Effect of Lipoic Acid on Serum Paraoxonase-1 and Paraoxonase-3 Protein Levels and Activities in Diabetic Rats

Abstract

The aim of the present study was to investigate the effect of streptozotocin-induced diabetes mellitus and lipoic acid treatment on serum paraoxonase-1 and paraoxonase-3 protein levels and paraoxonase, arylesterase and lactonase activities.36 rats were equally and randomly divided into 4 groups as control, lipoic acid, diabetes and diabetes+lipoic acid. To induce diabetes, a single dose of streptozotocin (40 mg/kg) was injected intraperitoneally to diabetes and diabetes+lipoic acid groups. Lipoic acid (10 mg/kg/day) was injected intraperitoneally for 14 days to lipoic acid and diabetes+lipoic acid groups. Serum PON1 and PON3 protein levels were measured by western blotting. Serum paraoxonase, arylesterase and lactonase activities were determined by the measuring initial rate of substrate (paraoxon, phenylacetate and dihydrocoumarin) hydrolysis.Streptozotocin-induced diabetes mellitus caused a significant decrease whereas lipoic acid treatment caused a significant increase in serum PON1 and PON3 protein levels and paraoxonase, arylesterase and lactonase activities. The increase percent of serum PON3 protein was higher than that of serum PON1 protein and the increase percent of serum lactonase activity was higher than that of serum paraoxonase and arylesterase activities in diabetes+lipoic acid group.We can report that, like PON1 protein, PON3 protein and actually its lactonase activity may also have a role as an antioxidant in diabetes mellitus and lipoic acid treatment may be useful for the prevention of the atherosclerotic complications of diabetes by increasing serum PON1 and PON3 protein levels and serum enzyme activities.

Effect of lipoic acid on paraoxonase-1 and paraoxonase-3 protein levels, mRNA expression and arylesterase activity in liver hepatoma cells

“…In our study 200 μM lipoic acid caused a significant increase on both PON3 protein level and mRNA expression. This finding indicates that lipoic acid induces PON3 gene expression and supports our previous study which showed that lipoic acid increases serum PON3 protein levels and the increase percent of serum PON3 protein is higher than that of serum PON1 protein in lipoic acid-treated diabetic rats (Ozgun et al 2016).…”

“…In our previous study, we reported that lipoic acid prevents an increase in lipid peroxidation of the liver; therefore it has protective effects against to hepatic ischemia/reperfusion injury in rats (Ozgun et al 2014). In another study, we also reported that lipoic acid treatment causes an increase in serum PON1 and PON3 protein levels and enzyme activities in diabetic rats (Ozgun et al 2016). Despite several previous reports on the effects of lipoic acid on paraoxonase enzymes protein and activity, no study has ever been performed to specifically examine the effect of lipoic acid on PON1 and PON3 mRNA expression.…”

The effect of lipoic acid in the prevention of myocardial infarction in diabetic rats

“…LA has direct and indirect antioxidant properties and has been proposed as a potent antioxidant for the treatment of DM and its complications (19,20). In our previous study, we showed that LA increased serum PON activities and decreased serum lipid peroxidation in experimental diabetes (18).…”

“…PON enzymes have different activities toward different substrates, but their primary activity is lactanose activity (14). It has been shown that serum PON enzyme activities are decreased in both myocardial infarction (15,16) and diabetes (17,18).…”

Serum Paraoxonase-1 Levels are Significantly Decreased in the Presence of Insulin Resistance

“…PON1 arylesterase activity was found to be an independent predictor of myeloperoxidase levels in general or when studied separately in the subgroups with or without cardiovascular complications [17]. In addition it has been shown that in experimental animals diabetes causes a significant decrease whereas lipoic acid treatment caused a significant increase in serum PON1 levels [18]. PON1 levels were not different between patients with acromegaly and controls despite elevated oxidative stress and increased prolidase activity in acromegaly patients [19].…”