Anticryptococcal activity of hexane extract from Spondias tuberosa Arruda and associated cellular events.

Cryptococcosis is an opportunistic systemic mycosis whose treatment is limited to three drugs. In this work, we evaluated the antifungal activity of a hexane extract (HE) from Spondias tuberosa leaves against Cryptococcus neoformans and Cryptococcus gattii. Minimal inhibitory concentrations (MIC) were determined, and putative mechanisms were evaluated by flow cytometry. In addition, an in vivo infection assay was performed using Tenebrio molitor larvae. Treatment with HE inhibited the growth of standard and clinical isolates of C. neoformans and C. gattii (MICs ranging from 0.78 to 3.12mg/mL), significantly (P<0.05) increased mitochondrial superoxide anion levels, and induced mitochondrial membrane depolarization, loss of lysosomal membrane integrity, and phosphatidylserine externalization. The mean survival time of C. gattii-infected T. molitor larvae significantly (P<0.05) increased from 1.225 days in control to 3.067 and 3.882 days in HE-treated groups (78 and 156mg/kg, respectively). In conclusion, HE showed anticryptococcal activity, induced mitochondrial and lysosomal damage in yeast cells, and exhibited anti-infective action against C. gattii in T. molitor larvae.

Curcumin enhances the activity of fluconazole against Cryptococcus gattii-induced cryptococcosis infection in mice.

AIM: The aim of this study was to investigate the in vitro and in vivo activities of pure curcumin, as well as its combination with fluconazole, against Cryptococcus gattii. METHODS AND RESULTS: The minimal inhibitory concentrations (MIC) of curcumin and its interactions with fluconazole against C. gattii were assessed in vitro using standard methods. This same combination was used to treat C. gattii-induced cryptococcosis in mice. The behavioural and functional assessment of the mice during treatment was also performed. The average MIC for curcumin was 19·8 µg ml(-1) . Its combination with fluconazole resulted in FICΣ (fractional inhibitory concentration index) values between 0·79 and 2·29. Curcumin (alone or combined with fluconazole) significantly reduced pulmonary damage and fungal burden in the brain. No colonies were found in the brain following combination treatment, which was also confirmed by the improved behaviour of mice. CONCLUSIONS: The combination therapy with curcumin and fluconazole was the most effective among the treatments tested, as in addition to reducing the fungal burden and damage on lung tissues, it was able to eliminate the fungal burden in the brain, enhancing the survival of mice. SIGNIFICANCE AND IMPACT OF THE STUDY: This study points to the possibility of using curcumin in combination with fluconazole as a clinical treatment of cryptococcosis.

Rat visceral yolk sac cells: viability and expression of cell markers during maternal diabetes.

The function of the visceral yolk sac (VYS) is critical for embryo organogenesis until final fetal development in rats, and can be affected by conditions such as diabetes. In view of the importance of diabetes during pregnancy for maternal and neonatal health, the objective of this study was to assess fetal weight, VYS cell markers, and viability in female Wistar rats (200-250 g) with induced diabetes (alloxan, 37 mg/kg) on the 8th gestational day (gd 8). At gd 15, rats from control (n=5) and diabetic (n=5) groups were anesthetized and laparotomized to remove the uterine horns for weighing of fetuses and collecting the VYS. Flow cytometry was used for characterizing VYS cells, and for determining mitochondrial activity, cell proliferation, DNA ploidy, cell cycle phases, and caspase-3 activity. Fetal weight was reduced in the diabetic group. Expression of the cell markers CD34, VEGFR1, CD115, CD117, CD14, CCR2, CD90, CD44, STRO-1, OCT3/4, and Nanog was detected in VYS cells in both groups. In the diabetic group, significantly decreased expression of CD34 (P<0.05), CCR2 (P<0.001), and OCT3/4 (P<0.01), and significantly increased expression of CD90 (P<0.05), CD117 (P<0.01), and CD14 (P<0.05) were observed. VYS cells with inactive mitochondria, activated caspase-3, and low proliferation were present in the rats with diabetes. Severe hyperglycemia caused by maternal diabetes had negative effects on pregnancy, VYS cell viability, and the expression of cell markers.