Neuroprotector Effect of Daily 8-Minutes of High-Intensity Interval Training in Rat Aß1-42 Alzheimer Disease Model.

BACKGROUND: Alzheimer's disease (AD) is the most common and irreversible neurodegenerative disorder, and amyloid peptide plays a central role in its pathogenesis. Physical training contributes as a beneficial adaptation to AD. However, these effects may be underestimated because much of the literature used fixed training prescription variables (intensity and volume) throughout the protocol. Moreover, researchers poorly understand whether chronic high-intensity interval training (HIIT) exerts similar effects on the brain tissue of individuals with AD. OBJECTIVE: This study evaluated the effect of 8 minutes of HIIT with incremental overload in an AD model. METHODS: Forty male Wistar rats were divided into four groups: an untrained Sham group, Sham trained group, Aß1-42 (Alzheimer's) untrained group, and Aß1-42 (Alzheimer's) trained group (n=10 rats per group). Animals underwent stereotactic surgery and received a hippocampal injection of Aß1-42 or a saline solution. Seven days after surgery, two weeks of treadmill adaptation followed by a maximal running test (MRT) was performed. Then, animals were subjected to eight weeks of HIIT. Rats were sacrificed 24 h after the behavioral tests (open field and Morris water maze), hippocampal tissue was extracted to analyze the redox balance and BDNF/TrkB pathway, and neuritic plaques (NP) were detected by evaluating silver impregnation. RESULTS: The AD trained group presented a physical capacity amelioration every two weeks and locomotor, learning, and memory improvements (p<0.05). These effects were accompanied by increased CAT and SOD levels, followed by decreased lipid peroxidation (p<0.05). Furthermore, increased activation of the BDNF/TrkB (p<0.05) pathway and decreased NP was observed. CONCLUSION: Based on these results, MRT was essential for an excellent chronic training protocol prescription and overload adjustment. Therefore, 8 minutes of HIIT daily for 8 weeks may reduce behavioral deficits by promoting a positive redox balance and increased activity of the BDNF/TrkB pathway that may contribute to NP attenuation.

New properties of the soybean trypsin inhibitor: Inhibition of human neutrophil elastase and its effect on acute pulmonary injury.

Seeds from legumes including the Gilcine max are known to be a rich source of protease inhibitors. The soybean Kunitz trypsin inhibitors (SKTIs) have been well characterised and have been found to exhibit many biological activities. However their effects on inflammatory diseases have not been studied to date. In this study, SKTI was purified using anion exchange chromatography using a Resource Q column. The purified protein was able to inhibit human neutrophil elastase (HNE) and bovine trypsin. Purified SKTI inhibited HNE with an IC(50) value of 8mug or 0.3nM. At this concentration SKTI showed neither cytotoxic nor haemolytic effects on human blood cell populations. SKTI showed no deleterious effects on organs, blood cells or the hepatic enzymes ALT and AST in the mouse model of acute systemic toxicity. Human neutrophils incubated with SKTI released less HNE than control neutrophils when stimulated with PAF or fMLP (83.1% and 70% respectively). These results showed that SKTI affected both pathways of elastase release by PAF and fMLP stimuli, suggesting that SKTI is an antagonist of fMLP/PAF receptors. In an in vivo mouse model of LPS acute lung injury, SKTI significantly suppressed the inflammatory effects caused by elastase in a dose-dependent manner. Histological sections stained by hematoxylin/eosin confirmed this decrease in inflammation. These results showed that SKTI could be used as a pharmacological agent for the therapy of many inflammatory diseases.

Effects of a novel pathogenesis-related class 10 (PR-10) protein from Crotalaria pallida Roots with papain inhibitory activity against root-knot nematode Meloidogyne incognita.

A novel pathogenesis-related class 10 (PR-10) protein with papain inhibitory activity, named CpPRI, was purified from Crotalaria pallida roots by ammonium sulfate precipitation followed by three reverse-phase high-performance liquid chromatographies (HPLCs). CpPRI is made up of a single polypeptide chain with a M(r) of 15 kDa, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This protein exhibited a K(i) value of 1.8 x 10(-9) M and operates via a noncompetitive inhibition mechanism. The alignment of the N-terminal amino acid sequence of CpPRI with other proteins revealed its identity with PR-10 proteins. CpPRI acts against digestive proteinase from root-knot nematode Meloidogyne incognita and demonstrated nematostatic and nematicide effects on this parasite in bioassays. In a localization study, fluorescein-5-isothiocyanate (FITC)-CpPRI was observed to internalize and diffuse over the entire J2 body after 6 h of incubation. This fact could explain the natural tolerance of this plant species to nematodes.

A lactose specific lectin from the sponge Cinachyrella apion: purification, characterization, N-terminal sequences alignment and agglutinating activity on Leishmania promastigotes.

