Association of Apelin, Chemerin and Omentin Levels with Oxidative Stress Markers in Non-Diabetic and Induced Diabetic Rats

Abstract 
    Oxidative stress has a significant impact on the etiology of type 1 diabetes mellitus (T1DM). However, associations of adipokines with oxidative stress biomarkers have yet to be investigated. Therefore, the present study aimed to investigate the estimation of serum apelin, chemerin, and omentin levels in induced TIDM and their correlations with oxidative stress markers. The study included sixty male albino rats divided into two groups. The first group (n = 30) was diabetic (TIDM induced with an intraperitoneal injection of 40mg/kg STZ). The non-diabetic control group was the second (n: 30). The enzyme-linked immunosorbent (ELISA) test was used to quantify the serum levels of apelin, chemerin, omentin and asymmetric dimethylarginine (ADMA). Furthermore, blood glucose, lipid profile triglyceride (TG), cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL), very low-density lipoprotein (VLDL), liver enzymes (alanine aminotransferase (ALT) and aspartate transaminase (AST)), malondialdehyde (MDA) and nitric oxide (NO) parameters were evaluated. Rats with induced TIDM had significantly higher serum levels of apelin, chemerin, omentin, malondialdehyde MDA, ADMA, and NO compared to non-diabetics. According to the coefficient of correlation analysis, the results revealed a positive association between apelin and LDL, ALT, and MDA and a negative correlation between apelin and AST: ALT.  In addition, no correlation was found between apelin and serum levels of glucose, cholesterol, HDL, LDL: HDL TG, TG: HDL, VLDL, AST, creatinine, uric acid, albumin, NO, and ADMA. LDL, ALT, and MDA. Serum chemerin level correlated positively with LD: HDL and ADMA. Also, the plasma level of omentin showed a significant and positive correlation with both TG: HDL and MDA values. In conclusion, the results of this study introduced apelin and chemerin as potential biomarkers for the early detection of diabetes. Elevated serum apelin levels in induced T1DM could provide compensatory action for low insulin levels. While, apelin, chemerin and omentin’s positive correlations with MDA level suggest the potential roles of these adipokines in diabetes-induced complications caused by oxidative stress.