Effects of bolesatine on a cell line from the SP2/O thymic lymphosarcoma.

Bolesatine, a toxic protein isolated from Boletus satanas Lenz inhibits in vitro protein synthesis in a concentration-dependent manner in a cell line from a radiation-induced thymic lymphosarcoma (SP2/O) with a 50% inhibitory concentration (IC50) of 9.5 nM (0.6 microgram/ml). In vivo, an i.p. single injection of bolesatine, corresponding to 1/6 and 1/10 of 24-h 50% lethal dose, in Balb/c mice having ascitic tumour induced by the i.p. preinjection of SP2/O cells allows a remission of 50% and 30%, respectively. Treated mice survived 120 days after the treatment, i.e. 90 days after the death of control animals.