Anti-dermatophytic activity of bakuchiol: in vitro mechanistic studies and in vivo tinea pedis-inhibiting activity in a guinea pig model.
Bakuchiol was an active antifungal compound isolated from Psoraleae Fructus by means of bioassay-guided fractionation in our previous study. The present work aimed to investigate the underlying mechanisms and the therapeutic effect of bakuchiol in Trichophyton mentagrophytes-induced tinea pedis. After exposure to bakuchiol at 0.25-fold, 0.5-fold and 1-fold of minimum inhibitory concentration (MIC) (3.91 μg/ml) for 24h, the fungal conidia of T. mentagrophytes demonstrated a significant dose-dependent increase in membrane permeability. Moreover, bakuchiol at 1-fold MIC elicited a 187% elevation in reactive oxygen species (ROS) level in fungal cells after a 3-h incubation. However, bakuchiol did not induce DNA fragmentation. In a guinea pig model of tinea pedis, bakuchiol at 1%, 5% or 10% (w/w) concentration in aqueous cream could significantly reduce the fungal burden of infected feet (p<0.01-0.05). In conclusion, this is the first report to demonstrate that bakuchiol is effective in relieving tinea pedis and in inhibiting the growth of the dermatophyte T. mentagrophytes by increasing fungal membrane permeability and ROS generation, but not via induction of DNA fragmentation.
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Kit-Man
KM
Lau
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Jack Ho
JH
Wong
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Yu-On
YO
Wu
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Ling
L
Cheng
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Chun-Wai
CW
Wong
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Ming-Ho
MH
To
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Ching-Po
CP
Lau
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
David Tai-Wai
DT
Yew
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Ping-Chung
PC
Leung
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Kwok-Pui
KP
Fung
Department of Microbiology, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China.
Mamie
M
Hui
School of Biomedical Sciences, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China. Electronic address: tzibunng@cuhk.edu.hk.
Tzi-Bun
TB
Ng
Institute of Chinese Medicine, The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China; State Key Laboratory of Phytochemistry and Plant Resources in West China (CUHK), The Chinese University of Hong Kong, Shatin, N.T., Hong Kong, China. Electronic address: claralau@cuhk.edu.hk.
Clara Bik-San
CB
Lau
D000818:Animals; D000935:Antifungal Agents / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D004195:Disease Models, Animal; D004305:Dose-Response Relationship, Drug; D005260:Female; D006168:Guinea Pigs; D008826:Microbial Sensitivity Tests; D010636:Phenols / Q000494:pharmacology*; D017382:Reactive Oxygen Species / Q000378:metabolism; D014008:Tinea Pedis / Q000188:drug therapy* / Q000382:microbiology; D014249:Trichophyton / Q000187:drug effects* / Q000378:metabolism / Q000472:pathogenicity
D000935:Antifungal Agents; D010636:Phenols; D017382:Reactive Oxygen Species; C012765:bakuchiol
Antifungal; Bakuchiol; Membrane permeability; ROS production; Tinea pedis; Trichophyton mentagrophytes