Abstract: This study was designed to investigate the effect of mangiferin on CD4⁺ T lymphocyte percentage and its producing interleukin-2 (IL-2),interleukin-4 (IL-4) lymphokine in rats with cigarette smoke-induced chronic bronchitis.The rat model with chronic bronchitis was established by daily exposure to cigarette smoke for 6 weeks.The rats were randomly divided into normal control,model control and mangiferin group［200,100 mg/ (kg·d),gavage administration within following 4 weeks］.The percentage of CD4⁺ T lymphocyte was analyzed by flow cytometry assay. CD4⁺ T lymphocytes were sorted with flow sorter and followed by a measurement for IL-2 and IL-4 by enzyme linked immunosorbent assay (ELISA).The real-time reverse transcription-polymerase chain reaction (RT-PCR) was executed to evaluate the gene expression of IL-2 and IL-4 in CD4⁺ T lymphocyte.The histopathological images were obtained by lung tissue HE staining microscopy,and then proceed the observation to pathology morphological characteristics of bronchial inflammation.The results showed that the percentage of CD4⁺ T lymphocyte was markedly lowered in mangiferin-treated group compared with the model group.Both of the gene and the protein expressions of IL-2,IL-4 was down regulated in CD4⁺ T lymphocyte.Following the previous changes,the alleviated chronic bronchial inflammation was noticed.These results suggested that mangiferin can notably down-regulate the percentage of CD4⁺ T lymphocyte and then decrease the productions of IL-2 and IL-4,and this regulation might be linked to an amelioration of chronic bronchiolar inflammation by mangiferin.

Key words: Mangiferin, chronic bronchitis, CD4⁺ T lymphocyte, Interleukin-2, Interleukin-4