Effects of andrographolide on the expression of eosinophil granulocytes and possible mechanisms

Objective Andrographolide,the active component in andrographis paniculata,has potent anti-inflammatory actions.This study aimed to evaluate the effects of andrographolide on eosinophil granulocytes(EOS) and the expression of eotaxin and IL-5 in mice with asthma.Methods BALB/c mice were randomly assigned into normal control,asthma,budesonide treatment and andrographolide treatment groups(n=8 each).Mice in the latter three groups were sensitized and challenged with ovalbumin(OVA) to induce asthma.ELISA was used to detect the concentrations of eotaxin and IL-5 in bronchoalveolar lavage fluid(BALF) and peripheral blood.The expression of eotaxin mRNA and IL-5 mRNA in lung tissues was detected by real-time quantitative PCR.Results Andrographolide treatment significantly decreased EOS count in BALF(P0.05) and the effect of andrographolide was better than the effect of budesonide.Andrographolide treatment significantly down-regulated the expression of eotaxin and IL-5 in BALF,lung eotaxin mRNA expression and blood IL-5 expression(P0.05),but the effects of andrographolide were poorer than the effects of budesonide.Andrographolide treatment resulted in a decrease in blood eotaxin expression and lung IL-5 mRNA expression and the effects of andrographolide were similar to budesonide.Conclusions Andrographolide can down-regulate the expression of IL-5 and eotaxin and thus suppress the inflitration of EOS in a mouse model of asthma.