Antimicrobial photodynamic therapy with Brazilian green propolis controls intradermal infection induced by methicillin-resistant Staphylococcus aureus and modulates the inflammatory response in a murine model.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the leading causes of skin and soft tissue infections worldwide. This microorganism has a wide range of antibiotics resistance, a fact that has made the treatment of infections caused by MRSA difficult. In this sense, antimicrobial photodynamic therapy (aPDT) with natural products has emerged as a good alternative in combating infections caused by antibiotic-resistant microorganisms. The objective of the present study was to evaluate the effects of aPDT with Brazilian green propolis against intradermal MRSA infection in a murine model. Initially, 24 Balb/c mice were infected intradermally in the ears with 1.5 × 108 colony-forming units of MRSA 43300. After infection, they were separated into 4 groups (6 animals per group) and treated with the vehicle, only Brazilian green propolis, only blue LED light or with the aPDT protocol (Brazilian green propolis + blue LED light). It was observed in this study that aPDT with Brazilian green propolis reduced the bacterial load at the site of infection. Furthermore, it was able to inhibit weight loss resulting from the infection, as well as modulate the inflammatory response through greater recruitment of polymorphonuclear cells/neutrophils to the infected tissue. Finally, aPDT induced an increase in the cytokines IL-17A and IL-12p70 in the draining retromaxillary lymph node. Thus, aPDT with Brazilian green propolis proved to be effective against intradermal MRSA infection in mice, reducing bacterial load and modulating the immune response in the animals. However, more studies are needed to assess whether such effects are repeated in humans.

Characterization of Brazilian green propolis as a photosensitizer for LED light-induced antimicrobial photodynamic therapy (aPDT) against methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-intermediate Staphylococcus aureus (VISA).

Staphylococcus aureus is the primary cause of skin and soft tissue infections. Its significant adaptability and the development of resistance are the main factors linked to its spread and the challenges in its treatment. Antimicrobial photodynamic therapy emerges as a promising alternative. This work aimed to characterize the antimicrobial photodynamic activity of Brazilian green propolis, along with the key bioactive compounds associated with this activity. Initially, a scanning spectrometry was conducted to assess the wavelengths with the potential to activate green propolis. Subsequently, reference strains of methicillin-resistant Staphylococcus aureus (MRSA ATCC 43300) and vancomycin-intermediate Staphylococcus aureus (VISA ATCC 700699) were exposed to varying concentrations of green propolis: 1 µg/mL, 5 µg/mL, 10 µg/mL, 50 µg /mL and 100 µg/mL and were stimulated by blue, green or red LED light. Finally, high-performance liquid chromatography coupled with a diode array detector and tandem mass spectrometry techniques, along with classic molecular networking analysis, was performed to identify potential bioactive molecules with photodynamic activity. Brazilian green propolis exhibits a pronounced absorption peak and heightened photo-responsiveness when exposed to blue light within the range of 400 nm and 450 nm. This characteristic reveals noteworthy significant photodynamic activity against MRSA and VISA at concentrations from 5 µg/mL. Furthermore, the propolis comprises compounds like curcumin and other flavonoids sourced from flavone, which possess the potential for photodynamic activity and other antimicrobial functions. Consequently, Brazilian green propolis holds promise as an excellent bactericidal agent, displaying a synergistic antibacterial property enhanced by light-induced photodynamic effects.

Photoactivated resveratrol controls intradermal infection by Staphylococcus aureus in mice: a pilot study.

Staphylococcus aureus is one of the main causative agent of infections acquired in both community and hospital environment. In this context, photodynamic therapy (PDT) consists in using a photosensitizer that, activated by light, evokes the formation of reactive oxygen species (ROS), which lead to the death of microorganisms due to oxidative damage; it is useful tool since this action, harmful to pathogens, does not significantly injure human cells. In view of this, this work proposes a more in-depth study on the use of resveratrol (RSV) as a possible photosensitizer. It was observed, in the intradermal infection model in animals' ear dermis, that photoactivated resveratrol promotes an increase in myeloperoxidase expression with reduced bacterial load in the draining lymph node. Besides that, the draining lymph node of the animals treated with photoactivated RSV controls inflammation through IL-10 production. These are pioneers data and this work being a pilot study; then, other works must be conducted with the objective of elucidate the photoactivated resveratrol mechanism of action.

