The aim of this study was to investigate the responses of creatine kinase (CK) and lactate dehydrogenase (LDH) after performing different resistance and aerobic exercise protocols. Twelve recreationally trained men (age, 23.2 ± 5.6 years; body mass, 84.3 ± 9.3 kg; body height, 178.9 ± 4.5 cm; and BMI, 26.3 ± 2.3 kg·m2) volunteered to participate in this study. All subjects were randomly assigned to four experimental protocols (crossover): (a) aerobic training at 60% of VO2max, (b) aerobic training at 80% of VO2max, (c) a resistance exercise (RE) session with a bi-set protocol, and (d) an RE session with a multiple sets protocol. Blood samples were collected before, immediately after and 24 hours following the experimental protocols. After 24 hours, there was a significant increase in CK for the 80% of VO2max protocol vs. the bi-set RE session (p = 0.016). Immediately after the protocols, we observed a significant increase in LDH among certain groups compared to others, as follows: multiple sets RE session vs. 60% of VO2max, bi-set RE session vs. 60% of VO2max, multiple sets RE session vs. 80% of VO2max, and bi-set RE session vs. 80% of VO2max (p = 0.008, p = 0.013; p = 0.002, p = 0.004, respectively). In conclusion, aerobic exercise performed at 80% of VO2max appears to elevate plasma CK levels more than bi-set RE sessions. However, the bi-set and multiple sets RE sessions appeared to trigger greater levels of blood LDH compared to aerobic protocols performed at 60% and 80% of VO2max.

The antioxidant properties of purple grape juice, organic and conventional, in brain tissues are not well known. In this study our objective was to evaluate the antioxidant activity in substantia nigra and striatum of rats chronically treated with organic or conventional purple grape juice and to correlate the results obtained with the polyphenol content (total polyphenolic content, resveratrol, and anthocyanins [malvidin, delphinidin, peonidin, and cyanidin]). We observed that CCl₄ damage decreased significantly in the grape juice-treated groups when compared with the control group. In the grape juice-treated groups we further observed a decrease of lipid (thiobarbituric acid-reactive substances assay) and protein (carbonyl) peroxidation, as well as a significant antioxidant protection through the increase of enzyme activity. Antioxidant activities were significantly correlated with polyphenol content. These findings demonstrated that both grape juices have potent antioxidant properties and these activities could be at least attributed to the high phenolic content present in these juices.

Oxidative stress is implicated in several human illnesses, including neurological disorders such as Parkinson's and Alzheimer's diseases. Acai is largely consumed in Brazil and contains high levels of antioxidant compounds. This work aims to study the antioxidant activity of acai frozen fruit pulp in the cerebral cortex, hippocampus, and cerebellum of rats treated with the oxidizing agent hydrogen peroxide (H₂O₂). Pretreatment of tissue with acai decreased H₂O₂-induced damage of both lipids and proteins in all tissues tested. This fruit was also able to reduce the activities of the antioxidant enzymes superoxide dismutase and catalase to basal levels. We observed a negative correlation between the polyphenol content of acai and the levels of lipid (r = −0.689; P ≤ .05) and protein damage (r = −0.569; P ≤ .05), suggesting the participation of polyphenols in the observed antioxidant activity. These data suggest that acai has a positive contribution in the development of age-related neurodegenerative diseases.