Researchers from Liverpool Sir John Moores University in the UK have investigated the effect of dietary supplementation with aged garlic extract (AGE) on blood plasma and urine concentrations of F2-isoprostanes, well known indicators of lipid peroxidation.
The researchers from the University's School of Biomolecular Sciences, studied whether AGE affected concentrations of F2-isoprostane 8-iso-prostaglandin F2 (8-iso-PGF2) in plasma and urine.
Both smokers and non-smokers were tested, as smokers generally suffer from higher levels of oxidative stress. The researchers used Kyolic, an AGE supplement made by Wakunaga of America.
Plasma and urine concentrations of 8-iso-PGF2 in non-smoking individuals were 1.25 plus or minus 0.19 nmol/L and 272 plus or minus 53 pmol/mmol of creatinine respectively. In age- and sex-matched smokers, plasma and urine concentrations of 8-iso-PGF2 were 58 per cent and 85 per cent higher respectively.
The study showed that dietary supplementation with AGE for 14 days reduced plasma and urine concentrations of 8-iso-PGF2 by 29 per cent and 37 per cent in non-smokers and by 35 per cent and 48 per cent in smokers.
However, 14 days after the supplements were stopped, both plasma and urine concentrations of 8-iso-PGF2 in both groups returned to roughly the same levels as before the study began.