Table 2 Representative antimicrobial agents and their mechanisms of action (modified from ref. 22)
From: Advancing antimicrobial strategies for managing oral biofilm infections
Material type | Representative compounds | Mechanisms of action | Reference |
|---|---|---|---|
Antibiotics | Aminoglycosides (e.g., gentamicin, tobramycin) | Bind to the bacterial 30S ribosomal subunit and inhibit protein synthesis | |
Glycopeptides (e.g., vancomycin) | Bind to amino acids and disrupt cell wall peptidoglycan synthesis | ||
Penicillins (e.g., ampicillin) | Inhibit related enzymes and disrupt cell wall peptidoglycan synthesis | ||
Quinolones (e.g., ciproflaxin, norfloxacin) | Inhibit DNA replication and transcription, targeting DNA topoisomerases II and IV | ||
Rifamycins (e.g., rifampin) | Bind to RNA polymerase and inhibit transcription | ||
Tetracyclines (e.g., minocycline, tetracycline) | Inhibit protein synthesis | ||
Antimicrobial enzymes (AMEs) | Lysozyme | Catalyze glycosidic bond hydrolysis in bacterial cell wall peptidoglycans | |
Acylase | Quorum-quenching | ||
Antimicrobial peptides (AMPs) | Natural AMPs (e.g., human β-defensin 1–3, magainin and nisin) | Transmembrane pore formation, intracellular targeting and metabolic inhibition mechanisms (inhibition of microbial functional proteins, DNA and RNA synthesis) | |
Synthetic AMPs (e.g., β-17, human neutrophil peptides 1 and 2, histatins 5 and 8) | |||
Cationic compounds | Chitosan | Interaction between positively charged chitosan molecules and negatively charged bacterial cell membranes leads to disruption of cell membrane | |
Chlorhexidine | Bind to negatively charged bacterial walls and disrupt cell walls | ||
Poly(ε-lysine) | Electrostatic adsorption onto bacterial cell membranes and stripping of the outer membrane, resulting in cell death | ||
Quaternary ammonium compounds (QACs) | Disruption of bacterial enzymes and cell membranes by positively charged polymers | ||
Metal and metal oxides | Ag NPs | Induce oxidative stresses, deactivate bacterial enzymes by binding to thiol groups and affect the function and permeability of the cell membranes | |
Cu NPs | Contribute to ROS formation and induce lipid peroxidation in bacterial membranes | ||
TiO2 NPs | Photocatalytically activate the production of ROS and interfere with phosphorylation, thereby causing oxidative cell death | ||
ZnONPs | Generate ROS and binds to lipids and proteins, thus changing the osmotic balance and increasing membrane permeability | ||
Other non-cationic compounds | Nitric oxide (NO) donors | Induce cellular nitrosative and oxidative stresses and act as a bacterial signaling disruptor | |
Triclosan | Deactivate bacterial fatty acid biosynthesis through inhibition of the enoylacyl carrier protein reductase enzyme | ||
Natural products | Tea (e.g., tea catechins) | Irreversible damage to the microbial cytoplasmic membrane, inhibit the activity of salivary amylase, leading to reduced cariogenicity of starch-containing foods | |
Propolis (e.g., trans–trans farnesol) | The lipophilic moiety interaction with bacterial membrane | ||
Cranberry (e.g., proanthocyanins, flavonol) | Inhibition of biofilm formation to prevent bacterial coaggregation, reduction of bacterial hydrophobicity, and alternation of cell surface molecules | ||
Amino acids | Arginine | Counter the acid stress imposed by acidogenic bacteria and maintain a healthy oral biofilm | |
Antioxidants | N-acetylcysteine (NAC) | Inhibit bacterial cysteine, react with bacterial cell proteins, reduce bacterial extracellular polymeric substances, and disturb intracellular redox equilibrium |
