Photo-irradiated caffeic acid exhibits antimicrobial activity against Streptococcus mutans biofilms via hydroxyl radical formation
Abstract An antimicrobial technique based on photo-oxidation of caffeic acid (CA) has recently been developed, but its effect on biofilm-forming bacteria is unknown. The present study aimed to evaluate the effect of photo-irradiated CA against Streptococcus mutans (cariogenic bacteria) biofilm as it...
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| Format: | Article |
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Nature Portfolio
2017-07-01
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| Series: | Scientific Reports |
| Online Access: | https://doi.org/10.1038/s41598-017-07007-z |
| _version_ | 1818752533304180736 |
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| author | Keisuke Nakamura Midori Shirato Taro Kanno Peter Lingström Ulf Örtengren Yoshimi Niwano |
| author_facet | Keisuke Nakamura Midori Shirato Taro Kanno Peter Lingström Ulf Örtengren Yoshimi Niwano |
| author_sort | Keisuke Nakamura |
| collection | DOAJ |
| description | Abstract An antimicrobial technique based on photo-oxidation of caffeic acid (CA) has recently been developed, but its effect on biofilm-forming bacteria is unknown. The present study aimed to evaluate the effect of photo-irradiated CA against Streptococcus mutans (cariogenic bacteria) biofilm as it relates to hydroxyl radical formation. S. mutans biofilms grown on hydroxyapatite disks were immersed in CA solution (0–2 mg/mL) and irradiated with LED light at wavelengths of 365, 385, and 400 nm and at irradiances of 500, 1000, and 2000 mW/cm2 for 4 min. Biofilm viable bacterial counts were determined by colony counting. The yield of hydroxyl radicals generated by the LED irradiation of CA solution was quantified by electron spin resonance analysis. Of the conditions tested, the highest bactericidal effect, with a > 5-log reduction in viable bacterial counts, was obtained by irradiation of a 1 mg/mL CA solution with 385 nm LED and at an irradiance of 2000 mW/cm2. Hydroxyl radical formation was related to this bactericidal effect. The present study suggests that the antimicrobial technique based on the 385 nm LED irradiation of CA is effective against cariogenic biofilms and can be applied as an adjunctive chemotherapy for dental caries. |
| first_indexed | 2024-12-18T04:52:58Z |
| format | Article |
| id | doaj.art-1091b075b2044c7c9a4d287e6660ba0e |
| institution | Directory Open Access Journal |
| issn | 2045-2322 |
| language | English |
| last_indexed | 2024-12-18T04:52:58Z |
| publishDate | 2017-07-01 |
| publisher | Nature Portfolio |
| record_format | Article |
| series | Scientific Reports |
| spelling | doaj.art-1091b075b2044c7c9a4d287e6660ba0e2022-12-21T21:20:22ZengNature PortfolioScientific Reports2045-23222017-07-017111310.1038/s41598-017-07007-zPhoto-irradiated caffeic acid exhibits antimicrobial activity against Streptococcus mutans biofilms via hydroxyl radical formationKeisuke Nakamura0Midori Shirato1Taro Kanno2Peter Lingström3Ulf Örtengren4Yoshimi Niwano5Laboratory for Redox Regulation, Tohoku University Graduate School of DentistryLaboratory for Redox Regulation, Tohoku University Graduate School of DentistryDivision of Molecular and Regenerative Prosthodontics, Tohoku University Graduate School of DentistryDepartment of Cariology, Institute of Odontology, Sahlgrenska Academy, University of GothenburgDepartment of Cariology, Institute of Odontology, Sahlgrenska Academy, University of GothenburgLaboratory for Redox Regulation, Tohoku University Graduate School of DentistryAbstract An antimicrobial technique based on photo-oxidation of caffeic acid (CA) has recently been developed, but its effect on biofilm-forming bacteria is unknown. The present study aimed to evaluate the effect of photo-irradiated CA against Streptococcus mutans (cariogenic bacteria) biofilm as it relates to hydroxyl radical formation. S. mutans biofilms grown on hydroxyapatite disks were immersed in CA solution (0–2 mg/mL) and irradiated with LED light at wavelengths of 365, 385, and 400 nm and at irradiances of 500, 1000, and 2000 mW/cm2 for 4 min. Biofilm viable bacterial counts were determined by colony counting. The yield of hydroxyl radicals generated by the LED irradiation of CA solution was quantified by electron spin resonance analysis. Of the conditions tested, the highest bactericidal effect, with a > 5-log reduction in viable bacterial counts, was obtained by irradiation of a 1 mg/mL CA solution with 385 nm LED and at an irradiance of 2000 mW/cm2. Hydroxyl radical formation was related to this bactericidal effect. The present study suggests that the antimicrobial technique based on the 385 nm LED irradiation of CA is effective against cariogenic biofilms and can be applied as an adjunctive chemotherapy for dental caries.https://doi.org/10.1038/s41598-017-07007-z |
| spellingShingle | Keisuke Nakamura Midori Shirato Taro Kanno Peter Lingström Ulf Örtengren Yoshimi Niwano Photo-irradiated caffeic acid exhibits antimicrobial activity against Streptococcus mutans biofilms via hydroxyl radical formation Scientific Reports |
| title | Photo-irradiated caffeic acid exhibits antimicrobial activity against Streptococcus mutans biofilms via hydroxyl radical formation |
| title_full | Photo-irradiated caffeic acid exhibits antimicrobial activity against Streptococcus mutans biofilms via hydroxyl radical formation |
| title_fullStr | Photo-irradiated caffeic acid exhibits antimicrobial activity against Streptococcus mutans biofilms via hydroxyl radical formation |
| title_full_unstemmed | Photo-irradiated caffeic acid exhibits antimicrobial activity against Streptococcus mutans biofilms via hydroxyl radical formation |
| title_short | Photo-irradiated caffeic acid exhibits antimicrobial activity against Streptococcus mutans biofilms via hydroxyl radical formation |
| title_sort | photo irradiated caffeic acid exhibits antimicrobial activity against streptococcus mutans biofilms via hydroxyl radical formation |
| url | https://doi.org/10.1038/s41598-017-07007-z |
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