UC San Diego

The level of Matrix Metalloproteinases (MMPs) in whole blood has been investigated, with an emphasis on the effect of certain MMP inhibitors. A synthetically derived charge changing substrate, which has a cleavage site specific to enzymes MMP-2 and MMP-9, was used for detection. Presence of these enzymes was tested both with and without inhibitors, first in a buffer solution, and then in whole blood. The blood was taken from insulin resistant volunteers at different time points after the consumption of a meal rich in protein and fat. The volunteers were part of a twelve-week study performed to assess the change in levels of MMPs in the blood after being on a low-glycemic index diet. The presence of these enzymes in blood was assessed by reacting the blood with the synthetic substrate for a fixed period of time, and then using PAGE (polyacrylamide gel electrophoresis). After electrophoresis, the gel was imaged and enzyme levels quantified using a fluorescent detector. The gels were analyzed for intensity of fluorescence, which had a direct correlation with the amount of the MMP-2/9 present. Results indicated that there were slight changes in the levels of these enzymes after the 12-week period. However, the various MMP inhibitors such as grape seed extract (GSE), and doxycycline showed a definite decrease in enzyme activity, after reacting these inhibitors in whole blood in reaction tubes