Abstract: Objective To investigate the antitumor activity of tannin part of Phyllanthi fructus on S180 and H22 tumor-bearing mice. Methods The ICR mice were divided into control group, model group, tannin part of Phyllanthi fructus low (0.5 g·kg^-1, the equivalent of crude drug 3.64 g·kg^-1), medium (1.0 g·kg^-1, the equivalent of crude drug 7.27 g·kg^-1), high (2.0 g·kg^-1, the equivalent of crude drug 14.54 g·kg^-1) dose group, a separate cyclopho-sphamide group. After continuous intragastric administered 10 d(S180) and 12 d(H22), the tumor inhibition rate, thymus index and spleen index were calculated respectively. Results The tumor inhibition rate of low, medium and high dose groups of tannin part of Phyllanthi fructus on S180 tumor-bearing mice were 16.52%,40.08% (P<0.05),56.19%(P <0.01), on H22 tumor-bearing mice were 18.36%, 34.01% (P <0.05), 51.02% P <0.01). Compared to the model group, thymus index and spleen index of all tannin part of Phyllanthi fructus treated groups were not significantly different(P>0.05). Conclusion Intragastric administration of tannin part of Phyllanthi fructus significantly inhibited the tumor growth in the tumor-bearing mice in a dose-dependent manner. No obvious changes were detected in immune organs in the trial groups.

Key words: Phyllanthi fructus, tannin part, sarcoma S180, hepatic carcinoma H22, thymus and lienal index