盛云華,喬靖怡,金若敏,姚廣濤,周 璐,唐黎明(.上海市食品藥品檢驗(yàn)所,上海 003;.上海中醫(yī)藥大學(xué)藥物安全評(píng)價(jià)研究中心,上海 003;3.河南中醫(yī)學(xué)院,河南鄭州 45006)
基于1H-核磁共振代謝組學(xué)研究黃藥子乙醇提取物致肝損傷的潛在生物標(biāo)志物
盛云華1,2,喬靖怡2,3,金若敏2,姚廣濤2,周 璐2,唐黎明1
(1.上海市食品藥品檢驗(yàn)所,上海 201203;2.上海中醫(yī)藥大學(xué)藥物安全評(píng)價(jià)研究中心,上海201203;3.河南中醫(yī)學(xué)院,河南鄭州 450016)
目的 采用基于1H-核磁共振(NMR)的代謝組學(xué)方法,分析黃藥子乙醇提取物(RDB)致肝損傷大鼠血清和尿液中代謝產(chǎn)物隨時(shí)間的動(dòng)態(tài)變化,探尋RDB肝毒性早期的潛在生物標(biāo)志物。方法 大鼠ig給予RDB 5 g·kg-1,連續(xù)給藥28 d,于給藥后3,7,14和28 d及停藥后7 d(恢復(fù)期)取6只大鼠采血,進(jìn)行常規(guī)血液生化分析;取肝組織,計(jì)算肝指數(shù),并用HE染色進(jìn)行肝組織病理觀察。收集給藥后0,3,7,14和28 d及停藥后7 d血清和尿液,進(jìn)行1H-NMR的代謝組學(xué)研究,采用主成分分析和正交偏最小二乘法分析對(duì)早期潛在生物標(biāo)志物進(jìn)行篩選和鑒別。結(jié)果 與正常對(duì)照組相比,RDB組血清總膽紅素(TB)和總膽固醇(TC)于給藥后3~28 d顯著升高(P<0.05),總膽汁酸(TBA)于7~28 d顯著升高(P<0.05),TB,TC和TBA于停藥后7 d恢復(fù)正常,谷丙轉(zhuǎn)氨酶和谷草轉(zhuǎn)氨酶活性以及葡萄糖含量均無顯著變化。RDB組給藥后肝指數(shù)顯著升高(P<0.01),停藥后7 d恢復(fù)正常;肝組織于給藥后7 d開始出現(xiàn)單細(xì)胞壞死和肝細(xì)胞腫大,隨給藥時(shí)間延長(zhǎng),病變程度加重;停藥7 d后有所恢復(fù)。代謝組學(xué)檢測(cè)顯示,RDB給藥早期血清脂質(zhì)〔低密度脂蛋白(LDL)/極低密度脂蛋白(VLDL)〕、谷氨酸、磷酸膽堿和甘油磷酸膽堿等升高(P<0.05),尿液丙酮酸鹽和N-乙酰谷氨酸等降低(P<0.05);上述代謝產(chǎn)物在停藥7 d后均恢復(fù)正常。結(jié)論 早期肝損傷與糖脂代謝、能量代謝和膽汁淤積有關(guān)。隨著RDB給藥的持續(xù),產(chǎn)生了組織過氧化損傷。線粒體損傷導(dǎo)致體內(nèi)能量代謝不足。血清脂質(zhì)(LDL/VLDL)、谷氨酸、磷酸膽堿和甘油磷酸膽堿,及尿液丙酮酸鹽和N-乙酰谷氨酸均可作為RDB致肝損傷的早期潛在生物標(biāo)志物。
黃藥子;肝損傷;核磁共振;代謝組學(xué);生物標(biāo)志物
DOl:10.3867/j.issn.1000-3002.2016.04.002
近年來,中藥致肝損傷的臨床報(bào)道逐年增多,成為中藥新藥研發(fā)失敗或撤市的主要原因之一[1]。因此,探索高敏感性和特異性的肝毒性的早期潛在生物標(biāo)志物,對(duì)早預(yù)防早治療有著積極的意義。黃藥子(Rhizone Dioscoreae Bulbiferae,RDB)為薯蕷科屬植物黃獨(dú)(Dioscorea bulbifera L.)的塊莖,具有解毒消腫、化痰散結(jié)和涼血止血的作用[2]。RDB的毒性成分為二萜內(nèi)酯類成分,其中黃獨(dú)毒B是毒性成分之一,可引起肝的一系列病理變化[3-4]。
代謝組學(xué)是研究生物體受外部刺激或內(nèi)部基因改變所產(chǎn)生的所有內(nèi)源性代謝產(chǎn)物動(dòng)態(tài)的變化,是從整體分析內(nèi)源性代謝產(chǎn)物的一種技術(shù)方法。代謝組學(xué)技術(shù)常采用高效液相-質(zhì)譜串聯(lián)(HPLC-MS/ MS)、超高壓液相色譜-質(zhì)譜聯(lián)用(UPLC-MS)及核磁共振(1H-NMR)等方法進(jìn)行體內(nèi)代謝產(chǎn)物分析,現(xiàn)已用于對(duì)雄黃、金銀花和芫花等藥物的肝毒性特點(diǎn)與機(jī)制的研究[5-7]。本研究采用基于1H-NMR的代謝組學(xué)方法,結(jié)合血液生化檢測(cè)和肝組織病理觀察,對(duì)RDB乙醇提取物(以下簡(jiǎn)稱RDB)所致肝損傷大鼠的血清和尿液進(jìn)行研究,分析其代謝產(chǎn)物譜隨時(shí)間的動(dòng)態(tài)變化,以期探尋作為RDB肝毒性的早期潛在生物標(biāo)志物的內(nèi)源性代謝產(chǎn)物,為臨床藥物肝毒性早預(yù)警、早治療提供實(shí)驗(yàn)依據(jù),同時(shí)也為藥物肝毒性早期潛在生物標(biāo)志物的研究提供一種實(shí)驗(yàn)?zāi)J健?/p>
