PHYTOMILK

Bioactive components in organic milk with suggested health beneficial effects

The milk samples that will be collected from the Nordic countries in the project will represent a repository of milk samples collected from cows at different breed and lactation- and pregnancy stages, and from cows fed rations high in clover, grass, birdsfoot trefoil, corn etc. This repository of complex mixtures containing naturally occurring bioactive components is suitable for studies of cellular effects of bioactive components with suggested health beneficial importance. In vitro cell-based models will be used for assessing the biological activity in specific human tissues. Relevant cell-based models include normal- and cancer cell lines of gastro-intestinal, mammary or prostate origin exposed to different concentrations of milk samples or specific bioactives for different time-intervals. Cellular endpoints such as proliferation, viability and apoptosis as well as estrogenic or anti-estrogenic activity of milk will be evaluated. Milk samples having the ability to inhibit proliferation of human breast, prostate and intestinal cancer cells will receive a high priority. The milk samples for testing will be selected mainly based on the content of bioactive components. 

Progress of work 

Status for analyses of phytoestrogens and bioactive components in organic milk with suggested health effects:

Analyses of Phytoestrogens: Relevant milk samples collected from the Nordic countries will be analysed for phytoestrogens as described previously (Steinshamn et al., 2008). Phytoestrogens will include both isoflavones and lignans including equol, daidzein, genestein, formononetin, courmestrol, prunetin, biochanin A, seco, mata, enterodiol and enterolactone. Analyses have not yet started.

Bioactive components in organic milk: Based on the content of bioactive components like fatty acids and phytoestrogens, milk samples collected from the Nordic countries in the project will be studied in in vitro cell-based models to assess the biological activity in specific human tissues. Human colon cancer cells (HT-29), human prostate cancer cells (PC-3) and human breast cancer cells (MCF-7) have been selected from our portfolio of cell-based models to study effects of different concentrations of milk samples on cell viability and apoptosis (HT-29 and PC-3) and estrogenic/anti-estrogenic activity (MCF-7). Furthermore, an assay with human breast cancer cells (Mvln) is currently being developed to study estrogen-receptor activation by milk components. At the moment, 64 milk samples from the grazing experiment APC-UMP in Norway are being tested for estrogenic/anti-estrogenic activity in breast cancer cells. These samples were prepared by centrifugation and precipitation of casein, and are being tested in concentrations of 1.25, 2.5, 5 and 10% in cell culture medium. As soon as milk samples from other studies from the Nordic countries have been analysed for bioactive components, selected samples will be tested in the cell-based models.

Bioactivity

Analysis of phyto-oestrogenes.