Faculty of Pharmacy Mansoura University Department of Biochemistry Presented by Nada Fawzy Ibrahim AboElMagd B. Pharm. Sci., (2012) Demonstrator at Biochemistry Dept. Faculty of Pharmacy-Mansoura University Supervisors Prof. Dr. Prof. Dr. Mammdouh M. El-Shishtawy Laila A. Eissa Prof. of Biochemistry Faculty of Pharmacy Mansoura University Prof. and Head of Biochemistry Dept. Faculty of Pharmacy Mansoura University Thesis submitted as a Partial Fulfillment for Master Degree in Pharmaceutical Sciences (Biochemistry) 2015 كلية الصيدلة جامعة المنصورة قسم الكيمياء الحيوية رسالة مقدمة من الصيدالنية ندى فوزى ابراهيم ابو المجد غازى بكالوريوس العلوم الصيدلية دور مايو 2102بتقدير عام امتياز مع مرتبة الشرف معيدة بقسم الكيمياء الحيوية كلية الصيدلة -جامعة المنصورة المشرفون أ.د/ممدوح محمد الششتاوي أ.د/ليلى احمد عيسي أستاذ الكيمياء الحيوية كلية الصيدلة جامعة المنصورة أستاذ و رئيس قسم الكيمياء الحيوية كلية الصيدلة جامعة المنصورة كجزء من متطلبات الحصول على درجة الماجستير فى العلوم الصيدلية (الكيمياء الحيوية) 2102 Summary and Conclusion Summary and Conclusion Chronic liver disease is an increasing cause of mortality and morbidity all over the world. Most chronic liver disease like hepatitis B virus, hepatitis C virus and cholestatic liver disease leads to liver fibrosis. Without early treatment of liver fibrosis, it may progress to liver cirrhosis and hepatocellular carcinoma. Usage of anti-fibrotic drugs may halt or reverse fibrosis progression. Usage of anti-oxidant drugs that decrease oxidative stress is an effective strategy to prevent liver fibrosis. So in this study, natural compounds which have anti-oxidant properties have been used to protect against liver fibrosis. The present study aimed to evaluate the hepatoprotective effect of glycyrrhizin (GL) (the major bioactive component of liquorice extract), omega-3 fatty acids (ω-3) (a combination of eicosapentaenoic acid and docosahexaenoic acid) and their combination in thioacetamide (TAA)-induced liver fibrosis in rats. The present study elucidated the effect of GL, ω-3 and their combination on liver lipid peroxidation, liver inactive toll like receptor-4 (TLR-4) concentration, liver TLR-4 gene expression, liver nuclear factor kappa B (NF-κB) concentration and liver NF-κB tissue expression. The studied groups: Fifty male Sprague-Dawley rats were randomized into 5 groups as following: 1) Control group (8 rats): rats received sterile saline i.p. injection twice weekly for 8 weeks. 2) TAA group (12 rats): TAA-induced liver fibrosis. Rats injected 200 mg/kg of TAA in sterile saline solution i.p. twice weekly for 8 weeks. 3) GL group (10 rats): rats received 25 mg/kg of GL in distilled water by oral tube daily along with TAA for 8 weeks. 4) ω-3 group (10 rats): rats received 150 mg/kg of ω-3 by oral tube daily along with TAA for 8 weeks. 5) GL + ω-3 group (10 rats): rats received GL and ω-3 with the same doses by oral tube along with TAA for 8 weeks. - 90 - Summary and Conclusion Twenty-four h after the last dose of treatment, blood samples (around 4 mL) were taken from the retro-orbital puncture under light ether anesthesia after a fast of 12 h. Blood samples were left 20 min to clot, serum was separated by centrifugation then aliquoted for analysis and stored at -80°C for determination of liver function tests: Alanine aminotransferase (ALT) and aspartate aminotransferase (AST) enzyme activities by kinetic methods. Total bilirubin, albumin and total protein concentrations by spectophotomertic methods. Rats were sacrificed by decapitation, and their livers were removed, rinsed in ice cold PBS PH 7.4, blotted dry on a filter paper, weighed and divided into 4 parts as follow: 1- Part was immediately immersed in liquid nitrogen and stored at -80°C for quantitative real-time reverse transcription-polymerase chain reaction (qRTPCR) analysis of the expression of TLR-4 gene. 2- A small