1.1黃藥子乙醇提取物的制備
RDB由南京澤朗醫(yī)藥科技有限公司制備,制備工藝:按藥材的8倍量加入70%乙醇,提取2次,每次提取2 h,提取液濃縮,比重為1.5,噴霧干燥后即得RDB粉末。批號(hào):ZL-091217,產(chǎn)品規(guī)格:10∶1,即每克生藥0.1 g提取物,每克提取物含6.7 mg黃獨(dú)毒B,避光儲(chǔ)存于陰涼干燥處。實(shí)驗(yàn)時(shí),稱取一定量RDB粉末,加蒸餾水配制成終濃度為RDB 0.25 g·L-1藥液。
1.2動(dòng)物和主要試劑
Wistar大鼠,60只,雌雄各半,SPF級(jí),體質(zhì)量100~120 g,由上海西普爾-必凱實(shí)驗(yàn)動(dòng)物有限公司提供,動(dòng)物許可證號(hào):SCXK(滬)2008-0016。大鼠均在上海中醫(yī)藥大學(xué)實(shí)驗(yàn)動(dòng)物中心SPF級(jí)飼養(yǎng)室飼養(yǎng)。飼養(yǎng)環(huán)境溫度20~25℃,濕度40%~70%,工作照度12 h明12 h暗,自由飲食飲水。重水和3-三甲基硅烷基-2,2,3,3-四氘代丙酸鈉(TSP)購自美國(guó)Cambridge Isotope Laboratories公司;谷丙轉(zhuǎn)氨酶(glutamic-pyruvic transaminase,GPT)、谷草轉(zhuǎn)氨酶(glutamic-oxaloacetic transaminase,GOT)、總膽固醇(total cholesterol,TC)和葡萄糖(glucose,GLU)檢測(cè)試劑盒,均購自日本世諾臨床診斷制品株式會(huì)社;總膽紅素(total bilirubin,TB)檢測(cè)試劑盒,日本和光純藥工業(yè)株式會(huì)社;總膽汁酸(total bile acid,TBA)檢測(cè)試劑盒,煙臺(tái)澳斯邦生物工程有限公司。
1.3給藥分組和樣本收集
將大鼠隨機(jī)分為正常對(duì)照組和RDB組,每組30只。經(jīng)預(yù)試后RDB組ig給予RDB 5 g·kg-1,給藥體積為20 mL·kg-1,正常對(duì)照組ig給予等容量蒸餾水,連續(xù)給藥28 d。分別于給藥后3,7,14和28 d及停藥后7 d(恢復(fù)期)每組大鼠各取6只,以烏拉坦溶液麻醉后,腹主動(dòng)脈取血,4°C,2292×g離心15 min,取血清進(jìn)行臨床生化指標(biāo)的檢測(cè),余下的血清-80℃凍存用于1H-NMR檢測(cè)。摘肝取左內(nèi)葉固定于10%甲醛溶液中用于組織病理學(xué)檢查。取6只大鼠,于給藥前和給藥3,7,14和28 d及停藥后7 d(恢復(fù)期)收集12 h尿液,收集器中加入1%疊氮鈉溶液,-80℃凍存用于1H-NMR檢測(cè)。
1.4生化和組織病理學(xué)檢測(cè)
采用日立7080全自動(dòng)生化分析儀測(cè)定血清GPT,GOT,TB,TBA和TC和GLU的水平;計(jì)算肝臟指數(shù),肝指數(shù)=肝質(zhì)量(g)/體質(zhì)量(g)×100。HE染色進(jìn)行肝組織病理形態(tài)檢查,根據(jù)損傷程度進(jìn)行病理分級(jí)評(píng)定[8]。
1.5血清和尿液的1H-NMR光譜
取血清400 μL,加入30 μL磷酸鹽緩沖溶液(600 mmol·L-1,pH 7.4),再加入170 μL重水?;靹?,室溫5 min,4℃,13 201×g離心10 min除去雜質(zhì)。取上清500 μL置于5 mm的核磁管中,用于1H-NMR譜的檢測(cè)。1H-NMR實(shí)驗(yàn)采用Varian 600譜儀,其1H共振頻率是599.93 Hz。血清1H-NMR光譜橫向弛豫加權(quán)實(shí)驗(yàn)是用水峰抑制的Carr-Pur?cell-Meiboom-Gill(CPMG)序列,信號(hào)累加次數(shù)128次,弛豫延遲2.1 s。參數(shù)如下:譜寬8000.0 Hz,采集時(shí)間1.0000 s,總回波時(shí)間100 ms。
