IADR Abstract Archives
in Vitro Evaluation of 2-(Chloroalkyloxy)Naphthalene-1,4-Dione Derivatives as Anticaries Agent
Objectives: This study investigated the potential anticaries properties (antimicrobial, antiglycolytic, and antibiofilm activities) of synthetic 2-(chloroalkyloxy)naphthalene-1,4-dione derivatives (Compounds 1-2).
Methods: Compounds 1-2 were synthesized by using lawsone as a lead compound via an alkylation reaction on the 2-hydroxyl group, and then were characterized by infrared spectroscopy, 1H-nuclear magnetic spectroscopy, 13C- nuclear magnetic spectroscopy, and high-resolution mass spectrometry. Microdilution method and pH drop assay were used to evaluate the antibacterial and antiglycolytic activity of compounds 1-2 against three bacterial species: Streptococcus mutans (S.mutans), Lacticaseibacillus casei (L.casei), and Actinomyces naeslundii (A.naeslundii). Chlorhexidine gluconate was used as a positive control for antibacterial activity testing. Crystal violet assay was used to evaluate the effect of compounds 1-2 on S. mutans biofilm formation.
Results: According to minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, S.mutans was more susceptible to compounds 1-2 (MIC 0.78, 1.56 µg/mL, respectively) than A.naeslundii (MIC 6.25, 12.50 µg/mL, respectively), while, L.casei was resistant. Only the MBC of compound 1 against A.naeslundii (100 µg/mL) was found. Both compounds 1-2 significantly retarded the pH decline by S.mutans, but had no effect on the pH drop profile of A.naeslundii. Only compound 1 significantly affected the pH drop profile of L.casei. At 12 hours, all sub-MIC concentrations (1/2 to 1/8) of compounds 1-2 significantly reduced S.mutans biofilm formation. However, at 24 hours, only sub-MIC 1/2 concentration significantly reduced biofilm formation.
Conclusions: Compound 1 was more potent than compound 2 in terms of inhibiting the growth of S.mutans and A.naeslundii, the biofilm formation of S.mutans, and the acid production of S.mutans and L.casei.
Methods: Compounds 1-2 were synthesized by using lawsone as a lead compound via an alkylation reaction on the 2-hydroxyl group, and then were characterized by infrared spectroscopy, 1H-nuclear magnetic spectroscopy, 13C- nuclear magnetic spectroscopy, and high-resolution mass spectrometry. Microdilution method and pH drop assay were used to evaluate the antibacterial and antiglycolytic activity of compounds 1-2 against three bacterial species: Streptococcus mutans (S.mutans), Lacticaseibacillus casei (L.casei), and Actinomyces naeslundii (A.naeslundii). Chlorhexidine gluconate was used as a positive control for antibacterial activity testing. Crystal violet assay was used to evaluate the effect of compounds 1-2 on S. mutans biofilm formation.
Results: According to minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values, S.mutans was more susceptible to compounds 1-2 (MIC 0.78, 1.56 µg/mL, respectively) than A.naeslundii (MIC 6.25, 12.50 µg/mL, respectively), while, L.casei was resistant. Only the MBC of compound 1 against A.naeslundii (100 µg/mL) was found. Both compounds 1-2 significantly retarded the pH decline by S.mutans, but had no effect on the pH drop profile of A.naeslundii. Only compound 1 significantly affected the pH drop profile of L.casei. At 12 hours, all sub-MIC concentrations (1/2 to 1/8) of compounds 1-2 significantly reduced S.mutans biofilm formation. However, at 24 hours, only sub-MIC 1/2 concentration significantly reduced biofilm formation.
Conclusions: Compound 1 was more potent than compound 2 in terms of inhibiting the growth of S.mutans and A.naeslundii, the biofilm formation of S.mutans, and the acid production of S.mutans and L.casei.
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