A diterpenoid taxodone from Metasequoia glyptostroboides with antimycotic potential against clinical isolates of Candida species

作者：Bajpai V K; Park Y H^*; Kang S C

来源：Journal de Mycologie Medicale, 2015, 25(1): E31-E38.

DOI：10.1016/j.mycmed.2014.10.017

• Metasequoia glyptostroboides
• Antimycotic potential
• Taxodone
• Candida species
• Clinical isolates

Objective. - The increasing importance of clinical isolates of Candida species and emerging resistance of Candida species to current synthetic antifungal agents have stimulated the search for safer and more effective alternative drugs from natural sources. This study was directed towards exploring the antimycotic potential of a diterpenoid compound taxodone isolated from Metasequoia glyptostroboides against pathogenic isolates of Candida species.
Materials and methods. - Antimycotic efficacy of taxodone was evaluated by disc diffusion assay, determination of minimum inhibitory (MIC) and minimum fungicidal (MFC) concentrations, and cell viability assay. To confirm a partial antimycotic mode of action of taxodone, the efficacy of taxodone was determined by measuring the release of 260 nm absorbing materials from the selected Candida species as compared to control.
Results. - The taxodone at the concentration of 400 mu g/disc displayed potential antimycotic effect against the tested clinical and pathogenic isolates of Candida species as diameters of zones of inhibitions, which were found in the range of 11 +/- 0.0 to 12.6 +/- 0.5 mm. The MIC and MFC values of taxodone against the tested clinical isolates were found in the range of 250 to 1000 and 500 to 2000 mu g/mL, respectively. On the other hand, the MIC and MFC values of positive control (amphotericin B) against the tested Candida isolates were found in the range of 62.5 to 250 and 500 to 2000 mu g/ml. On the viable counts of the tested fungal isolates, the taxodone exerted significant antimycotic effect. Elaborative study of partial mode of action conducted onto the release of 260 nm materials (DNA and RNA) revealed potential detrimental effect of taxodone on the membrane integrity of the tested pathogens at MIC concentration.
Conclusion. - With respect to the antimycotic effect of taxodone against pathogenic and clinical isolates of Candida species, it might be confirmed that bioactive compound taxodone present in M. glyptostroboides holds therapeutic value of medicinal significance.

• 出版日期2015-3