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

Abstract

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.

Decreased Serum Paraoxonase 1 Activity and Increased Serum Homocysteine and Malondialdehyde Levels in Age-Related Macular Degeneration

“…In the study by Baskol et al (2006), PON1 activity was lower in the patients with nonexudative-type AMD than in the controls. In another study, Ikeda et al (2001) reported that the paraoxonase gene polymorphisms might be a possible genetic risk factor for exudative-type AMD.…”

“…PON1 has been shown to neutralize the harmful effects of lipid peroxides by diminishing covalent linkages between lipid peroxidation products and LDL protein, as well as the accumulating lipid peroxides in LDL (Harangi et al 2008). Baskol et al (2006) concluded that the increased ROS levels might cause increased lipid peroxidation, and thus, result in decreased antioxidant PON1 activity and increased MDA levels. They also determined a significant negative correlation between MDA and PON1 activities in the patient group.…”

Comparative efficacy of captopril and allylmercaptocaptopril in the maintenance of oxidative-antioxidative equilibrium and attenuation of selenite-induced cataract in rats

“…PON1 catalyzes the breakdown of organophosphates (Jakubowski, 2000;Josse et al, 2001) and also hydrolyzes homocysteine thio-lactone, which can harm some proteins by homocysteinylation. Reduced PON1 activities have been reported in cardiovascular diseases (McElveen et al, 1986;Navab et al, 1997), diabetes mellitus (Abbott et al, 1995;Mackness et al, 1998;Sakai et al, 1998), chronic renal failure (Dantoine et al, 1998), rheumatoid arthritis (Baskol et al, 2005), hyperthyroidism (Raiszadeh et al, 2004), age-related macular degeneration (Baskol et al, 2006) and in cataract (Hashim and Zarina, 2007).…”

Serum PON1 arylesterase activity in relation to hyperhomocysteinaemia and oxidative stress in young adult central retinal venous occlusion patients

“…Thus, a strong correlation between PON1 levels and TBARS seems to be associated with the pathology of CRVO. Baskol et al 15 observed an increase in MDA levels related to decreased PON1 activity in patients with age-related macular degeneration.…”

“…14 The PON1 enzyme, which has been implicated in the pathogenesis of atherosclerosis, has not been studied in the context of RVO diseases, although a decreased PON1 activity correlating negatively with malondialdehyde (MDA) levels that evaluates oxidative stress has been reported in patients with age-related macular degeneration. 15 Serum PON1 is also one of the endogenous free-radical scavenging systems in the human body. Serum PON1, together with ARE, has been demonstrated to function as a single enzyme.…”