Rye-phytochemicals (benzoxazinoids) have shown suppressive effects on cancer cells in-vitro. In-vivo rye-enriched diets have shown to suppress prostate cancer development in human prostate cancer patients. To test a link between these observations a methodology was developed that could detect residual benzoxazinoids in peri-operative needle core biopsies and plasma and urine samples based on a pilot study including 10 newly diagnosed prostate cancer patients that followed a rye intensive diet for one week. In post-intervention plasma and urine samples 6 and 14 benzoxazinoids respectively were detected above LOD. The needle core biopsies presented a special challenge by their low concentrations and small sample sizes. However finally, seven benzoxazinoids were detected above LOD in the range of 0.15 to 10.59 pg/mg tissue. Biological samples like the present are liable to matrix effects, resulting in instrumental responses deviant from that of a corresponding standards in pure solvent, but also deviations in response between individual samples of same matrix type. A methodology was established for investigating both the general matrix effect and the variation in matrix effect between different samples of like matrix. For the low concentrations of the tissue and plasma samples the general matrix effect was concentration dependent in a non-linear manner as seen in Figure 1. For the high concentrations of the urine samples the general matrix effect was small, though a significant sample lot dependency was detected.

Testing for rye-phytochemicals in prostate tissue, plasma, and urine from prostate cancer patients

255th National Meeting (2018)

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