Effects of C-phycocyanin on Lipopolysaccharide–induced Acute Lung Injury in Rat

• Main Authors: Ming-Fan Tsai, 蔡旻汎
• Other Authors: Tz-Chong Chou
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/75480607283615300328

碩士 === 國防醫學院 === 生理學研究所 === 96 === Acute lung injury (ALI) is a serious and devastating clinical syndrome with high mortality. Clinically, it is characterized by severe hypoxemia, reduced lung compliance and the presence of diffuse pulmonary infiltrates on chest radiograph. When the pulmonary alveolus receives the infection, the neutrophils can migrated to the lungs organization, killed the foreign substance, but the inflammation material also can injure the lung tissue, which may lead to acute respiratory distress syndrome (ARDS). The current therapeutic strategies for ALI are ventilation and medicine treatment, however, the mortality remains high. The clinical research suggested that excessively many inflammation materials and the oxidized pressure are experienced by patients with ALI. Therefore, if reduced the inflammation material and the oxidized pressure may ameliorate the damage of the lung tissues. C-phycocyanin (C-PC), a phycobiliprotein, is one of the major constituents of blue-green algae, Spirulina platensis. C-PC is widely used in many nutrition dietary supplements. The recent literatures indicated that C-PC has anti-cancer, anti-oxidative and the anti-inflammatory properties. In the present study, we used lipopolysaccharide (LPS)-induced ALI with intratracheal (i.t.) instillation, and evaluated the prevention effects of C-PC on this animal model. In animals received pretreatment with C-PC one hour prior LPS IT instillation and sacrificed at 6 hours later, C-PC significantly suppressed pro-inflammatory cytokines (tumor necrosis factor-alpha、interleukin-1β and interleukin-6) and free radicals (hydrogen peroxide) in bronchoalveolar lavage fluid (BALF). Myeloperoxidase (MPO) activity was also reduced in lung tissues. In addition, C-PC inhibited LPS-induced inducible nitric oxide synthase (iNOS)、cycloxygenase-2 (COX-2)、Bax gene expression、caspase-3 protein level but upregulated Bcl-2、Bcl-xL gene expression in lung tissues. In conclusion, we demonstrated that C-PC has beneficial effects in LPS-induced ALI by the decrease of pro-inflammatory cytokines, the formation of free radicals, the gene expression of iNOS and COX-2.