室内气传真菌的呼吸道毒作用研究

[目的]研究室内常见气传真菌孢子及其代谢提取物对呼吸道的毒作用。[方法]采用现场监测和气管染毒试验以及体外试验方法试验研究室内常见气传真菌1，3-β-D-葡聚糖含量、室内常见气传真菌对大鼠肺损伤作用、真菌孢子及其代谢提取物对异型小鼠混合淋巴细胞反应的影响、对人胚肺细胞毒作用及胶元合成的影响以及真菌代谢提取物的遗传毒性。[结果]室内环境中的优势气传真菌属为芽枝菌属、曲霉属、交链孢属、镰刀霉属、青霉属等。常见气传真菌中1，3-β-D-葡聚糖含量从9．21pg／10^5个细胞到36．5pg/10^5个细胞。大鼠气管染毒试验研究结果表明常见气传真菌孢子气管染毒可以引起肺灌洗液中乳酸脱氢酶(LDH)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)含量增加，大鼠肺组织中超氧阴离子自由基含量明显升高。体外试验结果表明，室内气传真菌代谢提取物可以引起人胚肺细胞胶原合成量增加，大鼠外周血单个核细胞IL-4、IL-6 mRNA的表达明显增高，且都有剂量-反应关系。部分室内气传真菌(曲霉、青霉)代谢提取物可抑制异型小鼠脾细胞的混合淋巴细胞反应，在加S的情况下，部分室内气传真菌代谢提取物(曲霉、镰刀霉、青霉)可引起TA98菌株回变菌落数明显增加，可诱导大鼠肝细胞非S期DNA合成增加，曲霉、青霉的代谢提取物可以抑制IL60细胞的凋亡。[结论]室内常见真菌中含有与呼吸道炎症有关的1，3-β-D-葡聚糖。气传真菌孢子可以引起大鼠肺损伤，其代谢提取物可以引起肺组织胶原合成增加，并具有一定遗传毒性和免疫抑制作用。     

室内常见气传真菌对动物肺损伤的实验研究

目的：探讨室内常见气传真菌对肺组织的损伤作用及其机理。方法：室内常见气传真菌孢子混合悬液气管染毒大鼠，通过分析肺灌洗液生化指标的改变观察真菌所致肺损伤的情况，并检测肺组织氧自由基的变化。结果：染毒组动物肺灌洗液中，LDH，AKP，ACP浓度显增加，肺组织超氧阴离子自由基浓度亦较对照组高。结论：室内常见气传真菌孢子染毒可使机体气传真菌污染并对机体肺组织造成损伤，肺组织氧自由基可能是这种改变的原因之一。     

Percoll密度梯度离心法在血液组分分离及元素测定中的应用

目的探讨元素在大鼠血液经Percoll密度梯度离心法分离后的不同组分(全血、血浆、红细胞、外周血单个核细胞)中的分布特点。方法将SD大鼠随机分成对照组和不同剂量受试组,共9组。采用4种元素(Hg、I、Mn、Sr)的混合溶液气管滴注染毒,连续染毒10 d后股动脉取血。用Percoll液分离血液,分别收集血浆、红细胞、外周血单个核细胞(PBMC),并用电感耦合等离子体质谱仪(ICP-MS)测定全血及上述3种血液成分中4种染毒元素的含量。结果随染毒剂量增加,全血和血浆组分中的元素呈直线回归关系,红细胞与白细胞中部分元素含量与染毒剂量无线性回归关系。结论元素在血液的不同组分中的含量受呼吸道染毒的影响各不相同,利用Percoll密度梯度离心法选取合适的组分可以实现实验目的。     

