Effect of lipopolysaccharide-induced expression of inducible nitric oxide synthase by aloe-emodin in RAW264.7 cells

Aim To investigate the effect of aloe-emodin on lipopolysaccharide(LPS)-induced production of nitric oxide and expression of inducible nitric oxide synthase in RAW264.7 cells.Methods RAW264.7 macrophage line in mice was induced by LPS to set up the inflammatory model.Nitric oxide(NO)production was examined by Griess reaction;the expression of iNOS mRNA was detected by RT-PCR analysis;NO radical generation was tested by sodium nitroprusside method.Results Aloe-emodin at the dose of 0.69~2.5 mg·L-1 exhibited the inhibitory effect on LPS-induced NO production in a dose-dependent and time-dependent manner;aloe-emodin at the dose of 0.63~5.00 mg·L-1 suppressed LPS-induced iNOS mRNA expression in RAW 264.7 cells.However,aloe-emodin had no scavenging effect on sodium nitroprusside-triggered NO production,and didn′t affect iNOS enzyme activity.Conclusion Aloe-emodin inhibited signifi-cantly LPS-induced NO production through suppressing inducible NO synthase(iNOS)expression at mRNA level in a dose-dependent and time-dependent manner,but failed to affect sodium nitroprusside-triggered NO production and iNOS enzyme activity.