Photoactivated resveratrol against Staphylococcus aureus infection in mice

• Published in: Photodiagnosis and photodynamic therapy Vol. 25; pp. 227 - 236
• Main Authors: dos Santos, Denisar Palmito, Soares Lopes, Diego Patrick, de Moraes, Ricardo Costa, Vieira Gonçalves, Caroline, Pereira Rosa, Luciano, da Silva Rosa, Francine Cristina, da Silva, Robson Amaro Augusto
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.03.2019
• Subjects: Photodynamic therapy; Resveratrol; Staphylococcus aureus; Staphylococcus aureus; Photodynamic therapy; Resveratrol
• ISSN: 1572-1000; 1873-1597
• DOI: 10.1016/j.pdpdt.2019.01.005

•First work using resveratrol as a photosensitizer in antimicrobial photodynamic therapy.•Photoactivated resveratrol has a modified structure to resveratrone and produces singlet oxygen.•Photoactivation of resveatrol in the air pocket model in mice led to an increase in the production of TNF-α and IL-17A, with in vivo bacterial clearance. Among the pathogens, Staphylococcus aureus is the main causative agent of bacterial diseases in the world. In this context, antimicrobial photodynamic therapy (aPDT) appears as a promising tool by means of microbial inactivation with the use of light. aPDT is applied in treatments involving photosensitizers capable of generating oxygen free radicals. Thus, this work proposes the use of resveratrol as a photosensitizer. In vitro tests were performed to determine the antibacterial activity of photoactivated resveratrol with blue LED light, as well as uric acid experiments for verification of singlet oxygen formation. Possible resveratrol structural changes were evaluated by HPLC. In the in vivo assays, the air pouch model was performed in mice for antimicrobial activity and cytokine production. The photoactivated resveratrol exhibited an increase in its antibacterial action and it is possibly brought about by the singlet oxygen formation. In the air pouch model, TNF-α and IL-17A cytokines were produced, diminishing the bacterial load, and consequently, reducing inflammation after 24 h of infection. Cellular number decrease in the inflammatory environment was associated with resolution of inflammation along with greater IL-10 production. It is the first time that resveratrol has been associated with aPDT. It was demonstrated in this work that resveratrol activated by blue LED light can be a promising photosensitizer. This compound, after the light stimulus, produces singlet oxygen, in addition to having effects on the immune system triggering TNF-α and IL-17A production, aiding in the clearance of several bacteria, including S. aureus.