Andrographolide Protects against Cigarette Smoke‐Induced Lung Inflammation through Activation of Heme Oxygenase‐1

This study was conducted to check whether andrographolide, a bioactive molecule isolated from Andrographis paniculata, could protect against cigarette smoke (CS)‐induced lung injury through activation of heme oxygenase‐1 (HO‐1). Pretreatment with andrographolide (1 mg/kg body weight) markedly attenuated lung inflammation in CS‐exposed mice, coupled with reduced numbers of total cells, neutrophils, and macrophages in bronchial alveolar lavage fluid (BALF) and decreased production of cytokine/chemokine into BALF. Furthermore, andrographolide pretreatment increased the expression and activation of HO‐1 in the lung of CS‐exposed animals. Notably, these histological and biochemical changes induced by andrographolide were blocked by prior administration of zinc protoporphyrin IX (ZnPP; 20 mg/kg body weight), a potent heme oxygenase inhibitor. Moreover, andrographolide‐induced phosphorylation of signal transducer and activator of transcription 3 (STAT3) was attenuated by ZnPP treatment in CS‐exposed animals. Our data collectively demonstrate that andrographolide confers protection against CS‐induced lung inflammation, partially through activation of HO‐1 and STAT3. © 2013 Wiley Periodicals, Inc. J BiochemMol Toxicol 27:259‐265, 2013; View this article online at wileyonlinelibrary.com . DOI 10.1002/jbt.21483