Development of nanoparticles with peanut yegument extract as a potential ingredient for functional foods or phytopharmaceuticals

Abstract

The utilization of agroindustrial by-products, such as peanut tegument, adds value to food production in Argentina and particularly in Córdoba, while also reducing environmental impact. Peanut tegument contains numerous bioactive compounds that provide health benefits. However, some active principles of extracts often degrade before consumption or are lost after ingestion, which is why encapsulation techniques are employed.

The aim was to develop nanoparticles from peanut tegument extract, evaluate their antioxidant capacity, and assess their cytotoxicity.

The tegument ethanolic extract of peanut (TEE) was obtained through simple alcoholic maceration. Nanoparticles were then prepared using soybean lecithin and TEE, resulting in multilamellar vesicles that were subsequently subjected to extrusion to obtain unilamellar vesicles with extract (UVE). The sample was then loaded onto a Sephadex column to separate untrapped TEE molecules, resulting in purified unilamellar vesicles (PUV). Additionally, empty vesicles (EUV) were prepared. The vesicles were characterized by dynamic light scattering to determine polydispersity index (PDI) and fluorescence spectroscopy. Total phenols were measured using Folin-Ciocalteu and antioxidant capacity was assessed using FRAP. Cytotoxicity was evaluated in Vero cells after 7 days of incubation through neutral red uptake and MTT reduction. Statistical analysis was performed (ANOVA, t-test, and Boltzmann sigmoidal, p<0.05).

TEE showed maximum absorption at 280 nm and maximum emission at 315 nm, allowing monitoring of encapsulation. Vesicles of approximately 200 nm in size and uniform (PDI=0.12) were obtained. Folin-Ciocalteu results indicated that phenols from TEE were partially incorporated into UVE (40%) and PUV (26%), corresponding to good antioxidant capacity as determined by FRAP. Cytotoxicity results indicated that both nanoparticles, UVE and PUV, at concentrations ≤10% (TEE 50μg/mL) had ≥80% viability in Vero cells according to MTT and NRU assays.

In conclusion, stable and uniform nanoparticles with TEE were successfully developed, with high polyphenol content and antioxidant capacity, and safe concentrations were defined.