A new experimental model to study shrimp allergy.

Shrimp is among the most sensitizing food allergens and has been associated with many anaphylaxis reactions. However, there is still a shortage of studies that enable a systematic understanding of this disease and the investigation of new therapeutic approaches. This study aimed to develop a new experimental model of shrimp allergy that could enable the evaluation of new prophylactic treatments. BALB/c mice were subcutaneously sensitized with 100 µg of shrimp proteins of Litopenaeus vannamei adsorbed in 1 mg of aluminum hydroxide on day 0, and a booster (100 µg of shrimp proteins only) on day 14. The oral challenge protocol was based on the addition of 5 mg/ml of shrimp proteins to water from day 21 to day 35. Analysis of shrimp extract content detected at least 4 of the major allergens reported to L. vannamei. In response to the sensitization, allergic mice showed significantly enhanced IL-4 and IL-10 production in restimulated cervical draining lymph node cells. High detection of serum anti-shrimp IgE and IgG1 suggested the development of allergies to shrimp while Passive Cutaneous Anaphylaxis assay revealed an IgE-mediated response. Immunoblotting analysis revealed that Allergic mice developed antibodies to multiple antigens present in the shrimp extract. These observations were supported by the detection of anti-shrimp IgA production in intestinal lavage samples and morphometric intestinal mucosal changes. Therefore, this experimental protocol can be a tool to evaluate prophylactic and therapeutic approaches.

The sweet fuel of inflammation: New perspectives on the complex web that interconnects diabetes.

Due to the inflammatory nature of type 2 diabetes mellitus (T2DM) and the increased cardiovascular risk, there is a growing need for innovative strategies to change our identification and treatment approach to avoid clinical complications. One approach would be the use of circulating biomarkers to track disease progression and management. Thus, this study aimed to evaluate the concentrations of inflammatory biomarkers in patients diagnosed with type 2 diabetes mellitus and systemic arterial hypertension, correlating inflammatory cytokines and disease severity. Initially, 259 individuals were stratified into different degrees of disease: low risk, moderate risk, high risk, and very high risk, according to the European Society of Cardiology, which correlates blood pressure values with the presence of cardiovascular risk factors. For this stratification, analysis of body composition, blood pressure measurement, and questionnaires were applied. Blood was collected for biochemical measurements and for ELISA to detect concentrations of cytokines IL-17, IL-1ß, IFN-Y, TNF-α, and IL-10. The findings suggest that inflammation is present, contributing to the worsening of systemic arterial hypertension and type 2 diabetes mellitus. Through Bayesian analysis, we found that hyperglycemia plays a role in fueling inflammation, contributing to the maintenance of the state of dysregulation and persistent inflammation, which can contribute to systemic damage. Our work correlates biochemical, glycemic, body composition, blood pressure and inflammatory profiles, showing how they participate together in worsening the prognosis of patients diagnosed with chronic non-communicable diseases. We have seen that all these parameters can be changed with the practice of physical activity, even in conditions of obesity, hyperglycemia or dyslipidemia, when patients do not control the changes with standard pharmacological treatment. Thus, the management measures of these chronic non-communicable diseases must take into account the crosstalk between the systems, and the dysregulation of just one of these systems is enough to generate consequences in all the other systems.

Inflammaging and body composition: New insights in diabetic and hypertensive elderly men.

