Antioxidant activity of pomegranate juice reduces acute lung injury secondary to hyperoxia in an animal model

BACKGROUND: Hyperoxia triggers the release of toxic reactive oxygen species (ROS). Pomegranate Juice (PJ) is a rich source of potent antioxidants. We assessed the effects of PJ supplementation on Acute Lung Injury (ALI) in adult rats exposed to hyperoxia for 5 days. METHODS: Adult rats were divided into four different groups: control, hyperoxia, hyperoxia + PJ and PJ. Animals were placed in chambers containing either room air or oxygen above 95% for a total of 5 days. Two different PJ concentrations were utilized and the control group received placebo water. Animals were euthanized and their lungs were excised. Assessment of lung injury was accomplished by: a) wet to dry ratio (W/D) method, b) measurement of albumin concentration in the bronchoalveolar lavage fluid (BALF), c) oxidative stress, d) histological evaluation of the lung e) apoptosis and f) transcriptional expression levels of the inflammatory mediators IL-1β, IL-6 and TNF-alpha. RESULTS: An increase in the W/D and albumin leak was noted in Hyperoxia (p < 0.05). Those findings were attenuated by the higher dose of PJ supplementation. Hyperoxia increased ROS production. Again PJ significantly reduced oxidative stress. Lung sections showed significant reduction in inflammation, edema, and infiltrating neutrophils in Hyperoxia + 80 μmol/kg when compared with Hyperoxia. TUNEL demonstrated significant apoptosis in the Hyperoxia, which was diminished in the Hyperoxia + 80 μmol/kg. Furthermore, increase in IL-1β and IL-6 was noted in Hyperoxia. Again, 80 μmol/kg of PJ significantly reduced the expression of inflammatory mediators. CONCLUSION: In this animal model, PJ supplementation attenuated ALI associated with hyperoxia.