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

RIBAS, LUCAS EMANUEL; BARAVALLE, MARÍA EUGENIA ; GASSER, FÁTIMA BELÉN ; RENNA, MARÍA SOL ; ADDONA, SILVINA ; HUGO HÉCTOR ORTEGA; SAVINO, GRACIELA HILDA ; VAN DE VELDE, FRANCO; HEIN, GUSTAVO JUAN

Journal of Food Science

John Wiley and Sons Inc

Año: 2021 vol. 86 p. 5409 - 5423

The water extraction of phenolic compounds from two varieties (“Mahan” and “Marameck”) of pecan nutshells (Carya illinoinensis) without and with sonication, varying the solvent/solid ratio (S), the pH, and the refluxing time (t), was studied. Additionally, the in vitro cytotoxicity and the determination of the cell death mechanism of the extracts against the colon cancer cell line HT-29 were investigated. The content of total phenolic compounds (TPC) of “Marameck” nutshells resulted higher than for the “Mahan” variety, and the pH increase resulted in higher TPC contents for both cultivars. The optimized conditions for TPC extraction without and with sonication resulted: S = 33 ml/g, pH = 12, and t = 9.6 min, and yielded ≈ 70 and 90 mg/g of TPC for “Mahan” and “Marameck” nutshells, respectively. The optimized extracts of pecan nutshells without 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 apoptosis was the main mechanism of cell death induced by the nutshell extracts.