Relationship between Human Aging Muscle and Oxidative System Pathway

Ageing is a complex process that in muscle is usually associated with a decrease in mass, strength, and velocity of contraction. One of the most striking effects of ageing on muscle is known as sarcopenia. This inevitable biological process is characterized by a general decline in the physiological and biochemical functions of the major systems. At the cellular level, aging is caused by a progressive decline in mitochondrial function that results in the accumulation of reactive oxygen species (ROS) generated by the addition of a single electron to the oxygen molecule. The aging process is characterized by an imbalance between an increase in the production of reactive oxygen species in the organism and the antioxidant defences as a whole. The goal of this review is to examine the results of existing studies on oxidative stress in aging human skeletal muscles, taking into account different physiological factors (sex, fibre composition, muscle type, and function)

Serenoa repens extracts: In vitro study of the 5α-reductase activity in a co-culture model for benign prostatic hyperplasia

Objectives. Benign Prostatic Hyperplasia (BPH) is a form of benign tumor that occurs in humans mainly with ageing. It affects more than 50% of over 50 years old males and it is characterized by an increased synthesis of dihydrotestosterone (DHT), due to the 5α-reductase activity. The BPH therapeutic approach mainly uses 5α-reductase inhibitors, such as the active compounds present in the extracts deriving from species Serenoa repens. Many lipidosterolic extracts are available on the market, which are obtained with different solvents, among them ethanol is recognized as non-toxic and has less handling risks than hexane. The purpose of the present experimental study was to investigate in-vitro the potency of an ethanol extract of S. repens comparing it with an n-hexane one. Materials and methods. Two different lipido-sterolic extracts of S. repens have been tested: ethanol extract and n-hexane extract, two batches for each one. The inhibitory action of the extract was evaluated estimating in-vitro the activity of enzyme 5α-reductase type I (5α-RI), which was mainly active under the experimental condition of pH 7.5. DHT amount, synthesized from testosterone (1 μM), was evaluated in a co-culture model of epithelial cells and fibroblasts resulting from prostatic biopsy of a patient with BPH.Results. The analysis of the resulting dose-response curves showed that the entire S. repens extracts inhibited the 5α-RI showing no difference between the two kinds of extract or between the batches. The resulting IC50 values were the following: 8.809 (95% CI = 5.133-15.56) and 9.464 (95% CI = 5.094- 18.27) for ethanol extracts; 11.08 (95% CI = 6.389-19.98) and 12.72 (95% CI = 7.758-21.53) for n-hexane extracts. Conclusions. The potency of ethanol extracts of S. repens was comparable with the one of n-hexane extracts

Molecular cloning, differential expression and 3D structural analysis of the MHC class-II β chain from sea bass (Dicentrarchus labrax L.)

The major histocompatibility complex class I and II molecules (MHC-I and MHC-II) play a pivotal role in vertebrate immune response to antigenic peptides. In this paper we report the cloning and sequencing of the MHC class II b chain from sea bass (Dicentrarchus labrax L.). The six obtained cDNA sequences (designated as Dila-DAB) code for 250 amino acids, with a predicted 21 amino acid signal peptide and contain a 28 bp 50-UTR and a 478 bp 30-UTR. A multiple alignment of the predicted translation of the Dila-DAB sequences was assembled together with other fish and mammalian sequences and it showed the conservation of most amino acid residues characteristic of the MHC class II b chain structure. The highest basal Dila-DAB expression was found in gills, followed by gut and thymus, lower mRNA levels were found in spleen, peripheral blood leucocytes (PBL) and liver. Stimulation of head kidney leukocytes with LPS for 4 h showed very little difference in the Dila-DAB expression, but after 24 h the Dila-DAB level decreased to a large extent and the difference was statistically significant. Stimulation of head kidney leukocytes with different concentrations of rIL-1b (ranging from 0 to 100 ng/ml) resulted in a dose-dependent reduction of the Dila-DAB expression. Moreover, two 3D Dila-DAB*0101 homology models were obtained based on crystallographic mouse MHC-II structures complexed with D10 T-cell antigen receptor or human CD4; features and differences between the models were evaluated and discussed. Taken together these results are of interest as MHC-II structure and function, molecular polymorphism and differential gene expression are in correlation with disease resistance to virus and bacteria in teleost fish.L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com/This work was supported by the European Commission within the project IMAQUANIM (EC contract number FOOD-CT-2005-007103)

