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

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.

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.

Andrographolide treatment significantly decreased EOS count in BALF (P<0.05) 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 (P<0.05), 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.

Andrographolide can down-regulate the expression of IL-5 and eotaxin and thus suppress the inflitration of EOS in a mouse model of asthma.