Serum paraoxonase activity and protein thiols in patients with hyperlipidemia

Objective: In the present study we evaluated the paraoxonase activity and protein thiols level in south Indian population with newly diagnosed hyperlipidemia.Methods: The study was conducted on 55 newly diagnosed hyperlipidemic patients and 57 healthy controls.Serum paraoxonase activity and protein thiols were estimated by spectrophotometeric method and lipid profile by enzymatic kinetic assay method.Results: Serum paraoxonase activity,protein thiols and high density lipoprotein levels were low and total cholesterol,triglycerides and low density lipoprotein levels were high in patients with hyperlipidemia compared to healthy controls(P<0.01).Serum paraoxonase activity correlated positively with protein thiols and high density lipoprotein(P<0.01).Conclusion: Decreased paraoxonase activity and protein thiols were found in patients with hyperlipidemia.This may indicate the susceptibility of this population to accelerated atherogenesis and protein oxidation.

Relationship between serum copper and protein thiols in hyperlipidemic patients

Objective:To measure serum copper and protein thiols along with lipid profile in hyperlipidemic patients and to establish the relationship between serum copper,protein thiols and lipid profile parameters.Methods: The study group consisted of 26 newly diagnosed hyperlipidemic patients not associated with any other systemic diseases and 26 age and sex matched healthy controls.Fasting lipid profile was done by enzymatic method using automated analyzer.Serum copper and protein thiols were measured spectrophotometrically.Results: Serum copper and protein-SH levels were significantly decreased in cases(P<0.01,P<0.01) compared to controls.Serum copper correlated positively with protein thiols(r=0.800,P<0.01) and negatively with LDL cholesterol(r=-0.351 P<0.05).Conclusion: Serum copper and protein thiols were decreased in hyperlipidemia and they correlated positively indicating protective role of copper in preventing homocysteinylation of protein and hence in preventing atherosclerosis.

Association of bilirubin and protein thiols in relation to copper and ceruloplasmin in hyperbilirubinemic patients

Objective:Bilirubin is a double edged sword in biological system,acting as a toxic molecule and cytoprotectant.Unconjugated bilirubin is proved to show antioxidant activity in vitro and in vivo.In the current work we tried to know the relationship between both conjugated and unconjugated bilirubin with copper and protein thiols in patients with hyperbilirubinemia.Methods:Study was conducted on 56 hyperbilirubinemic cases and 56 healthy controls.Serum copper,ceruloplasmin,protein thiols,total bilirubin,conjugated and unconjugated bilirubin,unconjugated bilirubin/albumin ratio,total protein,albumin,AST,ALT and ALP were estimated.Results:There was significant increase in serum copper,total bilirubin,conjugated and unconjugated bilirubin,unconjugated bilirubin/albumin ratio,AST,ALT,and ALP,and decrease in serum ceruloplasmin,protein thiols,total protein,and albumin in hyperbilirubinemic cases when compared to healthy controls.Conjugated bilirubin correlated positively with liver enzymes AST and ALP,and negatively with protein thiols,total protein and albumin.Unconjugated bilirubin correlated positively with ALT.Protein thiols correlated negatively with copper and positively with ceruloplasmin,and also correlated negatively with liver enzymes like AST,ALT and ALP,and positively with total protein and albumin.Conclusion:Combination of elevated levels of trace elements like copper and availability of reducing agent like bilirubin may prove deleterious by generating free radicals.