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

Figure 7 H₂O₂ scavanging activity of doxycycline. A: Gelatin zymography of phosphate buffered saline (PBS) extract from control gastric tissue was incubated with H₂O₂ (500 mmol/L) at 37°C for 1 h. Equal amounts of PBS extract were pretreated with doxycycline (200 μmol/L) before incubation with H₂O₂. In one lane (Cat, lane 4), the extract was pretreated with catalase before reaction with H₂O₂; B: Histographic representation of pro-matrix metalloproteinase (MMP)-2 and MMP-2 activities as measured by Lab Image software using the above zymograms and two other representative zymograms from independent experiments. Veh: Vehicle; Cat: Catalase. Data expressed as mean ± SE. ^bP < 0.01, ^dP < 0.001 vs control; ^eP < 0.05, ^fP < 0.01 vs vehicle.