2.4. Experimental design
Mice were randomly classified into 3 groups (n=7 each) one group served as a control nondiabetic group and two groups were injected with streptozotocin (45mg/kg, intraperitoneally) to induce diabetes, then the three groups received their respective drug treatments daily for 16 consecutive weeks according to the following design:
• Group 1; control non-diabetic mice treated with distilled water orally and citrate buffer intraperitoneally.
• Group 2; nontreated induced diabetic mice.
• Group 3; induced diabetic mice treated with vitamin A (4- IU/ day orally) as suggested by (Beck and Spiegelberg, 1989). At 2nd and 16th weeks, the levels of fasting blood glucose, fasting insulin levels, lipid profile were examined. After 16 weeks, free radicals and antioxidants were examined.