, whereas the lysoPC (9.6, 27.2%), β-carotene (19.2, 35.4%), and dietary fiber (3.1, 88.4%) groups were lower than the control group.

Conclusion

Results indicate that soybean oil and soy phospholipids greatly sway lutein absorption in aged rats with lutein deficiency. The results also suggest that ingestion of lutein with pectin and β-carotene suppresses lutein absorption. Hence, to improve the absorption of lutein in older adults with macular pigment deficiency, foods with sufficient fat with low dietary fiber and β-carotene may be suggested.     

The impact of macular pigment augmentation on visual performance in normal subjects: COMPASS

This study was conducted to investigate whether augmentation of macular pigment (MP) enhances visual performance (VP). 121 normal subjects were recruited. The active (A) group consumed 12 mg of lutein (L) and 1 mg of zeaxanthin (Z) daily. MP optical density (MPOD) was assessed by customized heterochromatic flicker photometry. VP was assessed as best corrected visual acuity (BCVA), mesopic and photopic contrast sensitivity (CS), glare disability, photostress, and subjective visual function. Subjects were assessed at baseline; 3; 6; 12 months (V1, V2, V3 and V4, respectively). Central MPOD increased significantly in the A group (p < 0.05) but not in the placebo group (p > 0.05). This statistically significant increase in MPOD in the A group was not, in general, associated with a corresponding improvement in VP (p > 0.05, for all variables), with the exception of a statistically significant time/treatment effect in “daily tasks comparative analysis” (p = 0.03). At V4, we report statistically significant differences in mesopic CS at 20.7 cpd, mesopic CS at 1.5 cpd under high glare conditions, and light/dark adaptation comparative analysis between the lower and the upper MP tertile groups (p < 0.05) Further study into the relationship between MP and VP is warranted, with particular attention directed towards individuals with low MP and suboptimal VP.     

北京市常见食物熟制前后叶黄素和玉米黄素及β-胡萝卜素的含量比较

目的 测定北京市常见食品中叶黄素、玉米黄素和β-胡萝卜素的含量,并比较熟制后其含量的变化.方法 于2009年9-10月在北京市海淀区选取8类46种食物,使用高效液相色谱法对其熟制前后叶黄素、玉米黄素和β-胡萝卜素的含量进行检测.结果 茄果瓜菜类蔬菜、葱蒜类蔬菜和坚果中叶黄素含量丰富,其中韭菜(18 226.9μg/100 g)和甘栗南瓜(13 265.2μg/100 g)中含量较高.甘栗南瓜、蒜薹、玉米和蛋类中含有较丰富的玉米黄素,分别为444.6、283.5、279.7、118.6～377.9 μg/100 g,熟制后其含量分别改变为483.9、239.3、279.1、149.5～594.7μg/100 g;生韭菜中未检出玉米黄素,熟制后其玉米黄素含量达1081.2μg/100 g.β-胡萝卜素广泛存在于各种蔬菜水果中,其中胡萝卜中含量最高,达17 234.3 μg/100 g,熟制后其β-胡萝卜素含量变为17 013.5 μg/100 g.结论 选择性摄入不同种类食物及改变食物的加工制作方法将有利于增加膳食叶黄素、玉米黄素和β-胡萝卜素的摄入量.

Abstract：

Objective To measure lutein, zeaxanthin and β-carotene level in foods commonly consumed in Beijing,and compare the content difference between raw and cooked food. Methods Forty-six commonly consumed foods of 8 classes were collected in Haidian district of Beijing from September to October in 2009. A high performance liquid chromatography method was used to determine the content of lutein, zeaxanthin and β-carotene in both raw and cooked samples. Results Lutein was abundant in cucurbitaceous and solanaceous,alliums and nuts,especially in Chinese chive (18 226. 9 μg/100 g) and pumpkin (13 265.2 μg/100 g). Major sources of zeaxanthin included round pumpkin,green garlic shoot,corn and eggs, whose level of zeaxanthin were 444.6, 283.5, 279.7, 118.6-377.9 μg/100 g,respectively. Zeaxanthin level of those cooked foods changed to 483.9, 239. 3, 279. 1, 149. 5-594. 7 μg/100 g, respectively. The zeaxanthin level of cooked Chinese chive reached 1081.2 μg/100 g, while we did not detect any zeaxanthin in raw Chinese chive. β-carotene was present in a wide variety of vegetables and fruits. Carrot (17 234. 3 μg/100 g) was a good source of β-carotene,while its level in cooked carrot was 17 013.5 μg/100 g. Conclusion Consuming the proper kinds of foods and changing the method of food processing were beneficial to increase the intake of lutein, zeaxanthin and β-carotene.     

Hypocarotenemia After Bariatric Surgery: A Preliminary Study

Background  Dietary carotenoids have attracted a great deal of attention due to their potential clinical relevance in conditions such as age-related maculopathy, osteoporosis, cardiovascular disease, and cancer. Surgical procedures have become the primary treatment of severe obesity, although nutrient deficiencies are common and long-term metabolic sequelae remain unknown. Thus, our aim was to assess the carotenoid status in serum of subjects after obesity surgery. Methods  We evaluated the status of lutein, zeaxanthin, α- and β-cryptoxanthin, lycopene, α- and β-carotene, and fat-soluble vitamins by a quality-controlled high-performance liquid chromatography method in serum of 53 patients. Subjects were consecutively included as they were monitored for nutritional status after Roux-en-Y gastric bypass (RYGBP) or biliopancreatic diversion (BPD). Average follow-up time was 18 and 14 months for each protocol, respectively. Results  After obesity surgery, a consistent and continuous decline in all carotenoids to almost undetectable levels occurs, especially in those who underwent BPD diversion who, on average, displayed serum levels about one half to one third of those found in RYGBP patients. Conclusion  The hypocarotenemia observed after bariatric surgery may compromise the availability of carotenoids to tissues and the vitamin A status, reducing the fat-soluble antioxidant capacity and constituting an additional risk factor for several clinical conditions. Given the emerging role of carotenoids in disease prevention, dietary advice on carotenoid-rich and fortified foods or the use of supplements in these patients should be considered.