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Oxidative Medicine and Cellular Longevity
Volume 2017 (2017), Article ID 7468538, 15 pages
Research Article

A Carotenoid Extract from a Southern Italian Cultivar of Pumpkin Triggers Nonprotective Autophagy in Malignant Cells

1Istituto di Scienze dell’Alimentazione, Consiglio Nazionale delle Ricerche, 83100 Avellino, Italy
2Istituto di Scienze delle Produzioni Alimentari, Consiglio Nazionale delle Ricerche, 73100 Lecce, Italy
3Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Università del Salento, 73100 Lecce, Italy
4Dipartimento di Farmacia, Università di Salerno, Fisciano, Italy

Correspondence should be addressed to Gian Luigi Russo

Maria Russo, Stefania Moccia, and Stefania Bilotto equally contributed to the data presented.

Received 11 June 2017; Revised 10 October 2017; Accepted 24 October 2017; Published 21 December 2017

Academic Editor: Kota V. Ramana

Copyright © 2017 Maria Russo et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Carotenoids, including β-carotene, lycopene, and derivatives, such as retinoic acid, have been studied for their significant antiproliferative and differentiating activity on cancer cells in experimental models and in clinics. We are presenting here data on the mechanism of action of a carotenoid-enriched extract obtained from the pumpkin Cucurbita moschata, variety “long of Naples,” on two malignant human cell lines, Caco-2 and SAOs, derived from a colon adenocarcinoma and an osteosarcoma, respectively. The carotenoid extract has been obtained from pumpkin pulp and seeds by supercritical CO2 extraction and employed to prepare oil-in-water nanoemulsions. The nanoemulsions, applied at a final carotenoid concentration of 200–400 μg/ml, were not cytotoxic, but induced a delay in cell growth of about 40% in both SAOs and Caco-2 cell lines. This effect was associated with the activation of a “nonprotective” form of autophagy and, in SAOs cells, to the induction of cell differentiation via a mechanism that involved AMPK activation. Our data suggest the presence of a pool of bioactive compounds in the carotenoid-enriched extract, acting additively, or synergistically, to delay cell growth in cancer cells.