香烟烟雾暴露对大鼠睾丸组织雄激素结合蛋白mRNA及蛋白表达水平的影响

目的探讨香烟烟雾暴露对大鼠睾丸结构及睾丸组织雄激素结合蛋白(ABP)mRNA及蛋白表达水平的影响。方法清洁级成年雄性SD大鼠160只,随机分为对照组和低(10支)、中(20支)、高(30支)剂量染毒组,各组大鼠分别染毒2、4、6、8、12周,共16组,每组10只。实验组采用呼吸道静式染毒,每日1次,每次30 min。观察大鼠睾丸组织结构,采用RT-PCR及Western Blot法检测睾丸组织ABP mRNA及蛋白表达水平。结果染毒组大鼠睾丸病理切片可见,生精细胞排列紊乱疏松,支持细胞呈现空泡化。大鼠睾丸组织ABP mRNA和蛋白表达水平均随染毒剂量的增加而降低,染毒4周及12周后中、高剂量组ABP基因mRNA表达水平低于对照组,染毒6周后高剂量组ABP基因mRNA表达水平低于对照组,染毒4~8周后高剂量组ABP蛋白表达水平低于对照组,染毒12周后低、中、高剂量组ABP蛋白表达水平低于对照组,差异均有统计学意义(P0.05)。结论香烟烟雾暴露可引起雄性大鼠睾丸组织受损,且睾丸组织ABP基因mRNA及蛋白的表达水平下降。     

氯乙烯染毒对大鼠肝细胞P16、CCND1和CDK4基因mRNA表达的影响

目的通过检测氯乙烯(VCM)对大鼠肝脏细胞P16、CCND1和CDK4基因mRNA表达的变化,从细胞周期调控角度,探讨VCM可能的致癌机制。方法选用健康SD大鼠32只,按体重随机分为4组:阴性对照组,5、25、125mg/kg氯乙烯染毒组。采用腹腔注射染毒,隔日染毒,每周3次,连续6周。采用实时荧光定量PCR方法,测定大鼠肝脏细胞P16、CCND1和CDK4基因mRNA表达量。结果氯乙烯对大鼠肝脏细胞CCND1和CDK4基因mRNA表达量随着染毒剂量的升高而降低,且125 mg/kg染毒组与对照组比较,差异均有统计学意义(P<0.05)。P16基因mRNA表达量没有明显改变,差异无统计学意义。结论 VCM对大鼠肝脏细胞周期的影响可能是通过下调CCND1和CDK4基因mRNA的表达。     

硫酸铅对大鼠心肌Th1/Th2细胞相关细胞因子的影响

[目的]通过观察硫酸铅对大鼠心肌辅助性T细胞1(Th1)和辅助性T细胞2(Th2)相关细胞因子的影响,探讨铅对心肌损伤的免疫调节机制,以及铅对心血管系统损伤的可能作用机制. [方法] Wistar大鼠气管滴注硫酸铅,染毒剂量(按体重计)分别为13.5、67.5、337.5 μg/kg,1次/d,连续3d.最后一次染毒24h后,取大鼠心脏,采用实时荧光定量-聚合酶链式反应测定大鼠心肌组织中Th1和Th2相关转录因子的mRNA水平,使用酶联免疫吸附法测定心肌组织上清液中Th1和Th2相关细胞因子的表达水平,采用免疫组化方法观察Th1和Th2相关细胞因子的蛋白表达水平.[结果]心肌组织上清液中白细胞介素(IL)-4、IL-13和干扰素-γ(IFN-γ)的表达,染毒组与对照组差异有统计学意义;IL-13的表达,高剂量组与低剂量组间差异有统计学意义.Th1和Th2相关转录因子的mRNA表达水平,染毒组与对照组间差异有统计学意义,且高剂量组与低剂量组间差异有统计学意义.左心室中IL-4和IFN-γ的蛋白表达,染毒组与对照组间差异有统计学意义. [结论]进入肺脏的硫酸铅可致心脏出现明显的炎症反应和免疫毒性,Th1和Th2相关细胞因子水平的改变可能是铅导致心肌损伤的机制之一.     

