Therapeutic Effect of C-Phycocyanin Extracted from Blue Green Algae in a Rat Model of Acute Lung Injury Induced by Lipopolysaccharide

Abstract EN

C-Phycocyanin (CPC), extracted from blue green algae, is a dietary nutritional supplement due to its several beneficial pharmacological effects.

This study was conducted to evaluate whether CPC protects against lipopolysaccharide- (LPS-) induced acute lung injury (ALI) in rats.

Rats were challenged with LPS (5 mg/kg body weight) intratracheally to induce ALI.

After 3 h LPS instillation, rats were administrated with CPC (50 mg/kg body weight, i.p.) for another 3 h.

Our results showed that posttreatment with CPC significantly inhibited LPS-induced elevation of protein concentration, nitrite/nitrate level, release of proinflammatory cytokines, the number of total polymorphonuclear cells in bronchoalveolar lavage fluid, and lung edema evidenced by decrease of lung wet/dry weight ratio accompanied by a remarkable improvement of lung histopathological alterations.

Furthermore, CPC significantly attenuated LPS-induced myeloperoxidase activity, O2− formation, expression of inducible nitric oxide synthase, and cyclooxygenase-2 as well as nuclear factor-kappa B (NF-κB) activation in lungs.

Additionally, CPC significantly downregulated proapoptotic proteins such as caspase-3 and Bax, but upregulated antiapoptotic proteins such as Bcl-2 and Bcl-XL in lungs exposed to LPS.

These findings indicate that CPC could be potentially useful for treatment of LPS-related ALI by inhibiting inflammatory responses and apoptosis in lung tissues.