取尿液500 μL,加入100 μL含TSP的磷酸鹽緩沖溶液(D2O配制,1 mol·L-1,pH 7.4)。混勻,室溫5 min,然后4℃,13 201×g離心10 min。取上清500 μL置于核磁管中。尿1H-NMR光譜采用預(yù)飽和核奧添豪斯效應(yīng)光譜學(xué)(nuclear-Over?hauser-effect spectroscopy,NOESY)序列,信號(hào)累加次數(shù)128次,弛豫延遲2.5 s。參數(shù)同血清檢測(cè)。
1.6數(shù)據(jù)處理
血清NMR譜圖以乳酸在1.33 ppm處的雙峰定標(biāo),積分區(qū)間為9.0~0.5 ppm,積分間距為0.002 ppm。在模式識(shí)別分析前去掉5.23~4.662和4.636~4.438 ppm 2段包含尿素峰和殘余的水峰,以消除溶劑峰和尿素峰的干擾。尿樣NMR譜圖以TSP在0 ppm處的單峰定標(biāo),積分區(qū)間為9.5~0.5 ppm,積分間距為0.005 ppm。去掉6.0~5.5 ppm 和5.36~4.50 ppm 2段包含尿素峰和殘余的水峰。使用TopSpin軟件(V3.0,BrukerBiospin,Germany)對(duì)譜圖進(jìn)行傅立葉變換、相位調(diào)整、基線校正及定標(biāo)等處理,所有譜圖在進(jìn)行傅立葉變換時(shí)均乘以增寬因子為1 Hz的指數(shù)窗函數(shù)。
1.7模式識(shí)別分析和統(tǒng)計(jì)學(xué)分析
使用SIMCA-P+軟件(V11.0,Umetrics AB,Umea,Sweden)對(duì)歸一化后的數(shù)據(jù)進(jìn)行模式識(shí)別多變量分析,依次采用主成分分析(principal component analysis,PCA)和正交偏最小二乘法分析(orthogonal partial least squares-discriminant analysis,OPLS-DA),最大化地凸顯模型內(nèi)部不同組別之間的差異。實(shí)驗(yàn)結(jié)果數(shù)據(jù)以x±s表示,采用SPSS16.0軟件單因素方差分析進(jìn)行組間比較。等級(jí)資料采用非參數(shù)檢驗(yàn)。采用Ridit法對(duì)肝組織病理積分的數(shù)據(jù)進(jìn)行統(tǒng)計(jì)分析。P<0.05認(rèn)為差異有統(tǒng)計(jì)學(xué)意義。
2.1黃藥子乙醇提取物對(duì)大鼠臨床生化和組織病理變化的影響
由圖1所示,與同時(shí)間點(diǎn)正常對(duì)照組相比,RDB組血清TB和TC于給藥后3,7,14和28 d顯著升高(P<0.05,P<0.01);TBA于給藥后7,14和28 d顯著升高(P<0.05,P<0.01);TB,TC和TBA于停藥后7 d恢復(fù)期恢復(fù)正常;血清GPT和GOT活性及GLU含量均無明顯變化。RDB組肝指數(shù)顯著升高(P<0.01),恢復(fù)期肝指數(shù)有所恢復(fù)(圖2)。
Fig.1 Effect of ethanol extract of Rhizoma Dioscoreae Bulbiferae(RDB)on clinical chemical parameters of rat serum.Rats were ig administered with RDB 5 g·kg-1for 28 d.Blood was taken for analysis of glutamine-pyruvic transami?nase(GPT)(A),glutamine-oxaloacetic transaminase(GOT)(B),total bilirubin(TB)(C),total bile acid(TBA)(D),total choles?terol(TC)(E)and glucose(GLU)(F)by automatic biochemical analyzer at 3,7,14 and 28 d after RDB administration,as well as at 7 d after final RDB administration(recovery period),respectively.x±s,n=6.*P<0.05,**P<0.01,compared with normal control group.
