| Abstract | 第1-14页 |
| 摘要 | 第14-17页 |
| Abbreviations | 第17-22页 |
| Introduction | 第22-25页 |
| Part one Review of literature | 第25-47页 |
| Chapter 1 Aflatoxin B1 | 第25-33页 |
| ·Background | 第25-26页 |
| ·Introduction | 第26-27页 |
| ·Chemical nature of aflatoxin | 第27-28页 |
| ·Occurrence of aflatoxin | 第28-29页 |
| ·Maximum tolerable limit of aflatoxin B1 | 第29页 |
| ·Mechanism of Action | 第29-30页 |
| ·Oxidative stress | 第30-33页 |
| Chapter 2 Selenium | 第33-41页 |
| ·Selenium | 第33页 |
| ·Selenium history | 第33-34页 |
| ·Chemical nature of selenium | 第34页 |
| ·Natural occurrence of selenium | 第34-35页 |
| ·Importance as dietary element | 第35页 |
| ·Forms of selenium | 第35-36页 |
| ·Metabolism of selenium | 第36-37页 |
| ·Nutritional requirement of selenium for different animals | 第37-38页 |
| ·Selenoprotein | 第38-39页 |
| ·Antioxidant enzyme | 第39-41页 |
| Chapter 3 Beta-carotene | 第41-47页 |
| ·Carotenoids | 第41页 |
| ·History | 第41-43页 |
| ·Beta-carotene | 第43页 |
| ·Bioavailability of beta-carotene | 第43-44页 |
| ·Chemical nature of beta carotene | 第44-45页 |
| ·Metabolism of beta carotene | 第45-46页 |
| ·Nutritional requirement of beta carotene for different animals | 第46-47页 |
| Part 2 Research work | 第47-123页 |
| Chapter 4 Cytotoxicity of AFB1 and protective effect of selenomethionine and sodium selenite in MDCK cells | 第47-67页 |
| ·Introduction | 第48-50页 |
| ·Material and method | 第50-57页 |
| ·Materials | 第50页 |
| ·Sterilization of glass wares | 第50页 |
| ·Preparation of culture media | 第50-51页 |
| ·Preparation of D-hanks | 第51页 |
| ·Preparation of trypsin | 第51页 |
| ·Preparation of AFB1 stock solution | 第51页 |
| ·Preparation of MTT stock solution | 第51页 |
| ·Cell culture | 第51-53页 |
| ·Experimental design | 第53-54页 |
| ·MTT assay with toxin | 第54-55页 |
| ·Determination of IC50 for AFB1 | 第55页 |
| ·MTT assay with selenium and aflatoxin | 第55-56页 |
| ·Measurement of lactic dehydrogenase activity in the incubation medium | 第56页 |
| ·Statistical analysis | 第56-57页 |
| ·Results | 第57-63页 |
| ·Cytotoxic effects of various concentrations of aflatoxin B1 on MDCK cells | 第57-59页 |
| ·Protective effect of SeMet against AFB1 induced toxicity | 第59-60页 |
| ·Protective effect of sodium selenide against AFB1 induced toxicity | 第60-61页 |
| ·Effect of AFB1 and SeMet on LDH release | 第61-62页 |
| ·Effect of AFB1 and SS on LDH release | 第62-63页 |
| ·Discussion | 第63-67页 |
| Chapter 5 Selenomethionine and sodium selenite ameliorate cytotoxicity of AFB1 by improving antioxidationability in MDCK cells | 第67-95页 |
| ·Introduction | 第68-71页 |
| ·Material and Methods | 第71-79页 |
| ·Materials | 第71-72页 |
| ·Sterilization of glass wares | 第72页 |
| ·Preparation of culture media | 第72页 |
| ·Preparation of D-hanks | 第72页 |
| ·Preparation of trypsin | 第72页 |
| ·Cell culture and treatment | 第72-74页 |
| ·Experimental design | 第74-75页 |
| ·Preparation of cell lysates | 第75页 |
| ·Determination of protein concentration | 第75页 |
| ·MDA determination | 第75-76页 |
| ·GSH determination | 第76-77页 |
| ·GPX1 activity assay | 第77页 |
| ·Determination of GPX1 mRNA through quantitative RT-PCR | 第77-79页 |
| ·Statistical analysis | 第79页 |
| ·Results | 第79-87页 |
| ·Effect of AFB1 and SeMet on MDA release | 第79-80页 |
| ·Effect of AFB1 and SS on MDA release | 第80-81页 |
| ·Effect of AFB1 and SeMet on intracellular GSH | 第81-82页 |
| ·Effect of AFB1 and SS on intracellular GSH | 第82-83页 |
| ·Effect of AFB1 and SeMet on Gpx1 activity | 第83-84页 |
| ·Effect of AFB1 and SS on Gpx1 activity | 第84-85页 |
| ·Effect of AFB1 and SeMet on GPX1 mRNA expression | 第85-86页 |
| ·Effect of AFB1 and SS on GPX1 mRNA expression | 第86-87页 |
| ·Discussion | 第87-95页 |
| Chapter 6 Beta-carotene ameliorates AFB1-induced cytopathogenicity and apoptosis in MDCK cells throughregulation of Bcl-2 mRNA and caspase-3 activity | 第95-123页 |
| ·Introduction | 第96-98页 |
| ·Material and methods | 第98-106页 |
| ·Materials | 第98页 |
| ·Sterilization of glass wares | 第98-99页 |
| ·Preparation of culture media | 第99页 |
| ·Preparation of D-hanks | 第99页 |
| ·Preparation of trypsin | 第99页 |
| ·Preparation of AFB1 stock solution | 第99页 |
| ·Preparation of MTT stock solution | 第99-100页 |
| ·Cell culture | 第100-101页 |
| ·Experimental design | 第101-102页 |
| ·Beta-carotene treatments and cell viability assay | 第102页 |
| ·Protective effect of beta-carotene against AFB1 | 第102页 |
| ·Cytopathological examination | 第102-103页 |
| ·Preparation of cell lysates | 第103页 |
| ·Determination of protein concentration | 第103页 |
| ·MDA determination | 第103-104页 |
| ·GSH determination | 第104页 |
| ·Caspase-3-activity | 第104-105页 |
| ·Bcl2 mRNA quantification | 第105-106页 |
| ·Statistical analysis | 第106页 |
| ·Results | 第106-119页 |
| ·Cytotoxic effects of various concentrations of AFB1 on MDCK cells | 第106-108页 |
| ·Protective effect of beta-carotene | 第108-110页 |
| ·Protective effect of beta-carotene against AFB1 induced toxicity | 第110-112页 |
| ·Cytopathological examination | 第112-115页 |
| ·Effect of AFB1 and beta-carotene on MDA release | 第115-116页 |
| ·Effect of AFB1 and beta-carotene on Intracellular GSH | 第116-117页 |
| ·Bcl2 mRNA quantification | 第117-118页 |
| ·Caspase-3-activity | 第118-119页 |
| ·Discussion | 第119-122页 |
| ·Conclusion | 第122-123页 |
| Summary of the thesis | 第123-127页 |
| New knowledge | 第127-129页 |
| Publications | 第129-131页 |
| ACKNOWLEDGEMENTS | 第131-133页 |
| References | 第133-144页 |
