In: Sydowia 72, (2020): 207-214; ISSN 0082-0598, DOI 10.12905/0380.sydowia72-2020-0207, Published online on July 06, 2020

Synergistic interaction of carvacrol and fluconazole on growth inhibition of Candida albicans in vitro and in vivo mouse model

Fereshteh Beheshtirooy1, Fahimeh Alizadeh1,*, Esmaeel Panahi Kokhdan2 & Alireza Khodavandi3,*
1 Department of Microbiology, Yasooj Branch, Islamic Azad University, Yasooj, Iran
2 Medicinal Plants Research Center, Yasuj University of Medical Sciences, Yasuj, Iran
3 Department of Biology, Gachsaran Branch, Islamic Azad University, Gachsaran, Iran
* e-mails: mnalizadeh@yahoo.com, alireza_khodavandi@yahoo.com

Beheshtirooy F., Alizadeh F., Panahi Kokhdan E. & Khodavandi A. (2020) Synergistic interaction of carvacrol and fluconazole
on growth inhibition of Candida albicans in vitro and in vivo mouse model. – Sydowia 72: 207–214.
Candida albicans is a major human fungal pathogen. Infections caused by the C. albicans are a challenge to antifungal treatment,
especially in immunocompromised patients. Antifungal combinations that target critical cellular pathways are a mainstay
of candidiasis care. To improve current approaches for treatment of gastrointestinal candidiasis and gain insights into the underlying
synergistic interaction, we studied the effect of carvacrol alone and in combination with fluconazole by analysing in vitro
and in vivo susceptibility of C. albicans. Susceptibility of oral clinical isolates of C. albicans were assessed using the CLSI reference
method. BALB/c mouse were given as the sole food source food containing C. albicans. The mice were treated intragastrically
with carvacrol and fluconazole alone and in combination. The quantification of the antifungal agent treatments was submitted
for microbiological and histopathological examination. Combination of carvacrol with fluconazole demonstrated partial
synergistic (66.67 %) and indifferent (33.33 %) effects with FIC values 0.56-1.50. Gastrointestinal candidiasis was confirmed by
colony counts of homogenized liver, as well as by histological examination. Carvacrol in combination with fluconazole was more
efficacious than carvacrol and fluconazole alone at reducing the fungal loads (P < 0.01). Taken together, our study shows that
carvacrol and fluconazole combination effects can be effectively queried in C. albicans cells, which could provide a means to test
novel therapeutic strategies.

Keywords: Candidiasis, Fluconazole, Gastrointestinal tract.