Doxycycline blocks gastric ulcer by regulating matrix metalloproteinase-2 activity and oxidative stress

Figure 5 Effect of doxycycline on matrix metalloproteinase and tissue inhibitors of metalloproteinase activity and expression during protection against ethanol-treated gastric ulcer. Ulcers were induced in rat using 70% ethanol at low and high doses, and protection by doxycycline was performed. Casein zymography (A) was performed using phosphate buffered saline (PBS) extract of different gastric tissues. Histographic representation (B) of arbitrary activity of pro-matrix metalloproteinase (MMP)-3 as measured by Lab Image software using the above zymograms and two other representative zymograms from independent experiments. PBS extracts of gastric tissues from different experimental groups were subjected to Western blot blotting (C) and probed with polyclonal anti-MMP-9 and -3, tissue inhibitors of metalloproteinase (TIMP)-1 and -2, and anti-β-tubulin antibodies. Fold changes of proteins as represented below each band were measured by Lab Image software using the above wester blots and two other blots from independent experiments. Data expressed as mean ± SE. ^aP < 0.05 vs low-dose ethanol; ^dP < 0.01 vs high-dose ethanol. L.EtOH: Low dose ethanol; H.EtOH: High dose ethanol.