Artikel
Degradation of the retinal pigment epithelium by oxidative stress: protective effects of Pyruvate
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Autoren
Veröffentlicht: | 22. September 2004 |
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Gliederung
Text
Objective
Reactive oxygen species (ROS) play an important role in the development of age-related macular degeneration (AMD) thus causing an intensive search for suitable radical scavengers. Pyruvate is a naturally occurring metabolite in glycolosis and its chemical structure promises an interesting high anti-oxidative potential. This work compares the anti-oxidative properties of pyruvate and vitamine C.
Methods
Initially the in-vitro anti-oxidative properties of pyruvate and vitamine C were examined without cells using the DHR-Assay for Hydroxyl radicals (MoBiTec, Germany). Subsequently ARPE-19 cells were used for the in-vivo tests of the radical scavenging potentials of vitamin C and pyruvate. The cells were cultured in FCS free RPMI medium without pyruvate and vitamine C. Afterwards they were incubated with radicals for 2 minutes using constantly circulating medium. The Hydroxyl radicals were generated through the Fenton reaction from H2O2 and Fe3+. The cell survival rate was determined with the life-dead-assay from MoBiTec, Germany.
Results
Without the addition of the scavengers the DHR-Assay exhibited an increase in average fluorescence to 8.8±0.1 (n=4) relative Light-units (LU). Vitamin C was able to reduce this increase in a concentration dependant manner to 1.0±0.0 LU at 1 mM vitamine C (n=4), pyruvate to 1.2±0.1 LU at 3 mM (n=4). In the in-vivo RPE-cell-system a concentration of only 0.01 mM pyruvate was sufficient to increase the survival rate of the ARPE-19 cells up to Sham-control levels while 10 mM vitamine C was necessary to achieve the same result.
Conclusions
In cultured ARPE-19 cells pyruvate exhibits a high anti-oxidative potential seemingly superior to that of vitamine C. Pyruvate naturally occurs in the human body and is thus presumed highly tolerable. Therefore it could be an interesting option for future use in the anti-oxidative therapy.