Isoespintanol Antifungal Activity Involves Mitochondrial Dysfunction, Inhibition of Biofilm Formation, and Damage to Cell Wall Integrity in Candida tropicalis

Abstract

The growing increase in infections caused by C. tropicalis, associated with its drug resistance and consequent high mortality, especially in immunosuppressed people, today generates a serious global public health problem. In the search for new potential drug candidates that can be used as treatments or adjuvants in the control of infections by these pathogenic yeasts, the objective of this research was to evaluate the action of isoespintanol (ISO) against the formation of fungal biofilms, the mitochondrial membrane potential (ΔΨm), and its effect on the integrity of the cell wall. We report the ability of ISO to inhibit the formation of biofilms by up to 89.35%, in all cases higher than the values expressed by amphotericin B (AFB). Flow cytometric experiments using rhodamine 123 (Rh123) showed the ability of ISO to cause mitochondrial dysfunction in these cells. Likewise, experiments using calcofluor white (CFW) and analyzed by flow cytometry showed the ability of ISO to affect the integrity of the cell wall by stimulating chitin synthesis; these changes in the integrity of the wall were also observed through transmission electron microscopy (TEM). These mechanisms are involved in the antifungal action of this monoterpene.

Transcriptional Reprogramming of Candida tropicalis in Response to Isoespintanol Treatment

“…Given that the cell wall plays a crucial role in maintaining cellular osmotic integrity, any damage to it triggers various responses [99], previous studies have shown that inhibiting β-(1,3)-glucan synthesis leads to compensatory chitin synthesis and alterations in wall macromolecule arrangements in C. albicans. Similarly, C. tropicalis has been shown to activate a chitin compensatory response upon exposure to D-limonene [98] and ISO [84].…”

“…In prior studies, we established the efficacy of isoespintanol (ISO) against clinical Candida spp. isolates, including C. tropicalis, and elucidated its molecular targets [26,27,84]. In this study, we employ a transcriptomic approach to delineate gene expression profiles, providing insights into the intricate mechanisms underlying ISO's antifungal activity.…”

Discovery of Novel Cinnamic Acid Derivatives as Fungicide Candidates

“…27 Rhodamine 123 staining of B. cinerea hyphae indicated impaired mitochondrial function following 7n treatment. 28 As ROS accumulation is the most conspicuous, we evaluated the effect of treatment with 7n on cell membranes.…”

Cytotoxic Potential of the Monoterpene Isoespintanol against Human Tumor Cell Lines

“…Furthermore, its activity against human pathogenic bacteria and yeasts has also been documented [26][27][28][29]. The cytotoxicity of this compound has been studied in the line of immortalized African green monkey kidney epithelial cells (VERO) [28], human peripheral blood lymphocytes [30] and murine macrophages (RAW 264.7) [31]. However, there are no reports on its potential against tumor cells, then we hypothesize that ISO has a cytotoxic effect against them based on the wide range of described activities.…”

“…Chemical and biological activities such as antioxidant [19], anti-inflammatory [20], antispasmodic [21], vasodilator [22] and cryoprotective of canine semen, has been reported for this compound [23], as well as insecticidal [24] and antifungal activities against Colletotrichum [25]. Furthermore, its activity against human pathogenic bacteria and yeasts has also been documented [26][27][28][29]. The cytotoxicity of this compound has been studied in the line of immortalized African green monkey kidney epithelial cells (VERO) [28], human peripheral blood lymphocytes [30] and murine macrophages (RAW 264.7) [31].…”