Effect of the Ag₃PO₄on Staphylococcus aureus Growth and Human Immunity

Abstract

Silver (Ag) has been widely used in commercial products and medical fields since ancient times because of its antibacterial effect. It is harmless and non-toxic to the human body. For this reason, recent research has actively evaluated antimicrobial activity using silver (Ag). In this study, we investigated the inhibitory effect of a silver-based compound, silver phosphate (Ag 3 PO 4) on the growth of Staphylococcus aureus and the activation of human immunity. First, the inhibitory effect of Ag 3 PO 4 on the growth of Staphylococcus aureus was confirmed by a growth curve and a colonyounting method. As a result, the growth inhibitory effect increased as the concentration of Ag 3 PO 4 increased. Specifically, treatment with 5 μg/mL of Ag 3 PO 4 resulted in no bacteria growth, and the colony-counting method showed a remarkable inhibition. In addition, the expression of cytokine IL-8 by Ag 3 PO 4 was examined to investigate the cellular immune system activation by Ag 3 PO 4. After pretreatment of Staphylococcus aureus for 1 hour with 50 μg/mL Ag 3 PO 4 , an increased IL-8 mRNA expression resulted. In cells treated with Ag 3 PO 4 , we found that the expression of IL-8 was enhanced in a time-dependent fashion compared to non-treated cells. These results indicate that Ag 3 PO 4 induces antimicrobial activity against Staphylococcus aureus and activates human immunity. These results are expected to contribute to the future study of the mechanism of silver (Ag) and silver-based compounds in relation to antibacterial activity.

Shape-Depended Biological Properties of Ag3PO4 Microparticles: Evaluation of Antimicrobial Properties and Cytotoxicity in In Vitro Model—Safety Assessment of Potential Clinical Usage

“…It may suggest that they act as proinflammatory agents. Similar to our findings, literature data suggest that Ag 3 PO 4 in 50 μ g/mL concentration in human non-small-cell lung carcinoma cells (H1299) can increase levels of IL-8, which is a proinflammatory cytokine [42].…”

“…It should be highlighted that Ag 3 PO 4 itself in a concentration of 5 μ g/mL can inhibit the growth of S . aureus as well [42].…”