ABSTRACT
Staphylococcus aureus is one of the major microorganisms that cause human diseases, leading from mild skin infections to serious diseases. With the use of semi-synthetic penicillins, methicillin-resistant strains called Methicillin-resistant Staphylococcus aureus (MRSA) have emerged, whose resistance pattern extends to other beta-lactam antibiotics. It has already been shown that photodynamic therapy is capable of inactivating MRSA as the laser excites the photosensitizer responsible for transferring its electrons to the molecular oxygen, generating extremely reactive molecules, such as singlet oxygen, being these reactive components the chemicals that promote the bacterial clearance. Thus, the research aiming at the development of new photosensitizers becomes important, especially to increase the amount of therapeutic resources available for the treatment of persistent infections related to this bacterium. In this context, Myrciaria cauliflora is a plant that has antimicrobial action and there are no reports of the use of its crude extract as a photosensitizer in antimicrobial photodynamic therapy. In that way, this work conveys an innovative way of the use of M. cauliflora extract as a photosensitizer, comprising its use as an antimicrobial agent when activated by light, against S. aureus. In vitro tests were performed where it was observed that after the photoactivation with blue LED light, the extract presented an augment in its antimicrobial activity, together with production of singlet oxygen. In the model of intradermal infection in Balb/c mice, a reduction in bacterial load was also detected, with raised expression of TNF-α, IL-17A, and MPO. Here, we demonstrate that the extract of M. cauliflora has photosensitizing action, promoting the production of singlet oxygen, besides IL-17A, TNF-α, and MPO.
Subject(s)
Myrtaceae/chemistry , Photochemotherapy/methods , Photosensitizing Agents/chemistry , Staphylococcal Infections/therapy , Animals , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Bacterial Load/drug effects , Cytokines/blood , Cytokines/drug effects , Humans , Methicillin-Resistant Staphylococcus aureus , Mice , Mice, Inbred BALB C , Pilot Projects , Plant Extracts/chemistry , Singlet Oxygen/metabolismABSTRACT
A atividade física tem sido utilizada como ferramenta de auxílio para a diminuição da incidência de diversos riscos, tais como obesidade, desenvolvimento de doenças cardiovasculares e diabetes. Além disso, ela tem sido descrita como medida imunomodulatória. O exercício físico possui algumas variáveis, dentre elas a frequência do exercício e a intensidade do mesmo. As variáveis nesse âmbito têm sido relacionadas a diferentes efeitos na modulação da resposta desenvolvida em diferentes sistemas e por vezes pode estar associada ao aumento da suscetibilidade a infecções ou ao aumento da resistência a infecções. O sistema respiratório representa uma das maiores portas de entrada para microrganismos patogênicos apresentando grande incidência de doenças infecciosas em atletas de elite. O exercício moderado tem sido associado a uma proteção contra infecções respiratórias causadas por vírus e por bactérias quando comparado ao exercício intenso, que de forma contrária, tem sido relacionado ao aumento da suscetibilidade a essas infecções principalmente em atletas praticantes de atividade física intensa. Nessa revisão pontuamos os aspectos mais recentes associados à modulação da resposta imune pela atividade física e suas implicações em infecções no sistema respiratório.
Physical activity has been employed as a tool to lessen the occurrence of several types of risks, such as obesity, development of cardiovascular diseases and diabetes. In fact, it has been described as an immunomodulating measure. Physical exercise has several variables among which may be mentioned frequency of exercises and their intensity. Variables have been related to different effects in the modulation of response developed in several systems and frequently due to its association to increase in susceptibility to infections or to increase in the resistance to infections. The respiratory system is one of the biggest entrances for pathogenic microorganisms with the occurrence of infectious diseases in athletes. Moderate exercises have been associated to the protection against respiratory infections caused by viruses and bacteria when it is compared to intense exercises; otherwise, it is related to increase in susceptibility to these infections mainly in athletes who practice intense physical activity. Current review demonstrates the most recent aspects associated to the modulation of immune response by physical activity and its implications in the infections of the respiratory system.
