Cranberry ( Vaccinium macrocarpon ) flavonoids inhibit matrix metalloproteinases (MMPs) in human prostate cancer cells

Blueberry ( Vaccinium angustifolium ) flavonoid‐containing fractions have been shown to inhibit MMP activity (MMP‐2/‐9) in DU145 prostate cancer cells. This study examined the effect of a whole cranberry extract on MMP activity in DU145 cells. MMP‐2/‐9 activity was inhibited by this cranberry extract in a dose/time dependent manner. The effect of cranberry extract treatment on TIMP‐1/‐2 was also examined. TIMP‐1 protein levels increased in response to 1.0 mg/ml cranberry extract at 6 & 24h of treatment. TIMP‐2 protein levels increase when cells were treated with 0.1 mg/ml cranberry extract for 6h. RECK protein levels decrease in a dose dependent manner in response to cranberry. EMMPRIN protein levels decrease when cells were treated with 0.1 mg/ml cranberry extract for 6h and continue to decrease in response to increasing concentrations of cranberry extract. EMMPRIN protein levels decrease in a dose dependent manner when cells were treated with blueberry extract (24h). RECK protein levels apparently decrease in a dose‐dependent manner following 24h treatment with whole blueberry extract. This study suggests that cranberry (and blueberry) flavonoid‐containing extracts have the ability to modulate MMP‐2/‐9 activity in DU145 cells and to also affect the expression of a number of activities linked to MMP expression in cells. (ACOA‐Atlantic Innovation Fund‐2 & UMass Dartmouth Cranberry Research Program funded)