Post-initiation chemopreventive effects of dietary bovine lactoferrin on 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone-induced lung tumorigenesis in female A/J mice.

We investigated the effects of bovine LF (bLF) on different phases of NNK-induced lung tumorigenesis in A/J mice. Mice were orally administered 0.02, 0.2 and 2% bLF during the initiation phase, and 2% bLF during the whole tumorigenesis phase or post-initiation phase. Administered bLF during the post-initiation phase showed significant reduction of macroscopical lung nodules, and immunohistochemically decreased expression levels of cell proliferation marker and increased expression levels of apoptosis marker in lung proliferative lesions. bLF might inhibit NNK-induced mouse lung tumorigenesis, only when given limited to the post-initiation phase, through modification of cell proliferation and/or apoptosis.