Antisera are used as effective antidotes against the local effects of
snake bites. To improve
antisera production and extend the life of surrogates used to produce
antibodies, the chronic effects of
venom toxicity must be reduced. The present study evaluated the effectiveness of gamma irradiation to reduce the local effects associated with viperid
snake bites by evaluating in NMRI mice the toxicity and edematic, hemorrhagic, and myonecrotic activities of native and irradiated Cerastes cerastes
venoms. These results indicated that the toxicity of irradiated
venoms (1 and 2 kGy) decreased as compared with that of native
venom. The edematic and hemorrhagic activities were also reduced in the detoxified samples, particularly with the 2-kGy radiation dose. Furthermore, the
creatine phosphokinase (CPK) activity was significantly increased in the serum and decreased in the myocardium after envenomation with native
venom, but no significant enzymatic changes were observed in mice envenomated with irradiated
venom. Histopathologic evaluation showed that native
venom caused severe degenerative changes in the myocardium. In the case of 2-kGy-irradiated
venom, no tissue alterations were observed. These results indicate that irradiation of
venom with a 2-kGy dose may offer an effective method for reducing the chronic toxic effects of
venom in immunized animals.