Pharmacological Potential of Agave sisalana Plant Residue: Antioxidant and Antifungal Activities

Sisal (Agave sisalana) is a plant widely cultivated in Brazil for fiber extraction, generating large volumes of underutilized residues with pharmacological potential. In this study, an aqueous extract and its alcoholic fraction were obtained from the plant’s residual mucilage, aiming to investigate their antifungal activity, antioxidant capacity, and cellular safety. Phytochemical screening revealed high levels of phenols, flavonoids, and saponins, particularly in the aqueous fraction. The extracts were evaluated for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and for antifungal activity against the yeasts Candida albicans and Malassezia pachydermatis, as determined by the Minimum Inhibitory Concentration (MIC). The aqueous extract exhibited strong antioxidant activity and inhibited 99% of C. albicans and M. pachydermatis growth at concentrations of 87 μg/mL and 1400 μg/mL, respectively. Furthermore, it showed low cytotoxicity in NIH/3T3 fibroblasts. These findings indicate that sisal residue contains promising bioactive compounds with relevant pharmacological properties, reinforcing its potential as a sustainable source for the development of antifungal and antioxidant phytotherapeutics.