Forskning

October 7, 2011

High molecular weight coffee melanoidins are inhibitors for matrix metalloproteases

L M De Marco et al, High molecular weight coffee melanoidins are inhibitors for matrix metalloproteases, Journal of Agricultural and Food Chemistry, 2011, published online ahead of print.

ABSTRACT:

High-molecular (above 10 kDa) melanoidins isolated from coffee beans of varying roasting degree were found to be efficient inhibitors for the zinc-containing matrix metalloproteases MMP-1, MMP-2 and MMP-9 with IC50 values ranging 0.2 and 1.1 mg/ml in vitro. Inhibitory potential increased with roasting degree. No or only slight inhibition of other zinc-containing peptidases closely related to MMPs, namely Clostridium histolyticum collagenase and angiotensin converting enzyme, was found, indicating specific structural features of melanoidins to be responsible for the interaction with MMPs. A continuous increase on the apparent molecular weight of melanoidins as well as incorporation of phenolic substances into the melanoidin structure with progress of roasting was observed, concomitant with a significant increase in the carbon/nitrogen of the melanoidins. This suggests that the melanoidins are mainly formed by incorporation of carbohydrates and phenolic compounds onto a proteinaceous backbone. As MMP-1, MMP-2 and MMP-9 play a pivotal role in pathogenesis of colorectal cancer, studies on possible physiological effects of melanoidins are mandatory.