Comparative Efficacy of Zinc and Vitamin A on Alloxan and N-Alkyl Alloxan Induced Toxicity in Adult Male Albino Rats

Background: Diabetes has been associated with several complications occasioned by oxidative stress. High levels of free radicles lead to damage of cellular organelles and enzymes. Aim of the study: The aim of this work was to assess the beneficial effect of zinc or vitamin A (vit. A) on alloxan or N-alkyl (N-A.) alloxan induced toxicity. Materials and Methods: 110 male adult albino rats were used in this study and were divided into 11 equal groups, 10 rats each. GI: The negative control group, GII: Saline group, GIII: Corn oil group, GIV: Zinc chloride group, GV: Vit. A group, GVI:  Alloxan group, GVII: NA. alloxan group, GVIII: Alloxan-zinc group, GIX: Alloxan-vit. A group while groups X and XI were N-A. alloxan-zinc and N.A. alloxan-vit. A groups respectively. Oxidative stress markers [superoxide dismutase (SOD), reduced glutathione (GSH) and malondialdehyde (MDA)] concentrations were measured in addition to blood glucose and glycosylated hemoglobin (Hb) levels as well as liver enzymes as alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Lipid profile [total cholesterol (TC), triglycerides (TG), high density lipoproteins (HDLP) and low density lipoproteins (LDLP)] was also assessed. Semen analysis including sperm motility and count was evaluated. Furthermore, histopathological examination of the liver and pancreas was carried out. Results: Alloxan or N-alkyl alloxan led to diabetes (hyperglycaemia and increased glycosylated Hb levels). There was also decrease in the levels of SOD and GSH with increase of MDA level. Considering ALT and AST concentrations, there was significant increase of both enzymes. Hyperlipidaemia was also evident in the form of increased total cholesterol, TG and LDLP levels with reduction of HDLP level. Nevertheless, semen analysis showed significant reduction both in number and motility of sperms. Histopathological examination of both the liver and the pancreas showed severe changes in both hepatic and pancreatic architecture after alloxan or N-A. alloxan (being more toxic) intake. Zinc supplementation caused a favorable protective effect with normalization of almost all the biochemical parameters as well as improvement of the histopathological changes. Vit. A also protected against alloxan or N-A. alloxan induced toxicity but was less effective than zinc. Conclusion: Zinc is more effective than vit. A. in protecting against alloxan or N-A. alloxan induced toxicity not only on the pancreatic tissue but also on other tissues as the liver.