*6.7. Antibacterial Effect of PTS*

Stilbene compounds, including PTS, are natural antibacterial agents due to their low hydrophilicity, enabling them to penetrate hydrophobic biological membranes [121]. PTS with cyclodextrin exerts antimicrobial effects by inducing bacterial cell content leaks, resulting in a reduction in bacterial cell viability. It also inhibits *F. nucleatum* biofilm formation, making it a potential candidate for treating periodontitis [55]. Bacillus cereus, a foodborne pathogen contaminating uncooked food, was tested with PTS. Following treatment, apoptosis-like cell death (ALD) was induced and increased intracellular ROS in

bacterial cells. Additionally, an improvement in the beneficial gut microbiota Bacteroidetes was also documented [122].

PTS, along with gentamicin, was tested against six Gram-positive and Gram-negative bacteria, and the combination was found to be synergistic against three susceptible strains, *Staphylococcus aureus* ATCC 25923, *Escherichia coli* O157, and *Pseudomonas aeruginosa* 15442. However, no significant difference was observed from gentamicin treatment alone. Bacterial growth was fully diminished after 2–8 h treatment with PTS and gentamicin, exhibiting the potential to delay the development of bacterial resistance by utilizing lower concentrations of antibacterial agents [123]. Methicillin-resistant S. aureus (MRSA) is a multi-drug-resistant S. aureus strain, whose biofilm thickness was reduced from 18 to 10 μm when treated with PTS. Topical administration ameliorated the abscess formation induced by MRSA, thereby lowering the bacterial burden and improving the architecture of the skin [124]. PTS has also been used to treat infections with Staphylococcus spp. or Enterococcus faecalis in biofilms due to a reduction in the growth capacity of Gram-positive cocci [121].
