RESUMO
Recognizing that enteric tuft cells can signal the presence of nematode parasites, we investigated whether tuft cells are required for the expulsion of the cestode, Hymenolepis diminuta, from the non-permissive mouse host, and in concomitant anti-helminthic responses. BALB/c and C57BL/6 mice infected with H. diminuta expelled the worms by 11 days post-infection (dpi) and displayed DCLK1+ (doublecortin-like kinase 1) tuft cell hyperplasia in the small intestine (not the colon) at 11 dpi. This tuft cell hyperplasia was dependent on IL-4Rα signalling and adaptive immunity, but not the microbiota. Expulsion of H. diminuta was slowed until at least 14 dpi, but not negated, in tuft cell-deficient Pou2f3-/- mice and was accompanied by delayed goblet cell hyperplasia and slowed small bowel transit. Worm antigen and mitogen evoked production of IL-4 and IL-10 by splenocytes from wild-type and Pou2f3-/- mice was not appreciably different, suggesting similar systemic immune reactivity to infection with H. diminuta. Wild-type and Pou2f3-/- mice infected with H. diminuta displayed partial protection against subsequent infection with the nematode Heligmosomoides bakeri. We speculate that, with respect to H. diminuta, enteric tuft cells are important for local immune events driving the rapidity of H. diminuta expulsion but are not critical in initiating or sustaining systemic Th2 responses that provide concomitant immunity against secondary infection with H. bakeri.
Assuntos
Himenolepíase , Hymenolepis diminuta , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Animais , Hymenolepis diminuta/imunologia , Camundongos , Himenolepíase/imunologia , Himenolepíase/parasitologia , Intestino Delgado/imunologia , Intestino Delgado/parasitologia , Intestino Delgado/patologia , Camundongos Knockout , Feminino , Hiperplasia/imunologia , Hiperplasia/parasitologia , Células em TufoRESUMO
The inflamed mucosa contains a complex assortment of proteases that may participate in wound healing or the development of inflammation-associated colon cancer. We sought to determine the role of protease-activated receptor 2 (PAR2) in epithelial wound healing in both untransformed and transformed colonic epithelial cells. Monolayers of primary epithelial cells derived from organoids cultivated from patient colonic biopsies and of the T84 colon cancer cell line were grown to confluence, wounded in the presence of a selective PAR2-activating peptide, and healing was visualized by live cell microscopy. Inhibitors of various signaling molecules were used to assess the relevant pathways responsible for wound healing. Activation of PAR2 induced an enhanced wound-healing response in T84 cells but not primary cells. The PAR2-enhanced wound-healing response was associated with the development of lamellipodia in cells at the wound edge, consistent with sheet migration. The response to PAR2 activation in T84 cells was completely dependent on Src kinase activity and partially dependent on Rac1 activity. The Src-associated signaling molecules, focal adhesion kinase, and epidermal growth factor receptor, which typically mediate wound-healing responses, were not involved in the PAR2 response. Experiments repeated in the presence of the inflammatory cytokines TNF and IFNγ revealed a synergistically enhanced PAR2 wound-healing response in T84s but not primary cells. The epithelial response to proteases may be different between primary and cancer cells and is accentuated in the presence of inflammatory cytokines. Our findings have implications for understanding epithelial restitution in the context of inflammatory bowel disease (IBD) and inflammation-associated colon cancer.NEW & NOTEWORTHY Protease-activated receptor 2 enhances wound healing in the T84 colon cancer cell line, but not in primary cells derived from patient biopsies, an effect that is synergistically enhanced in the presence of the inflammatory cytokines TNF and IFNγ.
