Effect of ethanolic extract of Zataria multiflora Boiss (Shiraz thyme extract) on the kidney and spleen tissues of mice infected with visceral candidiasis and the stimulation of Th1, Th17, and Treg immune cells

Background and aims: Candidiasis is one of the most important fungal infections, which has been associated with antimicrobial resistance. Materials and Methods: Candida albicans ATCC10231 strain were isolated from the patient's body. To prepare the desired yeast number in a specific size, the serial dilution was performed. Doses of 2 × 107–108 were used and four mice were selected for each dose. The PAS staining was performed on the sections of the kidney and spleen prepared in paraffin blocks. The chloroform fraction of Zataria multiflora Boiss ethanolic extract was obtained and standardized by HPLC. Forty-two female BALB/C mice were randomly included with ages of 6–8 weeks. The administration of drugs into mice in each group was performed 24 h of C. albicans injection (the onset of the visceral candidiasis appearance in mice), and a single dose of 0.1 ml of the extract was injected to each group for every 6 days. Mononuclear cells of spleen and kidney were prepared from buffy coat layer and culture in 50 ml of 1640 RPMI medium. Th1, Th17, and Treg cells were measured in MNCs. Results: In mice that had medication intervention (including chloroform fraction of Shiraz thyme, thymol, carvacrol, or fluconazole), the fungal purification rate in the spleen was higher than the kidney (groups 1–5). In mice with no medication (group 6), the fungal purification rate in the kidney was higher than the spleen. All groups having medication intervention had a significant difference in terms of fungal elimination with group 7 and their fungal load was significantly decreased. In this regard, the amounts of fungal load reduction in spleen and kidney tissues in relation to extracts were the most. After extract, the highest rate of tissue cleansing was related to fluconazole followed by thymol and carvacrol. Thymol and carvacrol had no significant difference in terms of the effect on reducing the fungal load in the studied tissues. The percentage of TH1 cells in the culture of these cells was higher than that of the kidney cells. The highest percentage of TH17 cells was observed in group 1. The percentage of Treg cells in the kidney and spleen in the extract-receiving group had a significant decrease compared with the nondrug-receiving group. Conclusion: The Z. multiflora Boiss fraction can be considered as a powerful alternative to other drug treatments for achieving proper outcomes. Therefore, the use of this compound as a therapeutic agent in visceral candidiasis is possibly a new turning point in treatment, which can postpone the progress of the disease among patients.