Cancer development and progression are closely associated with inflammation. NF-κB (nuclear factor κB) provides a mechanistic link between inflammation and cancer, and is a major factor controlling the ability of malignant cells to resist tumour surveillance mechanisms. NF-κB might also regulate tumour angiogenesis and invasiveness and the signalling pathways that mediate its activation provide attractive targets for new chemopreventive and chemotherapeutic approaches. ROS (reactive oxygen species) initiate inflammation by up-regulation of pro-inflammatory cytokines and therefore antioxidants provide a major defence against inflammation. α-Tocopherol is a lipid-soluble antioxidant. In addition to decreasing lipid peroxidation, α-tocopherol may exert intracellular effects. Hence, the aim of this study was to test the effect of α-tocopherol supplementation in cancer prevention via suppression of NF-κB-mediated pro-inflammatory cytokines. α-Tocopherol treatment significantly down-regulates expression, synthesis as well as secretion of pro-inflammatory cytokine IL-6 (interleukin-6) in cancerous mice. It also suppresses NF-κB binding to IL-6 promoter in liver leading to decreased secretion of IL-6 in serum. The regulation of the signalling pathway by α-tocopherol is found apart from its antioxidant capacity to reduce lipid peroxidation. Thus, the present study provides evidence for the hypothesis that besides the powerful free radical scavenging effects, α-tocopherol has genomic effects in down-regulation of pro-inflammatory cytokine and cancer prevention via the NF-κB-dependent pathway.

The effect of α-tocopherol on the frequency of the CH 2 stretching bands of infrared spectra of dipalmitoylphosphotidylcholine multibilayers has been investigated, both in H 2 O and 2 H 2 O buffer, to determine the reason for the discrepancy in the literature between the results of different spectroscopic techniques relating to the effect of α-tocopherol on membrane order in the gel phase. In contrast to previous FTIR studies, the present FTIR results indicate that αT increases the frequencies of the CH 2 stretching bands in the gel phase, which implies an increase in the number of gauche conformers (increase in disordering), which is in agreement with other ESR and NMR spectroscopic studies.

The effect of α -tocopherol (αT) on partitioning and fluidity changes occurring in phospholipid liposomes have been investigated by monitoring the X-band ESR spectrum of the high resolution amphiphilic spin probe perdeutero-di-t-butyl nitroxide (PDDTBN), which partitions in the lipid and water phase of liposomes, showing all the three resonances from each phase well resolved.