ABSTRACT
2-Nitropropane [2-NP] is an important industrial solvent and a component of cigarette smoke. It is mutagenic in bacteria and carcinogenic in rats.The liver is the target organ in 2-NP -treated rats. This study was conducted on 480 adult male and female albino rats to evaluate the genotoxic and hepatotoxic effects of 2-NP and to evaluate the protective role of alpha -tocophero L. The rats were divided into 8 groups equally. The 1[st] group: was used as a negative control group to measure the basic parameters; the 2[nd]. Group [positive control group]: Each rat was given 2 C.C. distilled water twice weekly by gavage for 12 weeks; the 3[rd] group: Each rat was given 2 C.C. corn oil daily by gavage for 13 weeks; the 4[th] group: Each rat was given; 2 C.C. corn oil containing alpha-tocopherol 100 mg/kg daily by gavage for 13 weeks; the 5[th] group: Each rat was given 2 C.C. distilled water containing 1/10 of the LD50 of 2-NP [50 mg/kg] twice weekly by gavage for 12 week.; the 6[th] group: Each rat was given alpha-tocopherol [100mg/kg] daily for 13 weeks and 2-NP [50 mg/kg] [started one week after the begining. of alpha-tocopherol] twice weekly by gavage for 12 weeks; the 7[th]. group: Each rat was given 2 C.C. distilled water containing 1/5 of the LD50 of 2-NP [l00mglkg] twice weekly by gavage for 12 weeks and the 8[th],. group: Each rat was given alpha-tocopherol [100mg/kg] daily for 13 weeks and 2-NP [I00 mg/kg] [started one week after the begining of alpha-tocopherol] twice weekly by gavage for 12 weeks. Every 4 weeks, 10 rats from each group were used for studying their chromosomal pattern and another 10 rats were used for histopathological and electron microscopical examination of the liver .Regarding cytogenetic study, 2-NP groups showed a significant increase in chromosomal aberrations when compared with the control group throughout the period of the study.The effect of 2-NP showed a progression that was time dependent but was not dose dependent. The frequencies of chromosomal aberrations induced in 2-NP + alpha-tocopherol groups were less than that induced in 2-NP groups indicating that, alpha-tocopherol has a partial protective effect against 2-NP genotoxicity. Regarding histopathological and electron microscopy study, 2-NP [50 mg/kg] group and [2-NP [50mg/kg] + alpha.-tocopherol] group showed mild toxic hepatitis allover the period of the study, meaning that alpha- tocopherol was not effective against toxic hepatitis induced by 2-NP [50mg/kg]. While in 2-NP [100mglkg] group, hepatic lesions started as mild dysplesia then hepatocellular carcinoma developed by the end of the study. In [2-NP [l00mg/kg] + alpha- tocopherol] group,hepatic histopathological and electron microscopical results of this group were improved when compared with 2-NP[l00mg/kg] group, meaning that alpha-tocopherol was partially effective in protection against hepatic carcinogenicity induced by 2-NP[100mg/kg]. It can be concluded that, 2-NP is genotoxic and hepatotoxic in albino rats and alpha-tocopherol has a partial protective effect against these toxicities