彭曉華 周旭春 潘慧
·論著·
姜黃素對(duì)大鼠慢性酒精性胰腺炎的作用和機(jī)制研究
彭曉華 周旭春 潘慧
目的觀察姜黃素對(duì)大鼠實(shí)驗(yàn)性慢性胰腺炎的干預(yù)作用。方法18只1月齡雄性SD大鼠按數(shù)字表法隨機(jī)分為對(duì)照組、ANP組和姜黃素組,每組6只。以25%乙醇代水飲12周后每周1次腹腔注射脂多糖(2 mg/kg體重)、共4次的方法建立慢性胰腺炎模型。姜黃素組制模同時(shí)飼以姜黃素。17周后處死動(dòng)物。測(cè)血糖濃度,常規(guī)胰腺病理檢查及膠原纖維染色,檢測(cè)胰腺組織淀粉酶和脂肪酶水平。采用RT-PCR法檢測(cè)胰腺組織轉(zhuǎn)化生長(zhǎng)因子β1(TGF-β1)mRNA表達(dá)。結(jié)果對(duì)照組、ANP組和姜黃素組胰腺病理評(píng)分分別為1.17±0.41、7.33±2.58和3.50±1.05,姜黃素組較ANP組降低(P<0.01),但仍高于對(duì)照組(P<0.05)。各組血糖值無(wú)統(tǒng)計(jì)學(xué)差異。姜黃素組胰腺組織勻漿淀粉酶和脂肪酶含量分別為(7348±102)、(14135±1272)U/g,均高于ANP組的(5428±547)和(9123±1250)U/g(P值均<0.05)。對(duì)照組、ANP組和姜黃素組胰腺TGF-β1 mRNA表達(dá)量分別為0.618±0.019、0.818±0.012、0.745±0.088,ANP組顯著高于對(duì)照組和姜黃素組(P值均<0.01)。結(jié)論在長(zhǎng)期攝入乙醇的基礎(chǔ)上反復(fù)腹腔注射脂多糖可誘導(dǎo)慢性胰腺炎;姜黃素可能通過(guò)抑制TGF-β1表達(dá)而產(chǎn)生抗胰腺纖維化的作用。
姜黃素; 慢性胰腺炎; 內(nèi)毒素類; 乙醇
胰腺纖維化是慢性胰腺炎(chronic pancreatitis, CP)最重要的病理改變,目前尚無(wú)有效的治療手段。姜黃素(curcumin)是從姜黃根莖中提取的一種天然酚類抗氧化劑,具有廣泛的抗炎、抗氧化、抗誘變等藥理作用[1]。本實(shí)驗(yàn)應(yīng)用姜黃素干預(yù)CP大鼠,觀察姜黃素對(duì)CP胰腺纖維化的影響。
一、實(shí)驗(yàn)動(dòng)物與分組
18只1月齡雄性SD大鼠,體重95~105 g,由重慶醫(yī)科大學(xué)實(shí)驗(yàn)動(dòng)物中心提供,使用合格證:SCXK(渝)2007-0001。大鼠適應(yīng)飼養(yǎng)一周,按數(shù)字表法隨機(jī)分為對(duì)照組、ANP組和姜黃素治療組,每組6只。ANP組和姜黃素組以25%乙醇代替飲水。姜黃素組同時(shí)飼以300 mg/kg體重姜黃素(生工生物工程上海有限公司)。飼養(yǎng)后第13、14、15、16周,ANP組和姜黃素組大鼠腹腔內(nèi)各注射2 mg/kg體重脂多糖,每周1次,共4次,于最后一次注射一周后處死動(dòng)物,取靜脈血及胰腺組織。
二、觀察指標(biāo)與檢測(cè)方法
1.胰腺病理學(xué)檢測(cè):部分胰腺組織常規(guī)病理檢查,并行Masson膠原染色。胰腺病變程度評(píng)分標(biāo)準(zhǔn):(1)炎細(xì)胞浸潤(rùn):5個(gè)高倍視野內(nèi)炎癥細(xì)胞數(shù)均值<5個(gè)為0 分,6~20個(gè)為1分,21~40個(gè)2分,>40為3分;(2)壞死:無(wú)為0分,小灶狀壞死為1分,小片狀壞死為2分,大片狀壞死為3分;(3)結(jié)構(gòu)破壞:無(wú)為0分,灶性破壞為1分,小部分破壞為2分,大部分破壞為3分;(4)黏液水腫:無(wú)為0分,有為1分;(5)萎縮:無(wú)為0分,有為1分;(6)纖維化:膠原纖維占總面積0~1%為0分,1.1%~5.0%為1分,5.1%~10%為2分,10.1%~20%為3分,>20%為4分。以上分值相加,0~3分為正常,4~6分為輕度CP,7~9分為中度CP,>9分為重度CP。
2.胰腺分泌功能測(cè)定:取血測(cè)血糖濃度。取部分胰腺組織制成勻漿,檢測(cè)淀粉酶和脂肪酶含量。
3.胰腺組織TGF-β1 mRNA 檢測(cè):應(yīng)用RT-PCR
法檢測(cè)。采用RNAisoTHPlus試劑(大連寶生物公司)抽提胰腺組織總RNA。TGF-β1上游5′-CTACTA-CGCCAAAGAAGTCACC-3′;下游5′-GAAAGCCCT-GTATTCCGTCTC-3′;產(chǎn)物大小347 bp,內(nèi)參β-actin上游5′-CCTGAAGTACCCCATTGAACAC-3′;下游5′-CTCATTGCCGATAGTGATGACC-3′,產(chǎn)物大小562 bp。引物由大連寶生物公司合成。PCR反應(yīng)條件:94℃ 2 min,94℃ 30 s、58℃ 30 s、72℃ 30 s,30個(gè)循環(huán),最后72℃ 10 min。產(chǎn)物經(jīng)電泳后掃描,以目的條帶與內(nèi)參條帶灰度值之比值表示mRNA相對(duì)表達(dá)量。
