Influence of lactobacilus casei in rat bladder carcinogenesis

Abstract

The inhibitory effect of Lactobacillus casei (L. casei) in superficial bladder tumors was investigatedin an experimental study using N-butyl-N (4-hydroxybutyl) nitrosamine (BBN)-induced rat bladder cancer as an experimental system. The study consisted of two experiments; in a short-term experiment, the inhibitory effect of 6-week treatment withL. casei was assessed in vitro in terms of the capacity for agglutination by concanavalin A (Co A) of bladder epithelial cells in their incipient stage of malignant transformation induced by 1-week exposure to BBN. As a result, the number of bladder epithelial cell aggregates caused by Con A was significantly smaller in the L. casZ-treated group than in the non-L. casei-treated group (p<0.001). In a long-term experiment, treatment with L. casei of varying duration was investigated for effectiveness against bladder tumors induced by 7-weeks exposure to BBN that arose 22 weeks. The results indicate that both bladder weight and tumor volume per organ were significantly lower in the L. casei-trtdXeA than non-L. caseitreated group (p<0.05). The inhibitoryeffect on these parameters was more pronounced with treatment with L. caesi of longer duration. While there wasno significant difference among the treatment groups in the degree of extension of induced malignancy, tumors with a high degree of extension (Tib, T2) developed only in the non-L. casei-trtdXtA group. The degree of malignancy ofinduced tumors was significantly lower in those groups receiving L. casei while BBN was being administered as compared to the non-L. caseitreated group (P<0.05). These results clearly indicate a bladder carcinogenesis-suppressant effect of orally administered L. casei, suggesting clinical usefulness of this probioticpreparation. © 1994, THE JAPANESE UROLOGICAL ASSOCIATION. All rights reserved.