Synergistic Antifungal Effect and In Vivo Toxicity of a Monoterpene Isoespintanol Obtained from Oxandra xylopioides Diels.

Candida sp. infections are a threat to global health, with high morbidity and mortality rates due to drug resistance, especially in immunocompromised people. For this reason, the search for new alternatives is urgent, and in recent years, a combined therapy with natural compounds has been proposed. Considering the biological potential of isoespintanol (ISO) and continuing its study, the objective of this research was to assess the effect of ISO in combination with the antifungals fluconazole (FLZ), amphotericin B (AFB) and caspofungin (CASP) against clinical isolates of C. tropicalis and to evaluate the cytotoxic effect of this compound in the acute phase (days 0 and 14) and chronic phase (days 0, 14, 28, 42, 56, 70 and 84) in female mice (Mus musculus) of the Balb/c lineage. The results show that ISO can potentiate the effect of FLZ, AFB and CASP, showing synergism with these antifungals. An evaluation of the mice via direct observation showed no behavioral changes or variations in weight during treatment; furthermore, an analysis of the cytokines IFN-γ and TNF in plasma, peritoneal cavity lavage (PCL) and bronchoalveolar lavage (BAL) indicated that there was no inflammation process. In addition, histopathological studies of the lungs, liver and kidneys showed no signs of toxicity caused by ISO. This was consistent with an analysis of oxaloacetic transaminases (GOT) and pyruvic transaminases (GPT), which remained in the standard range. These findings indicate that ISO does not have a cytotoxic effect at the doses evaluated, placing it as a monoterpene of interest in the search for compounds with pharmacological potential.

Cytotoxic Potential of the Monoterpene Isoespintanol against Human Tumor Cell Lines.

Cancer is a disease that encompasses multiple and different malignant conditions and is among the leading causes of death in the world. Therefore, the search for new pharmacotherapeutic options and potential candidates that can be used as treatments or adjuvants to control this disease is urgent. Natural products, especially those obtained from plants, have played an important role as a source of specialized metabolites with recognized pharmacological properties against cancer, therefore, they are an excellent alternative to be used. The objective of this research was to evaluate the action of the monoterpene isoespintanol (ISO) against the human tumor cell lines MDA-MB-231, A549, DU145, A2780, A2780-cis and the non-tumor line MRC-5. Experiments with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and fluorescence with propidium iodide (PI), 4',6-diamidino-2-phenylindole dilactate (DAPI) and green plasma revealed the cytotoxicity of ISO against these cells; furthermore, morphological and chromogenic studies revealed the action of ISO on cell morphology and the inhibitory capacity on reproductive viability to form colonies in MDA-MB-231 cells. Likewise, 3D experiments validated the damage in these cells caused by this monoterpene. These results serve as a basis for progress in studies of the mechanisms of action of these compounds and the development of derivatives or synthetic analogues with a better antitumor profile.