香烟烟雾暴露对大鼠睾丸转铁蛋白mRNA及蛋白表达水平的影响

目的探讨香烟烟雾暴露对大鼠睾丸结构及睾丸组织转铁蛋白(Tf)mRNA及其蛋白表达水平的影响。方法清洁级成年雄性SD大鼠160只,随机分为对照组及低(10根香烟)、中(20根香烟)、高(30根香烟)剂量染毒组,各染毒组大鼠分别染毒2、4、6、8、12周,共16组,每组10只。染毒组大鼠采用呼吸道静式染毒,1次/d,30 min/次。观察大鼠睾丸组织结构,采用RT-PCR及Western blot法检测睾丸组织Tf mRNA及其蛋白表达水平。结果染毒组大鼠睾丸病理切片可见生精上皮层次减少,生精细胞排列疏松,支持细胞空泡化。染毒4、8、12周时高剂量组大鼠睾丸组织Tf mRNA表达水平低于对照组和低剂量组,染毒8周时高剂量组大鼠睾丸组织Tf蛋白表达水平低于对照组,染毒12周时中、高剂量组大鼠睾丸组织Tf蛋白表达水平低于低剂量组,差异均有统计学意义(P0.05)。结论香烟烟雾暴露可导致雄性大鼠睾丸组织损伤,并抑制Tf基因及蛋白表达。     

苯对小鼠骨髓单个核细胞多药耐药基因1和P-糖蛋白表达的影响

目的 探讨苯染毒对C57BL/6小鼠骨髓单个核细胞多药耐药基因1(multidrug resistance 1,MDR1)基因和P-糖蛋白(P-glycoprotein,P-gp)表达的影响.方法 实验动物随机分为对照组、低剂量组、中剂量组、高剂量组,每组24只,分别以单纯玉米油及25、50、100 mg/kg剂量苯灌胃染毒C57BL/6小鼠,每日1次,每周5次,连续染毒4周,染毒12、26、29 d后分批处死小鼠,检测C57BL/6小鼠外周血常规,实时定量PCR检测骨髓单个核细胞MDR1基因表达,免疫印迹法检测骨髓单个核细胞的P-gp表达.结果 染毒12d,高剂量组红细胞、血红蛋白明显低于对照组、低剂量组、中剂量组,差异有统计学意义(P＜0.01、P＜0.05).染毒26 d,高剂量组白细胞明显低于对照组、低剂量组、中剂量组,差异有统计学意义(P＜0.01、P＜0.05).各时间点各染毒组的MDR1基因mRNA表达均明显低于对照组,差异均有统计学意义(P＜0.01).染毒26 d,高剂量组P-gp表达低于对照组、低剂量组和中剂量组,中剂量组P-gp表达低于低剂量组,差异均有统计学意义(P＜0.01、P＜0.05);染毒29 d,各染毒组P-gp表达均低于对照组,差异均有统计学意义(P＜0.05).结论 苯染毒干扰骨髓单个核细胞MDR1基因和P-gp表达,可能是苯血液毒性的机制之一.     

氡及其子体吸入对大鼠外周血损伤的生物学效应

[目的 ]研究不同剂量氡暴露致大鼠外周血损伤的生物学效应。 [方法 ] 2 0 0 1年至 2 0 0 2年选用 2个月龄的雄性SD大鼠 ,吸入氡及子体的累积剂量分别为 66、111、174工作水平月 (WLM)后 ,观察外周血中白细胞计数与分类的变化 ,检测血清中LDH、GSH和总蛋白含量 ;用SCGE和RT PCR方法检测外周血单个核细胞 (PBMC)的DNA链断裂情况及IL 6mRNA的表达情况。 [结果 ]大鼠吸入氡及其子体后 ,66WLM组外周血中粒细胞的数量明显低于对照组 ;最高剂量组血清总蛋白明显低于对照组 ;各剂量组PBMC的DNA迁移长度与对照组相比显著增加 ,而且呈现剂量效应关系 ;IL 6mRNA的表达在 66和 174WLM剂量组均显著高于对照组。 [结论 ]在本实验的染毒剂量下 ,大鼠吸入氡及其子体后血清中总蛋白降低 ,PBMC的DNA损伤程度随着暴露剂量的升高而增加     

