Evaluación de la actividad antioxidante de extractos de zapote negro (Diospyros nigra) en la línea celular 3T3-L1

Abstract

This study evaluated the antioxidant activity and cytoprotective effect of extracts obtained from the pulp, peel, and seeds of the black sapote (Diospyros nigra). A Box-Behnken experimental design was used to optimize extraction conditions by varying the water-ethanol ratio, temperature, and time. The extracts were characterized by quantifying total phenols, flavonoids, and ascorbic acid, as well as by their antioxidant capacity against DPPH• and OH•- radicals. In addition, their cytotoxic and cytoprotective effects on murine 3T3-L1 fibroblasts were evaluated using cell viability (MTT) assays, lipid peroxidation (TBARS) assays, reduced glutathione (GSH) levels, and cellular morphological analysis. The results showed that extraction conditions significantly influence the recovery of bioactive compounds, with intermediate water-ethanol mixtures and temperatures near 80°C standing out, as they favored the extraction of phenols and flavonoids, increasing antioxidant activity, mainly in the seed. A correlation was observed between phenolic content and antioxidant activity, while the pulp had the highest vitamin C content. All extracts exhibited low cytotoxicity in the range of 25–200 μg/mL, maintaining cell viability above 80%. Under H₂O₂-induced oxidative stress, the extracts significantly increased cell viability, reduced lipid peroxidation, and promoted the recovery of intracellular GSH. The extracts from the pulp (14P), peel (15C), and seed (13S) stood out for their cytoprotective capacity, with the seed extract (13S) exhibiting the greatest antioxidant effect at 200 μg/mL, comparable to the quercetin standard. Black sapote (Diospyros nigra) extracts constitute an important source of bioactive compounds with antioxidant and cytoprotective properties, with the seed showing the greatest potential. These findings suggest their use as an underutilized byproduct for the development of functional and nutraceutical products aimed at reducing oxidative stress and preserving cellular integrity.

En la presente investigacion se evaluo la actividad antioxidante y el efecto citoprotector de extractos obtenidos de pulpa, cascara y semilla del zapote negro (Diospyros nigra). Se empleo un diseno experimental Box-Behnken para optimizar las condiciones de extraccion mediante la variacion de la proporcion agua-etanol, temperatura y tiempo. Los extractos fueron caracterizados con la cuantificacion de fenoles totales, flavonoides y acido ascorbico, asi como por su capacidad antioxidante frente a los radicales DPPH. y OH.-. Ademas, se evaluo su efecto citotoxico y citoprotector en fibroblastos murinos 3T3-L1 mediante ensayos de viabilidad celular (MTT), peroxidacion lipidica (TBARS), niveles de glutation reducido (GSH) y analisis morfologico celular. Los resultados mostraron que las condiciones de extraccion influyen significativamente en la recuperacion de compuestos bioactivos, destacando mezclas intermedias de agua-etanol y temperaturas cercanas a 80 ‹C, las cuales favorecieron la extraccion de fenoles y flavonoides, incrementando la actividad antioxidante, principalmente en semilla. Se observo una correlacion entre el contenido fenolico y la actividad antioxidante, mientras que la pulpa presento el mayor contenido de vitamina C. Todos los extractos mostraron baja citotoxicidad en el rango de 25-200 ƒÊg/mL, manteniendo viabilidades superiores al 80%. Bajo estres oxidativo inducido con H2O2, los extractos incrementaron significativamente la viabilidad celular, redujeron la peroxidacion lipidica y propiciaron la recuperacion de GSH intracelular. Los extractos de pulpa (14P), cascara (15C) y semilla (13S), destacaron por su capacidad citoprotectora, siendo el extracto de semilla (13S) el de mayor efecto antioxidante a 200 ƒÊg/mL, comparable al estandar quercetina. Los extractos del zapote negro (Diospyros nigra) constituyen una fuente importante de compuestos bioactivos con propiedad antioxidante y citoprotectora, siendo la semilla la de mayor potencial. Estos hallazgos sugieren su aprovechamiento como residuo infravalorado para el desarrollo de productos funcionales y nutraceuticos orientados a disminuir el estres oxidativo y preservar la integridad celular.