Effect of different forms of vitamin E (E) on prostaglandin (PG)E2 production and in vitro T cell proliferation of old mice

Abstract

α-Tocopherol (T) is the most common form of E in biological fluids and the most biologically active T. We have shown that α-T supplementation increases lymphocyte proliferation (LP) in old mice and humans, which is associated with decreased PGE2 production and cyclooxygenase (COX) activity. γ-T has been shown to be more effective than α-T in inhibiting peroxynitrite-induced lipid oxidation. We compared the effect of γ-, β-, and δ-T with that of α-T on splenocyte LP, peritoneal macrophage (Mφ) COX activity, and PGE2 production in old mice. While α-T increased mitogenic LP at concentrations of 20 and 60 mg/mL (26% to 156%), γ-, β-, and δ-T reduced it at these concentrations (24% to 99%). α-T decreased PGE2 production (20%), COX activity (44%), and IL-6 release (14%) in LPS-activated Mφ. γ-, β-, and δ-T supplementation resulted in higher % decrease in PGE2 production (25-98%), and COX activity (81-98%). Cell viability studies indicated that the lack of mitogen-stimulated LP and the much lower Mφ PGE2 and IL-6 production and COX activity in the presence of γ-, β-, and δ-T compared with α-T are due to their cytotoxic effect. Mφ cultured in 60 mg/mL of γ-, β-, and δ-T had 72%, 73%, and 95% cell death, respectively, while cell death in α-T-cultured Mφ was 24%. δ-T was toxic at 20 mg/mL (95% cell death). Cell death at 20 mg/mL γ- and β-T was lower (30% and 26%, respectively. Similar results were seen with splenocytes; lower concentrations of β-, δ-T (1 μg/mL), and γ-T (5 μg/mL) were not toxic. Studies are underway to compare the effect of non-toxic levels of γ-, β-, and δ-T on Mφ and spleen cell functions.

Publication Title

FASEB Journal

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