Diabetes Mellitus (DM) is a major public health concern and a common chronic metabolic disease worldwide. It is characterized by hyperglycaemia due to a total or relative lack of insulin secretion and insulin resistance or both. WHO has recently declared it to be a pandemic. The major concern in diabetes is increased oxidative stress. Therefore, dietary supplementation with antioxidants such as vitamins and flavonoids such as garlic and onion has been used in attempts to prevent the occurrence of many diabetic complications. So, the aim of this study was to assess the possible effect of onion...