Flavanols from Japanese quince (Chaenomeles japonica) fruit suppress expression of cyclooxygenase-2, metalloproteinase-9, and nuclear factor-kappaB in human colon cancer cells

Natural polyphenols and polyphenol-rich extracts have been found to possess preventive and therapeutic potential against several types of cancers, including colorectal cancer (CRC), which is an example of an inflammation-associated cancer. The study examines the chemopreventive effect of a Japanese quince (Chaenomeles japonica) fruit flavanol preparation (JQFFP) in colon cancer SW-480 cells. JQFFP, rich in procyanidin monomers and oligomers, was found to inhibit SW-480 cell viability by 40% compared to control at 150 µM catechin equivalents (CE) for 72 h incubation, but it was non-toxic to normal colon fibroblast CCD-18Co cells. Furthermore, 100 µM CE JQFFP suppressed COX-2 mRNA expression to 36.7% of control values and protein expression to 77%. In addition, JQFFP reduced MMP-9 protein expression (to 24% vs. control at 100 µM CE) and caused inhibition of its enzymatic activity (to 35% vs. control at 100 µM CE). Not only did JQFFP inhibit COX-2 and MMP-9 levels, but it also reduced NF-κB protein expression (to 65% of control) and phosphorylation of its p65 subunit (to 51%) for 100 µM CE. These results provide the first evidence that JQFFP inhibits COX-2, MMP-9, and  NF-κB expression, which may suggest it has cytotoxic, anti-inflammatory, and anti-metastatic activities towards colon cancer SW-480 cells.