大黄素对急性淤胆型肝炎模型大鼠的治疗作用及机制

Therapeutic effects of emodin on acute cholestatic hepatitis and mechanism thereof： experiment with rats

目的初步探讨大黄素对急性淤胆型肝炎模型大鼠的治疗作用及机制。方法SD大鼠分为5组：大黄素组、熊去氧胆酸组、地塞米松组、模型组、正常对照组，各24只。除正常对照组外，其余4组均给予α-异硫氰酸萘酯（ANIT）50mg／kg一次灌胃大鼠建立淤胆型肝炎动物模型，并给予相应的药物干预。造模后24、48、72h3个时间点采集标本（每时间点8只），检测肝功能和肝脏病理学检查。实时荧光定量PCR检测肝组织中细胞因子诱导的中性粒细胞趋化因子1（CINC-1）、巨噬细胞炎症蛋白2（MIP-2）mRNA表达，Western印迹法检测肝组织中细胞间黏附分子1（ICAM-1）蛋白表达。结果大黄素组24、48、72h各时问点总胆红素[TB，（32．8±3．7）μmol／L、（61．0±16．4）μmol／L、（10．8±4．5）μmol／L]，直接胆红素[DB，（26．03±3．10）μmol／L、（49．40±18．16）μmol／L、（8．04±3．03）μmol／L]，丙氨酸氨基转移酶[ALT，（314±50）U／L、（664±97）U／L、（200±60）U／L]均明显低于模型组（均P〈0．05），天冬氨酸氨基转移酶（AST）48、72h时间点、碱性磷酸酶（ALP）48h、γ-谷氨酰转移酶（GGT）72h、总胆汁酸（TBA）48、72h时间点均明显低于同时间点模型组（均P〈0．05）；TB24、48h，DB、ALT24h，TBA24h[（204±55）μmol／L]、72h，均明显低于同时间点熊去氧胆酸组（均P〈0．05）；TB、TBA24、48h，ALT、AST、GGT各时间点，时间点均明显低于同时间点地塞米松组（均P〈0．05）。各时间点大黄素组的CINC-1、MIP-2mRNA表达和ICAM．1蛋白表达水平均明显低于同时间点模型组（均P〈0．05）。结论大黄素治疗ANIT诱导的急性淤胆型肝炎模型大鼠的作用以降低TB、DB、ALT最为显著，起效比熊去氧胆酸快，其对ALT、AST、GGT、TBA的作用优于地塞米松。其作用机制可能与抑制CINC-1、MIP-2、ICAM．1的活化有关。

Objective To investigate the therapeutic effects of emodin on acute cholestatic hepatitis and mechanism thereof. Methods 96 SD rats were randomly divided into 4 groups to be treated with emodin, ursodeoxycholic acid, dexamethasone, or normal saline respectively for 4 days. On the 5th day gastric peffusion of alpha-naphthylisothiocyanate （ANIT） was performed to establish models of cholestatic hepatitis. 4-6 hours after the establishment of model the above mentioned agents were given continuously. 24, 48, and 72 hours after the model establishment blood samples were collected from abdominal aorta to examine the total bilirubin （TB）, direct bilirubin （DB）, alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, alkaline phosphatase （ALP）, gamma glutamyltransferase （GGT）, and total bile acid （TBA）. Specimen of liver was collected to undergo pathological examination. PCR was used to detect the mRNA expression of eytokine-induced neutrophil chemoattractant 1 （CINC-1） and macrophage inflammatory protein 2 （MIP-2）, and Western blotting was used to detect the protein expression of intercellular adhesion molecule 1 （ ICAM-1 ） . Twenty-four rats treated with NS only were used as controls. Results The pathological changes of behaviors and liver of the emodin and ursodeoxycholic acid groups were all remarkably milder than those of other model groups. The levels of TB [ （ 32.8 ± 3.7 ） μmol/L, （61.0 ±16.4）μ mol/L, （10.8 ±4.5） μmol/L], DB[ （26.03±3.10）μmol/L, （49.40 ±18.16） μmol/ L, （8.04±3.03）μmol/L], and ALT [ （314 ±50）U/L, （664 ±97）U/L, （200 ±60） U/L], at the time points 24, 48, and 72 hours , the 48 and 72 hours AST levels, the 48 hours ALP level, the 72 hours GGT level , and the 48 and 72 hours TBA levels of the emodin group were all significantly lower than those of the model group （ all P 〈 0.05 ）. The 24 and 48 hours TB levels, 24 hours DB and ALT, and 24,72 hours TBA levels of the emodin group were all significantly lower than those of the ursodeoxycholie acid group （ all P 〈 0.05）. The 24,48 hours TB and TBA levels, and the ALT,AST and GGT levels at all time points of the emodin group were all significantly lower than those of the dexamethasone group （ all P 〈 0.05 ）. The CINC- 1 and MIP-2 mRNA expression levels and ICAM-1 protein expression levels at all time points of the emodin group were all significantly lower than those of the model group （ all P 〈 0.05 ）. Conclusion Decreasing the levels of TB, DB and ALT in particular, emodin has a protective effect on cholestatic hepatitis. Its effects are quicker than ursodeoxycholic acid, and it has better effects on ALT, AST GGT, and TBA than dexamethasone . These effects may be due to inhibition of the activation of CINC-1, MIP-2, and ICAM-1.