Abstract—D-amino acids are predominantly produced and utilized by bacteria. They are involved in the synthesis and cross-linking of peptidoglycan. Furthermore, oxidative catabolism of D-amino acids, via the D-amino acid dehydrogensae pathway, sustains energy production for cellular functions. Only a few decades ago, it was largely believed that free D-amino acids were restricted to bacteria. Often, D-amino acids were considered as the by-products of bacterial metabolism. Nevertheless, the occurrence of D-amino acids in mammals was recently confirmed by means of sensitive and advanced analytical methods. The physiological functions of D-amino acids in humans are still under investigation. The presence of astonishing amounts of certain D-amino acids in the human Central Nervous System suggests a vital role of D-amino acids in neuromodulation. Apparently, both prokaryotes and eukaryotes maintain tight regulation on the occurrence of D-amino acids in their systems through specific metabolic pathways. Previously, it had been reported that the accumulation of certain D-amino acids results in cellular toxicity. In this study, we investigate the potential of D-amino acids as prospective new therapeutic agents. Antibacterial, antifungal, and cytotoxic activities were evaluated against representative cellular models. Our findings indicate that, although D-amino acids are toxic on their own, their efficacy can be significantly improved by synergism with other therapeutic agents. The ability to use lower doses of both, the drug and D-amino acids, may be beneficial for the development of combinational remedies against resistant pathogens or cancerous cells.

Index Terms—D-amino acids, antibacterial, antifungal, cytotoxicity

Cite: Sanaa K. Bardaweel, "D-amino Acids: Prospects for New Therapeutic Agents," Journal of Medical and Bioengineering, Vol. 3, No. 3, pp. 195-198, September 2014. Doi: 10.12720/jomb.3.3.195-198