ABSTRACT
AIM: The present study was designed to investigate the effect of red onion scales extract (ROS) against diabetic nephropathy, in relation to its metabolic profiling. METHODS: Four groups of male Wistar rats were assigned as follows; 1st untreated group, 2nd group (animals with diabetes) treated with streptozotocin (STZ, 50â¯mg/kg) IP, 3rd group co-treated with ROS (150â¯mg/kgâ¯+â¯STZ, 50â¯mg/kg) and 4th group co-treated with ROS by a dose (300â¯mg/kgâ¯+â¯STZ, 50â¯mg/kg) daily. After four weeks, random and fasting blood glucose (FBG) levels, serum insulin, advanced glycation end products (AGEs), urea, uric acid and inflammatory and fibrotic gene expression were evaluated. Moreover, histopathological examination of the renal tissues was performed. In addition, the metabolic profiling of ROS was performed via RP-HPLC-DAD-QTOF-MS and -MS/MS. RESULTS: The metabolic profiling of ROS revealed that protocatechuic acid and cyanidin-3-O-glucoside were the predominant compounds among 32 metabolites identified in the extract. ROS treated groups showed improvement of FBG and AGEs levels, whereas serum insulin level showed significant elevation. In addition, down-regulation of inflammatory mRNA expression associated with the hyperglycemic condition and amelioration in histopathological alterations in kidney tissues were observed. CONCLUSION: This study displayed the presence of 32 phenolic compounds in the ethanolic extract of ROS, a common by-product of the industrial production of onion in Egypt. This study proved the therapeutic potential of ROS as antidiabetic agent and its preventive effect against diabetic nephropathy. Therefore, this study represents a perspective of the utilization of food waste products.
