Summary: The authors state that antioxidant properties of wine have been largely related to the reactive oxygen species (ROS) scavenging ability of phenolic compounds. Polyphenolic compounds are hardly absorbed and are quickly transformed into metabolites. Their antioxidant activities just as radical scavenging properties are therefore limited, but it is worth looking to other mechanisms. This study intended to test whether wine consumption affects antioxidant enzyme activity and gene expression. For this purpose, eight subjects drank 300 mL of red wine every day for a week and ate a low phenolic diet (LPD + W) specifically designed to avoid interferences from other polyphenols in the diet. The control period was a week with this diet, and volunteers refrained from drinking wine (LPD). Blood samples were taken at 0, 1, and 7 days. Superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), and glutathione reductase (GR) activities were determined in erythrocytes (SOD), plasma (CAT and GR), and blood (GPx). Gene expression was determined in macrophages.
Results indicated that oxidative stress caused by LPD reduced SOD, CAT, and GR activities. After wine consumption, these activities significantly increased (P < 0.05), and this overcame the effect of oxidative stress on enzyme activity. The modulation of CAT activity may be independent of changes in their gene expression, which significantly increased after LPD. However, SOD gene expression increased only during the LPD + W week. Enzyme activities are not all regulated in the same way. The results show that subacute moderate wine ingestion modulated antioxidant enzyme expression and activity, which is important for the prevention of ROS-associated diseases.
Professor R. Curtis Ellison comments: In this well-done small clinical trial, anti-oxidant levels in eight human volunteers were evaluated after a week of no alcohol and a week of 10 ounces (300 ml) of red wine each day. To test the effects of only the polyphenols ( antioxidants) present in the wine administered, the subjects were placed on a low-polyphenol diet that excluded virgin olive oil, tea, almost all fruits, and many vegetables. The main results were that the wine consumption increased the activity of key anti-oxidants in the body, especially superoxide dismutase (SOD) and glutathione reductase (GR); these changes were associated with expected changes in gene expressions.
The investigators did not measure the extent to which wine adds to the anti-oxidant activity that would be associated with the intake of other foods containing polyphenols, such as fruits, vegetables, and chocolate. We agree that these findings support a potential role for moderate wine consumption in increasing anti-oxidant activity in the human body, which should result in lower risk for many diseases.
Source: Fernandez-Pachon MS, Berna G, Otaolaurruchi E, Troncoso AM, Martin F, Garcia-Parrilla MC. Changes in antioxidant endogenous enzymes (activity and gene expression levels) after repeated red wine intake. J. Agric. Food Chem 2009;57:65786583.