Flavanols from Japanese quince (Chaenomeles japonica) fruit inhibit human prostate and breast cancer cell line invasiveness and cause favorable changes in Bax/Bcl-2 mRNA ratio.

Polyphenols are natural compounds of high structural diversity which translates into a very wide spectrum of biological activities, including chemoprevention. Here we report that a Japanese quince fruit flavanol preparation (JQFFP) caused favorable changes in Bax/Bcl-2 mRNA ratio, which rendered normal and cancer cells more resistant and more sensitive, respectively, to apoptosis. DU145 human prostate cancer cells were characterized by the most advantageous Bax/Bcl-2 ratio. The growth and invasiveness of MDA-MB-231 human breast cancer cells were strongly suppressed by JQFFP, which was accompanied with a decrease in MMP-9 activity and stimulation of TIMP-1 expression. Importantly, JQFFP did not decrease normal human prostate PNT1A cell number, whereas Bax/Bcl-2 ratio decreased which implies increased resistance to apoptosis. In conclusion, JQFFP exhibited a potent antiproliferative effect against cancer cells, inhibited their invasiveness, and decreased expression level of several genes involved in apoptosis, angiogenesis, and metastasis.