Liver catalase activity. A significant reduction in the activity of catalase was observed in the liver tissue of the CCl4-intoxicated experimental animals. Transplantation of UCMSCs both alone and after CCl4 administration, increased catalase activity compared to respective control groups. The injection of oil alone did not influence catalase activity. Values represent median, negative and positive error bars represent Q1 and Q3, respectively. * Mann Whitney U test vs. PBS group; # Mann Whitney U test vs. CCl4 group * or # p < 0.05; **p < 0.01; ### p < 0.001.