Dietary modulation of BALT on a rat mammary tumor model

Abstract

Murine bronchus associated lymphoid tissue (BALT) is a mirror of systemic immunity since it varies greatly with immune status of the animal and plays a pivotal role in local immune responses at the lung surface. BALT enhanced histopathology (EH) is a semiquantitative screening tool to determine whether there is a potential effect on the immune system of rats under controlled conditions.168 Sprague Dawley virgin female rats with 42 days were randomly distributed for seven groups of 24 animals each. Besides group I, at 55 days the groups were induced for mammary cancer with 20mg of 1,12‐dimetilbenzantracene (DMBA). Dietary protocols were applied for 150 days as following. Group I: standard diet (SD), 300Kcal/100g; Group II: DMBA +SD; Group III: SD + beans 40g/Kg of SD, 341Kcal/100g; Group IV: SD + olive oil (50ml/Kg of SD); Group V: fiber supplement 4× the SD, 250Kcal/100g; Group VI: fiber supplement 4× the SD + beans 19,95gr + olive oil 25ml on 1Kg of SD; Group VII: SD + mediterranean lyophilized diet (41Kcal). The animals were ethically euthanized and the lungs were routinely fixed and stained with hematoxylin‐eosin. BALT was evaluated by EH.The BALT morphology of tumoral rats with mediterranean diet and caloric restrain was similar to the BALT of control group. The other tumoral groups had decreased BALT in size and lymphocyte number compared to control group.These results suggest that diet can interfere on BALT morphology.