Crude extract from the sponge Cinachyrella apion showed cross-reactivity with the polyclonal antibody IgG anti-CvL (Cliona varians lectin) and also a strong haemagglutinating activity towards human erythrocytes of all ABO groups. Thus, it was submitted to acetone fractionation, IgG anti-deglycosylated CvL Sepharose affinity chromatography, and Fast Protein Liquid Chromatography (FPLC-AKTA Purifier) gel filtration on a Superose 6 10/300 column to purify a novel lectin. C. apion lectin (CaL) agglutinated all types of human erythrocytes with preference for papainized type A erythrocytes. The haemagglutinating activity is independent of Ca2+, Mg2+ and Mn2+ ions, and it was strongly inhibited by the disaccharide lactose, up to a minimum concentration of 6.25 mM. CaL molecular mass, determined by FPLC-gel filtration on a Superose 12 10/300 column and SDS gel electrophoresis, was approximately 124 kDa, consisting of eight subunits of 15.5 kDa, assembled by hydrophobic interactions. The lectin was heat-stable between 0 and 60 degrees C and pH-stable. The N-terminal amino acid sequence of CaL was also determined and a blast search on amino acid sequences revealed that the protein showed similarity only with a silicatein. Leishmania chagasi promastigotes were agglutinated by CaL and this activity was abolished by lactose, indicating that lactose receptors could be presented in this parasite stage. These findings are indicative of the potential biotechnological application of CaL as diagnostic of pathogenic protozoa.

Larvicidal effects of a chitin-binding vicilin from Erythrina velutina seeds on the mediterranean fruit fly Ceratitis capitata.

Chitin-binding vicilin from Erythrina velutina seeds was purified by ammonium sulfate followed by affinity chromatography on a chitin column and gel filtration on Superose-6-10-300-GL. The Erythrina velutina vicilin, called EvV, is a tetrameric glycoprotein composed of 1.85% carbohydrates and M r of 216.6 kDa, consisting of two subunits of M r of 54.8 and two subunits of M r of 50.8 kDa. The EvV homogeneity was confirmed in native PAGE where it was observed to be a unique acid-protein band with slow mobility in this gel. Effect of EvV on C. capitata larvae was examined by bioassay and its mechanism of action was determined by immunodetection techniques and fluorescence localization in chitin structures that are present in C. capitata digestory system. EvV when added to diet caused strong effect on mortality (ED50 of 0.14%) and larval mass (WD50 of 0.12%). These deleterious effects were associated to the binding to chitin structures present in peritrophic membrane and to gut epithelial cells, and its low digestibility in C. capitata digestive tract. These results are the first demonstration of a proteinaceous bioinsecticide from plant origin effective against C. capitata larvae. EvV may be part of the pest management programs or an alternative in plant improvement program.

Pro-inflammatory effect in mice of CvL, a lectin from the marine sponge Cliona varians.

CvL, a lectin from the marine sponge Cliona varians agglutinated type A papainized erythrocytes and was strongly inhibited by d-galactose and sucrose. Models of leukocyte migration in vivo were used to study the inflammatory activity of CvL through of mouse paw oedema and peritonitis. Effect of CvL on peritoneal macrophage activation was analysed. Effects of corticoids and NSAIDS drugs were also evaluated on peritonitis stimulated by CvL. Results showed that mouse hind-paw oedema induced by subplantar injections of CvL was dose dependent until 50 microg/cavity. This CvL dose when administered into mouse peritoneal cavities induced maxima cell migration (9283 cells/microL) at 24 h after injection. This effect was preferentially inhibited by incubation of CvL with the carbohydrates d-galactose followed by sucrose. Pre-treatment of mice with 3% thioglycolate increases the peritoneal macrophage population 2.3 times, and enhanced the neutrophil migration after 24 h CvL injection (75.8%, p<0.001) and no significant effect was observed in the presence of fMLP. Finally, pre-treatment of mice with dexamethasone (cytokine antagonist) decreased (65.6%, p<0.001), diclofenac (non-selective NSAID) decreased (34.5%, p<0.001) and Celecoxib (selective NSAID) had no effect on leukocyte migration after submission at peritonitis stimulated by CvL, respectively. Summarizing, data suggest that CvL shows pro-inflammatory activity, inducing neutrophil migration probably by pathway on resident macrophage activation and on chemotaxis mediated by cytokines.

Purification and characterization of a trypsin-papain inhibitor from Pithecelobium dumosum seeds and its in vitro effects towards digestive enzymes from insect pests.

A novel trypsin-papain inhibitor, named PdKI-2, was purified from the seeds of Pithecelobium dumosum seeds by TCA precipitation, Trypsin-Sepharose chromatography and reversed-phase HPLC. PdKI-2 had an M(r) of 18.1 kDa as determined by SDS-PAGE and was composed of a single polypeptide chain. The inhibition on trypsin was stable at pH range 2-10, temperature of 50 degrees C and had a K(i) value of 1.65 x 10(-8)M, with a competitive inhibition mechanism. PdKI-2 was also active to papain, a cysteine proteinase, and showed a noncompetitive inhibition mechanism and K(i) value of 5.1 x 10(-7)M. PdKI-2 was effective against digestive proteinase from bruchids Zabrotes subfasciatus and Callosobruchus maculatus; Dipteran Ceratitis capitata; Lepidopterans Plodia interpunctella and Alabama argillacea, with 74.5%, 70.0%, 70.3%, 48.7%, and 13.6% inhibition, respectively. Results support that PdKI-2 is a member of Kunitz-inhibitor family and its effect on digestive enzyme larvae from diverse orders indicated this protein as a potent insect antifeedant.