Background: Various plant extracts are used in the prevention and treatment of various disease states, with their beneficial effects mainly attributed to their antioxidant properties.
Materials and Methods: Knowledge of their localisation, the importance of selenium glutathione peroxidases, and the methodological options for their determination, led us to choose to investigate the affects of oregano, stevia, ginseng and agrimonia extracts on plasma, heart and kidney mitochondria under in vitro conditions.
Results: The lowest activity of selenium isoforms was observed in the heart mitochondria. In the kidney mitochondria, it was approximately 100-fold higher and the highest was observed in plasma. The same was detected for total glutathione peroxidases in the heart, although those in kidney mitochondria were higher than in plasma. Oregano caused a generally significant increase in selenium isoform activity and a decrease in total glutathione peroxidase activity in the heart, while both decreased in the kidney. Stevia significantly increased the activity of selenium isoforms in the heart at a concentration of 125 ÎĽg.ml-1, with while either having no effect, or a slightly opposite effect on total peroxidase activities. The same effect was observed at lower concentrations in the kidney. Conversely, stevia caused a significant reduction in selenium peroxidase activity in the plasma. Ginseng caused a statistically significant increase in selenium isoform activity in the heart but reduced its activity in the kidney and plasma, even in total glutathione peroxidases. Mutually comparable effects were observed with agrimony.
Conclusion: In terms of total glutathione peroxidases, the extracts can be assumed to have significant antioxidant effects. When considering the physiological functions of selenium isoforms, it is possible to predict the ability of oregano and stevia to significantly affect redox signalling pathways, especially in heart mitochondria, and to a lesser extent in the kidney.
agrimony, ginseng, glutathione peroxidase, oregano, stevia