Effect of usnic acid on TNF-α and no production in lipopolysaccharide-stimulated macrophages / 西安交通大学学报·英文版

ABSTRACT

Objective: To investigate the molecular mechanisms that are responsible for anti-inflammatory effect of usnic acid (UA), the effects of UA from usnea longissm on tumor necrosis factor-α (TNF-α) and nitric oxide (NO) production in peritoneal macrophages has been examined. Methods: The different concentrations of UA were added to peritoneal macrophages. The TNF-α and NO production in peritoneal macrophages were examined with mouse TNF-α ELISA kit and NO content by measuring the amount of nitrite (NO2- μmol/L) formed in the medium using Griess reaction. The activity of inducible nitric oxide synthase (i-NOS) was determined using i-NOS detection kit and the TNF-α mRNA expression was tested by reverse transcriptase polymerase chain reaction (RT-PCR). Results: UA decreased the TNF-α and NO level in LPS-stimulated peritoneal macrophages in dose-dependent manner, the IC50 values were 12.8 μmol/L and 5.7 μmol/L respectively. RT-PCR analysis indicated that UA could inhibit TNF-α mRNA expression; the activity analysis of i-NOS indicated that UA could inhibit the activity of i-NOS. Conclusion: UA could inhibit the TNF-α and NO production in peritoneal macrophages, it may be associated with the anti-inflammatory activity of UA.