Evaluation of the antifungal activity of (-) - myrtenol against strains of Sporothrix brasiliensis.

Evaluation of the antifungal activity of (-) - myrtenol against strains of Sporothrix brasiliensis.

• Author
• Larissa Alves da Silva
• Co-authors
• Luanna Oliveira de Lima , Felipe Queiroga Sarmento Guerra
• Abstract

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  INTRODUCTION: Sporotrichosis is a subacute or chronic fungal infection that affects humans and animals, caused by the traumatic implantation of the fungus of the genus Sporothrix. Therapies for this mycosis have faced several problems, related to toxicity, high therapeutic cost and isolation of resistant strains [1]. Thus, the importance of developing new alternatives to improve the management of this disease and reduce complications in relation to its treatment is evident, with emphasis on the use of natural products and their derivatives. Among these substances, there is (-) - myrtenol, a monoterpene that has several biological effects reported in the literature, including antibacterial and antifungal. [2,3]. AIMS: Therefore, this study evaluated the antifungal activity of (-) - myrtenol against strains of Sporothrix brasiliensis, obtained from the mycotheque collection of the Mycology laboratory - UFPB. METHODS: The Minimum Inhibitory Concentration (MIC) and Minimum Fungicide Concentration (MFC) were determined using the broth microdilution technique following CLSI M38-A. Next, the action of the test product on the virulence of Sporothrix brasiliensis was analyzed, with the analysis of the effects on the kinetics of fungal mycelial growth, using the solid medium dilution technique. Furthermore, the effect on the germination of conidia was carried out using the suspension of fungal conidia with RPMI medium plus the test substance at its respective MIC, and subsequent incubation at 28°C. After 5 days, the suspension was analyzed in a Neubauer chamber, and the percentage of inhibition of conidial changes was calculated, always comparing the test results with the control. RESULTS AND DISCUSSION: It was observed that the MIC of (-) - myrtenol was 128-256 µg/mL, depending on the strain tested, and the MFC values resulted in a MIC/MFC ratio of less than 4 for all strains tested, indicating fungicidal activity. Regarding mycelial growth, the test terpene was able to inhibit fungal growth until the 10th day. In the analysis of conidial germination, inhibition of conidia was visible when compared to the control. CONCLUSION: (-) - myrtenol exhibits strong fungicidal activity against strains of Sporothrix brasiliensis and their virulence factors, suggesting that it may present a new therapeutic option for infection control.

  ACKNOWLEDGMENT: To the rograma de Pós-graduação em Produtos Naturais e Sintéticos Bioativos, UFPB, CNPq, and CAPES.

  Citations and References

  [1] RODRIGUES, Anderson Messias; HAGEN, Ferry; DE CAMARGO, Zoilo Pires. A spotlight on Sporothrix and sporotrichosis. Mycopathologia, v. 187, n. 4, p. 407-411, 2022.

  [2] CORDEIRO, Laísa et al. Antibacterial and antibiofilm activity of myrtenol against Staphylococcus aureus. Pharmaceuticals, v. 13, n. 6, p. 133, 2020.

  [3] CAVALCANTI, Bruno Bezerra et al. Inhibitory Effect of (-)-myrtenol alone and in combination with antifungal agents on Candida spp. Research, Society and Development, v. 10, n. 15, p. e35101522434-e35101522434, 2021.

  Clinical and Laboratory Standards Institute. 2017. Reference method for broth dilution antifungal susceptibility testing of filamentous fungi; approved standard, 2nd ed. CLSI document M38-A2. Clinical and Laboratory Standards Institute, Wayne, PA

   

  LOPES-BEZERRA, Leila M.; MORA-MONTES, Héctor M.; BONIFAZ, Alexandro. Sporothrix and Sporotrichosis. In: Current Progress in Medical Mycology. Springer, Cham, 2017. p. 309-331.

   

   

• Keywords
• Sporotrichosis, natural products, monoterpene, antimicrobial activity.
• Modality
• Pôster
• Subject Area
• Biology, Pharmacology and Physiology