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.

Identification of UV-Induced Diterpenes Including a New Diterpene Phytoalexin, Phytocassane F, from Rice Leaves by Complementary GC/MS and LC/MS Approaches.

Rice phytoalexins are regarded as one of the most important weapons against pathogenic microorganisms. We attempted to identify novel phytoalexins and their derivatives using GC/MS and LC/MS analyses. Diterpene derivatives, 9ß-pimara-7,15-diene-3ß,6ß,19-triol, 1, stemar-13-en-2α-ol, 2, and 1α,2α-dihydroxy-ent-12,15-cassadiene-3,11-dione, 3, were isolated from UV-irradiated rice leaves by chromatographic methods. These structures were confirmed by 1D- and 2D-NMR and MS analyses. Interestingly, all three compounds were accumulated following an infection by the rice blast pathogen Magnaporthe oryzae. Compounds 1 and 2 exhibited weak antifungal activity and may be the biosynthetic intermediates of rice phytoalexins momilactones and oryzalexin S, respectively. Compound 3 exhibited relatively high inhibitory activity against the fungal mycelial growth of M. oryzae to the same extent as the known phytoalexin phytocassane A. We conclude that 3 is a member of the cassane-type phytoalexin family and propose the name phytocassane F.

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.