Age-related changes in the body's physiological responses play a critical role in systemic arterial hypertension (SAH) and type 2 Diabetes mellitus (T2DM). SAH and T2DM have clinically silent low-grade inflammation as a common risk factor. This inflammation has a relevant element, the excess of fatty tissue. In this scenario, little is known about how inflammatory markers interact with each other. Therefore, this work evaluated the interplay among anthropometric, biochemical, and inflammatory markers in the elderly with SAH and T2DM. Men aged 60-80 years old with SAH and T2DM were classified by body mass index (BMI) as eutrophic elderly (EE, 24 individuals) or overweight elderly (OE, 25 individuals). Body composition analysis was performed using bioimpedance. Blood samples were collected to perform inflammatory and biochemical evaluations. The cytokines IL-17A, IL-1ß, IFN-y, TNF-α, and IL-10, were evaluated by ELISA. Triglycerides, total and fractions of cholesterol, and glucose were measured by spectrophotometry. Overweight elderly men had a higher glycemic index and an increase in most anthropometric markers, as well as higher means for all pro-inflammatory cytokines analyzed (IL-17A, IL-1ß, IFN-y, and TNF-α) in comparison to their eutrophic elderly counterparts. However, there was a decrease in IL-10 anti-inflammatory cytokine and IL-10/IL-17A ratio compared to their eutrophic elderly counterparts. Although overweight elderly men have worsening inflammatory parameters, the magnitude of their correlations with anthropometric and biochemical parameters becomes less evident. The Bayesian networks highlight that in the eutrophic elderly, IL-17A and TNF-α are the cytokines most associated with interactions, and most of these interactions occur with biochemical parameters. It is worth highlighting the role of IFN-y in overweight elderly men. This cytokine influences IL-10 and TNF-α production, contributing to the inflammatory profile exacerbated in this group.

Antimicrobial photodynamic therapy (aPDT) with curcumin controls intradermal infection by Staphylococcus aureus in mice with type 1 diabetes mellitus: a pilot study.

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the main pathogens that cause infections in diabetic individuals. In this paper, we report the outcomes of our investigation on the intradermal application of antimicrobial photodynamic therapy (PDT) with curcumin in an infection induced by MRSA ATCC 43300 strain in the ear of mice with Type 1 Diabetes Mellitus (T1DM). A solution containing 100 µg of curcumin was photoactivated ex vivo with a LED light (450 nm) delivering a fluency of 13.5 J/cm3. This solution was administered in the ear intradermally, at the same inoculum site as the MRSA ATCC 43300 strain (PDT Group). This study also included the use of two control groups (both infected): One was treated with saline and the other was treated with non-photoactivated curcumin. The animals were euthanized 24 h after these treatments and samples of draining lymph node and treated ear were collected for examination. The PDT group showed lower bacterial load in the draining lymph node when compared to the saline and curcumin groups (p-value <0.05) 24 h after treatment. In addition to bacterial load, the PDT group presented a higher concentration of nitrates and nitrites in the draining lymph node when compared to the saline and curcumin groups (p-value <0.001). Examining the infectious site, despite apparently having similar inflammatory cell recruitment compared with the control groups, the PDT group showed a profile with less intense activity in the myeloperoxidase expression when compared to the saline group (p-value <0.001). Additionally, the detected concentration of cytokines such as IL-1ß, IL-12, and IL-10 was significantly lower in the PDT group when compared to the saline group (p-value <0.01; p-value <0.05; p-value <0.05, respectively), thus presenting a less intense inflammatory response during infection resolution. Our pilot study showed for the first time the therapeutic potential of PDT using curcumin when administered intradermally in the treatment of infections caused by S. aureus in mice with T1DM.

Efficacy of photoactivated Myrciaria cauliflora extract against Staphylococcus aureus infection - A pilot study.

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.

Ovariectomy Modifies TH2, and TH17 Balance in BALB/C Allergic Mice.

Asthma is a chronic inflammation of the airways affecting over 300 million people worldwide. As in the autoimmune diseases, it is well described that women are the most affected by asthma. The higher number of women presenting this pathology suggests the involvement of female sex hormones in the construction of the allergic immune response. Female Balb / c mice were used for the experiments. Thirty-eight animals were separated into four groups: OVX-Ova; Sham-Ova; OVX-Sal; Sham-Sal. Then animals underwent acute allergic induction protocol by Ovalbulmin (OVA). Ovariectomized animals showed greater number of leukocytes in bronchoalveolar lavage (BAL) and elevated white blood cells recruitment to the lung environment observed by histological analysis. There was a significant increase of eosinophils and mast cells in inflammatory sites at pulmonary tissue. The relative uterine and body weight were lower in ovariectomized animals and higher in Sham mice, respectively. Moreover, the lack of the sex hormones induced an increase in interleukin (IL)-4 and titers of immunoglobulin G1 (IgG1) antibodies. However, increased production of IL-17A was only observed in Sham animals. Altogether, data this study suggest that ovariectomy induces the formation of a stronger Th2 response in allergic animal. However, the immune processes involved in the allergic response in females currently remain unclear.