Effect of thyme extract supplementation on lipid peroxidation, antioxidant capacity, PGC-1α content and endurance exercise performance in rats.

BACKGROUND: Athletes have a large extent of oxidant agent production. In the current study, we aimed to determine the influence of thyme extract on the endurance exercise performance, mitochondrial biogenesis, and antioxidant status in rats. METHODS: Twenty male Wistar rats were randomly divided into two groups receiving either normal drinking water (non-supplemented group, n = 10) or thyme extract, 400 mg/kg, (supplemented group, n = 10). Rats in both groups were subjected to endurance treadmill training (27 m/min, 10% grade, 60 min, and 5 days/week for 8 weeks). Finally, to determine the endurance capacity, time to exhaustion treadmill running at 36 m/min speed was assessed. At the end of the endurance capacity test, serum and soleus muscle samples were collected and their superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity, as well as malondialdehyde (MDA) concentration were measured. Protein expression of PGC-1α, as a marker of mitochondrial biogenesis, was also determined in the soleus muscle tissue by immunoblotting assay. RESULTS: Findings revealed that the exhaustive running time in the treatment group was significantly (p < 0.05) prolonged. Both serum and soleus muscle MDA levels, as an index of lipid peroxidation, had a threefold increase in the thyme extract supplemented group (t18 = 8.11, p < 0.01; t18 = 4.98, p < 0.01 respectively). The activities of SOD and GPx of the soleus muscle were significantly (p < 0.05) higher in the non-supplemented group, while there was no significant difference in serum SOD, GPx activities, and total antioxidant capacity between groups. Furthermore, thyme supplementation significantly (p < 0.05) decreased PGC-1α expression. CONCLUSIONS: Thyme extract supplementation increased endurance exercise tolerance in intact animals, although decrease of oxidative stress and regulation of the PGC-1α protein expression are not considered as underlying molecular mechanisms.

Bone mineral density changes after physical training and calcium intake in students with attention deficit and hyper activity disorders.

In this study we investigate the effects of weight bearing exercise and calcium intake on bone mineral density (BMD) of students with attention deficit and hyper activity (ADHD) disorder. For this reason 54 male students with ADHD (age 8-12 years old) were assigned to four groups with no differences in age, BMD, calcium intake, and physical activity: exercise groups with or without calcium supplementation (Ex+Ca+ and Ex+Ca-) and non-exercise groups with or without calcium supplementation (Ex-Ca+ and Ex-Ca-). The intervention involved 50 min of weight bearing exercise performed 3 sessions a week and/or the addition of dietary calcium rich food using enriched cow milk with vitamin D containing 250 mg calcium per serving, over 9 months. Paired-samples t-test, one way ANOVA analysis, and Tukey tests were used to determine the main and combined effects of training and calcium on BMD. All groups showed greater femoral neck BMD after 9 months. The increase in femoral neck BMD was significantly different between all groups (p < 0.05). Ex+Ca+ group has greater increase in BMD than other groups. Apparently, the effect of training was greater than calcium intake (p < 0.05). These results help to provide more evidence for public health organizations to deal with both exercise and nutrition issues in children with ADHD disorder for the achievement of peak BMD.