RESUMO
Aim To explore the protective effect and mechanism of icariin ( ICA ) on acute lung injury ( ALI) in mice induced by activation of the comple-ment alternative pathway. Methods 32 healthy KM mice were randomly divided into four groups: the nor-mal group, the model group, the PDTC group and the Icariin group, which received 7-day intragastric admin-istration respectively. Then cobra venom factor ( CVF) was used to activate specifically complement alternative pathway to induce acute lung injury in mice by intrave-nous injection. Myeloperoxidase ( MPO ) activity of lung homogenate, the cell count and the protein con- tent of bronchoalveolar lavage fluid ( BALF ) were measured. The concentration of IL-6, TNF-α, P-selec-tin and ICAM-1 in BALF and serum were determined by ELISA. The pathological change of lung tissue was observed by HE staining. The phosphorylation of NF-κB p65 in lung tissues was checked by immunohisto-chemistry. The effect of the transcriptional activity of NF-κB signal pathway in microvascular endothelial cells was measured by employing dual-luciferase re-porter assay system. Results ICA reduced MPO ac-tivity of lung homogenate, the cell count and the con-tent of IL-6, TNF-α, P-selectin in BALF obviously. The level of TNF-α, P-selectin and ICAM-1 in serum was decreased, the pulmonary inflammatory cell infil-tration was reduced, the phosphorylation of NF-κB p65 in lung was inhibited significantly and the transcrip-tional activity of NF-κB was also down-regulated. Con-clusion ICA can alleviate acute inflammatory re-sponse of ALI mice induced by activation of the com-plement alternative pathway. The mechanism may be highly related to the inhibition of inflammatory cell in-filtration in lung tissue, the down-regulation of phos-phorylation of NF-κB p65 and nuclear transcriptional activity.
RESUMO
Aim To explore the anticomplementary ac-tivity and active constituents of Phyllanthus urinaria. Methods Being guided by bioactive screening,the anticomplementary constituents of P.urinaria were iso-lated and purified by solution partition and chromato-graphic techniques,and their structures were identified by 13C-NMR spectrum and the comparison of reported data. The anticomplementary activity and possible mechanism were assayed.Results The EtOAc fraction of the methanol extract of P.urinaria was shown to be the active fraction,and two compounds were purified from the fraction and were identified as corilagin and ellagic acid.The EtOAc and the two compounds signifi-cantly inhibited the hemolysis of the complement classi-cal pathway,with IC50values of 53.77 mg·L-1, 176.54 mg·L-1and 102.23 mg·L-1,respectively. While they just showed slight effect on inhibiting the hemolysis of the complement alternative pathway. All of them affected the formation of C3 convertase of the classical pathway. Conclusions The polyphenols are main anticomplentary constituents of P. urinaria,and its mechanism is related to inhibiting formation of C3 convertase of the classical pathway.