Title Page
Contents
Part Ⅰ. Evaluation of antioxidant activity and photosensitizing property of turmeric oleoresin during its photo-degradation 12
1. Introduction 13
2. Materials and Methods 18
2.1. Chemicals and cell line 18
2.2. Light sources and intensity 18
2.3. Measurement of photostability of turmeric pigment under lights 19
2.4. Analysis of each curcuminoid level by photodegradation 19
2.5. Measurement of antioxidant activity changes by photodegradation 19
2.6. Analysis of photosensitizing activity changes by photolysis 20
2.7. Determination of cytotoxic effects 20
2.8. Data analysis 21
3. Results and discussion 22
3.1. Color changes of turmeric pigment under light irradiation 22
3.2. Fluorescence changes of turmeric pigment under light irradiation 26
3.3. Analysis of individual curcuminoid levels during light irradiation 30
3.4. Changes in antioxidant activity by photodegradation of turmeric pigments 34
3.5. Analysis of photosensitizing property of turmeric pigment and its photodegradation products 37
3.6. Effects of turmeric photodegradation products on lipid photo-oxidation 41
3.7. Changes in cytotoxic activity by photodegradation of turmeric pigments 43
4. Conclusion 46
Part Ⅱ. Photosensitizing mechanism of curcuminoids and their effects on cells 47
1. Introduction 48
2. Materials and Methods 52
2.1. Chemicals and cell lines 52
2.2. Light sources and intensity 52
2.3. Photo-stability of individual curcuminoid under different lights 53
2.4. Effects of curcuminoids on lipid peroxidation under light 53
2.5. Photosensitizing properties of each curcuminoid under light 54
2.6. Effects of curcuminoids on DCF fluorescence by ROS 54
2.7. Determination of cytotoxic effects by each curcuminoid 54
2.8. Intracellular ROS level by each curcuminoid under light irradiation 55
2.9. Determination of photo-protection effects by curcumin 55
2.10. Colony formation assay on HaCaT cells 56
2.11. Data analysis 56
3. Results and discussion 57
3.1. Photostability of individual curcuminoid under different LED lights 57
3.2. Changes in photostability of curcuminoids interacted with detergent and oil 63
3.3. Effects of curcuminoids on hydroperoxide level under light in the emulsion system 66
3.4. Lipid peroxidation induced by the photosensitizing activity of curcuminoids 70
3.5. ROS production of curcuminoids under light irradiation 72
3.6. NBT reduction potential of photosensitized curcuminoids 74
3.7. Formazan decolorization activity of photosensitized each curcuminoid 78
3.8. Effects on cytotoxic effect by individual curcuminoid under light 80
3.9. Effects of ROS and singlet oxygen on the phototoxicity of BMC 82
3.10. Photoprotective effects of curcumin on skin cells 85
3.11. Photoprotective effects of curcumin on lens epithelial cells 90
4. Conclusion 92
Reference 94
초록 99
Fig. 1. Structures of curcuminoids including (A) curcumin, (B) DMC, (C) BMC used in the present study. 16
Fig. 2. Emission spectrum profiles of fluorescent light (A) and white LED (B) used in the present study. 17
Fig. 3. Color stability of turmeric pigment under irradiation of fluorescent light or white LED. 25
Fig. 4. Changes in fluorescence intensity of turmeric pigment under irradiation of fluorescence light or white LED. 29
Fig. 5. Changes of individual curcuminoid levels in turmeric pigment by light irradiation. 33
Fig. 6. Changes in DPPH or ABTS radical scavenging activities of turmeric pigments by light irradiation. 36
Fig. 7. Analysis of photosensitizing property of turmeric pigment and its photo-degradation products using the formazan probe. 40
Fig. 8. Effects of turmeric pigment and its photodegradation products under different light conditions on light-induced lipid peroxidation. 42
Fig. 9. Cytotoxic effects of turmeric pigment and its photodegradation products on B16F10 melanoma. 45
Fig. 10. Emission spectrum profiles of red (A), green (B), and blue (C) LED used in this study. 51
Fig. 11. Comparison of absorbance property and photostability of individual curcuminoid under different LED lights. 62
Fig. 12. Changes in photostability of curcuminoids in different emulsion systems. 65
Fig. 13. Induction of lipid photooxidation by curcuminoids in different oil in water (O/W) emulsion systems. 69
Fig. 14. Induction of lipid photooxidation by curcuminoids in the bulk oil system. 71
Fig. 15. Effects of curcuminoids on DCF fluorescence under light. 73
Fig. 16. Evaluation of photosensitizing property of curcuminoids in the NBT reduction system. 77
Fig. 17. Evaluation of photosensitizing activities of individual curcuminoid using the MTT formazan degradation method. 79
Fig. 18. Changes in cytotoxic effects of individual curcuminoid on B16F10 melanoma under blue LED irradiation. 81
Fig. 19. Changes of ROS levels in cells treated with different curcuminoid under light irradiation. 84
Fig. 20. Protective effects of curcumin on blue LED-induced skin cell death. 88
Fig. 21. Evaluation of protective effect of curcumin on blue LED-induced skin cell damages using the colony forming assay. 89
Fig. 22. Protective effects of curcumin on blue LED-induced eye cell death. 91
Fig. 23. Emulsion difference according to detergent concentration (A) and photosensitizing mechanism of curcuminoids (B). 93