Bożena Bałasińska

Green tea extract supplementation gives protection against exercise-induced oxidative damage in healthy men.

The purpose of this study was to evaluate the effects of a long-term (4-week) green tea extract (GTE) supplementation in combination with strength training on selected blood markers of oxidative stress and muscular damage after a short-term exercise in previously untrained men. We hypothesized that GTE supplementation would elevate antioxidant potential and attenuate exercise-induced oxidative stress and muscular damage. Thirty-five male students were exposed to 4 weeks of strength training and received (in a randomized, double-blind design) GTE (n = 17; 640 mg polyphenols/d) or placebo (P; n = 18). Before (term I) and after 4 weeks of strength training and supplementation (term II), students performed a short-term muscular endurance test. Blood samples were collected at rest, 5 minutes after the muscular endurance test, and after 24 hours of recovery. Supplementation with GTE enhanced plasma total polyphenols at rest and 5 minutes after the muscular endurance test. Supplementation also contributed to the rise of resting total antioxidant status in plasma. Throughout the experiment (terms I and II), a reduction in plasma lipid hydroxyperoxides was observed 24 hours after the muscular endurance test. Four weeks of strength training resulted in an increase in plasma lipid hydroxyperoxides at rest, but only in the P group. In term I, the muscular endurance test induced an increase in activity of creatine kinase in plasma after 24 hours of recovery in both the P and GTE groups. In term II, plasma creatine kinase activity after 24 hours of recovery was elevated only in the P group. In conclusion, in previously untrained men, dietary supplementation with GTE (in combination with strength training) enhances the antioxidant defense system in plasma at rest and, in turn, may give protection against oxidative damage induced by both short-term muscular endurance test and long-term strength training.

Age-related changes in the central nervous system in selected domestic mammals and primates.

Aging is a process which operates at many levels of physiological, genetic and molecular organization and leads inevitably to death. Brain macroscopic changes by MRI investigation during aging were observed in humans and dogs but chimpanzees did not display significant changes. This suggestion led to the statement that brain aging is different in various species. Although human brain changes, e.g. β-amyloid storage, neurofibrillary tangle formation, lipofuscin, are relatively well known, we are still looking for a suitable animal model to study the mechanisms of aging and neurodegenerative diseases. Therefore, this paper presents a comparative analysis of the changes described in the brains of senile dog, horse and gorilla. In addition we present the latest, non-invasive methods that can be applied in the diagnosis of old age in mammals. Our considerations have shown that the best animal model for further studies and observations on aging is the dog.

The influence of eicosapentaenoic acid and docosahexaenoic acid on expression of genes connected with metabolism and secretory functions of ageing 3T3-L1 adipocytes

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are n-3 long chain polyunsaturated fatty acids. The purpose of our study was to evaluate the influence of EPA and DHA on expression of genes connected with metabolism and secretory functions of ageing adipocytes. Young, mature and old differentiated 3T3-L1 adipocytes were cultured for 48h in the presence of EPA, or DHA. Both fatty acids increased the expression of Pparg, FATP1, FATP4 and ATGL genes, but only in young 3T3-L1 adipocytes. Moreover, in young, mature and old cells DHA elevated the expression of CPT1 gene. In addition, EPA and DHA enhanced the expression of leptin, adiponectin and apelin genes only in young cells. Investigated fatty acids changed mRNA levels of IL6 and MCP1 in young, mature and old cells. EPA increased the expression of these two genes, whereas DHA decreased it. Furthermore, EPA and DHA treatment changed the expression of IRS1 and GLUT4 genes involved in insulin signalling pathway, but their effects were opposite. Expression of these genes was decreased by EPA and increased by DHA in young, mature and old cells. In summary, the investigated fatty acids are able to affect the expression of genes associated with lipid metabolism, secretory functions and insulin resistance in ageing 3T3-L1 adipocytes, but their impact is age-dependant. Young cells seem to be more sensitive to EPA and DHA than mature and old ones. Furthermore, the effect of these two fatty acids is not always identical, and therefore requires further investigation.