Chemopreventive Actions of Blond and Red-Fleshed Sweet Orange Juice on the Loucy Leukemia Cell Line

Red-fleshed sweet orange juice (ROJ) comes from a new variety of citrus cultivated in Brazil that contains high levels of β-carotene and lycopene, and similar amounts of hesperidin (HSP) and nutrients, equivalently to blond orange juice (BOJ). Such bioactive compounds are associated with chemopreventive actions in several cancer cell lines. The purpose of this study was to examine the cytotoxicity, cell cycle, apoptosis, and cytokine secretion after BOJ, ROJ, and HSP treatment of a novel T acute lymphoblastic leukemia cell line, Loucy.

Loucy cells were incubated for 24-h with BOJ, ROJ, and HSP, and the viability was measured using trypan blue. Cell cycling and apoptosis were assessed by propidium iodide (PI) and annexin V-FITC/PI flow cytometry, respectively. Secretion of cytokines IL-1α, IL1-β, IL-2, IL-4, IL-6, IL-10, IL-17A, IFNγ, TNFα, TGFβ, MIPα, and MIPβ was determined by ELISA array.

BOJ and ROJ treatments promoted Loucy cell cytotoxicity. Additionally, BOJ induced cell cycle arrest in the G0/G1 phase, and decreased the cell accumulation in the G2/M. ROJ decreased only the G0/G1 fraction, while HSP did not change the cell cycle. BOJ led to apoptosis in a different fashion of ROJ, while the first treatment induced apoptosis by increase of late apoptosis and primary necrotic fractions, the second increased early and late apoptosis, and primary necrotic fraction compared to positive controls. HSP had no effect on apoptosis. IL-6 and IL-10 were abrogated by all treatments.

Taking together, these results suggest potential chemopreventive effects of BOJ and ROJ on Loucy cells.