一次性气管滴注PM10所致大鼠肺脏和心脏的炎症反应

目的观察大气可吸入颗粒物一次气管滴注染毒后,大鼠肺脏、心脏的炎症反应,初步探讨大气可吸入颗粒物对大鼠的急性损伤及可能的作用机制。方法将32只体重为380～470g的雄性Wistar大鼠随机分为4组,即空白对照组、颗粒物低、中、高剂量组(5、15和45mg/kg)。采用气管滴注染毒颗粒物,24h后处死动物,进行支气管肺泡灌洗液(BALF)细胞计数,并对BALF中总蛋白(TP)、乳酸脱氢酶(LDH)和炎性因子(IL-6、TNF-α)的水平进行测定;采用实时荧光定量逆转录-聚合酶链反应(realtimeRT-PCR)法检测各组心肌组织白细胞介素6mRNA(IL-6mRNA)的表达,并观察心脏、肺脏组织病理切片。结果各染毒组大鼠BALF白细胞总数、中性粒细胞数、TP、LDH及IL-6水平均较对照组高,差异有统计学意义(P﹤0.05),BALF中TNF-α含量较对照组有所增加,但差异无统计学意义。中、高剂量染毒组大鼠心肌IL-6mRNA水平较对照组显著升高(P﹤0.05)。肺组织病理显示大鼠肺部炎症,各染毒组均可见炎性细胞浸润,中、高剂量组还能看到肺泡壁增厚,肺泡间隔增宽,并可见散在黑色颗粒状物质沉积。心肌组织病理未见异常。结论可吸入颗粒物一次性气管滴注染毒后可引起大鼠肺脏炎症损伤,进而造成心肌的炎性反应,大气可吸入颗粒物可能通过炎性机制造成脏器损伤。     

新生儿严重细菌感染白介素—6水平变化及临床意义

目的：探讨白细胞介素－6（IL－6）在新生儿败血症及败血症休克中的变化及临床意义。方法：采用酶联免疫吸附法（ELISA）检测正常与严重感染新生儿血清IL－6的水平，用逆转录聚合酶链反应（RT－PCR）技术测定外周血单个核细胞（PBMC）IL－6mRNA表达情况。结果：感染组血清IL－6水平升高，其中败血症性休克组尤为明显，并随病情好转而下降，检测时病程有3天以内的患儿血清IL－6显著高于病程在4天以上者；另检测5例败血症患儿PBMC均见IL－6mRNA的表达，而6例对照新生儿中仅3例有IL－6mRNA表达，按百分位数法初步确定血清IL－6≥23ng/L为诊断新生儿败血症的参考指标，此指标敏感性为81％，特异性为83％。结论，新生儿败血症及败血症休克早期血清IL－6水平升高、IL－6mRNA表达增强，与病情、预后有关，早期检测意义较大。     

缺锌对大鼠肺组织IFN—r及IL—4的影响

目的:探讨缺锌对大鼠肺组织γ干扰素(IFN—r)和白细胞介素4(IL—4)的影响。方法:SD大鼠24只,按体重随机分为3组,每组8只。A组为缺锌饲料组;B组为正常锌饲料组;C组为正常锌饲料配对饲养组。建立缺锌模型,利用酶联免疫吸附法(enzyme linked immunosorbent assay,ELISA)检测肺组织匀浆中IFN—r和IL—4的含量;RT—PCR检测肺组织中IFN—r、IL—4 mRNA表达。结果:与B组相比,A组大鼠肺组织匀浆中IFN—r含量、IFN—r mRNA的表达均明显减少(P<0.05),而IL—4含量I、L—4 mRNA的表达两组无显著差异(P>0.05)。B组与C组相比所有检测结果无显著性差异。结论:大鼠缺锌时其肺组织IFN—r明显减少,而IL—4不受影响,Thl/Th2细胞比例失衡,这可能是缺锌导致呼吸道疾病增加的重要原因。     