Assuntos
Neoplasias do Colo , Receptor PAR-2 , Humanos , Linhagem Celular , Movimento Celular , Neoplasias do Colo/metabolismo , Citocinas/metabolismo , Células Epiteliais/metabolismo , Inflamação/metabolismo , Peptídeo Hidrolases/metabolismo , Peptídeo Hidrolases/farmacologia , Receptor PAR-2/metabolismoRESUMO
The gut microbiome contributes to inflammatory bowel disease (IBD), in which bacteria can be present within the epithelium. Epithelial barrier function is decreased in IBD, and dysfunctional epithelial mitochondria and endoplasmic reticulum (ER) stress have been individually associated with IBD. We therefore hypothesized that the combination of ER and mitochondrial stresses significantly disrupt epithelial barrier function. Here, we treated human colonic biopsies, epithelial colonoids, and epithelial cells with an uncoupler of oxidative phosphorylation, dinitrophenol (DNP), with or without the ER stressor tunicamycin and assessed epithelial barrier function by monitoring internalization and translocation of commensal bacteria. We also examined barrier function and colitis in mice exposed to dextran sodium sulfate (DSS) or DNP and co-treated with DAPK6, an inhibitor of death-associated protein kinase 1 (DAPK1). Contrary to our hypothesis, induction of ER stress (i.e. the unfolded protein response) protected against decreased barrier function caused by the disruption of mitochondrial function. ER stress did not prevent DNP-driven uptake of bacteria; rather, specific mobilization of the ATF6 arm of ER stress and recruitment of DAPK1 resulted in enhanced autophagic killing (xenophagy) of bacteria. Of note, epithelia with a Crohn's disease-susceptibility mutation in the autophagy gene ATG16L1 exhibited less xenophagy. Systemic delivery of the DAPK1 inhibitor DAPK6 increased bacterial translocation in DSS- or DNP-treated mice. We conclude that promoting ER stress-ATF6-DAPK1 signaling in transporting enterocytes counters the transcellular passage of bacteria evoked by dysfunctional mitochondria, thereby reducing the potential for metabolic stress to reactivate or perpetuate inflammation.
Assuntos
Proteínas Quinases Associadas com Morte Celular/metabolismo , Estresse do Retículo Endoplasmático , Mitocôndrias/metabolismo , Fator 6 Ativador da Transcrição/metabolismo , Idoso , Animais , Linhagem Celular Tumoral , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Epitélio/efeitos dos fármacos , Epitélio/metabolismo , Escherichia coli/efeitos dos fármacos , Escherichia coli/fisiologia , Feminino , Humanos , Masculino , Camundongos , Mitocôndrias/efeitos dos fármacos , Fosforilação Oxidativa/efeitos dos fármacos , Permeabilidade , Tunicamicina/farmacologiaRESUMO
Type II arabinogalactan (AG) is a polysaccharide found in Maytenus ilicifolia (Celastraceae), a plant reputed as gastroprotective. Oral and intraperitoneal administration of the AG protected rats from gastric ulcers induced by ethanol. No alteration of mechanisms related to acid gastric secretion and gastrointestinal motility were observed. In vitro, the AG showed a potent scavenging activity against the radical of DPPH (2,2-diphenyl-1-picrylhydrazyl) with an IC50 value of 9.3 microM. However, the mechanism of the gastroprotective action remains to be identified.
