[Protective effect of bicyclol on concanavalin A-induced liver nuclear DNA injury in mice]

To study the protective effect of bicyclol on concanavalin A (Con A) induced liver nuclear DNA injury in mice.

Bicyclol was fed into the stomachs of 32 mice. Then Con A was injected into their caudal veins. Six, twelve, twenty-four, and forty-eight hours after the injection, 8 mice were killed at each time point and their blood and livers were taken to be tested. Serum alanine aminotransferase (ALT), and nuclear DNA fragmentation, DNA ladder, H2O2 level, and sensitivity of nuclear DNA to oxidative damage by CuSO4-ortho-phenanthrolin-vitamin C-H2O2 system in hepatocytes of mice were determined. The protective effect on damage of pure DNA by CuSO4-ortho-phenanthrolin-vitamin C-H2O2 system was determined in vitro too. Eight mice were injected with Con A only as normal controls. Nine mice were injected with Con A only as Con A controls.

In the experimental groups, six hours after the injection of Con A, the serum ALT level increased significantly (P < 0.05), reached the peak after 12 hours (P < 0.01), and then decreased. The liver nuclear DNA fragmentation increased 12 hours after injection of Con A in the Con A control group. However, the liver nuclear DNA fragmentation was significantly less in bicyclol groups (P < 0.05 and P < 0.01). The percentage of DNA ladder in the 150 mg/kg bicyclol group was 25%, significantly lower than that in Con A control group (100%). The H2O2 level in liver was significantly increased 12 hours after injection of Con A in the Con A control group, and remained normal in the 150 mg/kg bicyclol group. The Con A-induced decrease of sensitivity of liver nuclear DNA to damage by CuSO4-ortho-phenanthrolin-vitamin C-H2O2 system was counteracted by bicyclol injection.

Bicyclol is significantly effective in protecting liver from nuclear DNA injury of hepatocytes induced by Con A in mice.