Beneficial effects of Houttuynia cordata polysaccharides on “two-hit” acute lung injury and endotoxic fever in rats associated with anti-complementary activities

Lu, Yan; Jiang, Yun; Ling, Lijun; Zhang, Yunyi; Li, Hong; Chen, Daofeng

The systemic activation of the complement system generates C5-derived chemotactic activity. This causes blood neutrophils to sequester in pulmonary capillaries and dramatically result in the release of toxic oxygen species, which can destroy pulmonary endothelial cells as well as basement membranes 34 . And an oxidant-antioxidant imbalance is thought to underlie as one of the important pathogenesis of lung injury 10 . These findings provide strong evidence that ALI following the over-activation of complement system is closely linked to the production of oxygen metabolites by lung-sequestered neutrophils. In the experiment, the proportions of neutrophils were actually suppressed with the administration of CHCP, suggesting that CHCP potently attenuated the neutrophil respiratory burst. SOD is an important antioxidant enzyme that scavenges the superoxide free radicals 35 . MDA is recognized as a standard measurement for the degree of oxidation 36 . The pathogenesis of ALI resulted in the decreased SOD level and the elevated MDA content. Taking CHCP could reduce the pulmonary oxidative stress to modulate the oxidantantioxidant balance.