Study of immune cells involved in the antitumor effect of kefir in a murine breast cancer model

DE MORENO DE LEBLANC, ALEJANDRA; MATAR, CHANTAL; FARNWORTH, EDWARD; PERDIGON, GABRIELA

JOURNAL OF DAIRY SCIENCE

Año: 2007 vol. 90 p. 1920 - 1928

0022-0302

The administration of kefir and kefir cell-free fraction (KF) to mice injected with breast tumour cells produced, locally in the mammary glands, different profiles of cells secreting cytokines. Here, the immune cell populations in mammary glands affected by the cyclic consumption, during 2 or 7 days, of kefir or KF were evaluated using the breast tumour model. Apoptosis was also assayed as another mechanism involved in  tumour growth delay. Rate of tumour development, IgA(+) cells, CD4+ and CD8+ T lymphocytes were monitored in mammary gland tissues. The number of Bcl-2(+) cells in mammary glands was compared with the apoptosis observed in the tumour. Two day-cyclical administration of both products delayed tumour growth and increased IgA(+) cells in mammary glands. Changes in the balance between CD4+ and CD8+ cells in mammary glands were observed in mice from the group fed 2 days cyclically with KF; CD4+ cell numbers increased when CD8+ cells number remained constant. Mice that received 2 day-cyclic administration of KF showed significant increases in the number of apoptotic cells and decreases for Bcl-2 positive cells in mammary glands, compared to the tumour control group. The present study allowed us to better understand the mechanisms (immune and non-immune) involved in the antitumour effect observed in mice administered kefir or KF. The importance of non-microbial components released during milk fermentation to obtain the antitumour beneficial effects were also reported.