Fig.2 Effect of RDB on rat liver indexes.See Fig.1 for the rat treatment.±s,n=6.**P<0.01,compared with normal control group.
光鏡下觀察,與同時(shí)間點(diǎn)正常對(duì)照組相比,在給藥7 d時(shí)RDB組2/6大鼠肝組織開始出現(xiàn)單細(xì)胞壞死,隨給藥時(shí)間增加,損傷加重,在14和28 d時(shí)5/6大鼠肝組織出現(xiàn)單細(xì)胞壞死和肝小葉中心性肝細(xì)胞變性腫大程度加重(P<0.01);停藥7 d后大鼠肝損傷有所恢復(fù)(圖3,表1)。
Fig.3 Liver histomorphology of rats administrated with RDB(HE×200).See Fig.1 for the rat treatment.↑:hepatocytic necrosis;?:hepatocytic degeneration.
2.2.黃藥子乙醇提取物對(duì)大鼠血清代謝組的影響
由圖4可見,與正常對(duì)照組相比,RDB組1H-NMR譜代謝產(chǎn)物有的消除,有的產(chǎn)生;在不同時(shí)間點(diǎn)RDB組之間也如此。
初始PCA顯示,R2X=75.1%,即第1主成分和第2主成分能解釋原始總體信息的75.1%,Q2=0.725,即模型的預(yù)測(cè)能力較好,R2和Q2較為接近,均>0.4,即該模型穩(wěn)定可靠(圖5)。
為進(jìn)一步放大各組間的差異找到含量發(fā)生改變的代謝產(chǎn)物,采用OPLS-DA進(jìn)一步凸顯區(qū)分不同組別的差異代謝產(chǎn)物。OPLS-DA左為得分圖,右為載荷圖(圖6)。載荷圖中標(biāo)示了能區(qū)分組別的差異代謝產(chǎn)物。負(fù)方向則對(duì)應(yīng)對(duì)照組,正方向?qū)?yīng)RDB組。各時(shí)間點(diǎn)對(duì)照組和RDB組比較,出現(xiàn)7種顯著變化的差異代謝產(chǎn)物(表2)。
Tab.1 Ridit analysis of effect on histomorphology in rat liver adminstered with extract from RDB
Fig.4 600 MHz1H-NMR spectra(δ 0.5-5.5 and δ 6.0-9.0)of serum obtained from normal control rats(A)and dosed rats at 3 d(B),7 d(C),14 d(D),28 d(E)and recovery period(F)following RDB administration.See Fig.1 for the rat treatment.The region of δ 6.0-9.0(in the dashed box)was magnified 64 times compared with corresponding region of δ 0.5-5.5 for clarity.1-MH:1-methylhistidene;3-HB:3-hydroxybutyrate;AA:acetoacetate;Ace:acetate;Acet:acetone;Ala:alanine;All:allantion;Cit:citrate;Cr:creatine;Eth:ethanol;For:formate;GL:glycerol of lipids;Gln:glutamine;Glu:glutamate;Gly:glycine;GPC:glycerolphosphocholine;Ileu:isoleucine;L1:low density lipoprotein/very low density lipoprotein(LDL/VLDL),L2:LDL,L3:VLDL,L4:VLDLL5:lipid,L6:lipid,L7:lipid,L8:lipid,L9:lipid,-CH=CH-;Lac:lactate;Leu:leucine;Lys:lysine;MA:methylamine;NAG:N-acetyl glycoprotein signals;PC:phosphocholine:Phe:phenylalanine;Py:pyruvate;TMA:trimethylamine;Tyr:tyrosine;Val:valine;Ur:urethane;α-Glc:α-glucose;β-Glc:β-glucose;HOD:mixture of water and deuterium oxiue;m-I:myo-inositol.
