Future directions in clinical vitamin E research: panel discussion B.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
Joe Lunec
Publications and source records attributed to Joe Lunec.
Vitamin C supplementation in normal subjects reduces constitutive ICAM-1 expression.
Regulation of monocyte adhesion molecule gene expression is via redox sensitive transcription factors. We have investigated whether dietary antioxidant supplementation with vitamin C (250 mg/day) can modulate monocyte ICAM-1 expression in healthy male subjects with low plasma vitamin C at baseline. In a randomised, double-blind, crossover study, monocyte ICAM-1 mRNA was analysed using quantitative reverse transcriptase PCR. Protein was determined by flow cytometry (monocytes) and ELISA (plasma). Monocyte numbers were unaltered by supplementation. Subjects with low plasma vitamin C (<50 microM) prior to supplementation expressed higher levels of monocyte ICAM-1mRNA, and showed a significant (50%) reduction in ICAM-1mRNA expression after 6 weeks of 250 mg/day vitamin C supplementation (p<0.05). This was paralleled by a reduction in sICAM-1 (p<0.05). For the first time, these results show that dietary vitamin C can modulate monocyte ICAM-1 gene expression in vivo, where regulation of gene expression represents a novel mechanism for benefit from dietary antioxidants.
Adult↗
Effects of oral vitamin C on monocyte: endothelial cell adhesion in healthy subjects.
Monocyte recruitment and retention in the vasculature is influenced by oxidative stress and is involved in cardiovascular disease (CVD). Individuals with low plasma ascorbate are at elevated risk of CVD. It is unknown whether vitamin C supplementation affects monocyte adhesion to endothelial cells (ECs) in healthy non-smokers. In a randomised double-blind crossover study the effect of vitamin C supplementation (six weeks, 250 mg/day) was determined in subjects with normal (HIC) and below average (LOC) plasma vitamin C concentration at baseline (mean=67 microM, n=20, mean=32 microM, n=20, respectively). LOC subjects showed 30% greater monocyte adhesion to ECs. This was significantly reduced by 37% (P<0.02) following vitamin C supplementation to levels of HIC monocyte adhesion. No differences in plasma malondialdehyde concentrations were observed between groups or after supplementation. In conclusion, vitamin C supplementation normalises monocyte adhesion in subjects with low plasma vitamin C (LOC). This process may be related to a direct effect on monocytes, independent of lipid peroxidation.
Administration, Oral↗