Seasonal pattern of vitamin D in male elite soccer players

The phopho-calcium metabolism and the maintenance of bone mass is not the only important role vitamin Dplays. Vitamin D is also known for its anti-inflammatory function and for modulating the immune defence system. The vitamin D deficit is to be referred not simply to a bone tissue worsening, but to cardiovascular diseases, various types of tumours and some autoimmune diseases. In the sport life, a vitamin D deficit is often related to muscular problems, neuromuscular pains, predisposition to injuries, and can affect one’s performance. Since indoor athletes have reduced exposition to sun rays, they are more likely to be subjected to these risks than outdoor athletes. However, in soccer, the athletes can experience vitamin D deficit not just during the winter but in other periods too, most likely due to several reasons such as, dark complexion, coming from high altitude championships, injuries, or inadequate exposition to sun rays during the summer. The purpose of this study was to examine the vitamin D shortage and BMC variations in Italian Serie A elite male soccer player

CD4 homologue in sea bass (Dicentrarchus labrax): molecular characterization and structural analysis

CD4 is a transmembrane glycoprotein fundamental for cell-mediated immunity. Its action as a T cell coreceptor increases the avidity of association between a T cell and an antigen-presenting cell by interacting with portions of the complex between MHC class II and TR molecules. In this paper we report the cDNA cloning, expression and structural analysis of a CD4 homologue from sea bass (Dicentrarchus labrax). The sea bass CD4 cDNA consists of 2071 bp that translates in one reading frame to give the entire molecule containing 480 amino acids. The analysis of the sequence shows the presence of four putative Ig-like domains and that some fundamental structural features, like a disulphide bond in domain D2 and the CXC signalling motif in the cytoplasmic tail, are conserved from sea bass to mammals. Real-time PCR analysis showed that very high levels of CD4 mRNA transcripts are present in thymus, followed by gut and gills. In vitro stimulation of head kidney leukocytes with LPS and PHA-L gave an increase of CD4 mRNA levels after 4 h and a decrease after 24 h. Homology modelling has been applied to create a 3D model of sea bass CD4 and to investigate its interaction with sea bass MHC-II. The analysis of the 3D complex between sea bass CD4 and sea bass MHC-II suggests that the absence of a disulfide bond in the CD4 D1 domain could make this molecule more flexible, inducing a different conformation and affecting the binding and the way of interaction between CD4 and MHC-II. Our results will add new insights into the sea bass T cell immune responses and will help in the identification of T cell subsets in teleost fishes to better understand the evolution of cell-mediated immunity from fish to mammals.L'articolo è disponibile sul sito dell'editore http://www.sciencedirect.com

Antihepatotoxic and Antioxidant Activities of Methanol Extract and Isolated Compounds from Ficus chlamydocarpa

Free radicals, in particular radical oxygen species (ROS), play an important role in the aetiology and pathogenesis of various diseases. Current research in many countries focuses on the use of local medicinal plants as a promising source of liver protective agents. This paper describes the hepatoprotective effects of the methanol extract and four isolated compounds from Ficus chlamydocarpa on CCl4-induced liver damage, as well as the possible antioxidant mechanisms involved in this protection. The DPPH test, along with the ß-Carotene-Linoleic Acid Model System and Ferric-Reducing Antioxidant Power assays, as well as the inhibition of microsomal lipid peroxidation were used to measure radical-scavenging and antioxidant activities. Pretreatment of rats with the methanol extract of F. chlamydocarpa before CCl4administration, significantly prevented serum increase of hepatic enzyme markers, glutamate oxaloacetate transaminase (GOT) and glutamate pyruvate transaminase (GPT), in a dose-dependent manner. The hepatoprotection was also associated with a significant enhancement in hepatic reduced glutathione (GSH) and a marked decrease of liver malondialdehyde (MDA). Among the four compounds 1-4, isolated from the methanol extract, α-amyrin acetate (1) and luteolin (4) showed a significant hepatoprotective activity, as indicated by their ability to prevent liver cell death and lactate dehydrogenase (LDH) leakage during CCl4intoxication