Histopathological Effects of Multiwall Carbon Nanotubes on Rat Liver

Application of carbon nanotubes in medicine may bring about toxicity of these compounds. In the present study, the effects of carbon nanotubes were studied on liver tissue through creating oxidative stress. In this experimental study, concentrations of 10 and 20mg/kg of multiwall carbon nanotubes functionalized with carboxyl groups (10-20nm), were intraperitoneally injected into male rats in 21 stages and the control group received normal saline. Blood sampling and animal dissection were performed in two stages (24hours and 144hours after the last injection). Histological sections were prepared from the liver by hematoxylin-eosin staining and examined by optical microscopy. The concentration of thiol groups and malondialdehyde were measured and analyzed using one way ANOVA test. Histological studies revealed disorders, such as hyperemia in the centrilobular vein, accumulation of inflammatory cells, abnormalities of sinusoids and vacuolation of hepatocytes, which were significantly higher with the dose of 20mg/kg and 144 hours after the treatment compared to the other groups. In the first blood collection, the plasma levels of thiol groups significantly increased with the dose of 10mg/kg (p<0.05) compared to other groups and in the second stage, the level of malondialdehyde showed a significant increase in both doses compared to the control group (p<0.05). Carbon nanotubes probably cause liver tissue disorder by aggregation and binding to various cellular components in the liver and creating oxidative stress; but, given the lack of mortality in animals, these disorders may decrease over time.