Changes in Aqueous Humor Lutein Levels of Patients with Cataracts after a 6-Week Course of Lutein-Containing Antioxidant Supplementation.

PURPOSE: Oxidative damage is known to be an important cause of age-related cataracts and it has been suggested that administration of antioxidants, such as lutein, may delay the onset and progression of cataracts. Our previous investigation of human aqueous humor after the intake of a lutein-containing supplement demonstrated decreases in peroxidative products. This study evaluated the transportation of lutein into aqueous humor which is an important factor when measuring the antioxidant effects of lutein on the lens. METHODS: This study enrolled 155 patients with binocular cataracts of the same grade. Serum and aqueous humor samples were collected during cataract surgery before (as pre-intake samples) and after 6 weeks of oral intake of Ocuvite + Lutein® (as post-intake samples). Lutein levels were measured with high-performance liquid chromatography. RESULTS: Lutein levels in both the serum and aqueous humor were significantly higher in the post-intake than the pre-intake samples. There were significant increases in the lutein levels in patients with lower pre-intake lutein serum levels. There was also a tendency for greater increases in patients with lower pre-intake aqueous humor lutein levels. CONCLUSIONS: These results demonstrate that oral lutein supplementation increases lutein levels, which further induce decreases in peroxidation in the aqueous humor. Furthermore, lutein supplementation may be more effective in patients with lower serum lutein levels.

Changes in Macular Pigment Optical Density among Pseudophakic Patients following Intake of a Lutein-Containing Supplement.

INTRODUCTION: Cataract surgery has been reported as a long-term risk of reduced macular pigment optical density (MPOD). This study investigated changes in MPOD in pseudophakic patients after lutein supplementation. METHODS: Fifty-seven patients who had no ocular diseases and underwent cataract surgery with concurrent implantation of clear intraocular lenses were included. MPOD was measured before lutein supplementation and every week during 6 weeks of supplementation. Two additional measurements were conducted after the end of supplementation. RESULTS: Compared with baseline, MPOD was increased after 1 week of supplementation (p < 0.01) and remained elevated after cessation of supplementation. After 3 weeks of supplementation, MPOD in females was higher than that in males (p < 0.05). Compared with patients at the highest quintile baseline MPOD, patients of both genders at the lowest quintile had significant increases after 6 weeks of supplementation (p < 0.05). CONCLUSION: MPOD increased after lutein supplementation in patients who had undergone cataract surgery. With the same amount of lutein supplementation, MPOD increased more in patients with low MPOD at baseline; it also increased more in females than in males. Lutein supplementation is presumed to support increased MPOD, which can reduce the risk of age-related macular degeneration, especially in females with low MPOD.

Gender differences in mRNA expression of aquaporin 8 and glutathione peroxidase in cataractous lens following intake of an antioxidant supplement.

Antioxidants can decrease oxidative damage and prevent age-related ocular disease. Our previous investigation on human aqueous humor following intake of a lutein-containing antioxidant supplement reported an increase in the scavenging activity of superoxide in both genders and an increase in the amount of hydrogen peroxide (H2O2) in females. Aquaporin 8 (AQP8) is a diffusion facilitator of H2O2 and glutathione peroxidase (Gpx) is a H2O2 scavenging enzyme. The correlation between AQP8 and Gpx may be the key to determining how oxidative stress in the aqueous humor affects the lens after intake of antioxidant supplements. In this study, 24 patients with the same grade of binocular cataract were included. Anterior capsule samples, including lens epithelial cells (LECs), were collected during cataract surgery before (as pre-intake samples) and after 6 weeks of oral intake of Ocuvite Lutein ® (as post-intake samples). The mRNA expression of APQ8 and Gpx was measured using real-time polymerase chain reaction. Among males, AQP8 expression decreased significantly after the supplementation (P = .03), while there was no statistical change among females. AQP8 expression was significantly correlated to that of Gpx in post-intake samples among females (R = 0.69, P = .02), while no correlation was evident among males. The results suggest antioxidant supplementation may work by different mechanisms on LECs between genders. After supplementation, a decrease in AQP8 in LECs may inhibit the influx of H2O2 from the aqueous humor in males. In females however, the correlation between AQP8 and Gpx in LECs may indicate an increase in Gpx activity following the influx of H2O2 from the aqueous humor and further scavenging of H2O2.

