30 research outputs found
Processing of leather using deep eutectic solvents
Processing of leather has an historical reputation as a chemically and energetically intensive process that produces large volumes of aqueous waste. Saline pollution combined with heavy-metal, dyes and acid and base streams make leather production an ecologically sensitive industry. The current study shows that a variety of deep eutectic solvents (DESs) may be used for the tanning, fatliquoring and dyeing of animal hides, being particularly useful for mineral (chromium) and vegetable tanning processes. The tanning agents are able to penetrate rapidly into the hide, driven by lyotropic swelling due to their high ionic strength. The samples are shown to have similar tanning agent content to the currently used aqueous chromium(III) sulfate solution; however, the waste metal content is shown to be significantly reduced. Incorporation of the DES Ethaline into the leather significantly alters the swelling properties of the leather increasing the flexibility and ductility of the material, therefore acting in the same manner as a fatliquor that lubricates or plasticizes the fibrous structure of the collagen. Ethaline was also used to transport a lysochromic dye throughout the cross section of the leather, and the hydrophobicity of the dye prevents leaching into the aqueous wash solution. Physical measurements show that leather processed using DESs have similar mechanical properties to that processed using conventional aqueous systems
Melatonin protects against heart ischemia-reperfusion injury by inhibiting mitochondrial permeability transition pore opening
Melatonin, a well-known antioxidant, has been shown to protect against
ischemia-reperfusion myocardial damage. Mitochondrial permeability transition
pore (MPTP) opening is an important event in cardiomyocyte cell death occurring
during ischemia-reperfusion and therefore a possible target for cardioprotection.
In the present study, we tested the hypothesis that melatonin could protect heart
against ischemia-reperfusion injury by inhibiting MPTP opening. Isolated perfused
rat hearts were subjected to global ischemia and reperfusion in the presence or
absence of melatonin in a Langerdoff apparatus. Melatonin treatment significantly
improves the functional recovery of Langerdoff hearts on reperfusion, reduces the
infarct size, and decreases necrotic damage as shown by the reduced release of
lactate dehydrogenase. Mitochondria isolated from melatonin-treated hearts are
less sensitive than mitochondria from reperfused hearts to MPTP opening as
demonstrated by their higher resistance to Ca(2+). Similar results were obtained
following treatment of ischemic-reperfused rat heart with cyclosporine A, a known
inhibitor of MPTP opening. In addition, melatonin prevents mitochondrial NAD(+)
release and mitochondrial cytochrome c release and, as previously shown,
cardiolipin oxidation associated with ischemia-reperfusion. Together, these
results demonstrate that melatonin protects heart from reperfusion injury by
inhibiting MPTP opening, probably via prevention of cardiolipin peroxidation
EGCG, a green tea polyphenol, improves endothelial function and insulin sensitivity, reduces blood pressure, and protects against myocardial I/R injury in SHR RID B-1970-2008
Epigallocatechin gallate (EGCG), a bioactive polyphenol in green tea, may augment metabolic and vascular actions of insulin. Therefore, we investigated effects of EGCG treatment to simultaneously improve cardiovascular and metabolic function in spontaneously hypertensive rats (SHR; model of metabolic syndrome with hypertension, insulin resistance, and overweight). In acute studies, EGCG (1-100 microM) elicited dose-dependent vasodilation in mesenteric vascular beds (MVB) isolated from SHR ex vivo that was inhibitable by N(omega)-nitro-L-arginine methyl ester (L-NAME; nitric oxide synthase antagonist) or wortmannin [phosphatidylinositol (PI) 3-kinase inhibitor]. In chronic studies, 9-wk-old SHR were treated by gavage for 3 wk with EGCG (200 mg.kg(-1).day(-1)), enalapril (30 mg.kg(-1).day(-1)), or vehicle. A separate group of SHR receiving L-NAME (80 mg/l in drinking water) was treated for 3 wk with either EGCG or vehicle. Vasodilator actions of insulin were significantly improved in MVB from EGCG- or enalapril-treated SHR (when compared with vehicle-treated SHR). Both EGCG and enalapril therapy significantly lowered systolic blood pressure (SBP) in SHR. EGCG therapy of SHR significantly reduced infarct size and improved cardiac function in Langendorff-perfused hearts exposed to ischemia-reperfusion (I/R) injury. In SHR given L-NAME, beneficial effects of EGCG on SBP and I/R were not observed. Both enalapril and EGCG treatment of SHR improved insulin sensitivity and raised plasma adiponectin levels. We conclude that acute actions of EGCG to stimulate production of nitric oxide from endothelium using PI 3-kinase-dependent pathways may explain, in part, beneficial effects of EGCG therapy to simultaneously improve metabolic and cardiovascular pathophysiology in SHR. These findings may be relevant to understanding potential benefits of green tea consumption in patients with the metabolic syndrome
Registro de Phytotoma raimondii "cortarrama peruana" en Vir\ufa, Departamento La Libertad, Per\ufa, 2009
Volume: 16Start Page: 125End Page: 12