Influence of nicotinamide on the development of Propionibacterium acnes biofilm: A preliminary study

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Background: Propionibacterium acnes (P acnes) and its biofilm formation are considered to play important roles in the pathogenesis of acne. Previous studies have demonstrated that acne patients have more follicles containing P acnes and show greater numbers of bacteria in macrocolonies/biofilms than controls. P acnes biofilm produces biologic glue to form comedones, decreases the antimicrobial susceptibility, and increases the production of particular virulence factors and quorum-sensing molecules in biofilm-associated cells. Topical nicotinamide is an effective adjunctive treatment for acne. However, aside from the anti-inflammatory effect of nicotinamide, little is known about its influence on the development of P acnes biofilm.

Objective: To investigate the effect of nicotinamide on the formation and degradation of P acnes biofilm.

Methods: For the antibiofilm formation test and the biofilm degradation assay, P acnes strain LMG 16711 (ATCC 6919) was cultured with modified brain-heart infusion medium in vitro, and the tested agents was added in concurrent with or after biofilm formation. After culturing for 24 hours, the final biofilm was stained with fluorescein isothiocyanate and examined under fluorescence microscopy. MTT assay was performed to assure cell viability. To study the underlying mechanism for the antibiofilm effect of nicotinamide, the amount of extracellular DNA in biofilms were measured using electrophoresis, the expression of polysaccharides synthesis related genes were evaluated using real-time polymerase chain reaction, and the enzyme sets for polysaccharides degradation were quantified using enzyme-linked immunosorbent assay.

Results: Nicotinamide significantly inhibits biofilm formation and enhances biofilm degradation at 2 mg/mL. As the dosage increased, the antibiofilm effect also strengthened in a dose-dependent manner. No cytotoxicity to nicotinamide was noted under the concentration of 10 mg/mL. Combination use of nicotinamide and clindamycin has a synergistic antibiofilm effect. Further survey of the underlying mechanism for the antibiofilm effect of nicotinamide were to be presented.

Limitations: This is an in vitro study which may not reflect the real world acne.

Conclusion: Nicotinamide inhibits P acnes biofilm formation and increases biofilm degradation. Thus, nicotinamide makes a good candidate for longterm acne care.
Original languageUndefined/Unknown
Pages (from-to)AB8
JournalJournal of the American Academy of Dermatology
Issue number5, Supplement 1
Publication statusPublished - 2015

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