The gender-differentiated antioxidant effects of a lutein-containing supplement in the aqueous humor of patients with senile cataracts.

Antioxidant supplements are expected to decrease oxidative damage and prevent ocular diseases. In this study, changes in the anti-oxidative ability and oxidative status in the aqueous humor before and after intake of a lutein-containing supplement were measured. Forty patients who all had identical grades of cataracts in both eyes were included. The aqueous humor was collected as pre-intake samples during cataract surgery. Ocuvite + Lutein(Ⓡ), an antioxidant supplement, was administered orally beginning the day after surgery. Six weeks later, the aqueous humor was collected as a post-intake sample during cataract surgery of the opposite eye. To determine the anti-oxidative ability, the levels of superoxide (O2(*-)) scavenging activity were measured. To determine the oxidative status, the levels of hydrogen peroxide (H2O2) and total amount of hydroperoxides (TH, including H2O2 and peroxides of lipids, proteins, and nucleic acids) were measured. In post-intake samples, the O2(*-) scavenging activities were significantly higher in both genders (p < 0.05). The levels of H2O2 were significantly higher (p < 0.01) while the levels of TH were significantly lower (p < 0.01) only in females. The level of H2O2 was significantly negatively correlated to the TH in the post-intake samples of both genders (r = -0.50 and p < 0.05 for males; r = -0.59 and p < 0.01 for females) while the level of H2O2 was significantly positively correlated to the O2(*-) scavenging activity in both pre- and post-intake aqueous humor in females only (r = 0.66 and p < 0.01 for pre-intake samples, r = 0.71 and p < 0.01 for post-intake samples). After the introduction of the antioxidant supplement, O2(*-) scavenging activity increased while H2O2 levels remained the same in males, suggesting that scavenging rates are proportional. In postmenopausal females, the superoxide scavenging activity also increased, however unlike in males, the H2O2 levels also increased meaning H2O2 was not completely scavenged. H2O2 is a non-free radical and can be excreted from the aqueous humor to prevent further oxidation of lipids, proteins, and nucleic acids, which was confirmed by the low levels of TH in post-intake samples. Antioxidant supplements are suggested to be effective in reducing oxidation in the aqueous humor by different mechanisms in both genders.

Effects of antioxidant supplementation on mRNA expression of glucose-6-phosphate dehydrogenase, ß-actin and 18S rRNA in the anterior capsule of the lens in cataract patients.

This was a preliminary study of the effects of antioxidant supplementation on the peroxidation status of the lens by investigating mRNA expression of anti-oxidative enzymes in the lens. The mRNA expression levels of glucose-6-phosphate dehydrogenase (G6PDH), ß-actin (ß-ACT) and 18S rRNA (18S) were measured in this study because they are common reference genes for measuring mRNA levels by means of a real-time reverse transcription polymerase chain reaction (RT-PCR) in various tissues. Thirteen patients with binocular cataracts of the same grade were included in the study after giving informed consent. A piece of the anterior capsule, along with a sample of lenticular epithelial cells (LECs), was collected as a pre-intake sample during cataract surgery. Ocuvite + Lutein(®), an antioxidant supplement, was administered orally beginning the day after surgery. Six weeks later, a piece of the anterior capsule along with a sample of LECs, was collected as a post-intake sample during cataract surgery of the opposite eye. RNA was purified from the homogenized samples, and cDNA was reverse transcribed to measure mRNA levels. The expression levels of G6PDH, 18S and ß-ACT were measured using RT-PCR. The expression levels of G6PDH and 18S were significantly higher in the post-intake samples than they were in the pre-intake samples. Significant positive correlations between the expression levels of G6PDH and 18S were observed in both the pre- and post-intake samples. Following gender-specific analyses, the expression levels of G6PDH and 18S in the post-intake samples were found to be significantly higher among the female patients. A significant positive correlation between the expression levels of G6PDH and 18S was observed in the post-intake samples from the male patients. There were no significant changes in the gene expression levels of ß-ACT after supplementation among male or female patients. ß-ACT has been verified for use as a reference gene for measuring the effects of antioxidant supplementation in the lens by RT-PCR. Antioxidant supplementation was noted to increase G6PDH in the pentose phosphate cycle and 18S rRNA in the ribosome.