由表2可見,RDB給藥后,3~28 d血清中α-葡萄糖、β-葡萄糖降低;3~28 d磷酸膽堿、甘油磷酸膽堿升高;3 d和14~28 d脂質(zhì)〔低密度脂蛋白/極低密度脂蛋白,(low density lipoprotein/very low density lipoprotein,LDL/VLDL)〕升高;3~7 d和28 d三甲胺升高;7和28 d谷氨酸升高;恢復(fù)期除谷氨酸升高之外,其他代謝產(chǎn)物均恢復(fù)正常。
Fig.5 Principal component analysis(PCA)of1H-NMR spectra of serum obtained from normal control group and RDB treated group at various time points.See Fig.1 for the rat treatment.T3,T7,T14,T28 and R represent 3,7,14,28 d and recovery period of RDB group,respectively;C3,C7,C14,C28 and C represent 3,7,14,28 d and recovery period of normal control group,respectively.
Fig.6 Significance of metabolite variations between normal control and RDB groups at 3(A),7(B),14(C),28(D)d and recovery period(E)following RDB administration by orthogonal partial least squares-discriminant analysis (OPLS-DA)of1H-NMR spectra of serum.See Fig.1 for the rat treatment.See Fig.4 for the abbreviations.
Tab.21H-NMR spectral data of chemical shifts and changes in selective metabolites detected in serum from rats treated by RDB
2.3黃藥子乙醇提取物對(duì)大鼠尿代謝組學(xué)的影響
與正常對(duì)照組相比,RDB組1H-NMR譜代謝產(chǎn)物有的消除,有的產(chǎn)生;恢復(fù)期組1H-NMR譜無明顯差異(圖7)。
初始PCA顯示,R2X=53.0%,Q2=0.394,即第1主成分和第2主成分能解釋原始總體信息的53.0%,由PCA的得分圖見到與正常對(duì)照組相比,給藥后各時(shí)間點(diǎn)的在前2個(gè)主成分上能明顯區(qū)分開。從尿樣的代謝軌跡圖來看,大鼠的代謝呈有規(guī)律的變化,在恢復(fù)期已呈代謝轉(zhuǎn)歸現(xiàn)象(圖8)。
采用OPLS-DA,對(duì)PLS-DA模型進(jìn)行正交校正處理,進(jìn)一步凸顯區(qū)分不同組別的差異代謝產(chǎn)物。載荷圖中標(biāo)示了能區(qū)分組間差異的代謝產(chǎn)物(圖9)。各時(shí)間點(diǎn)RDB組與正常對(duì)照組比較,顯著變化的差異代謝產(chǎn)物見表3。
由表3可見,RDB給藥后,3~28 d尿中m-羥基苯乙酸、苯乙酰甘氨酸、丙酮酸、丙二酸二甲酯和α-羥基丁酸降低;3~14 d丙氨酸和乙酸降低;3和14~28 d牛磺酸降低;7和28 d乙酰乙酸降低;3和14 d N-乙酰谷氨酸降低;14~28 d N-甲基煙酰胺降低。3~28 d馬尿酸、α-羥基異戊酸和煙堿酸升高;3 和14~28 d p-羥基苯乙酸升高;3和14 d三甲胺和二甲胺升高;3和28 d丙二酸升高。尿液中差異代謝產(chǎn)物在恢復(fù)期均恢復(fù)正常。
Fig.7 600 MHz1H-NMR spectra(δ 0.8-4.5 and δ 5.3-9.5)of urine at various time points following administration of RDB.See Fig.1 for the rat treatment.The region of δ 5.3-9.5(in the dashed box)was magnified 4 times compared with corre?sponding region of δ 0.8-4.5 for the purpose of clarity.A:normal control group;B:3 d RDB group;C:7 d RDB group;D:14 d RDB group;E:28 d RDB group;F:recovery period group.AM:acetamide;B:butyrate;Cn:creatinine;DMA:dimethylamine;DMG:dimethylglycine;Hip:hippurate;IB:isobutyrate;M:malonate;m-HPA:m-hydroxaphenylacetate;MM:methylmalonate;N:nicotinate;NM:N-methylnicotinamide;PAG:phenylacetyllycine;p-HPA:p-hydroxyphenylacetate;Suc:succinate;Tau:taurine;TMAO:trimethylamine-N-oxide;α-HB:α-hydroxybutyrate;α-HIB:α-hydrxoy-iso-butyrate;α-HIV:α-hydrxoy-iso-valerate;α-HV:α-hydroxy-nvalerate;α-Kg:α-ketoglutarate.
Fig.8 PCA of1H-NMR spectra of urine from rats following administration of RDB.See Fig.1 for the rat treatment.T0,T3,T7,T14,T28 and TR represent pre-treatment,3,7,14,28 d and post-treatment.The bigger symbols represent the average values in the respective group.
