声明
Acknowledgements
CONTENTS
LIST OF TABLES
LIST OF FIGURES
ABBREVIATIONS
ABSTRACT
摘要
CHAPTER 1 General Introduction and Review of Literature
1．1 Cadmium in soil
1．2 Cadmium in food
1．3 Dietary intake of cadmium by human
1．4 Bioaccessibility and bioavailability of cadmium to human
1．4．1 Small intestinal absorption of cadmium
1．4．2 Distribution of cadmium after absorption
1．5 Cadmium induced toxicity in human liver
1．5．1 Cellular defense systems and thiol status
1．5．2 Enhancement of lipid peroxidation
1．5．3 Cellular enzymes and cadmium
1．6 Objectives of the study
CHAPTER 2 Impact Assessment of Cadmium Toxicity and its Bioavailability in Human Cell Lines (Caco-2 and HL-7702)
2．1 Introduction
2．2 Materials and methods
2．2．1 Chemicals and reagents
2．2．2 Preparation of the cadmium solutions
2．2．3 Cell culture
2．2．4 Cd uptake
2．2．5．Cytotoxieity assays
2．2．6 Enzyme assays
2．2．7．Protein assay
2．2．8．Statistical analysis
2．3 Results and discussion
2．3．1 Cellular Cd uptake
2．3．2 Effect of cadmium on LDH release and mitochondrial activity (MTT)
2．3．3 Effect of Cd on antioxidant enzymes activity
2．3．4 Effect of Cd on differentiation marker enzyme (AKP)
CHAPTER 3 In Vitro Determination of Cadmium Bioaceessibility and Bioavailability in Contaminated Soils and its Subsequent Toxicity in Normal Human Liver (HL-7702) Cells
3．1 Introduction
3．2 Materials and methods
3．2．1 Chemicals and reagents
3．2．2 Soil collection and analysis
3．2．3 Total Cd of soil samples
3．2．4 Oral bioaccessibility of soil Cd
3．2．5 Cell culture
3．2．6 Cd bioavailability assays by Caco-2 cells
3．2．7 Toxicity assays via normal human liver (HL-7702) cell
3．2．8 Transmission electron microscopic studies
3．2．9 Quality control of cadmium analysis
3．2．10 Statistical analysis
3．3 Results
3．3．1 Physico-chemical properties of soil
3．3．2 Cadmium bioaccessibility in soils
3．3．3 Cadmium bioavailability in contaminated soils
3．3．4 Cytotoxicity assays
3．3．5 Effect of Cd on lipid peroxidation and hydrogen peroxide activity in HL-7702 cells
3．3．6 Effect of Cd on antioxidant (SOD，GPx) activities in HL-7702 cells
3．3．7 Ultrastructural changes in HL-7702 cells
3．4 Discussion
CHAPTER 4 Uptake of Cadmium by Rice Grown on Contaminated Soils and its Bioavailability／Toxicity in Human Cell Lines (Caco-2／HL-7702)
4．1 Introduction
4．2 Materials and methods
4．2．1 Chemicals and reagents
4．2．2 Glass house experiment，sampling and analysis
4．2．3 Chemical analysis
4．2．4 Cadmium bioavailability and toxicity assays
4．2．5 Cadmium toxicity assays in HL-7702 cells
4．2．6 Transmission electron microscopy
4．2．7 Quality control of cadmium analysis
4．2．8 Statistical analysis
4．3 Results
4．3．1 Physico-chemical properties of soils
4．3．2 Yield of rice grain
4．3．3 Cd concentration in polished rice grain
4．3．4 Bioaccessibility of Cd in polished rice grain
4．3．5 Cadmium bioavailability of polished rice
4．3．6 Effect of cadmium on cytotoxicity assays (LDH release and MTT viability assay)
4．3．7 Effect of cadmium on lipid peroxidation and enzymes (oxidant+antioxidant) activities in HL-7702 cells
4．3．8 Effect of Cd Stress on ultrastructural changes in HL-7702 cells
4．4 Discussion
CHAPTER 5 In Vitro Assessment of Cadmium Bioavailability in Chinese Cabbage Grown on Different Soils and its Toxic Effects on Human Health
5．1 Introduction
5．2 Materials and methods
5．2．1 Chemicals and reagents
5．2．2 Ethics statement
5．2．3 Soil collection and analysis
5．2．4 Greenhouse experiment
5．2．5 Total Cd of soil and plant
5．2．6 Cadmium bioavailability and toxicity assays
5．2．7 Cadmium toxicity assays by HL-7702 cells
5．2．8 Cytotoxicity assay
5．2．9 Lipid peroxidation assay
5．2．10 Antioxidant and oxidant enzymes assays
5．2．11 Transmission electron microscopy
5．2．12 Quality control of cadmium analysis
5．2．13 Statistical analysis
5．3 Results
5．3．1 Characteristics of soils
5．3．2 Accumulation of Cd in Chinese cabbage
5．3．3 Bioaccessibility of Cd in Chinese cabbage shoots
5．3．4 Bioavailability of Cd from Chinese cabbage
5．3．5 Cd Affected cell viability (MTT) and stability (LDH release) in HL-7702 cells
5．3．6．Cd induced lipid peroxidation (MDA) in HL-7702 cells
5．3．7 Effect of Cd on antioxidant (SOD，GPx) and oxidant (H2O2) enzyme activities in HL-702 cells
5．3．8 Effects of Cd on morphological alterations in HL-7702 cells
5．4．Discussion
CHAPTER 6 Conclusions and Future Recommendations
6．1 Main conclusions
6．2 Future recommendations
References
List of Publications
