[Efficacy of a preparation based on Lactobacillus acidophilus for protection from myelotoxic effects of ionizing radiation and antineoplastic cytostatics].

The ability of a Lactobacillus acidophilius (LA) based preparation to prevent from a myelotoxic damage was studied on (CBA.C57BL/6)F1 mice upon total gamma-irradiation or single intraperitoneal injection of cyclophosphan. The antitumor and antimetastatic activity of LA-based preparation was studied in experiments with C57BL/6 mice bearing Lewis lung carcinoma or melanoma B16. The preparation obtained from heat-killed Lactobacillus acidophilius species provides protection of hemopoietic stem cells, as evidenced by the amount of endogenous CFUs increased 3.4-6.7 times. The LA-based preparation favored accelerated overcoming the radiation- and cyclophosphan-induced leukopenia. At the same time, the drug did not affect the proliferative activity and apoptosis of tumor cells, their growth rate, and metastatic activity. Nor did it reduce the efficacy of the experimental tumor radiotherapy.