Effect of Astaxanthin on High Mobility Group Box-1(HMGB-1) Expression, Histopathological Differences, and Arterial Oxygen Partial Pressure in Lung Contusion Model

Abstract

Background: Lung contusion is a frequent outcome of chest trauma and contributes substantially to morbidity and mortality, primarily through the development of acute respiratory distress syndrome (ARDS) and related inflammatory processes. High Mobility Group Box-1 (HMGB-1) is recognized as an essential mediator involved in the late phase of inflammation during lung injury. Astaxanthin, a potent antioxidant and anti-inflammatory carotenoid, has shown therapeutic potential in various inflammatory conditions. This study aimed to investigate the effects of astaxanthin administration on HMGB-1 expression, histopathological changes, and arterial partial pressure of oxygen (PaO2) in an experimental rat model of lung contusion.
Methods: A controlled experimental study was conducted on adult female Sprague-Dawley rats. Lung contusion was induced using a standardized weight-drop method. The rats were randomly divided into groups: a normal group (no contusion, no treatment), a control group (contusion without treatment), and treatment groups receiving fixed doses of astaxanthin after contusion. HMGB-1 mRNA expression in lung tissue was measured using real-time PCR. Lung tissues were examined histopathologically to assess alveolar edema and leukocyte infiltration using a semi-quantitative scoring system. Arterial blood gas analysis was performed to evaluate PaO2 levels at specific time points after injury.
Results: Astaxanthin treatment significantly reduced HMGB-1 mRNA expression in lung tissue compared to the untreated contusion group (p < 0.05). Histopathological evaluation showed a notable decrease in alveolar edema and leukocyte infiltration in groups receiving astaxanthin (p < 0.05). In addition, PaO2 levels improved significantly with astaxanthin treatment, indicating enhanced oxygenation (p < 0.05). A dose-dependent response was observed, with higher doses providing greater protective effects in several parameters.
Conclusion: Astaxanthin administration demonstrates significant therapeutic benefits in an experimental model of lung contusion by downregulating HMGB-1 expression, mitigating lung histopathological damage and improving arterial oxygenation. These findings suggest that astaxanthin holds promise as a potential adjunctive therapy for lung contusion, warranting further investigation in clinical settings.