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Infectious diseases remain as a significant cause of thousands of deaths annually worldwide. Therefore, this study aimed to investigate the antimicrobial and antiparasitic activity of the crude hydroalcoholic extract and compounds isolated from Brazilian Red Propolis (BRP) against oral pathogens and Toxoplasma gondii, using in vitro, in vivo and in silico approaches. Antimicrobial and synergistic activities were determined using the broth dilution method and the checkerboard assay, respectively. Antibiofilm activity was evaluated by staining with 2 % crystal violet and counting microorganisms. In vivo infection was carried out in Caenorhabditis elegans AU37 larvae and in silico analysis was performed using molecular docking simulations. The effect on growth modulation of T. gondii was evaluated through a β-galactosidase colorimetric assay. Minimum Inhibitory Concentration values ranged from 3.12 to 400 µg/mL. Biofilm Minimum Inhibitory Concentration (MICB 50 ) values ranged from 6.25 to 375 µg/mL, with a significant reduction in the number of viable cells. Furthermore, Guttiferone E and the crude extract reduced cell aggregation and caused damage to the biofilm cell wall. The highest concentrations of the crude extract and Guttiferone E increased the survival and reduced the risk of death of infected and treated larvae. Guttiferone E and Oblongifolin B inhibited the intracellular proliferation of T. gondii and demonstrated several targets of action against bacteria and T. gondii through in silico analysis. These data demonstrate that BRP has antimicrobial and antiparasitic activity against pathogens of clinical relevance, and can be used in the future as phytomedicines., Competing Interests: Declaration of Competing Interest We have nothing to declare, (Copyright © 2024. Published by Elsevier Masson SAS.)

The microorganisms that constitute the oral microbiome can cause oral diseases, including dental caries and endodontic infections. The use of natural products could help to overcome bacterial resistance to the antimicrobials that are currently employed in clinical therapy. This study assessed the antimicrobial activity of the Copaifera pubiflora oleoresin and of the compounds isolated from this resin against oral bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays provided values ranging from 6.25 to > 400 μg/mL for the C. pubiflora oleoresin and its isolated compounds. The fractional inhibitory concentration index (FICI) assay showed that the oleoresin and chlorhexidine did not act synergistically. All the tested bacterial strains formed biofilms. MICB 50 determination revealed inhibitory action: values varied from 3.12-25 μg/mL for the oleoresin, and from 0.78 to 25 μg/mL for the ent-hardwickiic acid. Concerning biofilm eradication, the C. pubiflora oleoresin and hardwickiic acid eradicated 99.9 % of some bacterial biofilms. Acid resistance determination showed that S. mutans was resistant to acid in the presence of the oleoresin and ent-hardwickiic acid at pH 4.0, 4.5, and 5.0 at all the tested concentrations. Analysis of DNA/RNA and protein release by the cell membrane demonstrated that the oleoresin and hardwiickic acid damaged the bacterial membrane irreversibly, which affected membrane integrity. Therefore, the C. pubiflora oleoresin and ent-hardwickiic acid have potential antibacterial effect and can be used as new therapeutic alternatives to treat oral diseases such as dental caries and endodontic infections., (Copyright © 2020. Published by Elsevier Masson SAS.)

This paper is the first report on the in vitro effects of licochalcone A, a chalcone isolated from Glycyrrhiza inflate Batalin (Leguminosae), on Schistosoma mansoni adult worms. In vitro, licochalcone A afforded lethal concentrations for 50% of parasites (LC 50 ) of 9.12±1.1 and 9.52±0.9μM against female and male adult worms, respectively, at 24h. Additionally, the compound reduced the total number of S. mansoni eggs and affected the development of eggs produced by S. mansoni adult worms. Together, the results achieved after 24h showed that licochalcone A was 55.7- and 53.3-fold more toxic to S. mansoni female and male adult worms than to Chinese hamster ovary fibroblasts cells, respectively. Treatment with licochalcone A elicited drastic changes in the tegument of S. mansoni adult worms, as well as mitochondrial alteration and chromatin condensation. Licochalcone A also increased the superoxide anion level and decreased the superoxide dismutase activity in S. mansoni adult worms. Overall, our results indicated that licochalcone A displays in vitro schistosomicidal activity. This effect may result from increased production of reactive oxygen species (ROS) induced by the action of licochalcone A. The resulting ROS could act on the S. mansoni tegument and membranes and help induce the death of S. mansoni adult worms., (Copyright © 2017 Elsevier Masson SAS. All rights reserved.)