三、統(tǒng)計(jì)學(xué)處理
一、胰腺組織病理學(xué)改變
對(duì)照組大鼠胰腺未見(jiàn)明顯病理改變。ANP組大鼠胰腺可見(jiàn)大量腺泡細(xì)胞空泡樣改變,部分發(fā)生壞死,腺泡周圍和管壁纖維組織增多,小葉內(nèi)和小葉間毛細(xì)血管充血、出血,并有單核細(xì)胞、淋巴細(xì)胞浸潤(rùn)。姜黃素組大鼠胰腺部分腺泡細(xì)胞空泡化,部分腺泡周圍和管壁纖維組織增多,小葉結(jié)構(gòu)完整(圖1)。對(duì)照組、ANP組和姜黃素組胰腺病理評(píng)分分別為1.17±0.41、7.33±2.58、3.50±1.05,姜黃素組較ANP組明顯降低(P<0.01),但仍高于對(duì)照組(P<0.05)。
二、胰腺分泌功能變化
ANP組胰腺組織淀粉酶和脂肪酶含量均較對(duì)照組下降,而姜黃素組較ANP組顯著升高,但仍低于對(duì)照組;各組血糖值無(wú)統(tǒng)計(jì)學(xué)差異(表1)。
三、胰腺組織TGF-β1 mRNA表達(dá)的變化
對(duì)照組、ANP組和姜黃素組胰腺TGF-β1 mRNA表達(dá)量分別為0.618±0.019、0.818±0.012、0.745±0.088,ANP組較對(duì)照組表達(dá)明顯增高(P<0.01),姜黃素組較ANP組明顯降低(P<0.01,圖2)。
圖1對(duì)照組(a)、ANP組(b)、姜黃素組(c)胰腺組織病理學(xué)改變(上圖,HE ×100;下圖,Masson染色 ×100)
表1 各組胰腺組織淀粉酶、脂肪酶含量和血糖濃度
注:與對(duì)照組比較,aP<0.01,bP<0.05;與ANP組比較,cP<0.01,dP<0.05
1:Maker;2、4、6:姜黃素組、ANP組和對(duì)照組的β-actin;3、5、7:姜黃素組、ANP組、對(duì)照組的TGF-β1 mRNA
圖2各組大鼠胰腺組織TGF-β1 mRNA的表達(dá)
姜黃素是從植物姜黃塊根提取的,已經(jīng)被證實(shí)具有抗炎、抗脂質(zhì)過(guò)氧化、抗纖維化等作用[1],并能夠通過(guò)抑制肝臟星狀細(xì)胞活化增殖、誘導(dǎo)其凋亡,減輕肝纖維化大鼠肝內(nèi)膠原的沉積[2-3]。體外研究結(jié)果顯示,姜黃素可抑制胰腺星狀細(xì)胞的激活[4]。
本實(shí)驗(yàn)應(yīng)用內(nèi)毒素聯(lián)合酒精喂飼造成胰腺病理?yè)p傷,且胰腺組織中淀粉酶和脂肪酶含量均明顯減少,表明酒精性慢性胰腺炎動(dòng)物模型成功建立。應(yīng)用姜黃素干預(yù)治療后,大鼠的胰腺病理?yè)p傷較ANP組降低,膠原纖維量減少,胰腺組織淀粉酶和脂肪酶水平也較ANP組升高。表明姜黃素可通過(guò)抗胰腺纖維化和抑制慢性胰腺炎癥反應(yīng),減少胰腺組織的膠原沉積,減少炎癥細(xì)胞浸潤(rùn),減輕胰腺損傷,改善胰腺外分泌功能。但姜黃素干預(yù)后,胰腺的損傷并非能恢復(fù)到正常,提示其作用有一定局限性。TGF-β1可誘導(dǎo)胰腺星狀細(xì)胞的激活和細(xì)胞外基質(zhì)的合成,刺激胰腺星狀細(xì)胞分泌基質(zhì)金屬蛋白酶,抑制金屬蛋白酶組織抑制劑的分泌,引起細(xì)胞外基質(zhì)降解減少和胰腺細(xì)胞外基質(zhì)蛋白的沉積增加,而活化的胰腺星狀細(xì)胞也可以通過(guò)自分泌作用促進(jìn)自身TGF-β1的表達(dá),產(chǎn)生自身放大效應(yīng),調(diào)節(jié)其他細(xì)胞因子生成,最終導(dǎo)致胰腺纖維化發(fā)生[5]。抑制TGF-β1 信號(hào)可減少細(xì)胞外基質(zhì)蛋白。因此TGF-β1是調(diào)控胰腺纖維化過(guò)程最重要的細(xì)胞因子,TGF-β1表達(dá)持續(xù)增強(qiáng)可能與CP胰腺進(jìn)行性纖維化的發(fā)生有關(guān)。本結(jié)果顯示,姜黃素組的胰腺組織TGF-β1 mRNA表達(dá)量顯著低于ANP組,提示姜黃素可能通過(guò)某種途徑抑制TGF-β1的表達(dá),從而減輕胰腺纖維化。但姜黃素是通過(guò)何種途徑抑制TGF-β1的表達(dá)目前尚不清楚,需進(jìn)一步研究。
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2010-11-23)
(本文編輯:屠振興)
Roleandmechanismofcurcuminonratswithchronicpancreatitis
