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.

Antinociceptive Effect of Dillenia indica (Linn.) Mediated by Opioid and Cannabinoid Systems: Pharmacological and Chemical Studies.

Dillenia indica (Linn.) has been reported by several biological activities, including anti-inflammatory, antioxidant, antidiabetic, anti-hyperglycemic, antiproliferative, antimutagenic, anticholinesterase, and antimicrobial. In Brazilian traditional medicine, the fruits of D. indica have been used to treat general topical pain and inflammation, but with no scientific validation. Thus, aiming to study its chemical constitution and antinociceptive properties, the crude extract (CE) and fractions obtained from the fruits of D. indica were submitted to an in vivo pharmacological evaluation and a dereplication study by LC-MS/MS analysis, assisted by the Global Natural Product Social Molecular Networking (GNPS). The oral antinociceptive activity of the fruits of D. indica and the possible participation of the opioid and cannabinoid systems were demonstrated in the formalin-induced nociception model. The chemical dereplication study led us to identify several known chemical constituents, including flavonoids, such as caffeoylmalic acid, naringenin, quercetin, and kaempferol. According to literature data, our results are compatible with significant antinociceptive and anti-inflammatory activities. Therefore, the flavonoid constituents of the fruits of D. indica are probably responsible for its antioxidant, anti-inflammatory, and antinociceptive effects mediated by both opioid and cannabinoid systems, confirming its folk use in the treatment and relief of pain.

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.

Seasonal variation in the chemical composition of two chemotypes of Lippia alba.

Lippia alba is a popular Brazilian herb known as 'cidreira' that presents several chemotypes which exhibit different chemical profile and they are widely used as seasonings and traditional medicine. This work describes the seasonal variation of metabolites of polar extracts of carvone and linalool chemotypes, identified by GC-MS analyses of the essential oils. A methodology was elaborated in order to obtain a seasonal variation in the chemical composition of leaf employing HPLC-DAD. Acteoside, isoacteoside, geneposidic acid, 8-epi-loganin, mussaenoside, luteolin 7-O-glucoside, apigenin 7-O-glucuronide and tricin 7-O-diglucuronide have been isolated and identified for validation procedures and chromatographic analysis. Geneposidic acid was presented in all samples, in contrast to the 8-epi-loganin and, mussaenoside which were presented only in the carvone-chemotype. Acteoside was the major metabolite detected from July to November while tricin-7-O-diglucuronide was the major compound in all other months. Besides, phenylpropanoids are predominant in winter and flavonoids in summer season.