Effect of Antioxidant Supplementation with Tempol on the Physical Performance of Trained Rats
Authors: Marostica Elisabeth , Maia Isabele Cristine , Brum Patricia Chakur , De Angelis Katia , da Silva Soares Pedro Paulo 
Published: November 2023

INTRODUCTION

Antioxidant supplementation is widely used by most of the population that cares about health and those who aiming to increase physical capacity. However, recent studies have shown conflicting results on the association of antioxidant supplementation and aerobic training in experimental models and humans (Am J Clin Nutr 87; 142–9, 2008).

OBJECTIVE

The purpose of this study was to investigate the effect of antioxidant treatment with tempol, a scavenger of free radical, superoxide dismutase (SOD) mimetic, in trained and sedentary animals.

METHODS

(CEUA‐UFF 698/15) Wistar rats 60 days old were adapted treadmill and after maximal exercise test (TEmax), were divided into four groups sedentary control (CS; n=12); training control (CT; n=10); sedentary tempol (TS; n=13) and training tempol (TT; n=9). The training consisted of treadmill running for ten weeks (50–70% of maximum speed, incline of 6%, 1 h/day, 5 days/week), with adjustable load at the 5th week after a new TEmax. Treatment with tempol was done in the last ten days of the training period (30 mg.kg−1.day−1, ip). Another TEmax was performed at the end of training. After 48 hours the animals were anesthetized (thiopental, 80mg.kg−1). Blood sample was collected for serum assays, and the heart and the soleus muscle was dissected, frozen in liquid N2 and stored at −80 °C, the first two for assay of biomarkers of oxidative stress (antioxidant enzyme activity, including SOD, catalase e glutathione peroxidase; total antioxidant capacity, lipid peroxidation and oxidation protein), and the last to qRT PCR assay of genes related to mitochondrial biogenesis (PGC‐1α and Nrf1) and antioxidant pathway (Nrf2). Results are means±SDs, analyzed by ANOVA two‐way and post hoc Bonferroni's. For the real time RT‐PCR, values were analyzed by Mann Whitney test (P<0,05).

RESULTS

At the end of the training, we observed an increase in physical performance of the animals in groups CT and TT (3.2±0.5; 2.6±0.3 km.h−1, respectively) compared to CS and TS (1.4±0.3; 1.9±0.4 km.h−1, respectively), but antioxidant supplementation with tempol reduced the gain on the physical capacity of the trained animals TT compared to CT. The TS group, that received tempol supplementation, did not increase performance as compared to CS. Although no change in the levels of lipid peroxidation, protein oxidation and antioxidant activity in serum and heart occurred, similar reduction in cardiac O2− levels were found in the groups CT, TS and TT (61.16±15.53; 60.76±21.37; 50.57±10.33 mmol.mg−1protein respectively), compared to CS (90.11±22.81 mmol.mg−1protein). In addition, the trained groups (CT and TT) increased gene expression of PGC‐1α in the soleus similarly. However, only TT increased the gene expression of Nrf2, while Nrf1 was not affected by any intervention (n=4–6)

CONCLUSION

Thus, our data showed that supplementation with tempol decreased the gain in physical performance of aerobically trained rats. However, the molecular mechanisms that may explain these adaptations apparently are not directly related to mitochondrial biogenesis or just with oxidative stress.

Support or Funding Information

CAPES, FAPERJ, CNPq.