Publications by authors named "Damiana R Vianna"
Coumarins are secondary metabolites that are widely distributed within the plant kingdom, some of which have been extensively studied for their antioxidant properties. The antioxidant activity of coumarins assayed in the present study was measured by different methods, namely the 1,1-diphenyl-2-picryl-hydrazyl (DPPH(•)) method, cyclic voltammetry and the antioxidant capacity against peroxyl radicals (ACAP) method. The 7,8-dihydroxy-4-methylcoumarin (LaSOM 78), 5-carboxy-7,8-dihydroxy-4-methylcoumarin (LaSOM 79), and 6,7-dihydroxycoumarin (Esculetin) compounds proved to be the most active, showing the highest capacity to deplete the DPPH radicals, the highest antioxidant capacity against peroxyl radicals, and the lowest values of potential oxidation.
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- Regular moderate physical activity benefits the immune system, enhancing infection resistance and inhibiting cancer growth, although the mechanisms behind this are not fully understood.
- In a study, sedentary rats showed significant increases in macrophage function after an acute swimming session, including a 2.4-fold rise in phagocytosis and a 95.5% increase in nitrite production.
- The exercise activated the expression of NOS-2 (an important enzyme related to immune response) without causing systemic oxidative stress or indicating stress in immune cells, suggesting local factors are involved in this activation.
Article Synopsis
- Striated muscle activity contributes to oxidative stress (OxStress), and while the intensity and duration of exercise can create a redox imbalance, the heart seems to resist significant damage from OxStress due to its unique protective mechanisms.
- Antioxidant strategies alone have been mostly ineffective in preventing cellular injury, suggesting that additional protective mechanisms may exist, particularly involving multidrug resistance-associated proteins (MRP).
- A study on Wistar rats revealed that MRP1 expression is induced in the heart in response to exercise but is absent in skeletal muscle, while the heat shock protein HSP70 shows different expression patterns, indicating complex responses to exercise-induced OxStress between heart and skeletal muscles.