28,463 research outputs found

    Utilization of seaweed resources

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    A brief discussion is presented on the commercial importance of seaweeds in the Philippines, which is mainly concerned with their use as sources of industrial gums such as agar, carrageenan, and alginic acid. Carrageenan as a substitute for microbiological agar and the use of seaweeds as a binder of heavy metal pollutants are examined

    Contrasting alterations to synaptic and intrinsic properties in upper-cervical superficial dorsal horn neurons following acute neck muscle inflammation

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    Background: Acute and chronic pain in axial structures, like the back and neck, are difficult to treat, and have incidence as high as 15%. Surprisingly, most preclinical work on pain mechanisms focuses on cutaneous structures in the limbs and animal models of axial pain are not widely available. Accordingly, we developed a mouse model of acute cervical muscle inflammation and assessed the functional properties of superficial dorsal horn (SDH) neurons.<p></p> Results: Male C57/Bl6 mice (P24-P40) were deeply anaesthetised (urethane 2.2?g/kg i.p) and the rectus capitis major muscle (RCM) injected with 40??l of 2% carrageenan. Sham animals received vehicle injection and controls remained anaesthetised for 2?hrs. Mice in each group were sacrificed at 2?hrs for analysis. c-Fos staining was used to determine the location of activated neurons. c-Fos labelling in carrageenan-injected mice was concentrated within ipsilateral (87% and 63% of labelled neurons in C1 and C2 segments, respectively) and contralateral laminae I - II with some expression in lateral lamina V. c-Fos expression remained below detectable levels in control and sham animals. In additional experiments, whole cell recordings were obtained from visualised SDH neurons in transverse slices in the ipsilateral C1 and C2 spinal segments. Resting membrane potential and input resistance were not altered. Mean spontaneous EPSC amplitude was reduced by ~20% in neurons from carrageenan-injected mice versus control and sham animals (20.63???1.05 vs. 24.64???0.91 and 25.87???1.32 pA, respectively). The amplitude (238???33 vs. 494???96 and 593???167 pA) and inactivation time constant (12.9???1.5 vs. 22.1???3.6 and 15.3???1.4?ms) of the rapid A type potassium current (IAr), the dominant subthreshold current in SDH neurons, were reduced in carrageenan-injected mice.<p></p> Conclusions: Excitatory synaptic drive onto, and important intrinsic properties (i.e., IAr) within SDH neurons are reduced two hours after acute muscle inflammation. We propose this time point represents an important transition period between peripheral and central sensitisation with reduced excitatory drive providing an initial neuroprotective mechanism during the early stages of the progression towards central sensitisation

    Myrtucommulone from Myrtus communis exhibits potent anti-inflammatory effectiveness in vivo.

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    Myrtucommulone a nonprenylated acylphloroglucinol contained in the leaves of myrtle (Myrtus communis), has been reported to suppress the biosynthesis of eicosanoids by inhibition of 5-lipoxygenase and cyclooxygenase-1 in vitro and to inhibit the release of elastase and the formation of reactive oxygen species in activated polymorphonuclear leukocytes. Here, in view of the ability of MC to suppress typical proinflammatory cellular responses in vitro, we have investigated the effects of MC in in vivo models of inflammation. MC was administered to mice intraperitoneally, and paw edema and pleurisy were induced by the subplantar and intrapleural injection of carrageenan, respectively. MC (0.5, 1.5, and 4.5 mg/kg i.p.) reduced the development of mouse carrageenan-induced paw edema in a dose-dependent manner. Moreover, MC (4.5 mg/kg i.p. 30 min before and after carrageenan) exerted anti-inflammatory effects in the pleurisy model. In particular, 4 h after carrageenan injection in the pleurisy model, MC reduced: 1) the exudate volume and leukocyte numbers; 2) lung injury (histological analysis) and neutrophil infiltration (myeloperoxidase activity); 3) the lung intercellular adhesion molecule-1 and P-selectin immunohistochemical localization; 4) the cytokine levels (tumor necrosis factor-α and interleukin-1 β in the pleural exudate and their immunohistochemical localization in the lung; 5) the leukotriene B 4, but not prostaglandin E2, levels in the pleural exudates; and 6) lung peroxidation (thiobarbituric acid-reactant substance) and nitrotyrosine and poly (ADP-ribose) immunostaining. In conclusion, our results demonstrate that MC exerts potent anti-inflammatory effects in vivo and offer a novel therapeutic approach for the management of acute inflammation. Copyright © 2009 by The American Society for Pharmacology and Experimental Therapeutics

    Design and in Vitro Evaluation of a New Nano-Microparticulate System for Enhanced Aqueous-Phase Solubility of Curcumin

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    Curcumin, a yellow polyphenol derived from the turmeric Curcuma longa, has been associated with a diverse therapeutic potential including anti-inflammatory, antioxidant, antiviral, and anticancer properties. However, the poor aqueous solubility and low bioavailability of curcumin have limited its potential when administrated orally. In this study, curcumin was encapsulated in a series of novel nano-microparticulate systems developed to improve its aqueous solubility and stability. The nano-microparticulate systems are based entirely on biocompatible, biodegradable, and edible polymers including chitosan, alginate, and carrageenan. The particles were synthesized via ionotropic gelation. Encapsulating the curcumin into the hydrogel nanoparticles yielded a homogenous curcumin dispersion in aqueous solution compared to the free form of curcumin. Also, the in vitro release profile showed up to 95% release of curcumin from the developed nano-microparticulate systems after 9 hours in PBS at pH 7.4 when freeze-dried particles were used.CONACYTCUPIAPharmac

    Citral inibe a inflamação aguda e nocicepção em camundongos: o papel dos receptores TLR4 e TLR2/DECTINA-1

