Systemic redox modifications in senile cataract.

UNLABELLED: Recent studies on cataract formation focus on a primary role of systemic oxidative stress, generated outside the lens. Plasma inflammatory markers are associated with senile cataract. OBJECTIVE: The aim of this study was to find correlations between blood oxidative stress markers and some inflammatory plasma markers in cataractous patients. DESIGN AND METHODS: The blood samples were collected from 38 patients (aged 50 to 80). Patients were subdivided according to two criteria. Considering age criteria, presenile and senile cataract groups were formed. According to the absence or presence of other ocular comorbidities (age-related macular degeneration, glaucoma), pure cataract and nonpure cataract groups were constituted. Fifteen age and sex matched healthy subjects were selected for the control group. RESULTS: In our study, for all groups of patients, the measured markers of oxidative stress were modified vs. control values. Plasma antioxidant capacity, plasma antioxidant "gap", cholesterol and albumin/globulin levels were significantly decreased while RBC SOD activity, RBC catalase activity and plasma ceruloplasmin were significantly increased. Inflammatory markers, ceruloplasmin and albumin/globulins were correlated with different parameters of oxidative stress. CONCLUSION: The blood redox values and the level of some inflammatory markers demonstrate that senile cataract is a systemic disease with an inflammatory component.

Plasma redox status and premature onset of senile cataract.

UNLABELLED: Dysfunction of the lens due to opacification is called cataract. Senile cataract is associated with old age. It is estimated that the need for cataract extractions would be diminished by half if onset of cataract would be delayed by only ten years. It thus appears crucial to have a better characterization of the etiology of cataract to detect modifiable factors. It seems that oxidative stress may play an important role in cataractogenesis. Also, it was demonstrated that some plasma constituents correlate with human cataract location. OBJECTIVE: We supposed that in senile cataract the oxidative insult may be systemic and not only at the lens level. The aim of our study was to evaluate the blood redox status in cataractous patients aged between 50-65. DESIGN AND METHODS: The blood samples were collected from 15 patients with pure nuclear cataract and/or posterior subcapsular cataract, without metabolic or somatic diseases and from 15 age and sex matched controls. Carbonyl content of plasma proteins was evaluated with 2,4-dinitro-phenyl-hydrazine method. The a-oxoaldehydes were measured in the presence of Girard T reactive. The lipid peroxides concentration was assessed measuring malondialdehyde concentration using thiobarbituric acid. For the other plasma parameters we used kits. RESULTS: The levels of plasma protein carbonyls and malondialdehyde were significantly increased in the cataract group. The plasma levels of: total proteins, globulins, total thiols, fasting glucose, triglycerides and alpha-oxoaldehydes were not modified comparing the groups. Plasma concentrations of albumin and cholesterol were significantly decreased. CONCLUSION: The study underlies the presence of an increased plasma oxidative stress in cataractous patients. The abnormal oxidative stress parameters are linked to the premature development of senile cataract. Preventive therapy in order to delay the onset of senile cataract requires more research work on plasma oxidative stress markers.

The effect of fasting on the parameters of the antioxidant defence system in the blood of vegetarian human subjects.

OBJECTIVES: Although the evidence is strong that fasting has anti-tumor, anti-inflammatory and anti-ageing actions, the mechanisms responsible for these phenomena are still unclear. An ameliorated antioxidative defence with fasting may be the cause of such effects. The objective of the present work was to determine the influence of fasting on antioxidant systems in healthy young vegetarian humans. DESIGN AND METHODS: We measured Trolox Equivalents Antioxidant Capacity (TEAC) of plasma, erythrocytes superoxide dismutase (SOD) activity, blood glutathione peroxidase (GPx) activity, level of total blood non-proteic thiols (TBNT), plasma ceruloplasmin activity, plasma level of NO metabolites (the sum of nitrites and nitrates, NOx), in 18 healthy young humans (age 20-27 years) after 12h (overnight fasting) and 80h of fasting. RESULTS: Trolox Equivalents Antioxidant Capacity of plasma, the level of total blood nonproteic thiols, plasma ceruloplasmin activity and plasma concentration of nitrites and nitrates were significantly increased after 80h of fasting. Superoxide dismutase activity and glutathione peroxidase activity were lower after 80h of fasting. CONCLUSIONS: Our results suggest that fasting induces the "reorganisation" of antioxidative defence lines: fasting increases especially plasma protective systems (total antioxidant capacity of plasma, plasma ceruloplasmin activity) and decreases an erythrocytes antioxidant enyzme (superoxide dismutase) and blood glutathione peroxidase.