Why do chronic wounds repair so slowly? Blame a toxic healing environment, new study results assert.

Investigators inhibited two antioxidant enzymes — glutathione peroxidase and catalase — in an effort to get some answers. Specifically, they wanted to identify the central role of reactive oxygen species (ROS) in the maintenance of chronic wound infections. 

While these enzymes help maintain normal tissue levels of ROS, they also can be harmful. For example, the amount of ROS in wounds increased and the biofilm strengthened when they were inhibited. Excessive ROS-induced chronic inflammation, combined with biofilm, results in a toxic environment that can delay or even prevent wound healing.

Study results also showed the two antioxidant enzymes were more damaging if they were inhibited in combination. 

The researchers, based out of the University of California-Riverside, also found that if they applied vitamin E and N-Acetyl cysteine, the activities of glutathione peroxidase and catalase were restored, ROS levels decreased and the bacterial biofilm disintegrated in the wound. In other words, wound tissue was healthier and healing was more likely.