Fig.9 OPLS-DA of1H-NMR spectra of urine from rats following administration of RDB at different time points. See Fig.1 for the rat treatment.The significance of metabolites variations between the control group and RDB group at 3(A),7(B),14(C),28(D)d and recovery period(E)following the administration.See Fig.7 for the abbreviations.
Tab.31H-NMR spectral data of chemical shifts and changes in selective metabolites in rats treated by RDB
本研究采用1H-NMR的檢測(cè)方法,高分辨率的1H-NMR能對(duì)藥物干預(yù)后大量的低分子化合物進(jìn)行檢測(cè)。根據(jù)前期預(yù)實(shí)驗(yàn)研究[9],分析RDB致肝損傷大鼠的血清和尿液代謝產(chǎn)物隨時(shí)間的動(dòng)態(tài)變化,結(jié)合血清生化和組織病理學(xué)的檢測(cè),探尋RDB肝毒性的早期潛在生物標(biāo)志物。
實(shí)驗(yàn)結(jié)果顯示,給藥后肝損傷經(jīng)典血清生化指標(biāo)GPT和GOT無明顯變化,與RDB致肝損傷膽汁淤積機(jī)制相關(guān)的TB,TBA和TC升高,肝指數(shù)升高,肝組織給藥7 d開始出現(xiàn)單細(xì)胞壞死與肝細(xì)胞腫大,隨給藥時(shí)間延長(zhǎng),病變程度加重,上述各指標(biāo)在恢復(fù)期有所恢復(fù)。代謝組學(xué)檢測(cè)顯示,給藥后血清中α-葡萄糖、β-葡萄糖降低、磷酸膽堿、甘油磷酸膽堿、三甲胺、谷氨酸和脂質(zhì)(LDL/VLDL)升高,恢復(fù)期除谷氨酸升高外,其他代謝產(chǎn)物均恢復(fù)正常。尿液中m-羥基苯乙酸、苯乙酰甘氨酸、丙酮酸、丙二酸二甲酯和α-羥基丁酸降低,丙氨酸、乙酸、?;撬?、乙酰乙酸、N-乙酰谷氨酸和N-甲基煙酰胺降低,馬尿酸、α-羥基異戊酸、煙堿酸、p-羥基苯乙酸、三甲胺、二甲胺和丙二酸升高。其中血清磷酸膽堿、甘油磷酸膽堿和脂質(zhì)(LDL/VLDL),尿液丙酮酸、乙酰乙酸和N-乙酰谷氨酸在給藥早期就發(fā)生變化。血清及尿液代謝產(chǎn)物的變化早于血清GPT、GOT和肝組織病理變化。
代謝組學(xué)檢測(cè)顯示,血中LDL和VLDL均升高。LDL是富含膽固醇的脂蛋白粒子,直徑約18~25 nm,負(fù)責(zé)在血液內(nèi)運(yùn)載脂肪酸分子至全身供細(xì)胞使用。LDL是由肝生成的VLDL代謝而來。血漿中65%~70%的LDL是依賴LDL受體清除,一旦LDL受體缺陷,VLDL殘粒由正常時(shí)大部分經(jīng)肝LDL受體識(shí)別,而改為大部分轉(zhuǎn)變成LDL,使血漿中LDL濃度增加。Zira等[10]報(bào)道,急性肝損傷時(shí),血清LDL和VLDL升高。RDB給藥后,各時(shí)間點(diǎn)血清TC含量顯著升高,肝指數(shù)增大,組織病理學(xué)檢查結(jié)果也顯示隨給藥時(shí)間的延長(zhǎng),肝細(xì)胞變形腫大的程度加重,同時(shí)肝細(xì)胞受損,膽汁淤積,導(dǎo)致脂類代謝受到影響,脂類物質(zhì)在肝內(nèi)蓄積,肝細(xì)胞脂肪樣變性引起肝腫脹,表明血清代謝產(chǎn)物L(fēng)DL/VLDL的變化與常規(guī)檢測(cè)指標(biāo)結(jié)果均相吻合,反映了肝損傷。
代謝組學(xué)檢測(cè)顯示尿液丙酮酸鹽含量降低,丙酮酸鹽作為與糖脂代謝相關(guān)的中間代謝產(chǎn)物含量均降低,提示了糖脂代謝受阻,上述中間產(chǎn)物進(jìn)入三羧酸循環(huán)的過程受到抑制。機(jī)體的能量代謝主要在線粒體中進(jìn)行,因此三羧酸循環(huán)過程受抑提示線粒體的功能可能發(fā)生異常,這與劉樹民等[11]報(bào)道的RDB致肝損傷的機(jī)制與內(nèi)質(zhì)網(wǎng)應(yīng)激和線粒體途徑引起的的細(xì)胞凋亡有關(guān)相一致。
血清代謝產(chǎn)物谷氨酸可與體內(nèi)甘氨酸、半胱氨酸合成體內(nèi)天然抗氧化劑谷胱甘肽,谷胱甘肽是機(jī)體內(nèi)的重要的防御自由基氧化的天然抗氧化劑,其作用為保護(hù)細(xì)胞免受氧化損傷。曾有文獻(xiàn)報(bào)道,RDB致肝損傷時(shí)肝組織中天然抗氧化劑谷胱甘肽過氧化物酶(GSH-PX)及超氧化物酸化酶(SOD)活性明顯降低[12]。本研究中血清谷氨酸升高表明可能是由于藥物的干預(yù),機(jī)體加強(qiáng)了調(diào)節(jié)氧化與抗氧化的平衡而反饋性地增加谷胱甘肽合成,導(dǎo)致尿谷氨酸的含量降低,
血清代謝產(chǎn)物檢測(cè)顯示,磷酸膽堿和甘油磷酸膽堿的含量增高。膽堿類物質(zhì)主要在肝腎中被氧化成甜菜堿,當(dāng)肝腎受損,膽堿類物質(zhì)代謝途徑會(huì)受阻,從而造成膽堿成分增多,這一變化提示RDB對(duì)肝造成了損傷。