Assuntos
Galactanos/farmacologia , Trato Gastrointestinal/efeitos dos fármacos , Maytenus/química , Animais , Feminino , Galactanos/isolamento & purificação , Técnicas In Vitro , Ratos , Ratos WistarRESUMO
BACKGROUND AND PURPOSE: Dietary fibre comprises a complex group of polysaccharides that are indigestible but are fermented by gut microbiota, promoting beneficial effects to the intestinal mucosa indirectly through the production of short chain fatty acids. We found that a polysaccharide, rhamnogalacturonan (RGal), from the plant Acmella oleracea, has direct effects on intestinal epithelial barrier function. Our objective was to determine the mechanism whereby RGal enhances epithelial barrier function. EXPERIMENTAL APPROACH: Monolayers of colonic epithelial cell lines (Caco-2, T84) and of human primary cells from organoids were mounted in Ussing chambers to assess barrier function. The cellular mechanism of RGal effects on barrier function was determined using inhibitors of TLR-4 and PKC isoforms. KEY RESULTS: Apically applied RGal (1000 µg ml-1 ) significantly enhanced barrier function as shown by increased transepithelial electrical resistance (TER) and reduced fluorescein isothiocyanate (FITC)-dextran flux in Caco-2, T84 and human primary cell monolayers, and accelerated tight junction reassembly in Caco-2 cells in a calcium switch assay. RGal also reversed the barrier-damaging effects of inflammatory cytokines on FITC-dextran flux and preserved the tight junction distribution of occludin. RGal activated TLR4 in TLR4-expressing HEK reporter cells, an effect that was inhibited by the TLR4 inhibitor, C34. The effect of RGal was also dependent on PKC, specifically the isoforms PKCδ and PKCζ. CONCLUSION AND IMPLICATIONS: RGal enhances intestinal epithelial barrier function through activation of TLR4 and PKC signalling pathways. Elucidation of RGal mechanisms of action could lead to new, dietary approaches to enhance mucosal healing in inflammatory bowel diseases.
Assuntos
Mucosa Intestinal , Ramnogalacturonanos , Receptor 4 Toll-Like , Células CACO-2 , Fibras na Dieta/farmacologia , Células Epiteliais/metabolismo , Humanos , Mucosa Intestinal/metabolismo , Microbiota , Permeabilidade , Ramnogalacturonanos/farmacologia , Junções Íntimas/metabolismo , Receptor 4 Toll-Like/metabolismoRESUMO
Many patients with visceral inflammation develop pain and psychiatric comorbidities such as major depressive disorder, worsening the quality of life and increasing the risk of suicide. Here we show that neuroimmune activation in mice with dextran sodium sulfate-induced colitis is accompanied by the development of pain and depressive behaviors. Importantly, treatment with the flavonoid luteolin prevented both neuroimmune responses and behavioral abnormalities, suggesting a new potential therapeutic approach for patients with inflammatory bowel diseases.
RESUMO
A glucan was extracted with hot water from the basidiomycete Pleurotus pulmonarius and shown to have a (1-->3)-linked beta-D-glucopyranosyl main-chain substituted at O-6 of every third unit by single beta-D-glucopyranosyl non-reducing end units. This was shown by mono- and bidimensional nuclear magnetic resonance (NMR) spectroscopy, methylation analysis, and a controlled Smith degradation. The glucan was tested for its effects on the acetic acid-induced writhing reaction in mice, a typical model for quantifying inflammatory pain. It caused a marked and dose-dependent anti-inflammatory response, demonstrated by the inhibition of leukocyte migration to injured tissues (82 +/- 6%) with an ID50 of 1.19 (0.74-1.92) mg/kg. Furthermore, animals previously treated with the glucan (3 mg/kg i.p.), showed a reduction of 85 +/- 5% of writhes, after receiving the acetic acid injection. Furthermore, in the formalin test, the glucan (3-30 mg/kg, i.p.) also caused significant inhibition of both the early (neurogenic pain) and the late phases (inflammatory pain) of formalin-induced licking. However, it was more potent and effective in relation to the late phase of the formalin test, with mean ID(50) values for the neurogenic and the inflammatory phases of > 30 and 12.9 (6.7-24.6) mg/kg and the inhibitions observed were 43 +/- 5% and 96 +/- 4%, respectively. These data showed that the glucan had potent anti-inflammatory and analgesic (antinociceptive) activities, possibly by the inhibition of pro-inflammatory cytokines.
