Proliferation and intracellular glutathione in Jurkat T cells with concentrated whey protein products

Abstract

The effect of two whey protein concentrates (WPCs) and three whey protein isolates (WPIs) on the growth and intracellular glutathione concentration of Jurkat T cells was determined. Standard RPMI 1640 media containing foetal calf serum with no WPC or WPI supplementation was used as the control, while supplementation with N-acetyl cysteine—a known glutathione promoter—was included as a positive control. Both WPCs lowered the cell count-adjusted glutathione concentration following a 24 h incubation period and one significantly (p<0.05) increased cell proliferation. Only one of the three WPIs significantly (p<0.05) inhibited cell proliferation although its composition with respect to β-lactoglobulin, glycomacropeptide, α-lactalbumin, IgG, proteose peptone and BSA content was almost identical to another WPI, as determined by HPLC. Based on co-migration with standards under two different modes of chromatography, lactoferrin was detected in the WPI showing the inhibitory effect at a level of 0.4 mg mL−1, but not in any of the other concentrated whey protein products. None of the whey protein products tested increased cell-adjusted intracellular glutathione concentration.