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This study investigated crotamine (CTA), a peptide derived from the venom of the South American rattlesnake Crotalus durissus terrificus, known for its exceptional cell penetration potential. The objective was to explore the antibacterial and antifungal activity of CTA, its ability to inhibit efflux pumps and evaluate the effectiveness of its pharmacological combination with antibiotics and antifungals. In microbiological assays, CTA in combination with antibiotics was tested against strains of S. aureus and the inhibition of NorA, Tet(K) and MepA efflux pumps was also evaluated. CTA alone did not present clinically relevant direct antibacterial action, presenting MIC > 209.7 µM against strains S. aureus 1199B, IS-58, K2068. The standard efflux pump inhibitor CCCP showed significant effects in all negative relationships to assay reproducibility. Against the S. aureus 1199B strain, CTA (20.5 µM) associated with norfloxacin diluted 10 × (320.67 µM) showed a potentiating effect, in relation to the control. Against the S. aureus IS-58 strain, the CTA associated with tetracycline did not show a significant combinatorial effect, either with 2304 or 230.4 µM tetracycline. CTA at a concentration of 2.05 µM associated with ciprofloxacin at a concentration of 309.4 µM showed a significant potentiating effect. In association with EtBr, CTA at concentrations of 2.05 and 20.5 µM potentiated the effect in all strains tested, reducing the prevention of NorA, Tet(K) and MepA efflux pumps. In the C. albicans strain, a potentiating effect of fluconazole (334.3 µM) was observed when combined with CTA (2.05 µM). Against the C. tropicalis strain, a significant effect was also observed in the association of fluconazole 334.3 µM, where CTA 2.05 µM considerably reduced fungal growth and decreased the potentiation of fluconazole. Against the C. krusei strain, no significant potentiating effect of fluconazole was obtained by CTA. Our results indicate that CTA in pharmacological combination potentiates the effects of antibiotics and antifungal. This represents a new and promising antimicrobial strategy for treating a wide variety of infections.

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BACKGROUND: Neglected parasitic diseases constitute a broad spectrum of clinical conditions that, in the chronic phase, lack effective therapies for the target population. The utilization of vaccines based on liposomal nanocarrier systems is emerging, thereby enhancing clinical outcomes in various comorbidities. Consequently, this study aims to assess the immunological activity induced by liposomal nanocarriers against neglected parasitic diseases. METHODS: For the review, the Pubmed, Embase, and Lilacs databases were used using the descriptors vaccine, parasite, and liposome. The following inclusion criteria were adopted: in vivo and in vitro experimental articles. As exclusion criteria: book chapters, editorials, literature reviews and duplicate articles found during the database search. RESULTS: A total of 226 articles were identified, from which 34 were selected for review. The primary diseases identified included Babesia bovis, Entamoeba histolytica, Leishmania braziliensis, Leishmania donovani, Leishmania major, Leishmania infantum, Plasmodium falciparum, Plasmodium chabaudi, Plasmodium chabaudi, Plasmodium yoelii, Toxoplasma gondii and Trypanosoma cruzi. An elevation in cytokines such as GM-CSF, MCP-1, INF-γ, TNF-α, IL-2, IL-4, IL-5, IL-6, IL-10, IL-12, and IL-17 was observed in the studies evaluated regarding the parasitic diseases. Furthermore, cytokines such as IL-4, IL-10, and TGF-ß were diminished with the administration of the vaccine systems in those studies. CONCLUSION: Therefore, the administration of liposomal nanovaccine systems can effectively ameliorate the clinical condition of patients by modulating their immunological profile.

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BACKGROUND: In a scenario of increased pathogens with multidrug resistance phenotypes, it is necessary to seek new pharmacological options. This fact is responsible for an increase in neoplasms and multiresistant parasitic diseases. In turn, snake venom- derived peptides exhibited cytotoxic action on fungal and bacterial strains, possibly presenting activities in resistant tumor cells and parasites. Therefore, the aim of this work is to verify an antitumor and antiparasitic activity of antimicrobial peptides derived from snake venom. METHODS: For this purpose, searches were performed in the Pubmed, Embase and Virtual Health Library databases by combining the descriptors peptides, venom and snake with antitumor/ antiparasitic agent and in silico. The inclusion criteria: in vitro and in vivo experimental articles in addition to in silico studies. The exclusion criteria: articles that were out of scope, review articles, abstracts, and letters to the reader. Data extracted: peptide name, peptide sequence, semi-maximal inhibitory concentration, snake species, tumor lineage or parasitic strain, cytotoxicity, in vitro and in vivo activity. RESULTS: In total 164 articles were found, of which 14 were used. A total of ten peptides with antiproliferative activity on tumor cells were identified. Among the articles, seven peptides addressed the antiparasitic activity. CONCLUSION: In conclusion, snake venom-derived peptides can be considered as potential pharmacological options for parasites and tumors, however more studies are needed to prove their specific activity.

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COVID-19 is an emerging outbreak similar to previous pandemics caused by Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS). Till date, SARS-CoV-2 infection is still spreading, representing a major threat to public health, where several control measures are being practiced in order to culminate its spread. The research and development of new drugs require a lot of funding in addition to being a slow and costly process. As a result, new techniques have been proposed to streamline this process. The repositioning or repurposing of drugs represents an attractive strategy, presenting a promising way to introduce new drugs. Currently, numerous reused drugs are already available in the market and are in practice. In this review, it was observed that the antiviral drugs Entricitabine and Tenofovir display potential therapeutic efficacy in preclinical studies. Therefore, in silico analyses were considered a potential tool for predicting the effectiveness of drugs, mainly as an effective approach to encourage a complementary in vitro and in vivo antiviral evaluation.

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