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    TCC(graduação) - Universidade Federal de Santa Catarina. Araranguá. Fisioterapia.Citral (3,7-dimethyl-2,6-octadienal), um monoterpeno de cadeia aberta e principal componente bioativo do capim limão, apresenta diferentes propriedades farmacológicas, tais como: i) inibidor da atividade oxidante de células apresentadoras de antígenos (APCs), tais como os macrófagos; ii) inibidor da ativação do fator de transcrição pró-inflamatório NF-κB; iii) inibidor da expressão da enzima ciclooxigenase do tipo 2 (COX-2); e iv) ativador do fator de transcrição pró-resolução receptor proliferador de peroxissomo (PPAR)-α e γ. Além disso, o citral atua como agonista inverso dos canais iônicos e receptores de potencial transitório (TRPs) expressos em neurônios sensoriais (TRPV1, TRPV3, TRPM8 e TRPA1), produzindo uma inibição de longa duração de TRPV1–3 e TRPM8, demonstrando potencial analgésico em diferentes tipos de dor. No entanto, até o presente momento, não existem relatos dos efeitos antiinflamatórios e analgésicos de citral em modelos inflamação aguda, assim como a sua interação com a produção de eicosanóides e modulação dos receptores do tipo Toll-like (TLR). Neste trabalho demonstramos que o tratamento oral com citral (nas doses de 50 – 300 mg/kg) significativamente inibiu o edema de pata e a alodinia térmica induzidos pela carragenina. Além disso, o pré- tratamento com o citral inibiu a resposta inflamatória induzida por LPS e zimosan, ligantes dos receptores TLR4- e TLR2/dectina-1, respectivamente. Por fim, nossos resultados demonstram os efeitos antiinflamatórios e analgésicos do citral, os quais parecem estar relacionados à modulação dos receptores da imunidade inata, tais como o TLR4 e o TLR2/dectina-1.Citral (3,7-dimethyl-2,6-octadienal), a bioactive component of lemongrass, can inhibit macrophage oxidant activity, and NF-κB activation, as well as COX- 2 expression and activation peroxisome proliferator-activated receptor (PPAR)-α and γ. In addition, citral activates TRP channels in sensory neurons (TRPV1 and TRPV3, TRPM8, and TRPA1), and produces long-lasting inhibition of TRPV1–3 and TRPM8, while transiently blocking TRPV4 and TRPA1, demonstrating analgesic potential for allodynia and other types of pain. However, there are no reports about the anti-inflammatory and analgesic effects of citral in induced inflammation by carrageenan- and TLR-depend pathways and algesic response. In this study, we investigated the effect of citral in experimental models of acute inflammation and nociception in mice. Oral treatment with citral (50 – 300 mg/kg) significantly inhibited carrageenaninduced paw edema and thermal allodynia. Furthermore, citral also modulated the inflammation induced by LPS and zymosan, a TLR4- and TLR2/dectin-1 ligand, respectively. Our results demonstrate that oral citral treatment displayed anti-inflammatory and analgesic effects, and these effects seem to be related to its TLR4 and TLR2/dectin-1 modulation

    Spinal release of tumour necrosis factor activates c-Jun N-terminal kinase and mediates inflammation-induced hypersensitivity.

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    BackgroundMounting evidence points to individual contributions of tumour necrosis factor-alpha (TNF) and the c-Jun N-terminal kinase (JNK) pathway to the induction and maintenance of various pain states. Here we explore the role of spinal TNF and JNK in carrageenan-induced hypersensitivity. As links between TNF and JNK have been demonstrated in vitro, we investigated if TNF regulates spinal JNK activity in vivo.MethodsTNF levels in lumbar cerebrospinal fluid (CSF) were measured by enzyme-linked immunosorbent assay, spinal TNF gene expression by real-time polymerase chain reaction and TNF protein expression, JNK and c-Jun phosphorylation by western blotting. The role of spinal TNF and JNK in inflammation-induced mechanical and thermal hypersensitivity was assessed by injecting the TNF inhibitor etanercept and the JNK inhibitors SP600125 and JIP-1 intrathecally (i.t.). TNF-mediated regulation of JNK activity was examined by assessing the effect of i.t. etanercept on inflammation-induced spinal JNK activity.ResultsTNF levels were increased in CSF and spinal cord following carrageenan-induced inflammation. While JNK phosphorylation followed the same temporal pattern as TNF, c-jun was only activated at later time points. Intrathecal injection of TNF and JNK inhibitors attenuated carrageenan-induced mechanical and thermal hypersensitivity. TNF stimulation induced JNK phosphorylation in cultured spinal astrocytes and blocking the spinal actions of TNF in vivo by i.t. injection of etanercept reduced inflammation-induced spinal JNK activity.ConclusionsHere we show that spinal JNK activity is dependent on TNF and that both TNF and the JNK signalling pathways modulate pain-like behaviour induced by peripheral inflammation

    Nitrogen sorption as a tool for the characterisation of polysaccharide aerogels

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    Supercritically dried aerogels of several polysaccharides (chitin, chitosan, alginate, alginic acid, k- carrageenan, and agar) have been characterised by physisorption ofN2. Surface areas as high as 570m2 g−1 have been measured. The nature of the functional groups of the polysaccharide significantly influences the adsorption of N2 on the surface of the aerogel. The net enthalpy of adsorption increases with the polarity of the surface groups of the polymer, in the order chitin < agar≤chitosan < carrageenan < alginic acid∼alginate. The surface area and the mesopore distribution of the aerogels depend both on the dispersion of the parent hydrogel and on the behaviour of each polymer in the drying treatment. Aerogels which retain the dispersion of the parent hydrogel are mainly macroporous (pores larger than 50 nm) while materials liable to shrink upon solvent exchange form mesoporous structures
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