本研究中,RDB在給藥期間血清GLU水平均較正常對(duì)照組偏低;在恢復(fù)期GLU水平恢復(fù)正常。血清代謝產(chǎn)物檢測(cè)顯示,在整個(gè)給藥過程中,血清GLU亦降低,這與文獻(xiàn)報(bào)道的血糖升高為急性肝損傷的標(biāo)志物[13]有所不同。機(jī)體供能主要依靠GLU有氧氧化,我們推測(cè),在RDB給藥后,當(dāng)肝細(xì)胞受損傷,GLU有氧氧化作用過程被抑制,肝細(xì)胞以無氧酵解來代償能量的供應(yīng)不足,因此乳酸含量增加,這與給藥后血清中乳酸先降后升是一致的。同時(shí)由于丙酮酸參與糖、脂代謝,是合成丙氨酸的前體物質(zhì),檢測(cè)結(jié)果顯示,尿液的丙酮酸和丙氨酸下降,表明糖、脂代謝紊亂。
尿液的差異代謝產(chǎn)物檢測(cè)顯示,?;撬岷拷档?,這與文獻(xiàn)報(bào)道的肝損傷時(shí)尿?;撬岷可卟灰恢?。膽汁中膽汁酸是由甘氨酸和牛磺酸結(jié)合而來,是膽汁的主要成分。現(xiàn)已知RDB肝毒性的特征為膽汁淤積型,推測(cè)可能由于膽汁不能順利排出,造成膽汁成分反流至血液,因而血清中膽汁酸增高,?;撬岷吭黾樱蚺;撬岷肯陆?,這一現(xiàn)象尚需進(jìn)一步驗(yàn)證。
尿液的代謝產(chǎn)物苯乙酸類、馬尿酸、三甲胺和二甲胺在給藥后降低。苯乙酸類主要是食物中蛋白經(jīng)腸道菌群分解而來,馬尿酸鹽芳環(huán)類氨基酸的產(chǎn)物[15],三甲胺、二甲胺及三甲胺氧化物是由腸道菌群代謝產(chǎn)生,尿液的代謝產(chǎn)物含量降低可能是RDB對(duì)腸道菌群與機(jī)體的共生關(guān)系有所影響,提示腸道微生物菌群受到了影響。
血清脂質(zhì)(LDL/VLDL)、谷氨酸、磷酸膽堿和甘油磷酸膽堿,及尿液丙酮酸鹽和N-乙酰谷氨酸在給藥早期就發(fā)生變化,反映了早期肝損傷與糖代謝、脂代謝、能量代謝和膽汁淤積有關(guān),隨著給藥的持續(xù),產(chǎn)生了過氧化損傷及線粒體損傷。代謝產(chǎn)物的變化早于血清GPT、GOT和肝組織病理的變化。因此提示,上述代謝產(chǎn)物可作為RDB致肝損傷的早期潛在生物標(biāo)志物。
基于1H-NMR的代謝組學(xué)研究采用的是動(dòng)物血液和尿液,結(jié)合血液生化和組織病理學(xué)常規(guī)檢查,動(dòng)態(tài)監(jiān)測(cè)藥物毒性的發(fā)生發(fā)展過程,有利于藥物早期肝毒性的連續(xù)監(jiān)測(cè)和預(yù)警。本研究對(duì)已公認(rèn)的肝毒性中藥RDB進(jìn)行了肝毒性早期潛在生物標(biāo)志物探索性研究,也為其他肝毒性中藥研究早期潛在生物標(biāo)志物的實(shí)驗(yàn)研究提供了陽性對(duì)照藥及實(shí)驗(yàn)?zāi)J健?/p>
致謝:感謝上海阿趣生物科技有限公司鄧軍亮對(duì)實(shí)驗(yàn)數(shù)據(jù)分析給予的幫助。
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(本文編輯:齊春會(huì))
Metabonomic study on early biomarkers of hepatic injury induced by ethanolic extract from Rhizoma Dioscoreae Bulbiferae in rats based on1H-NMR
SHENG Yun-hua1,2,QIAO Jing-yi2,3,JIN Ruo-min2,YAO Guang-tao2,ZHOU Lu2,TANG Li-ming1
(1.Shanghai Institute for Food and Drug Control,Shanghai 201203,China;2.Drug Safety Evaluation and Research Center,Shanghai University of Traditional Chinese Medicine,Shanghai 201203,China;3.Henan University of Traditional Chinese Medicine,Zhengzhou 450016,China)
OBJECTlVE Dynamics of serum and urine metabolites in hepatic injury rats induced by ethanolic extract from Rhizoma Dioscoreae Bulbiferae(RDB)was investigated by1H-NMR-based metabo?nomic methods in order to discover early biomarkers of liver toxicity induced by RDB.METHODS Rats were ig adminisetred with RDB at a dose of 5 g·kg-1for 28 d.Rats were sacrificed 3,7,14 and 28 d af?ter RDB administration,as well as after a recovery period,respectively.Blood was taken for routine bio?chemical