Inhibition by Xiao‐chai‐hu‐tang (TJ‐9) of Development of Hepatic Foci Induced by N‐Nitrosomorpholine in Sprague‐Dawley Rats

The effect of Xiao‐chai‐hu‐tang (TJ‐9) on hepatocarcinogenesis induced by N‐nitrosomorpholine (NNM) was investigated in male Sprague‐Dawley rats. Rats were given normal chow pellets containing 0.5% or 1.0% TJ‐9 until the end of the experiment, and drinking water containing NNM for 8 weeks. Pre‐neoplastic and neoplastic lesions staining for γ‐glutamyl transpeptidase (GGT) or the placenta] type of glutathione‐S‐transferase (GST‐P) were examined histochemically. In Week 15, quantitative histological analysis showed that prolonged treatment with 0.5% TJ‐9 significantly reduced the number and volume of GGT‐positive and GST‐P‐positive hepatic lesions. Treatment with 1.0% TJ‐9 inhibited the development of GGT‐positive and GST‐P‐positive lesions, but was less effective than 0.5% TJ‐9. Administration of 0.5% TJ‐9 also caused a significant increase in the proportion of helper T lymphocytes and a significant decrease in the labeling index of pre‐neoplastic lesions. These findings indicate that TJ‐9 inhibits the development of hepatic foci.