Title : Illuminating new frontiers: Exploring the photosensitizing potential of passiflora species in combatting Methicillin-Resistant Staphylococcus Aureus (MRSA) and their infection in senescent mice
Abstract:
Antimicrobial Photodynamic Therapy (aPDT) has become a potential alternative for treating multidrug-resistant bacterial skin infections like those caused by methicillin-resistant Staphylococcus aureus (MRSA), who are at high risk in older people. One of the main components of aPDT is the chemical agent called photosensitizer (PS). This work evaluated the photosensitizing activity of Passiflora edulis, Passiflora alata, and Passiflora cincinnata extracts. P. cincinnata was used to evaluate its activity in antimicrobial photodynamic therapy against an intradermal infection caused by MRSA in a murine senescence model of the C57BL/6 lineage. Tests in vitro were performed to determine the lowest dose of extracts that exert activity photosensitizer and to evaluate the cytotoxicity of the extracts and singlet oxygen production. For in vivo tests, all animals were infected with MRSA and divided into three groups: 1-Animals without treatment (Vehicle), 2- Animals infected and treated with P. cincinnata (P. cincinnata) and 3- Animals treated with P. cincinnata photoactivated (aPDT). We evaluated the production of cytokines in the draining lymph nodes, and the ears were collected to determine the bacterial load and characterize the inflammation in the tissue. The animals treated with P. cincinnata had better bacterial load control, less leukocyte infiltration, and lower weight loss throughout the MRSA infectious process. Moreover, the interactions between IL-10 with TNF-α and IL-12 with IL-17 became more prominent in an aPDT group. In this way, our results are promising because little is known about how aPDT acts in senescent animals and brings to light P. cincinnata as a photosensitizer.
