Extraction of phenolic compounds fromthe shells of pecan nuts with cytotoxic activity through apoptosis against the colon cancer cell line HT-29

RIBAS, L; BARAVALLE, M. E; GASSER, F.; RENNA, MS; ADDONA S; ORTEGA H.H.; SAVINO, G; VAN DE VELDE, F; HEIN, G

Journal of Food Science

Wiley-Blackwell Publishing, INC

Lugar: Londres; Año: 2021

1750-3841

The water extraction of phenolic compounds from two varietiesQ1Q2("Mahan" and "Marameck") of pecan nutshells (Carya illinoinensis) without andwith sonication, varying the solvent/solid ratio (S), the pH, and the refluxingtime (t), was studied. Additionally, the in vitro cytotoxicity and the determinationof the cell death mechanism of the extracts against the colon cancer cellline HT-29 were investigated. The content of total phenolic compounds (TPC)of "Marameck" nutshells resulted higher than for the "Mahan" variety, and thepH increase resulted in higher TPC contents for both cultivars. The optimizedconditions for TPC extraction without and with sonication resulted: S = 33ml/g,pH = 12, and t = 9.6 min, and yielded ≈ 70 and 90mg/g of TPC for "Mahan" and"Marameck" nutshells, respectively. The optimized extracts of pecan nutshellswithout sonication from both cultivars presented similar cytotoxicity against HT-29 colon cancer cells (IC50 ≈ 50 μg/ml), higher than for sonicated extracts (IC50 ≈88 and 138 μg/ml for "Mahan" and "Marameck," respectively). Cell death through Q3apoptosiswas the main mechanism of cell death induced by the nutshell extracts.Practical Application: The extraction of phenolic compounds (TPC) from theresidues of two varieties of pecan nutshells ("Mahan" and "Marameck")was stud- Q4ied. An optimal combination of variableswithin the pH range thatminimizes thesolvent-to-solid ratio (S) and the time of refluxing (t), saving at the same time,water and energy, was set up. The phenolic compound extracts obtained fromthe residues of the pecan nuts exhibit cytotoxic effects against colon cancer cellsand could be of interest as an alternative treatment of different types of cancer.Additionally, these extracts may be of importance to the food industry as theycan be used as antioxidant agents in food formulation. Also, the high levels ofanthocyanidins obtained from the pecan nut extracts after proanthocyanidins?strong acid hydrolysis can be purified and employed as natural red dyes.