Satellite and tower-based metrics of forest-scale photosynthesis generally increase with dry season progression across central Amazônia, but the underlying mechanisms lack consensus.
We conducted ...demographic surveys of leaf age composition, and measured the age dependence of leaf physiology in broadleaf canopy trees of abundant species at a central eastern Amazon site. Using a novel leaf-to-branch scaling approach, we used these data to independently test the much-debated hypothesis – arising from satellite and tower-based observations – that leaf phenology could explain the forest-scale pattern of dry season photosynthesis.
Stomatal conductance and biochemical parameters of photosynthesis were higher for recently mature leaves than for old leaves. Most branches had multiple leaf age categories simultaneously present, and the number of recently mature leaves increased as the dry season progressed because old leaves were exchanged for new leaves.
These findings provide the first direct field evidence that branch-scale photosynthetic capacity increases during the dry season, with a magnitude consistent with increases in ecosystem-scale photosynthetic capacity derived from flux towers. Interactions between leaf age-dependent physiology and shifting leaf age-demographic composition are sufficient to explain the dry season photosynthetic capacity pattern at this site, and should be considered in vegetation models of tropical evergreen forests.
The Caatinga is a unique Brazilian semi-arid biome in the north-east of the country, containing endemic plant species. Among these, Cordiaceae are traditionally used by local communities for the ...treatment of various diseases such as gastric pain, menstrual colic and arthritis. In this work, the antiproliferative activity of the species Varronia dardani was evaluated in chemoresistant human melanoma cells. The ethanolic extract of V.dardani root exerted high antiproliferative activity in A2058 cells and was selected for further phytochemical characterization and bioguided purification of antimelanoma compounds. The isopropanol fraction was the most active and contained a novel hydroanthraquinone which was isolated, characterized and named vardanone. This molecule is the first hydroanthraquinone reported in V. dardani and UPLC-MS/MS analysis revealed that it was composed of a mixture of isomers. When tested in melanoma cells, vardanone didn’t induce the inhibition of A2058 cell growth, indicating that the fraction's antimelanoma activity is attributable to other molecules which will be further characterized. This study is the first to demonstrate the presence of a hydroanthraquinone in V. dardani and paves the way for the identification of new antimelanoma phytochemicals in this species.
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•Varronia dardani roots ethanolic extract and its isopropanol fraction exerted high antiproliferative activity in A2058 human chemoresistant melanoma cells.•A novel hydroanthraquinone, vardanone, was isolated and characterized using high resolution MS, IR and NMR spectroscopy. It was the first hydroanthraquinone reported in Varronia dardani.•Vardanone had no antiproliferative activity in A2058 human chemoresistant melanoma cells, indicating that other apolar molecules that remain to be identifed in the isopropanol fraction exerted the antiproliferative activity.
A large number of experimental studies has demonstrated that angiotensin II (Ang II) is involved in key events of the inflammatory process. This study aimed to evaluate the role of Ang II type 1 ...(AT1) and Ang II type 2 (AT2) receptors on periodontitis.
Experimental periodontitis was induced by placing a 5.0 nylon thread ligature around the second upper left molar of AT1 mice, no-ligature or ligature (AT1-NL and AT1-L), AT2 (AT2-NL or AT2-L) and wild type (WT-NL or L). Alveolar bone loss was scanned using Micro-CT. Cytokines, peptides and enzymes were analyzed from gingival tissues by Elisa and RT-PCR.
The blockade of AT1 receptor resulted in bone loss, even in healthy animals. Ang II receptor blockades did not prevent linear bone loss. Ang II and Ang 1-7 levels were significantly increased in the AT2-L (
< 0.01) group compared to AT2-NL and AT1-L. The genic expression of the Mas receptor was significantly increased in WT-L and AT2-L compared to (WT-NL and AT2-NL, respectively) and in AT1-L.
Our data suggest that the receptor AT1 appears to be important for the maintenance of bone mass. AT2 receptor molecular function in periodontitis appears to be regulated by AT1.
Seeds are excellent sources of proteinase inhibitors, some of which may have satietogenic and slimming actions. We evaluated the effect of a trypsin inhibitor from Tamarindus indica L. seeds on ...weight gain, food consumption and cholecystokinin levels in Wistar rats.
A trypsin inhibitor from Tamarindus was isolated using ammonium sulfate (30–60%) following precipitation with acetone and was further isolated with Trypsin-Sepharose affinity chromatography. Analyses were conducted to assess the in vivo digestibility, food intake, body weight evolution and cholecystokinin levels in Wistar rats. Histological analyses of organs and biochemical analyses of sera were performed.
The trypsin inhibitor from Tamarindus reduced food consumption, thereby reducing weight gain. The in vivo true digestibility was not significantly different between the control and Tamarindus trypsin inhibitor-treated groups. The trypsin inhibitor from Tamarindus did not cause alterations in biochemical parameters or liver, stomach, intestine or pancreas histology. Rats treated with the trypsin inhibitor showed significantly elevated cholecystokinin levels compared with animals receiving casein or water.
The results indicate that the isolated trypsin inhibitor from Tamarindus reduces weight gain by reducing food consumption, an effect that may be mediated by increased cholecystokinin. Thus, the potential use of this trypsin inhibitor in obesity prevention and/or treatment should be evaluated.