子宫内膜息肉患者Th1/Th2细胞因子的血清学研究

目的探讨Th1/Th2细胞因子的变化与子宫内膜息肉(endometrial polyps,EP)的关系。方法回顾性分析2014年9~12月暨南大学附属深圳市宝安区妇幼保健院妇产科收治的45例患者的临床资料,采用流式微球分析法(cytometric bead array,CBA)分别检测25例EP患者(A组)和20例同期行宫腔镜检查未见异常者为对照组(B组),检测比较Th1[代表性细胞因子肿瘤坏死因子-α(TNF-α)、γ-干扰素(γ-IFN)、白细胞介素-2(IL-2)]/Th2[代表性细胞因子白细胞介素-4(IL-4)、白细胞介素-6(IL-6),白细胞介素-10(IL-10)]型细胞因子的表达水平。结果 EP患者TNF-α、γ-IFN、IL-2的表达高于对照组,IL-4、IL-6的表达低于对照组,差异均有统计学意义(P0.05)。IL-10的表达略低于对照组,差异无统计学意义(P0.05)。结论 Th1/Th2细胞失衡可能对EP的发生发展有重要作用。     

Effect of tumor weight and tube feeding on TNF-alpha and IL-1beta mRNA expression in the brain of mice.

BACKGROUND: Previous studies have shown that cytokine mRNA expression is elevated in the brains of anorectic, tumor-bearing rats. The objectives of the current study were as follows: (1) to determine whether a small tumor would result in up-regulation of tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta mRNA expression in the brain and other tissues of tumor-bearing mice; and (2) to determine whether hyperalimentation by tube feeding would prevent up-regulation of cytokine mRNA expression in the brain and other tissues of tumor-bearing mice. METHODS: Male C57BL/6 mice were divided into 4 groups: (1) control mice fed ad libitum (Control); (2) tumor-bearing mice fed ad libitum (TB); (3) control mice receiving tube feeding (CTF); and (4) tumor-bearing mice receiving tube feeding (TBTF). RESULTS: TNF-alpha and IL-1beta mRNA expression was elevated in the brains of mice with a 1% body weight tumor, relative to the control and CTF groups, without any detectable changes in the other organs. On the other hand, TNF-alpha and IL-1beta mRNA expression was elevated in all organs of mice with an 8% body weight tumor, relative to the control and CTF groups. Tube feeding did not change TNF-alpha and IL-1beta mRNA expression in mice burdened with either a 1% or 8% body weight tumor. CONCLUSIONS: Up-regulation of cytokine mRNA synthesis occurs earlier in the brain than in other organs, and hyperalimentation does not change cytokine mRNA expression in tumor-bearing mice.     

Glutamine Administration in Early or Late Septic Phase Downregulates Lymphocyte PD‐1/PD‐L1 Expression and the Inflammatory Response in Mice With Polymicrobial Sepsis

