Résumé
Objective: Invasive pulmonary Aspergillus infection has the characteristics of high morbidity, difficult to be treated, poor prognosis and high mortality. This study aims to investigate the effects of cinnamaldehyde on 1,3-β-D-glucans in the pulmonary Aspergillus fumigatus cell wall to provide a basis for developing novel antifungal drugs. Methods: Immunosuppressed ICR mice were intranasally inoculated with 50 µL of A. fumigatus suspension (1 × 107 CFU/mL) and then separated into two groups, for the experimental group cinnamaldehyde was orally administered at 240 mg/kg/d consecutively for 14 d. While for the control group, voriconazole was used to treat the fungus infection. Pulmonary tissues were then extracted for 1,3-β-D-glucans assay and electron microscopy. Results: The concentration of 1,3-β-D-glucans was significantly different between the cinnamaldehyde and voriconazole groups, which was (1160.89 ± 364.96) pg/mL and (3885.94 ± 845.45) pg/mL, respectively (P < 0.01). Electron microscopy showed that 2−3 outer layers (1,3-β-D-glucan layer) of A. fumigatus cell wall were damaged and fell off, resulting in serious defect of the cell wall, but the cell membrane was clear and intact. Conclusion: Cinnamaldehyde has a significant influence on the integrity of 1,3-β-D-glucans in the pulmonary A. fumigatus cell wall, but the cell membrane is unaffected, suggesting that cinnamaldehyde has unique antifungal properties depending on its action against the 1,3-β-D-glucans on the pulmonary A. fumigatus cell wall.
Résumé
Objective: Invasive pulmonary candidiasis is a disease with high incidence, difficult treatment, poor prognosis, and high mortality. The present study analyzed the influence of cinnamaldehyde on 1,3-β-D-glucans in the cell wall of Candida albicans in order to provide a theoretical basis for the research of antifungal drugs. Methods: An immunosuppressed BALB/c mouse model with invasive pulmonary candidiasis was established by nasal perfusion of 50 µL of C. albicans suspension (107 cfu/mL). 1,3-β-D-glucans examination and electron microscopy were carried out. Fluconazole was used as the control. Results: Cinnamaldehyde was administered at a dose of 240 mg/kg/d for 14 consecutive days, and the measured value of 1,3-β-D-glucans was (1160.62 ± 89.65) pg/mL, whereas that of fluconazole was (4285.87 ± 215.62) pg/mL. The difference between the two groups was statistically significant (P < 0.05). Electron microscopy observation indicated that the 2−3 layers outside the cell wall of C. albicans (1,3-β-D-glucans layer) were rough, deformed, and incomplete, although the cell membrane was clear and intact. Conclusion: Cinnamaldehyde demonstrated special efficacy on 1,3-β-D-glucans in the cell wall of C. albicans.