Evaluation of paraoxonase, arylesterase, and homocysteine thiolactonase activities in patients with diabetes and incipient diabetes nephropathy

SummaryBackgroundThe aim of this study is to examine the relationship among the changes in activities of paraoxonase (PON), arylesterase (ARE) and homocysteine thiolactonase (HTLase) enzyme having antioxidant properties and the development of diabetic nephropathy (DN), one of the most common complications of diabetes.MethodsNormoalbuminuric type-2 diabetic patients (Group II, n=100), microalbuminuric type 2 diabetic patients (Group III, n=100) and the control group (Group I, n=100) were included in the study. The age and gender of the patient groups matched with the age and gender of the control group. HTLase, PON and ARE enzyme activities were measured by the spectrophotometric method using a g-thiobutyrinolactone, paraoxon, and phenylacetate substrates respectively. In this study, an autoanalyzer application was developed in order to measure HTLase enzyme activity for the first time.ResultsSerum HTLase, ARE and PON activities of Group III and Group II were significantly low compared to HTLase, ARE and PON results of Group I (p<0.05).ConclusionsBased on our results, PON, ARE and HTLase enzyme activities were found to be decreased due to the increase in the degree of DN.

Protective Role of Dietary Curcumin in the Prevention of the Oxidative Stress Induced by Chronic Alcohol with respect to Hepatic Injury and Antiatherogenic Markers

Curcumin, an antioxidant compound found in Asian spices, was evaluated for its protective effects against ethanol-induced hepatosteatosis, liver injury, antiatherogenic markers, and antioxidant status in rats fed with Lieber-deCarli low menhaden (2.7% of total calories fromω-3 polyunsaturated fatty acids (PUFA)) and Lieber-deCarli high menhaden (13.8% of total calories fromω-3 PUFA) alcohol-liquid (5%) diets supplemented with or without curcumin (150 mg/kg/day) for 8 weeks. Treatment with curcumin protected against highω-3 PUFA and ethanol-induced hepatosteatosis and increase in liver injury markers, alanine aminotransferase, and aspartate aminotransferase. Curcumin upregulated paraoxonase 1 (PON1) mRNA and caused significant increase in serum PON1 and homocysteine thiolactonase activities as compared to highω-3 PUFA and ethanol group. Moreover, treatment with curcumin protected against ethanol-induced oxidative stress by increasing the antioxidant glutathione and decreasing the lipid peroxidation adduct 4-hydroxynonenal. These results strongly suggest that chronic ethanol in combination with highω-3 PUFA exacerbated hepatosteatosis and liver injury and adversely decreases antiatherogenic markers due to increased oxidative stress and depletion of glutathione. Curcumin supplementation significantly prevented these deleterious actions of chronic ethanol and highω-3 PUFA. Therefore, we conclude that curcumin may have therapeutic potential to protect against chronic alcohol-induced liver injury and atherosclerosis.