Antioxidant and antiproliferative activities of extracts from the wastes of pecan nut with potential nutraceutic applications

RIBAS LE; GASSER FB; PERELLO A; SIMONETTO C; BARAVALLE ME; SAVINO GH; ORTEGA HH; VAN DE VELDE F; HEIN GJ

Mar del Plata

Congreso; LXVIII Reunión Científica Anual de la Sociedad Argentina de Investigación Clínica (SAIC); 2023

SAIC

The waste fromthe pecan nut industry contains high contents of phenolic compounds with provenbiological activities. We aimed to evaluate the in vitro bioactivity ofenriched extracts from pecan nut shells and husks on the prostate cancer cellline PC3. Extracts were obtained through an optimized aqueous extractionprocess and purified by using SPE C18 columns (PES: shell and PEH: husk). Thecontent of total phenolics (TP) was determined by the Folin-Ciocalteu method(mg of gallic acid equivalent/g) and the antioxidant capacity by the DPPHmethod, determining the relative antioxidant activity (%RAA; IC50 Trolox/IC50Extract). The cytotoxic activity was studied by evaluating cell viabilitythrough the MTT assay with increasing concentrations of extracts (10-300 mg/L)and Doxorubicin (DO) as the positive control, for 48 h. Lactate dehydrogenase(LDH) activity released in the damaged cells was evaluated using a commercialkit (Wiener Lab) in the supernatant of the cell culture incubated with 200 mg/Lof each extract, DO, and triton as a positive control. In addition, the %RAA ofextracts at 200 mg/L and their combination with DO was evaluated by flowcytometry, analyzing the production of reactive oxygen species (ROS).TP values were80 mg/g and 3.8 mg/g, and the %RAA were 196.70 and 189.52, for the PES and PEHextracts, respectively. Both extracts demonstrated antioxidant activity(p<0.05) by reducing ROS levels in cells with oxidative stress caused by DO.PES and PEH were cytotoxic for cells when the concentration was greater than150 mg/L and 100 mg/L, respectively. Both extracts and DO significantlyincreased LDH activity in PC3 cells compared to the negative control, suggestingcell membrane damage as a possible mechanism of action. These results indicatea cytotoxic effect on the prostate cancer cell line, also presenting anantioxidant effect against DO, further enhancing its use as an antitumor agentand thus revaluing an agro-industrial waste.