(P04-033-24) Peanut Polyphenols Are Bioaccessible and Inhibit Proliferation of Cultured Jurkat Leukemia Cells

Objectives: To evaluate the efficacy and nutritional relevance of peanut polyphenols against cancer leukemia cells, using the Jurkat cell line model established from an acute T-cell leukemia patient.

Methods: Polyphenol-rich peanut skin extract (PSE) was prepared using acetone/water/acetic acid (70:29.5:0.5 v/v/v). To test the cytotoxic properties of PSE at different concentrations, Jurkat cell viability was assessed at multiple time points using RealTime-Glo™ MT Cell Viability Assay and XTT Assay. Based on cell viability assay results, cells were treated with PSE at 1000 ng/μL for 24 h. The cells were collected and extracted to evaluate PSE and its metabolites. To further evaluate the bioaccessibility of PSE, we examined the intestinal absorption and metabolism of PSE phenolics in Caco-2 cells, a model of the human intestinal barrier. PSE was applied to the apical chamber at 1000 ng/μL and incubated for 4 h at 37°C. The phenolics in PSE and media at both sides of the Caco-2 membranes and those that interact with Jurkat cells were analyzed using UHPLC-MS/MS. The data was processed using Freestyle 1.8 SP2 and Compound Discover 3.3 Software.

Results: PSE inhibited cell viability at 24, 48, and 72 h after application to Jurkat cells as determined by RealTime-Glo Assay. Proliferation rates were significantly reduced at 72 h as measured by XTT assay. Among the quantified PSE polyphenols extracted from Jurkat cells, Procyanidin A2 was the most abundant phenolic. Procyanidin A2 was bioaccessible to Caco-2 cells, and was most abundant phenolic detected in the basolateral compartment. High-resolution mass spectrometry revealed the presence of other type-A procyanidin dimers in the basolateral compartment.

Conclusions: Polyphenol-rich PSE inhibits the growth and proliferation of Jurkat cells. Our data suggest that A-type procyanidins are among the active and bioaccessible compounds in peanuts that interact with leukemia cells.

Funding Sources: The Peanut Institute