Inhibitory effect of kukoamine B on lung inflammatory responses in mice with sepsis / 中华危重病急救医学

ABSTRACT

Objective To investigate the inhibitory effect of kukoamine B (KB) on lung inflammatory responses in mice with sepsis and its possible molecular mechanism.Methods Twenty-eight male mice were randomly divided into control group (n=8),lipopolysaccharide (LPS) group (n=10),and LPS + KB group (n=10).Sepsis model was reproduced by intra-peritoneal injection of 20 mg/kg LPS,while equivalent normal saline was given in control group,and 20 μg/kg KB was injected through caudal vein 4 hours after LPS challenge in LPS + KB group.After 8 hours of LPS challenge,the concentration of LPS in plasma and the activity of myeloperoxidase (MPO) in the lung tissue were determined.The contents of tumor necrosis factor-α (TNF-α) and interleukin-lβ (IL-1β) in plasma,alveolar lavage fluid and lung tissue homogenates were assessed by enzyme linked immunosorbent assay (ELISA).The activation of nuclear factor-κB (NF-κB) and the expression of inducible nitric oxide synthase (iNOS) in lung tissue were determined by Western Blot.The pathological changes in lung tissues were observed with hematoxylin-eosin (HE) staining.The expression of intercellular adhesion molecule-1 (ICAM-1) in lung tissue was determined by immunohistochemistry.Results Compared with control group,the concentration of LPS in plasma (kEU/L1 155.650 ± 147.149 vs.31.390 ± 18.859),MPO activity (U/g1.177 ±0.093 vs.0.775 ±0.166),NF-κB activity (gray value1.557 ±0.105 vs.0.824 ±0.032) and the expression of iNOS (gray value0.650 ±0.129 vs.0.392 ±0.097) were significantly increased in LPS group (all P＜0.05).After KB intervention,the concentration of LPS (624.461 ± 149.012),MPO activity (0.919 ±0.023),NF-κB activity (1.127 ±0.074) and the expression ofiNOS (0.425 ± 0.066) were significantly lowered (all P＜0.05).Compared with control group,the contents of TNF-α (ng/L47.325 ± 13.864 vs.6.534 ± 0.544,13.382 ± 2.231 vs.3.748 ± 0.692,31.127 ± 7.399 vs.14.948 ± 4.673) and IL-1β (ng/L74.329 ± 11.890 vs.29.921 ± 6.487,9.422 ± 2.674 vs.1.105 ± 0.364,528.509 ± 32.073 vs.109.945 ± 13.561) in plasma,alveolar lavage fluid and lung tissue homogenates were obviously enhanced in LPS group (all P＜0.05).With KB intervention,the contents of TNF-α (20.331 ± 7.789,7.145 ± 1.202,15.966 ± 2.946) and IL-1β (57.707 ±8.098,2.212 ± 0.878,426.154 ± 11.270) were markedly reduced (plasma TNF-αF=16.052,P=0.002; IL-1βF=20.649,P=0.000; lung tissue homogenates TNF-αF=31.134,P=0.001; IL-1βF=22.792,P=0.002;alveolar lavage fluid TNF-αF=10.013,P=0.009; IL-1βF=319.857,P=0.000).In addition,leukocyte infiltration to the lung tissue was attenuated,and the expression of ICAM-1 was reduced by KB in histological examination.Conclusion KB,as a neutralizer of LPS,can inhibit the release of inflammatory mediators,reduce the pulmonary inflammatory response and protect the function of lung in septic mice.