Hyung-Jung Lee1, Si-Mook Kang2, Seung-Hwa Jeong3, Ki-Ho Chung4, Baek-Il Kim5. 1. Department of Preventive Dentistry & Public Oral Health, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-Gu, Seoul 03722, Republic of Korea. Electronic address: soulden@naver.com. 2. Department of Preventive Dentistry & Public Oral Health, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-Gu, Seoul 03722, Republic of Korea. Electronic address: simook@yuhs.ac. 3. Department of Preventice and Community Dentistry, School of dentistry, Pusan National University, 50-1 Yonsei-ro, Seodaemun-Gu, Seoul 03722, Republic of Korea. Electronic address: jsh0917@pusan.ac.kr. 4. Department of Preventive Dentistry & Public Oral Health, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-Gu, Seoul 03722, Republic of Korea. Electronic address: prevention@korea.com. 5. Department of Preventive Dentistry & Public Oral Health, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-Gu, Seoul 03722, Republic of Korea; BK21 PLUS Project, Oral Science Research Institute, Yonsei University College of Dentistry, 50-1 Yonsei-ro, Seodaemun-Gu, Seoul 03722, Republic of Korea. Electronic address: drkbi@yuhs.ac.
Abstract
BACKGROUND: Bacteria are becoming increasingly resistant to conventional antibacterial chemotherapy. This has prompted the application of antibacterial photodynamic therapy (aPDT) in bacteria-related diseases due to its excellent biocide effects. However, few studies have attempted to develop a novel photosensitizer based on natural components. The aim of the present study was to compare the aPDT effects of curcumin and Curcuma xanthorrhiza extract (CXE) against Streptococcus mutans. METHODS: A planktonic suspension containing an S. mutans strain was treated in three separate groups: aPDT with curcumin, CXE, and a mixture of curcumin and CXE (ratio= 1:1) at concentrations of 0, 10, 102, 103, and 104ng/ml. Light irradiation with a center wavelength of 405nm was applied using an LED (power density of 84.5mW for 300s at an energy density of 25.3J/cm2). The phototoxicity of photosensitizers against S. mutans was investigated using a colony-forming-unit assay. Percentage logarithmic reductions [log10(CFU/ml) values] were analyzed using one-way ANOVA followed by the Tukey test (p<0.05) and Student's independent t-test. RESULTS: The viability of S. mutans in the presence of curcumin, CXE, and a mixture of these two components was substantially reduced during irradiation with 405nm light. The phototoxicity of the photosensitizer varied with its solubility and concentration. CONCLUSION: These preliminary in vitro findings imply that combining curcumin and CXE with a 405nm LED may be a novel method of applying aPDT. This could be advantageous in preventing and treating dental caries using devices that are readily available in clinics.
BACKGROUND: Bacteria are becoming increasingly resistant to conventional antibacterial chemotherapy. This has prompted the application of antibacterial photodynamic therapy (aPDT) in bacteria-related diseases due to its excellent biocide effects. However, few studies have attempted to develop a novel photosensitizer based on natural components. The aim of the present study was to compare the aPDT effects of curcumin and Curcuma xanthorrhiza extract (CXE) against Streptococcus mutans. METHODS: A planktonic suspension containing an S. mutans strain was treated in three separate groups: aPDT with curcumin, CXE, and a mixture of curcumin and CXE (ratio= 1:1) at concentrations of 0, 10, 102, 103, and 104ng/ml. Light irradiation with a center wavelength of 405nm was applied using an LED (power density of 84.5mW for 300s at an energy density of 25.3J/cm2). The phototoxicity of photosensitizers against S. mutans was investigated using a colony-forming-unit assay. Percentage logarithmic reductions [log10(CFU/ml) values] were analyzed using one-way ANOVA followed by the Tukey test (p<0.05) and Student's independent t-test. RESULTS: The viability of S. mutans in the presence of curcumin, CXE, and a mixture of these two components was substantially reduced during irradiation with 405nm light. The phototoxicity of the photosensitizer varied with its solubility and concentration. CONCLUSION: These preliminary in vitro findings imply that combining curcumin and CXE with a 405nm LED may be a novel method of applying aPDT. This could be advantageous in preventing and treating dental caries using devices that are readily available in clinics.