大蒜素对脓毒症大鼠肠黏膜屏障的保护作用

目的 研究大蒜素对脓毒症大鼠肠黏膜屏障功能的保护作用,并初步探讨其机制.方法 24只雄性SD大鼠随机(随机数字法)分为假手术组、脓毒症模型组、大蒜素治疗组,每组8只.脓毒症模型采用盲肠结扎穿孔(cecum ligation and punctue,CLP),6h及12 h后用大蒜素(30 mg/kg,ip)干预,假手术组及模型组于同时间点给予等量生理盐水.24 h后处死大鼠检测血清D-乳酸、二胺氧化酶(diamine oxidase,DAO)活性、荧光异硫氰酸盐葡聚糖(fluorescence isothiocyanate dextran,FITC-Dextran,FD-40)水平;检测肠组织肿瘤坏死因子α(tumor necrosis factor alpha,TNF-α)、白介素-6(interleukin-6,IL-6)、丙二醛(malondialdehyde,MDA)水平及超氧化物歧化酶(superoxidedismutase,SOD)活性,并取部分小肠组织进行组织病理学分析.统计方法采用单因素方差分析.结果 与假手术组比较,CLP组大鼠血清D乳酸、DAO活性及FD40水平明显升高D-乳酸(nmol/mL):(599.4±101.1) vs.(149.2±20.63),t=11.84,P＜0.01;DAO (ng/mL):(302.1±64.56)vs.(76.57±14.76),t=9.433,P＜0.01;FD-40 (ng/mL):(6664.0±1437.0)vs.(1446.0±205.0),t=9.704,P＜0.01];病理切片示CLP组大鼠肠道形态学损伤明显;肠组织中TNF-α、IL-6、MDA水平明显升高TNF-α (pg/mL):(186.35±20.43)vs.(58.76±8.94),t=17.23,P＜0.01;IL-6 (pg/mL):(763.25±85.23)vs.(125.36±14.37),t=22.54,P＜0.01;MDA(nmol/mg prot):(29.36±3.27)vs.(7.24 ±0.85),t=16.61,P＜0.01],SOD活性降低SOD(U/mg prot):(35.75 ±6.53)vs.(73.26±8.35),t=10.57,P＜0.01].大蒜素显著减少脓毒症诱导的血清中D哥酸、DAO活性及FD-40的升高D-乳酸(nmol/mL):(330.1±81.77)vs.(599.4±101.1),t=7.086,P＜0.01;DAO (ng/mL):(171.8±49.70)vs.(302.1±64.56),t=5.45,P＜0.01;FD-40(ng/mL):(3349.0±1 167.0)vs.(6664.0±1437.0),t=6.165,P＜0.01];病理切片显示大蒜素减轻肠道形态学损伤;大蒜素明显抑制肠组织中TNF-α、IL-6、MDA水平TNF-α (pg/mL):(95.37±12.68)vs.(186.35±20.43),t=12.29,P＜0.01;IL-6 (pg/mL):(354.27±46.27)vs.(763.25 ±85.23),t=14.45,P＜0.01;MDA (nmol/mgprot):(16.27±3.14)vs.(29.36±3.27),t=9.831,P＜0.01],增加SOD活性SOD (U/mg prot):(55.35±6.23)vs.(35.75±6.53),t=5.522,P＜0.01].结论 大蒜素对CLP诱导的肠黏膜屏障功能具有保护作用,其机制可能与抑制炎症和氧化应激有关.

Protective effect of Allicin on intestinal mucosal barrier of septic rats

Objective To investigate the protective effect of allicin on intestinal mucosal barrier of septic rats so as to explore the possible mechanism.Methods Twenty-four male SD rats were randomly (random number) divided into sham,septic model and allicin treatment group.Septic model was established by cecal ligation and puncture (CLP) in rats.Rats in the treatment group were administered with allicin (30 mg/kg,ip)at 6 h and 12 h after modeling,while those in the model and sham groups were treated with equal amount of saline instead.Rats were sacrificed at 24 h and the serum D-lactic acid,diamine oxidase (DAO) and fluorescence isothiocyanate-dextran (FITC-Dextran,FD-40) were determined to evaluate the intestinal mucosal barrier function.The levels of tumor necrosis factor-α (TNF-α),interleukin-6 (IL-6),malondialdehyde (MDA),and the activity of superoxide dismutase (SOD) in intestinal tissue were measured.Histopathological changes of intestinal mucosa injury were assessed by Hematoxylin-eosin staining.Results Compared with the sham group,levels of serum D-lactic acid,DAO and FD-40 increased significantly in the CLP group (D-lactic acid:599.4±101.1 vs.149.2±20.63 nmoL/mL,t=11.84,P＜0.01;DAO:302.1 ±64.5 vs.76.57±14.76 ng/mL,t=9.433,P＜0.01;FD-40:6664.0±1437.0vs.1446.0±205.0 ng/mL,t =9.704,P ＜0.01);intestinal morphology damage occurred in the CLP group;intestinal levels of TNF-α,IL-6 and MDA increased greatly (TNF-αt:186.35 ±20.43 vs.58.76 ±8.94 pg/mL,t=17.23,P＜0.01;IL-6:763.25±85.23vs.125.36±14.37 pg/mL,t=22.54,P＜0.01;MDA:29.36±3.27vs.7.24±0.85 nmol/mg prot,t=16.61,P＜0.01),while SOD activity reduced (35.75±6.53 vs.73.26 ±8.35 U/rmg prot,t =10.57,P ＜0.01) in the CLP group.Allicin treatment greatly inhibited the increase of D-lactic acid,DAO and FD-40 levels in rat plasma caused by CLP (D-lactic acid:330.1 ±81.77 vs.599.4±101.1 nmol/mL,t=7.086,P＜0.01;DAO:171.8±49.70vs.302.1±64.56ng/mL,t=5.45,P＜0.01;FD-40:3349.0±1167.0 vs.6664.0±1437.0 ng/mL,t=6.165,P＜0.01);intestinal morphology damage was improved in the allicin treatment group;allicin treatment greatly inhibited the intestinal levels of TNF-o,IL-6 and MDA and preserved the intestinal SOD activity compared with the CLP group (TNF-α:95.37 ±12.68 vs.186.35 ±20.43 pg/mL,t =12.29,P＜0.01;IL-6:354.27±46.27vs.763.25±85.23pg/mL,t=14.45,P＜0.01;MDA:16.27±3.14vs.29.36±3.27 nmol/mgprot,t=9.831,P＜0.01;SOD:55.35 ±6.23vs.35.75±6.53 U/mgprot,t=5.522,P ＜0.01).Conclusions Allicin could inhibit local inflammation and oxidative stress in the intestine and exerts protective effect on intestinal mucosal barrier of septic rats.