Effects of Dietary fat on benz-a-pyrene-induced forestomach tumorigenesis in mice chronically exposed to arsenic.

SILVA, RA; MUÑOZ, SE; PEREZ, CA; EYNARD, AR

EXPERIMENTAL AND TOXICOLOGIC PATHOLOGY

Urban and Fisher. Elsevier

Año: 2000 vol. 52 p. 11 - 16

0940-2993

The modulating effect of As (AsrO,) in drinking water plus dietary fatty acids on benzo-a-pyrene (BP) induced forestomach tumorigenesis was assayed in mice fed with corn oil (CO). Olein (O), palmstearin (PS) and cod liver oil (CLO) enriched formulae and a mixed-fat (S-stock) diet  during 28 weeks.  Neither pre-or neoplastic lesions were recorded in esophagus or fore stomach of mice treated with As alone. CLO diet showed a protective effect.  Indeed,  multiple epidermal hyperplasia were significantly reduced compared to S group and a reduction in papillomas multiplicity with respect to S. CO and O groups was also observed Mice fed on PS formula showed minor papillomas per mouse with respect to CO and O. These results indicate that As plus BkP did not exhibit any synergistic effect on the development of epidermoid tumor lesions, whereas CI, O diet exerted antipromoting activity . In spite of their common essential fatty acid deficiency ( EFAD) condition, PS and O lots showed contradictory results. Hence, the dietary enrichment in 18:1 n-9 (O diet) per se, and not the EFAD state, may play a deleterious role. Corn diet showed no promoting activity on the epiderrnoid tumor development in this model