Blood superoxide dismutase (SOD) decrease following oral administration of plant SOD to healthy subjects

Abstract

We examined what changes occurred in the activity and content of superoxide dismutase (SOD) in the blood and the amount of 8-hydroxy-2′- deoxyguanosine (8-OHdG) in the urine as a consequence of oral administration of antioxidant health foods including plant-based SOD, vitamin C and vitamin E to seven healthy subjects every day for 15 days. Although there was a significant increase in the concentration of vitamins C and E in serum, there was a significant decrease in SOD (extracellular type) activity and Mn-SOD (mitochondrial type) content and a narrower range of variation therein. In contrast, there was a tendency toward an increase in the amount of 8-OHdG in the urine (observed in 6 of 7 subjects). We looked into the possibility that SOD activity was being inhibited by pycnogenol (water extract of the bark of the French maritime pine) as the main ingredient of the antioxidant health foods, and it became clear that SOD activity is included in pycnogenol. These results suggest that oral administration of antioxidant health foods containing SOD originating in plants has the effect of lowering the activity and content of SOD in the blood.