extremely significantp < 0.01
All statistical analyses were carried out using SPSS statistical package 12.0 (SPSS Inc, Chicago, IL, USA) to determine whether the treatments of results were significant (* p < 0.05) or extremely significant (** p < 0.01 and *** p < 0.001) different from the control groups without 4-NP. 3 Results 3.1 Body and liver weight At the beginning of the experiment, rats from different groups showed approximately similar body weight values.