Lactoferrin Protects Hyperoxia-Induced Lung and Kidney Systemic Inflammation in an In Vivo Imaging Model of NF-κB/Luciferase Transgenic Mice

Purpose: High levels of oxygen are usually used in ventilatory support and extracorporeal membrane oxygenation (ECMO) in the intensive care unit of hospitals. Hyperoxia may induce the production of reactive oxygen species (ROS) that can cause lung damage and even systemic injury. In this study, the NF-κB/luciferase transgenic mouse model with non-invasive real-time in vivo imaging was established to test the functions of lactoferrin (LF) in antioxidant and anti-inflammation.

Procedures: The NF-κB/luciferase transgenic mice were used to assess the effects of oral administration of LF on attenuation of the systemic inflammatory response and organ damage after 72 h of hyperoxia (FiO > 95 %) exposure via monitoring using an in vivo imaging system (IVIS).

Results: Using luciferase IVIS imaging, we found that the lungs and kidneys were the most evidently affected organs after hyperoxia treatment. The groups treated with low dose (150 mg/kg) or high dose (300 mg/kg) of LF had lower luciferase expression and less injury, with a dose-dependent effect on the lungs and kidneys. Moreover, ROS, mitogen-activated protein kinases (MAPK), and pro-inflammatory cytokine (TNF-α, IL-1ß, and IL-6) expression levels were all significantly decreased (P < 0.01), and the protein level of IκB was statistically increased (P < 0.01) after LF treatment.

Conclusions: Our results suggest that hyperoxia can induce systemic inflammation, and the oral administration of LF as a natural antioxidant decreases the production of ROS, attenuates inflammation, and lessens kidney and lung injuries from hyperoxia via the use of live image monitoring of the response in NF-kB/luciferase transgenic mice.