Intranasal curcumin ameliorates lipopolysaccharide-induced acute lung injury in mice

Lipopolysaccharide (LPS) is one of the most powerful proinflammatory factor and can induce acute pulmonary inflammation even lung injury after inhalation or systemic administration. LPS induces sepsis and multiple organ damage. Curcumin (diferuloylmethane), a major component of turmeric, exhibits protection against LPS-induced acute lung injury (ALI). We aimed to investigate effects of intranasal curcumin on LPS-induced ALI in mice where curcumin (10 mg/kg, intranasal (i.n.) was given an hour before LPS exposure. After 24 h of intranasal LPS instillation, a marked increase in neutrophil recruitment and myeloperoxidase (MPO) activity was noted which were significantly ameliorated in curcumin treatment group. Oxidative stress markers like nitric oxide (NO), malondialdehyde (MDA) level and evans blue capillary leakage assay also revealed suppression after curcumin treatment; interestingly, levels of anti-oxidative enzymes such as superoxide dismutase (SOD) and catalase were upregulated. Inflammatory cytokine, tumour necrosis factor alpha (TNF-α) level was significantly attenuated by curcumin. Hence, intranasal curcumin could be a novel therapeutic strategy for LPS-induced ALI by directly targeting the lungs and enhancing anti-oxidant levels.