Abstract
Background: Pesticides are developed for welfare of human beings, though they impose and challenge our existence by their long-term toxicity. Organophosphates such as diazinon contain phosphorus and derivatives of phosphoric acids.

Aims and Objectives: To evaluate the toxic effects of diazinon in separate lower doses on hepatotoxicity and possible ameliorative properties of vitamin E on diazinon-induced alterations on biochemical and histological parameters on liver functions.

Materials and Methods: Toxic effects of diazinon, dose levels 0 mg, 6 mg, 7.5 mg, and 10 mg/kg body weight daily orally for 30 days and ameliorative effect of vitamin E (2 mg) on diazinon-induced biochemical and histological alterations were investigated in Wistar albino male rats. The serum was used to evaluate the level of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), cholesterol, triglyceride, total protein, albumin, and malondialdehyde (MDA). Liver paraffin sections were cut into 5 µm thickness and stained with hematoxylin and eosin for light microscopic examination.

Results: Diazinon resulted in an increase in MDA level significantly, decrease in albumin, total protein, cholesterol levels, and rise in AST and ALT levels. LDH and ALP levels were elevated significantly (p < 0.001). Hepatocytes showed pyknotic changes in nucleus, ballooning degeneration (fatty changes), periportal inflammation and Kupffer cells hyperplasia in diazinon-treated groups. Pretreatment of the rats with vitamin E showed an insignificant protection in diazinon-induced liver damage.

Conclusion: In conclusion, this study suggests that diazinon induces hepatotoxicity in low doses and vitamin E partly ameliorates biochemical and histological alterations induced by diazinon.

Key words: Diazinon, hepatotoxicity, vitamin E, rats, liver histology