Schinopsis brasiliensis Engl. is a native plant of Caatinga which has high concentrations of compounds capable of absorbing ultraviolet light, suggesting its potential application for the development ...of sunscreen preparations. After its identification and collection, this vegetable drug was submitted to a physicochemical analysis through the preparation of ethanolic extract. The phytochemical screening and analysis of extracts were carried out by high-performance liquid chromatography (HPLC) evaluation. The antioxidant activity of the extract was evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) method and β-carotene bleaching test. Inhibitory hemolytic activity and morphological deformation of erythrocytes induced by H2O2 were also demonstrated and the antimicrobial activity was analyzed by the minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) method. For the in vitro determination of the sun protection factor (SPF), the spectrophotometric method was used. From the analyses carried out with this species, this plant showed significant results for the antioxidant and antimicrobial activities, as well as sunscreen action. Important flavonoids were identified. These data are an important step for the development of new photoprotective cosmetic with Caatinga species, revealing importance and representing another incentive for the preservation of the species involved and analyzed in the study.
The aim of this study was to evaluate the effects of azilsartan (AZT) on bone loss, inflammation, and the expression of matrix metallo proteinases (MMPs), receptor activator of nuclear factor κB ...ligand (RANKL), receptor activator of nuclear factor κB (RANK), osteoprotegerin (OPG), cyclooxygenase-2 (COX-2), and cathepsin K in periodontal tissue in a rat model of ligature-induced periodontitis.
Male Wistar albino rats were randomly divided into 5 groups of 10 rats each: (1) nonligated, water; (2) ligated, water; (3) ligated, 1 mg/kg AZT; (4) ligated, 5 mg/kg AZT; and (5) ligated, 10 mg/kg AZT. All groups were treated with saline or AZT for 10 days. Periodontal tissues were analyzed by histopathology and immunohistochemical detection of MMP-2, MMP-9, COX-2, RANKL, RANK, OPG, and cathepsin K. Levels of IL-1β, IL-10, TNF-α, myeloperoxidase (MPO), and glutathione (GSH) were determined by ELISA.
Treatment with 5 mg/kg AZT resulted in reduced MPO (p<0.05) and IL-1β (p<0.05), increased levels of IL-10 (p<0.05), and reduced expression of MMP-2, MMP-9, COX-2, RANK, RANKL, cathepsin K, and increased expression of OPG.
These findings reveal that AZT increases anti-inflammatory cytokines and GSH and decreases bone loss in ligature-induced periodontitis in rats.
Pain and inflammation are complex clinical conditions that are present in a wide variety of disorders. Most drugs used to treat pain and inflammation have potential side effects, which makes it ...necessary to search for new sources of bioactive molecules. In this paper, we describe the ability of LASSBio-1586, an N-acylhydrazone derivative, to attenuate nociceptive behavior and the inflammatory response in mice. Antinociceptive activity was evaluated through acetic acid-induced writhing and formalin-induced nociception tests. In these experimental models, LASSBio-1586 significantly (p<0.05) reduced nociceptive behavior. Several methods of acute and chronic inflammation induced by different chemical (carrageenan, histamine, croton oil, arachidonic acid) and physical (cotton pellet) agents were used to evaluate the anti-inflammatory effect of LASSBio-1586. LASSBio-1586 exhibited potent anti-inflammatory activity in all tests (p<0.05). Study of the mechanism of action demonstrated the possible involvement of the nitrergic, serotonergic and histamine signaling pathways. In addition, a molecular docking study was performed, indicating that LASSBio-1586 is able to block the COX-2 enzyme, reducing arachidonic acid metabolism and consequently decreasing the production of prostaglandins, which are important inflammatory mediators. In summary, LASSBio-1586 exhibited relevant antinociceptive and anti-inflammatory potential and acted on several targets, making it a candidate for a new multi-target oral anti-inflammatory drug.
The aim of this study was to manufacture and characterize bionanocomposites based on a poly(hydroxybutyrate)/polyethylene glycol blend (PHB/PEG) filled with an organobentonite (CLT1 and CLT3) or an ...organovermiculite (VMT1 and VMT3) in concentrations of 1 and 3wt%. The systems were prepared by solution intercalation and further characterized by X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. The use of these bionanocomposites aimed at improving the processing and compatibility of this blend in search of new properties and possible applications of these films in food disposable packaging. The thermal stability of the system varied according to the type of clay and, consequently, the chemical structure of the quaternary ammonium salt used. The VMT1, VMT3 and CLT3 systems showed increased degrees of crystallinity compared to neat PHB. Differences in bionanocomposites structure can be related to the type of clay used as two types of PHB/PEG blend.
We aimed to compare the measurements of sheep ruminal pH using a continuous telemetry system or a bench pH meter using sheep with different degrees of ruminal pH. Ruminal lactic acidosis was induced ...in nine adult crossbred Santa Ines sheep by the administration of 15 g of sucrose per kg/BW. Samples of rumen fluid were collected at the baseline, before the induction of acidosis (T0) and at six, 12, 18, 24, 48, and 72 hours after the induction for pH measurement using a bench pH meter. During this 72-hour period, all animals had electrodes for the continuous measurement of pH. The results were compared using the Bland-Altman analysis of agreement, Pearson coefficients of correlation and determination, and paired analysis of variance with Student’s t-test. The measurement methods presented a strong correlation (r=0.94, P<0.05) but the rumen pH that was measured continuously using a telemetry system resulted in lower values than the bench pH meter (overall mean of 5.38 and 5.48, resp., P=0.0001). The telemetry system was able to detect smaller changes in rumen fluid pH and was more accurate in diagnosing both subacute ruminal lactic acidosis and acute ruminal lactic acidosis in sheep.
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