analysis by an automatic biochemical analyzer.Liver/body mass indexes were calculated,and liver pathological changes were observed with hematoxylin-eosin staining.Urine samples were collected before and 3,7,14 and 28 d after RDB administration,respectively,as well as after withdrawal.Metabo?nomic analysis was carried out for serum and urine samples.Principal component analysis and orthogonal partial least squares-discriminant analysis were used for screening and identifiying early biomarkers.RESULTS Compared with the control group,total bilirubin(TB)and total cholesterol(TC)values were increased in 3-28 d in RDB group(P<0.05,P<0.01).Total bile acid(TBA)was elevated in 7-28 d (P<0.05,P<0.01).TB,TC and TBA became normal after discontinuation with RDB.There was no significant difference between RBD-treated group and control group in the activity of glutamic-pyruvic transaminase and glutamic-oxaloacetic transaminase,and the content of glucose also was not different between the two groups.The ratio of liver/body mass was elevated at 3-28 d(P<0.01)but returned to normal after withdraval of RDB.The enlargement and necrosis of hepatocytes were observed 7 d after RDB administration,and lesion degree was aggravated with the extension of RDB delivery time.Meta?bonomic analysis showed that the serum lipids(low density lipoprotein/very low density lipoprotein (LDL/VLDL),glutamic acid,choline phosphate and glycerolphosphatecholine were increased in the early stage.Pyruvate and N-acetylglutamate were decreased in urine.These metabolites became normal 7 d after discontinuation with RDB.CONCLUSlON The serum lipids(LDL/VLDL),glutamic acid,glycerol phosphate choline,as well as urine pyruvic acid salt and N-acetyl glutamate may be used as the early biomarkers for liver toxicity induced by RDB.
Rhizoma Dioscoreae Bulbiferae;liver injury;nuclear magnetic resonance;metabo?nomics;biomarker
The project supported by National Key Basic Research and Development Program(973 Program)(2009CB522807);and National Science and Technology Major Project of China(2009ZX0902-002)
JIN Ruo-min,E-mail:rmj801@126.com,Tel:(021)51322401
R965
A
1000-3002-(2016)04-0306-11
國(guó)家重點(diǎn)基礎(chǔ)研究發(fā)展計(jì)劃(973計(jì)劃)(2009CB522807);國(guó)家科技重大專項(xiàng)(2009ZX0902-002)
盛云華,博士研究生,從事藥檢藥理與毒理研究;金若敏,研究員,博士生導(dǎo)師,從事中藥新藥及毒理學(xué)研究。
金若敏,E-mail:rmj801@126.com
2016-03-31接受日期:2016-04-10)