part from the right lobe of the liver was cut and fixed in 10% phosphate buffered formalin (pH 7.2) for histopathological examination of: Assessment of necroinflammatory activity grade. Quantification of fibrotic areas. Immunohistochemical detection of NF-κB. 3- 0.5 gm of the liver tissue were homogenized in 5 mL cold PBS, homogenized with ultrasonic homogenizer, centrifuged then the supernatant removed and stored at -80°C for ELISA assay of liver NF-κB. 4- 1 gm of the remaining liver tissue were homogenized in 10 mL cold PBS, centrifuged then the supernatant removed and stored at -80°C in 2 parts, one for spectophotometric assay of malondialdehyde (MDA), and the second for assay of liver inactive TLR-4 by ELISA assay. The most important results of the present study are: 1) Glycyrrhizin, ω-3 and their combination significantly decreased serum AST activity and serum bilirubin level. 2) Glycyrrhizin and ω-3 combination significantly decreased serum ALT activity, while GL or ω-3 individually have no significant effect on serum ALT activity. - 91 - Summary and Conclusion 3) Glycyrrhizin, ω-3 and their combination significantly increased serum albumin and total protein levels so improve liver function and this indicate the protection effect of GL and ω-3 for liver synthetic ability. 4) Significant decrease in both liver necroinflammatory scores and liver fibrotic areas were observed in GL, ω-3 and GL + ω-3 (combination) groups. 5) Glycyrrhizin and ω-3 have anti-oxidant property as GL, ω-3 and their combination significantly decreased liver MDA level so they decrease lipid peroxidation. 6) Glycyrrhizin and ω-3 significantly increased liver inactive TLR-4 level, which indicates inhibition of TLR-4 pathway, which confirmed by the significant decrease of liver TLR-4 gene expression. 7) Glycyrrhizin, ω-3 and their combination significantly decreased liver NF-κB level as they decreased the TLR-4/NF-κB inflammatory cascade pathway. 8) Expression of NF-κB was increased in TAA group that co-localized at the same areas of increased necroinflammation and fibrosis which confirmed the relation between inflammation and both necroinflammation and fibrosis. 9) There are significant negative correlation between liver inactive TLR-4 level and NF-κB level which indicates the relation between TLR-4 activation and inflammatory pathway. 10) There are also significant positive correlation between liver NF-κB and the following parameters liver MDA level, liver necroinflammatory score, the liver percentage of fibrotic area, serum AST activity and serum total bilirubin level which indicates the relation between inhibition of inflammatory regulator, NFκB and the improvement of liver function and inhibition of lipid peroxidation. 11) Liver NF-κB has a significant negative correlation with both serum albumin level and serum total protein level which confirms the relation between inhibition of inflammatory regulator, NF-κB and the improvement of liver synthetic ability. From the results of this work, it can be concluded the following: Glycyrrhizin and ω-3 can be used for protection against liver fibrosis. Toll like receptor-4/NF-κB pathway has a potential role in the pathogenesis of liver fibrosis. - 92 - Summary and Conclusion The mechanism behind hepatoprotective effects of GL and ω-3 included suppression of oxidative stress and inhibition of TLR-4/NF-κB pathway. So, the hepatoprotective effects of GL, ω-3 and their combination against TAAinduced fibrosis appear to be mediated via its antioxidant, anti-inflammatory and anti-fibrotic properties. The protection potency of either GL or ω-3 alone is nearly the same as their combination against liver fibrosis. It is advised to fulfill some clinical studies on these natural compounds as supplementary nutrient to protect against liver fibrosis. - 93 -
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