[Protective effects of trichosanthin in Herpes simplex virus-1 encephalitis in mice]

Trichosanthin (TCS), a ribosome-inactivating protein extracted from the root tuber of Chinese medicinal herb Trichosanthes kirilowii maximowicz, has various pharmacological properties including abortifacient, anti-tumor and anti-virus. This study aimed to evaluate the effects of TCS on infectious brain injury induced by Herpes simplex virus-1 (HSV-1) in mice.

Ninety mice were randomly assigned into three groups: Normal control group (n=30), Model group (n=30) and TCS-treated group (n=30). Viral encephalitis was induced by intracranial inoculation of HSV-1 in the latter two groups. The TCS-treated group was injected with TCS 30 minutes before HSV-1 inoculation. The water content of brain tissue was measured at 1, 12, 24 and 48 hrs, and at 4 and 7 days after HSV-1 inoculation. The viral titer of brain tissue and brain histopathological changes were detected at 7 days after HSV-1 inoculation. The neurological deficient scores were determined daily.

The water content of brain tissue in the TCS-treated group between 48 hrs and 7 days after HSV-1 inoculation was significantly lower than that in the Model group (P < 0.05), although it was significantly higher than that in the Normal control group (P < 0.05). The viral titer of brain tissue in the TCS-treated group was markedly lower than that in the Model group (1.16 +/- 0.45 vs 2.89 +/- 0.44; P < 0.05) 7 days after HSV-1 inoculation. The neurological deficient scores of the TCS-treated group after 24 hrs of HSV-1 inoculation were significantly lower than that in the Model group but were higher than those of the Normal control group. TCS treatment resulted in alleviated pathological changes of brain tissue compared with the Model group 7 days after HSV-1 inoculation.

TCS has protective effects against infectious brain injury induced by HSV-1 in mice.