Changes in Antioxidant Enzyme Activity and Malondialdehyde Level in Patients with Age-Related Macular Degeneration

Yıldırım, Özlem; Ateş, Nurcan Aras; Tamer, Lülüfer; Muşlu, Necati; Ercan, Bahadır; Atik, Uğur; Kanık, Arzu

doi:10.1159/000076845

Cited by 42 publications

(32 citation statements)

References 21 publications

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“…Age-related decreases in the capacity of antioxidant systems have been found to be more pronounced in patients with AMD compared with controls [27][28][29] . Increased lipid peroxidation in serum samples from AMD patients is consistent with previous reports [30,31] . The high PUFA content of photoreceptor membranes particularly expose the retina to increased risk of lipid peroxidation by the unopposed action of free radicals [32] .…”

Section: Discussionsupporting

confidence: 92%

Serum Paraoxonase 1 Activity and Lipid Peroxidation Levels in Patients with Age-Related Macular Degeneration

Başkol¹,

Karaküçük

Öner

et al. 2005

Ophthalmologica

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Our objective was to investigate antioxidant paraoxonase 1 (PON1) activity together with malondialdehyde (MDA) levels to evaluate oxidative stress in patients with age-related macular degeneration (AMD), an important cause of blindness in the elderly population. Serum PON1 activity and MDA levels were analyzed in 37 patients with AMD and compared with 29 healthy controls using a spectrophotometric method. Serum MDA levels were significantly higher in the patient group (2.76 ± 1.28 nmol/ml) than controls (1.00 ± 0.36 nmol/ml; p < 0.001), whereas PON1 activity was lower in the patient group (132.27 ± 63.39 U/l) than controls (312.13 ± 136.23 U/l; p < 0.001). There was a negative correlation between MDA and PON1 levels (r = –0.470, p < 0.001). We conclude that the observed increase in MDA levels may be related to decreased PON1 activity; the present data also demonstrated that an obvious negative correlation between PON1 activity and MDA levels exists in patients with AMD. PON1 is also an antioxidant agent, therefore effective antioxidant therapy to inhibit lipid peroxidation is necessary and agents to increase PON1 activity may be a therapeutic option in AMD.

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Section: Discussionsupporting

confidence: 92%

Serum Paraoxonase 1 Activity and Lipid Peroxidation Levels in Patients with Age-Related Macular Degeneration

Başkol¹,

Karaküçük

Öner

et al. 2005

Ophthalmologica

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“…27 The multicentre, double-blind cross-sectional study reported by Everklioglu et al has shown that late ARMD patients had significantly lower antioxidant enzyme levels and higher MDA levels when compared with early ARMD patients, which may reflect the levels of the various antioxidants including GSH. 16 Therefore, grouping of the patients based on the clinical picture seems to be crucial before arriving at conclusions.…”

Section: Discussionmentioning

confidence: 99%

Plasma homocysteine and total thiol content in patients with exudative age-related macular degeneration

Coral

Raman

Rathi

et al. 2005

Eye

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Purpose Exudative age-related macular degeneration (ARMD) is one of the debilitating ocular complications, which results in permanent blindness. Elevated homocysteine (Hcys) levels have been associated in the development of several vascular diseases. Vascular and oxidative stress theories have been implicated for the development of choroidal neovascularization in exudative ARMD. The aim of the present study was to investigate the possible role of plasma Hcys and thiol content (tSH) as a risk factor for the development of exudative ARMD. Method A total of 16 patients with exudative ARMD and 20 age-matched controls were recruited for the study. Plasma Hcys levels were analysed using Reverse Phase High Performance Liquid Chromatography. Plasma glutathione (GSH) content was determined using o-phthalaldehyde (OPA) derivatization and subsequent detection by fluorimeter. Plasma tSH levels were determined by using thiol-specific reagent dithionitrobenzoic acid (DTNB) spectrophotometrically. Results Plasma Hcys levels in exudative ARMD were elevated three-fold (1875.0 lM) when compared to healthy controls (6.771.8 lM). There was a two-fold decrease in the GSH and tSH in exudative ARMD when compared with controls. Negative correlation was observed between diminished tSH and Hcys levels (r ¼ À0.4837, P ¼ 0.05). Similarly plasma Hcys levels negatively correlated with GSH content (r ¼ À0.6620, Po0.05). Conclusion Results from our present study revealed that there is an elevated Hcys level and diminished thiol pool content in exudative ARMD that are significant.

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“…Studies have also demonstrated that H 2 O 2 treated TM cell cultures show reduced amounts of glutathione. The plasma of patients with primary open angle glaucoma (POAG) has shown lower levels of glutathione and higher levels of the lipid peroxidation product malondialdehyde [50,51].…”

Section: Glaucoma and Oxidative Stressmentioning

confidence: 99%

Neuroprotection in Glaucoma Using Calpain-1 Inhibitors: Regional Differences in Calpain-1 Activity in the Trabecular Meshwork, Optic Nerve and Implications for Therapeutics

Govindarajan

Laird

Sherman

et al. 2008

CNSNDDT

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Glaucoma is a group of irreversible blinding eye diseases affecting over 70 million people worldwide. Systemic delivery of calpain-1 inhibitors was proposed as a neuroprotection strategy for the prevention of progressive optic nerve damage in glaucoma. We present a general review of calpain-1 and an account of vast differences in processing of calpain-1 in the trabecular meshwork (TM) and the optic nerve. Calpain-1 accumulates in the glaucomatous TM tissues in vivo. However, calpain-1 activity is substantially lower in the glaucomatous TM compared to controls, apparently owing to partial degradation, and modification by lipid oxidation products such as iso[4]levuglandin E2 (iso [4]LGE 2 ). Treatment of calpain-1 with iso [4]LGE 2 in vitro results in covalent modification, inactivation, and resistance to protease digestion. iso [4]LGE 2 -modified calpain-1 appeared to undergo ubiquitination in the TM by cellular degradation machinery mediated by ubch1-2, ubch5,6 and E6-AP, E2 and E3 enzymes respectively. In the TM, iso [4]LGE 2 -modified calpain-1 loading impairs the cellular proteasome activity consistent with competitive inhibition and formation of suicidal high molecular weight aggregates. In contrast, higher calpain-1 activity, that appears to be under translational control, was observed in glaucomatous optic nerve compared to control. Therapeutic neuroprotection strategies using calpain-1 inhibitors will require consideration of such anatomic differences in its activity and biosynthesis.

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Changes in Antioxidant Enzyme Activity and Malondialdehyde Level in Patients with Age-Related Macular Degeneration

Cited by 42 publications

References 21 publications

Serum Paraoxonase 1 Activity and Lipid Peroxidation Levels in Patients with Age-Related Macular Degeneration

Serum Paraoxonase 1 Activity and Lipid Peroxidation Levels in Patients with Age-Related Macular Degeneration

Plasma homocysteine and total thiol content in patients with exudative age-related macular degeneration

Neuroprotection in Glaucoma Using Calpain-1 Inhibitors: Regional Differences in Calpain-1 Activity in the Trabecular Meshwork, Optic Nerve and Implications for Therapeutics

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