Zehra Hashim1, Shamshad Zarina. 1. Department of Biochemistry, University of Karachi, Karachi-75270, Pakistan.
Abstract
OBJECTIVE: To determine the role of free radicals and antioxidant enzymes in patients suffering from cataract due to aging and diabetes. DESIGN: Experimental study. PLACE AND DURATION OF STUDY: Department of Biochemistry, University of Karachi from December 2004 to May 2005. PATIENTS AND 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. CONCLUSION: 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.
OBJECTIVE: To determine the role of free radicals and antioxidant enzymes in patients suffering from cataract due to aging and diabetes. DESIGN: Experimental study. PLACE AND DURATION OF STUDY: Department of Biochemistry, University of Karachi from December 2004 to May 2005. PATIENTS AND METHODS: The study was conducted on 80 cataractpatients. 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 diabeticpatients as compared to senile subjects, CAT activities was also lower (p<0.001) in lenses from diabetic cataractpatients when compared to lenses from senile cataractous subjects. Lens MDA levels were significantly higher (p<0.001) in cataract lenses from diabeticpatients than in senile subjects. Plasma MDA levels were lowest (p<0.001) in controls as compared to senile and diabetic cataractouspatients. CONCLUSION: 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.