PENGXiao-hua,ZHOUXu-chun,PANHui.
DepartmentofGastroenterology,FirstAffiliatedHospital,ChongqingMedicalUniversity,Chongqing400016,China
ZHOUXu-chun,Email:chqxchzh@163.com
ObjectiveTo investigate the effect of curcumin on chronic pancreatitis in rat.MethodsEighteen one-month old male SD rats were randomly divided into control group, ANP group and curcumin group with 6 rats in each group. After fed by 25% alcohol for twelve weeks, the rats in ANP group were intraperitoneally injected with lipopolysaccharides (LPS, 2 mg/kg body weight) once a week for 4 weeks. The rats in curcumin group were fed with curcumin when they were intraperitoneally injected with lipopolysaccharides. Seventeen weeks later, the rats were sacrificed. Serum glucose was measured, pancreatic morphology was routinely examined, collagen deposition was determined by Masson stain, and the amylase and lipase in pancreatic tissue were evaluated, TGF-β1 mRNA was determined by using RT-PCR.ResultsThe pathological score of control group, ANP group and curcumin group was 1.17±0.41, 7.33±2.58 and 3.50±1.05, and the score in curcumin group was lower than that of ANP group (P<0.01), but which was higher than that in control group (P<0.05). There was no difference in the serum glucose among the groups. The levels of amylase and lipase in pancreatic tissue were (7348±102), (14135±1272) U/g, which were significantly higher than those in ANP group [(5428±547) and (9123±1250) U/g,P<0.05]. The expressions of TGF β1 mRNA in control group, ANP group and curcumin group were 0.618±0.019, 0.818±0.012, 0.745±0.088, and the values in ANP group were significantly higher than those in control group and curcumin group (P<0.01).ConclusionsOn the basis of long term ethanol intake, repeatedly intraperitoneal injection of LPS can induce chronic pancreatitis, and curcumin has anti-fibrosis effect possibly by its inhibitory effect on the expression of TGF-β1.
Curcumin; Chronic pancreatitis; Endotoxins; Ethanol
10.3760/cma.j.issn.1674-1935.2011.05.013
重慶市衛(wèi)生局科研項(xiàng)目(062096);重慶醫(yī)科大學(xué)校辦課題(QD200508)
400016 重慶,重慶醫(yī)科大學(xué)附屬第一醫(yī)院消化內(nèi)科
周旭春,Email:chqxchzh@163.com