Role of Mitochondrial Oxidative Stress in Sepsis

Mitochondria are considered the power house of the cell and are an essential part of the cellular infrastructure, serving as the primary site for adenosine triphosphate production via oxidative phosphorylation. These organelles also release reactive oxygen species (ROS), which are normal byproducts of metabolism at physiological levels; however, overproduction of ROS under pathophysiological conditions is considered part of a disease process, as in sepsis. The inflammatory response inherent in sepsis initiates changes in normal mitochondrial functions that may result in organ damage. There is a complex system of interacting antioxidant defenses that normally function to combat oxidative stress and prevent damage to the mitochondria. It is widely accepted that oxidative stress-mediated injury plays an important role in the development of organ failure; however, conclusive evidence of any beneficial effect of systemic antioxidant supplementation in patients with sepsis and organ dysfunction is lacking. Nevertheless, it has been suggested that antioxidant therapy delivered specifically to the mitochondria may be useful.