Nutritional composition, biological activities, and cytotoxicity of the underutilized fruit of Eleiodoxa conferta

Abstract

Eleiodoxa conferta (Arecaceae) is a tropical palm, whose edible fruit is underutilized. This study was conducted to evaluate the fruit of E. conferta for nutritional composition, biological activities, and cytotoxicity. The nutritional composition of the fresh fruit was assessed using the standard methods of AOAC International. The fruit extracts were obtained by sequential solvent extraction with hexane, ethyl acetate, ethanol, and water, and evaluated for antioxidant activity using DPPH radical scavenging, ferric-reducing antioxidant power (FRAP), and oxygen radical absorbance capacity (ORAC) assays; enzyme inhibitory activity against α-amylase and α-glucosidase; antifungal activity using a colorimetric broth microdilution method; and cytotoxicity using African monkey kidney epithelial (Vero) cells. The fruit was high in moisture (85.22\u2009±\u20090.259% fw) but low in crude fat (0.02\u2009±\u20090.005% fw) and crude protein (0.01\u2009±\u20090.000% fw) contents. The ash and crude fiber contents were 4.13\u2009±\u20090.162% fw and 0.55\u2009±\u20090.007% fw, respectively. Among the four extracts, the water extract had the lowest median inhibitory concentration value (6.39\u2009±\u20090.390 µg/mL) for DPPH radical scavenging activity, the highest FRAP (0.79\u2009±\u20090.023 mmol Fe2+ equivalent/mg sample) and ORAC (2.56\u2009±\u20090.199 mmol Trolox equivalent/mg sample) values, the highest total phenolic content (373.24\u2009±\u20093.341 µg GAE/mg sample) and total flavonoid content (232.60\u2009±\u20096.825 µg QE/mg sample), and the lowest minimum inhibitory concentrations (0.001–0.02 mg/mL) against four species of human fungal pathogens. All the extracts exhibited stronger inhibition toward α-glucosidase than α-amylase. None of the extracts showed significant toxicity toward Vero cells. The results of this study suggest that the fruit of E. conferta contains many health-promoting effects and is safe for consumption.