[Effect of modified ricin on the reduction of hepatotoxicity in mice].

Objective: To observe the significance of ricin (RT) with chemical nidification to reduce the hepatotoxicity in mice and its anticancer effect.
Methods: Mice were exposed to RT and RT-PDP [ricin chemically modified by N-succinimidyl 3-(2-pyridyldithio)-propionate, (SPDP)] respectively, and their serum activity of glutathione-S-transferase (GST) and liver glutathione (GSH) content were determined. The ultramicro-structure under electron microscope was also observed.
Results: The GST activity increased with doses, and the increase in ricin group was higher than that in RT-PDP group; the activities of GST in RT group at 12.5, 15.0 micro g/kg [(93.65 +/- 12.30), (153.71 +/- 26.64) IU/L respectively] were higher than those in RT-PDP group [(62.97 +/- 11.22), (78.20 +/- 15.71) IU/L] (P < 0.05). The contents of GSH were decreased with doses; but the contents of GSH in RT-PDP group at 2.5, 5.0, 7.5, 10.0, 15.0 micro g/kg [(6.34 +/- 1.43), (4.14 +/- 1.82), (3.54 +/- 0.64), (2.73 +/- 1.82), (1.82 +/- 0.62) micro mol/L respectively] were still higher than those in RT group [(3.53 +/- 0.95), (2.12 +/- 0.54), (1.82 +/- 0.71), (1.52 +/- 0.34), (0.81 +/- 0.36) micro mol/L] (P < 0.01). Electron microscopic examination showed that the injury of liver cells in RT group was more severe than that in RT-PDP group.
Conclusion: The hepatotoxicity of ricin in mice may be reduced by chemical modification.