Assessment of paraoxonase activity and lipid peroxidation levels in diabetic and senile subjects suffering from cataract.
OBJECTIVE
The purpose of this study was to evaluate antioxidant effect of paraoxonase 1 activity and malondialdehyde (MDA) levels as a marker of oxidative stress in patients suffering from cataract due to diabetes and aging.


METHODS
One hundred cataract patients (senile and diabetic) and age- and sex-matched controls were studied. Paraoxonase 1 and arylesterase activities in plasma samples were measured using paraoxon and phenylacetate as substrates, respectively. The magnitude of lipid peroxidation was established by measuring plasma MDA and oxidized low-density lipoprotein (ox LDL) levels. One-way ANOVA was employed for analysis of results.


RESULTS
We observed significantly lower plasma paraoxonase and arylesterase activities in senile and diabetic cataractous patients as compared to respective controls (p<0.001). Plasma MDA and ox LDL levels were found to be higher in patients suffering from cataract (p<0.001).


CONCLUSIONS
The results of present study suggest that the observed decrease in PON1 activity may be due to increase in oxidative stress. It can be concluded that lower paraoxonase activity could contribute to the higher risk of cataract formation.
Hashim
Zehra
Z
Department of Biochemistry, University of Karachi, Karachi-75270, Pakistan.
Zarina
Shamshad
S
D000328:Adult; D000368:Aged; D000375:Aging / Q000097:blood*; D043303:Aryldialkylphosphatase / Q000097:blood*; D002265:Carboxylic Ester Hydrolases / Q000097:blood; D002386:Cataract / Q000097:blood / Q000201:enzymology* / Q000209:etiology; D002784:Cholesterol / Q000097:blood; D008076:Cholesterol, HDL / Q000097:blood; D008078:Cholesterol, LDL / Q000097:blood; D003924:Diabetes Mellitus, Type 2 / Q000201:enzymology*; D006801:Humans; D015227:Lipid Peroxidation / Q000502:physiology*; D008077:Lipoproteins, LDL / Q000097:blood; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D014280:Triglycerides / Q000097:blood
D008076:Cholesterol, HDL; D008078:Cholesterol, LDL; D008077:Lipoproteins, LDL; D014280:Triglycerides; C099252:oxidized low density lipoprotein; D008315:Malondialdehyde; D002784:Cholesterol; D002265:Carboxylic Ester Hydrolases; C019734:arylesterase; D043303:Aryldialkylphosphatase; C468406:PON1 protein, human