Background: Sepsis is a severe inflammatory response to infection. Excessive compensation to inflammation leads to dysregulated immune response that ultimately results in organ damage and lethality of sepsis. This study administered glutamine (GLN) in the early or late phase of sepsis to investigate its effects on regulating leukocyte programmed cell death 1 (PD‐1) and its ligand (programmed cell death ligand 1 [PD‐L1]) expression, macrophage function, inflammation, and acute kidney injury in sepsis. Methods: Mice were randomly assigned to cecal ligation and puncture (CLP) or sham‐operated groups. Septic mice were respectively injected once with saline or 0.75 g GLN/kg body weight at 3 or 10 hours post‐CLP via tail vein. All mice were sacrificed 24 hours after CLP. Results: Sepsis enhanced the percentage of interferon‐γ–expressing and interleukin (IL)‐17A–expressing CD4⁺ T cells, expression of PD‐1 on T cells, and PD‐L1 on B cells and monocytes. Inflammatory mediator messenger RNA (mRNA) expression in kidney tissues and proapoptotic caspase‐3 mRNA expression in mesenteric lymph nodes were also upregulated. GLN administration decreased plasma IL‐6 level, downregulated the percentage of IL‐17A–expressing CD4⁺ T cells, attenuated macrophage dysfunction, decreased caspase‐3 mRNA expression, and reduced PD‐1/PD‐L1 expression by T and B cells. Histological findings also showed that kidney damage was attenuated. GLN administered at 3 and 10 hours after CLP offered nearly equal effects on PD‐1/PD‐L1 and inflammatory mediator expression after CLP. Conclusions: These findings suggest that a single dose of GLN administration in either the early or late phase during sepsis promotes a more balanced immune regulation and reduced systemic and kidney inflammatory responses in mice.     

A dried tofu-supplemented diet affects mRNA expression of inflammatory cytokines in human blood

In order to develop a new model of diet research, blood was drawn from 12 adult volunteers for 3 wk on regular diets as controls, and for a subsequent 3 wk supplemented with 18.5 g of freeze-dried tofu (Koya tofu) every day. Triplicate aliquots of 0.06 mL each of whole blood were stimulated ex vivo with phytohemagglutinin (PHA)-P, heat aggregated human IgG (HAG), lipopolysaccharide (LPS), zymosan A, and anti-T cell receptor (TCR) monoclonal antibody to activate specific subsets of leukocytes, then the levels of various inflammatory cytokine mRNA were quantified by real time PCR. Koya tofu significantly (p<0.05) augmented the fold increase of PHA-induced tumor necrosis factor superfamily (TNFSF) 15, IL6, and IL8, HAG-induced TNFSF15 and IL8, LPS-induced IL6 and IL8, zymosan-induced TNFSF15, IL6 and IL8, and TCR-induced TNFSF2 in comparison to the regular diet. Such increase was due to the reduction of baseline mRNA expression, not the enhancement of mRNA induction after specific stimulations. Six (TNFSF15), 4 (IL6), and 3 (IL10) subjects showed significant reduction of baseline mRNA during the Koya tofu diet compared to that of the control diet. Despite large individual-to-individual and day-to-day variation of mRNA, the method employed in this study was sensitive enough to identify statistically significant results as a group as well as on an individual basis, which will be a foundation for tailored diet in the future. The results also indicated that Koya tofu had a power to alter mRNA expression in leukocytes, and TNFSF15, IL6, and IL10 would be biomarkers for soy.     

Low-dose ethanol aggravates allergic dermatitis in mice

Alcohol injures dendritic cells and suppresses cellular immunity, while some evidence indicates that drinking alcohol aggravates allergic asthma. This study investigated the effect of low doses of ethanol in enhancing allergic reactions in the skin of mice. Liquid food containing alcohol was administered to conventional NC/Nga mice to induce alcoholic hepatic steatosis, and spontaneous dermatitis was evaluated. BALB/c mice were administered approximately 1 g/kg body weight of ethanol by gavage, and contact hypersensitivity (CHS) or active cutaneous anaphylaxis (ACA) was induced. Spleens were collected 24 h after the elicitation of CHS and mRNA expressions of interferon (IFN)-γ, interleukin (IL)-4, IL-6, IL-10, and IL-18 were measured by quantitative RT-PCR. Alcohol-containing diet exaggerated spontaneous dermatitis in conventional NC/Nga mice and contact hypersensitivity in BALB/c mice. Ethanol administered by gavage for 5 days enhanced contact hypersensitivity in BALB/c mice. Ethanol administration with gavage also enhanced ACA of BALB/c mice. Ethanol did not affect mRNA expression of IFN-γ and IL-4, but did enhance IL-6, IL-10, and IL-18 mRNA expression. Histological evaluation revealed an absence of hepatic steatosis in mice administered ethanol by gavage for 5 days. In ethanol-administered mice, inflamed areas presented as lesions or a local extreme accumulation of mononuclear cells in the epidermis. These findings suggest that ethanol enhances the expression of inflammatory cytokines independently from T helper (Th)1/Th2 cytokine phenotypes, causing abnormalities in the epidermis resulting in exacerbated allergic reactivity.     

