ABSTRACT
This study dealt with the histopathological changes in the lungs, liver, small intestine, muscles, kidneys and brain of mice experimentally infected with Toxascaris leonina. Larvae were found on the 8th dpi (day post infection) in the liver. Also, they observed on the 4th dpi in the small intestine, 8th dpi in lungs, but it could not be seen in both kidneys and brain. In muscles, the larvae were detected after one week of infection. The histopathological changes were observed in the form of infiltration with lymphocytes, eosinophils, with few areas of hemorrhages indicating the migratory pathway of the larvae. Moreover, the main features in the portal spaces in the lungs were the presence of edema, hemorrhages and diffuse infiltration of alveolar wall which appeared thickened as a result of interstitial edema and vascular congestion.
The histopathological results were in high accordance with the biochemical results. At 10th dpi, there were significant rises in the parameters of oxidative damage to lungs with the highest extent (lipid peroxidation LPO, nitric oxide NO and total peroxides TP) followed by muscles (LPO) and liver (NO). Also, some antioxidants in infected mice showed significant decrease in liver (catalase activity) and muscles (glutathione, GSH). Kidneys did not show any biochemical change. It could be concluded that Toxascaris leonina infection induces histopathological changes and oxidative damage to some organs of mice especially the lungs, muscles and small intestine. Also, these changes may reflect the direct relationship between the severity of infection with larvae and the degree of oxidative damage.