| Hepatitis is a serious disease. With the entrance of the World Trade Organization, a lot of innovative liver-protective leading compounds and active components of the Chinese herbal medicine will be developed. It will be important to establish a model for efficient screening. Hepatitis is high correlated with the immunologic function. To establish an immunologic liver injury model, which was near to the pathology and physiology of human viral hepatitis, will show its unique ability of investigating the liver-protective drugs. In present study, primary rat hepatocytes cultured technique was used, BCG vaccine were injected to rats in vivo, combined with LPS was administered in vitro to establish an immunologic cytotoxicity-like model. Biphenyldimethylesterate (DDB), malotilate (MLT), silybinin (SB) and glycyrrhizin (GRZ) were coincubated along with the LPS to prevent the cytotoxicity. The model in vivo was prepared to verify the applicability and reliability of the model.Meanwhile, considering the mechanisms of hepatitis and the characteristics of immune response, it was researched that whether nitric oxide (NO), apoptosis andexpression of intercellular adhesion molecular-1 (ICAM-1) were appeared in this model. The aim of this study was to provide the model and technique for the quick and effective evaluation of innovative liver-protective drugs and to clarify the pathologic characters of this model and offer the pathologic rational for the establishment of this model.Major content and result1. Establishment of immunologic cytotoxicity-like model and hepatoprevention of drugsBCG-pretreated rat hepatocytes were isolated using two-step collagenase perfusion technique, followed with the stimulation of 10 mg ?L"1 LPS. Drugs were coincubated along with the LPS. After 3 h, 6 h, 12 h and 24 h, supernatant was collected to measure the AST, LDH activities with routine methods.As a result, in control group, no significant change of AST, LDH was found in 24 h, while in BCG+LPS group, AST, LDH elevated at 3 h, 6 h, 12 h, and 24 h, respectively, in a time-course increase manner (P < 0.05), and all the values were steady at 12 h. The enhancements of AST, LDH at 12 h, which induced by BCG+LPS were all prevented by DDB, MLT, SB and GRZ (P < 0.05). DMSO had no effects on above parameters (P > 0.05).Conclusion: BCG combined with LPS in vitro could induce the immunologic hepatotoxicity; this cytotoxicity could be prevented by DDB, MLT, SB and GRZ; this model could be expected to apply for screening of liver-protective drugs.2. Pharmacodynamics of four liver-protective drugs in vivoTo explore the reliability of the model above, the immunologic rat liver injury in vivo was prepared. Rats were iv BCG, and administered with drugs for 12 d. After the last administration, each rats were iv 2.5 u g LPS. The control rats were not treated. After 6 h, collect the serum to determine the AST, LDH activities with routine method and the NO with Griess method. The liver and spleen were weighed to calculate the liver index and spleen index. Examined the pathologic alterations of liver.Consequently, 6 h after the LPS treated, serum AST, LDH and NO were clear increased (P < 0.05), as well as the liver index and spleen index (P< 0.05 ). 25> 50 mg/kg/d GRZ could inhibit the elevation of AST, NO and liver and spleen index. 150 mg/kg/d DDB could lower the enhancements of AST, LDH, NO and liver index. 100^ 150 mg/kg/d MLT could inhibit the increase of AST and spleen index. 20 > 30 mg/kg/d SB could decrease the increase of AST, LDH and liver and spleen index.( P < 0.05). 0.5 % CMC had no effects on above parameters.Histopathologic evaluation of liver sections from control group showed a normal histopathologic picture without any apparent damages or disruptions. Sections from BCG+LPS group showed clear necrosis in all lobes including a number of focal necrosis or massive and submissive reticular necrosis. Cloudy swelling, ballooning degeneration, fatty degeneration were observed as well. Therewere a large number of inf...
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