Antioxidant markers in human senile and diabetic cataractous lenses.
OBJECTIVE
To determine the role of free radicals and antioxidant enzymes in patients suffering from cataract due to aging and diabetes.


METHODS
Experimental study.


METHODS
Department of Biochemistry, University of Karachi from December 2004 to May 2005.


METHODS
The study was conducted on 80 cataract patients. Lens and plasma samples from senile and diabetic subjects suffering from cataract were analyzed and activity of Cu, Zn-superoxide dismutase (Cu, Zn-SOD) was measured using xanthine oxidase system. Catalase (CAT) activity was estimated. Levels of malondialdehyde (MDA) was measured by thiobarbituric acid reaction. Student's t- test was employed for analysis of results.


RESULTS
Significant difference (p<0.001) was found in activity of Cu, Zn-SOD in cataract lenses from diabetic patients as compared to senile subjects, CAT activities was also lower (p<0.001) in lenses from diabetic cataract patients when compared to lenses from senile cataractous subjects. Lens MDA levels were significantly higher (p<0.001) in cataract lenses from diabetic patients than in senile subjects. Plasma MDA levels were lowest (p<0.001) in controls as compared to senile and diabetic cataractous patients.


CONCLUSIONS
Results of present study suggest that increased production of high levels of free oxygen species is linked to glucose oxidation and non-enzymatic glycation of proteins. Furthermore, elevated glucose levels might be involved in the insufficiency of antioxidant enzymatic activity and in the progression of lipid peroxidation.
Hashim
Zehra
Z
Department of Biochemistry, University of Karachi, Karachi-75270, Pakistan.
Zarina
Shamshad
S
D000368:Aged; D000975:Antioxidants / Q000032:analysis*; D002386:Cataract / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000150:complications*; D005260:Female; D017127:Glycation End Products, Advanced / Q000097:blood; D006801:Humans; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D018384:Oxidative Stress / Q000502:physiology; D017392:Thiobarbituric Acid Reactive Substances
D000975:Antioxidants; D017127:Glycation End Products, Advanced; D017392:Thiobarbituric Acid Reactive Substances; D008315:Malondialdehyde