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Updated: Jan 30, 2026
Development and Assessment of Intracellular Infection Models for Staphylococcus aureus
Published on: January 17, 2025
Photoactivated resveratrol against Staphylococcus aureus infection in mice
Denisar Palmito Dos Santos1, Diego Patrick Soares Lopes1, Ricardo Costa de Moraes1
1Federal University of Bahia, Anísio Teixeira Campus- Multidisciplinary Institute in Health, 58 Rio de Contas Street - 17 Block - 58 Lot, Candeias, ZIP 45.029-094, Vitória da Conquista, Bahia, Brazil.
Background:
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.
Methods:
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.
Results:
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.
Conclusion:
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.
Insights
Resveratrol activated by blue LED light shows antimicrobial photodynamic therapy (aPDT) potential against Staphylococcus aureus. This treatment generates singlet oxygen, reduces bacterial load, and modulates immune responses for infection resolution.
Area of Science:
- Photochemistry
- Microbiology
- Immunology
Background:
- Staphylococcus aureus is a major global bacterial pathogen.
- Antimicrobial photodynamic therapy (aPDT) offers a light-based approach for microbial inactivation.
- Photosensitizers are key components in aPDT, generating reactive oxygen species.
Purpose of the Study:
- To investigate resveratrol as a photosensitizer for antimicrobial photodynamic therapy.
- To evaluate the efficacy of photoactivated resveratrol against bacterial infections.
Main Methods:
- In vitro antibacterial assays of photoactivated resveratrol with blue LED light.
- Verification of singlet oxygen formation using uric acid experiments.
- In vivo studies using a mouse air pouch model to assess antimicrobial activity and cytokine production.
Main Results:
- Photoactivated resveratrol demonstrated enhanced antibacterial activity, likely due to singlet oxygen generation.
- In vivo, resveratrol-activated aPDT induced TNF-α and IL-17A production, reducing bacterial load and inflammation.
- Resolution of inflammation was observed with increased IL-10 production.
Conclusions:
- Resveratrol, activated by blue LED light, is a novel and promising photosensitizer for aPDT.
- The mechanism involves singlet oxygen production and modulation of immune responses (TNF-α, IL-17A, IL-10).
- This approach effectively aids in clearing bacteria, including Staphylococcus aureus, and resolving infection-related inflammation.
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