Conjugated linoleic acid ameliorates viral infectivity in a pig model of virally induced immunosuppression

We investigated the cellular and molecular immunoregulatory actions of conjugated linoleic acid (CLA) of relevance to viral disease pathogenesis and antiviral responses. To test the hypothesis that CLA ameliorates viral disease, we developed a viral challenge model by infecting pigs with type-2 porcine circovirus (PCV2). After 42 d of dietary supplementation with either soybean oil (n = 16) or CLA (n = 16), half of the pigs in each group were challenged with PCV2. We examined the effect of CLA on the development of lesions (i.e., lymphoid depletion and pneumonia) and observed the kinetics of the immune responses against PCV2. The viral infection depleted immature B cells (IgM+SWC3+) and favored proapoptotic mRNA expression profiles [i.e., suppressed B-cell leukemia/lymphoma-xl (Bcl-xl) and stimulated Bcl-2 homologous antagonist/killer (Bak)] in the external inguinal lymph nodes. B-cell depletion was more accentuated in pigs fed the control diet, whereas interleukin (IL)-2 mRNA expression was downregulated. Histopathological examination of the lungs revealed that the interstitial pneumonia tended to be more severe in infected pigs fed the control diet, which were also affected by growth retardation. CD8+ T cells were the primary cellular targets of CLA action in peripheral blood (CD8+CD29low and CD8+CD45RC+) and thymus (CD8+ and CD4+CD8+). CLA interacted with PCV2 to increase the proliferation of CD8+ T cells and to suppress PCV2-specific interferon (IFN)-gamma production in CD4+ T cells. At the molecular level, these cellular immunoregulatory properties were associated with differential patterns of peroxisome proliferator-activated receptor (alpha and gamma) mRNA expression between diets in virally infected pigs.     

Japanese Kampo Saireito Has a Liver‐Protective Effect Through the Inhibition of Inducible Nitric Oxide Synthase Induction in Primary Cultured Rat Hepatocytes

Background: Japanese herbal medicine, Kampo saireito, is used for treatments in patients with digestive diseases, including chronic hepatitis and cirrhosis. However, few studies demonstrate scientific evidence for liver‐protective effects of saireito. In inflamed liver, proinflammatory cytokines such as tumor necrosis factor (TNF)–α and interleukin (IL)–1β stimulate the induction of inducible nitric oxide synthase (iNOS) and nitric oxide (NO) production. Excessive levels of NO synthesized by iNOS have been implicated as one of the factors in liver injury, so it is essential to reduce the induction of iNOS for the prevention of liver injury. In this study, we examined IL‐1β–stimulated hepatocytes as a simple “in vitro injury model” to investigate liver‐protective effects of saireito. Method: Primary cultured rat hepatocytes were treated with IL‐1β in the presence or absence of saireito. The induction of NO production and iNOS and its signaling pathway were analyzed. Results: Saireito inhibited the production of NO dose and time dependently and reduced the expression of iNOS messenger RNA (mRNA) and its protein. Saireito had no effect on IκB degradation but inhibited the translocation of nuclear factor (NF)–κB to the nucleus and its DNA binding. Saireito also inhibited the activation of Akt, resulting in the reduction of type I IL‐1 receptor (IL‐1RI) mRNA and protein expression. Conclusion: These findings demonstrate that saireito suppresses iNOS gene expression through the inhibition of NF‐κB and IL‐1RI–dependent pathways, leading to the reduction of NO production. Saireito may have therapeutic potential for organ injuries, including liver.