Kuo-Chou Chiu1, Yin-Hwa Shih2, Tong-Hong Wang3, Wan-Chen Lan2, Po-Jung Li4, Hong-Syu Jhuang5, Shih-Min Hsia6, Yen-Wen Shen4, Michael Yuan-Chien Chen7, Tzong-Ming Shieh8. 1. Division of Oral Diagnosis and Family Dentistry, National Defense Medical Center, Taipei, Taiwan. 2. Department of Healthcare Administration, Asia University, Taichung, Taiwan. 3. Tissue Bank, Chang Gung Memorial Hospital, Linko, Taiwan. 4. School of Dentistry, China Medical University, Taichung, Taiwan. 5. Department of Dental Hygiene, China Medical University, Taichung, Taiwan. 6. School of Nutrition and Health Sciences, Taipei Medical University, Taipei, Taiwan. 7. School of Dentistry, China Medical University, Taichung, Taiwan; Department of Oral & Maxillofacial Surgery, China Medical University Hospital, Taichung, Taiwan. Electronic address: mychen@www.cmuh.org.tw. 8. School of Dentistry, China Medical University, Taichung, Taiwan; Department of Dental Hygiene, China Medical University, Taichung, Taiwan. Electronic address: tmshieh@mail.cmu.edu.tw.
Abstract
BACKGROUND/ PURPOSE: Honokiol and magnolol are natural components isolated from Magnolia bark that is used in traditional Chinese and Japanese herbal medicine. These two isomers are used as a component of dietary supplements and cosmetic products. In this study, we investigated the antimicrobial effect of honokiol and magnolol on pathogens causing oral diseases, their mechanism of action in biofilm formation and drug resistance of oral pathogens, and inflammatory regulation in mammalian cells. METHODS: We determined the minimum inhibitory concentration and minimum bactericidal concentration of honokiol and magnolol, and their stability at different temperatures and pH. We also evaluated their effect on biofilm formation, antibiotic-resistance gene expression in MRSA, and pro-inflammatory gene expression in mammalian cells. RESULTS: Honokiol showed better antimicrobial activity than magnolol. Both honokiol and magnolol showed stable bacterial inhibitory activity over a wide range of temperature and pH, reduced biofilm formation, and antibiotic resistance in oral pathogens. The biofilm formation- and antibiotic resistance-related gene expression was consistent with the respective phenotypes. Furthermore, these two isomers repressed the expression of pro-inflammatory genes in RAW264.7 cells. CONCLUSION: Our study provides evidence of the potential application of honokiol and magnolol in dental medicine to cure or prevent oral diseases.
BACKGROUND/ PURPOSE:Honokiol and magnolol are natural components isolated from Magnolia bark that is used in traditional Chinese and Japanese herbal medicine. These two isomers are used as a component of dietary supplements and cosmetic products. In this study, we investigated the antimicrobial effect of honokiol and magnolol on pathogens causing oral diseases, their mechanism of action in biofilm formation and drug resistance of oral pathogens, and inflammatory regulation in mammalian cells. METHODS: We determined the minimum inhibitory concentration and minimum bactericidal concentration of honokiol and magnolol, and their stability at different temperatures and pH. We also evaluated their effect on biofilm formation, antibiotic-resistance gene expression in MRSA, and pro-inflammatory gene expression in mammalian cells. RESULTS:Honokiol showed better antimicrobial activity than magnolol. Both honokiol and magnolol showed stable bacterial inhibitory activity over a wide range of temperature and pH, reduced biofilm formation, and antibiotic resistance in oral pathogens. The biofilm formation- and antibiotic resistance-related gene expression was consistent with the respective phenotypes. Furthermore, these two isomers repressed the expression of pro-inflammatory genes in RAW264.7 cells. CONCLUSION: Our study provides evidence of the potential application of honokiol and magnolol in dental medicine to cure or prevent oral diseases.