Assuntos
Analgésicos/farmacologia , Anti-Inflamatórios/farmacologia , Glucanos/farmacologia , Inflamação/prevenção & controle , Dor/prevenção & controle , Pleurotus , Ácido Acético , Analgésicos/isolamento & purificação , Animais , Anti-Inflamatórios/isolamento & purificação , Comportamento Animal/efeitos dos fármacos , Permeabilidade Capilar/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Formaldeído , Glucanos/isolamento & purificação , Inflamação/induzido quimicamente , Inflamação/imunologia , Leucócitos/efeitos dos fármacos , Masculino , Camundongos , Estrutura Molecular , Dor/induzido quimicamente , Dor/imunologia , Medição da Dor , Pleurotus/químicaRESUMO
Arctium lappa L. is used in folk medicine as a diuretic, depurative and digestive stimulant and in dermatological conditions. The objective of this study was to evaluate the effect and the possible mechanisms involved in the gastroprotective effects of a chloroform extract (CE) of the roots from A. lappa and its fractions. Oral pretreatment with CE (10, 30 and 100 mg kg(-1)) significantly reduced gastric lesions induced by ethanol by 61%, 70% and 76%, respectively. Oral administration of CE (100 mg kg(-1) per day for 7 days) reduced the chronic gastric ulceration induced by acetic acid by 52%. Intraduodenal CE (100, 300 and 600 mg kg(-1)) reduced the total acidity of gastric secretion by 22%, 22% and 33%, respectively, while i.p. administration (10, 30 and 100 mg kg(-1)) inhibited total acidity by 50%, 60% and 67%, respectively. In-vitro, CE inhibited H+, K+ -ATPase activity with an EC50 of 53 microgmL(-1) and fraction A (30 and 100 microgmL(-1)) reduced this by 48% and 89%, respectively. CE had no effect on gastrointestinal motility. CE (250 microgmL(-1)) and fraction B (100 and 250 microgmL(-1)) had free-radical scavenging ability, inhibiting 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical activity by 50%, 20% and 55%, respectively. Collectively, the results show that the CE protects animals from gastric lesions by reducing gastric acid secretion via inhibition of gastric H+, K+ -ATPase.
Assuntos
Antiulcerosos/farmacologia , Arctium/química , Extratos Vegetais/farmacologia , Úlcera Gástrica/prevenção & controle , Animais , Antiulcerosos/administração & dosagem , Relação Dose-Resposta a Droga , Feminino , Sequestradores de Radicais Livres/administração & dosagem , Sequestradores de Radicais Livres/farmacologia , Ácido Gástrico/metabolismo , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Motilidade Gastrointestinal/efeitos dos fármacos , Medicina Tradicional , Camundongos , Extratos Vegetais/administração & dosagem , Raízes de Plantas , Inibidores da Bomba de Prótons , Ratos , Ratos WistarRESUMO
Baccharis illinita DC (Compositae) is used in folk medicine to treat gastric disturbances. Preliminary studies with other extracts of B. Illinita showed gastric protection against ethanol-, indometacin- and stress-induced ulcers and the inhibition of gastric secretion. Based on these data, the aim of this study was to verify the pathways involved in the inhibition of gastric secretion. The chloroform extract (CE) of flowers from B. illinita (3, 10, 30 and 100 mg kg(-1) i.p.) tested on rats with pylorus ligature reduced the volume and the total acidity of gastric content by approximately 50% (ED50 = 69 mg kg(-1)). Treatment with CE (100 mg kg(-1) i.p.) reduced the gastric total acidity stimulated by histamine, bethanechol and pentagastrin to 42%, 27% and 57% of that in the stimulated control group, respectively. The CE (10, 30 and 100 microM) inhibited H+/K+ ATPase activity in-vitro, with an IC50 of 37 microM. The isolated flavonoid luteolin (1, 3, 10 and 30 microM) also inhibited H+/K+ ATPase activity by 50%, at a dose of 30 microM. Our results suggest that the reduction in gastric secretion occurs through inhibition of H+/K+ ATPase, which is the final step in acid secretion and therefore one of the most important steps.
Assuntos
Baccharis , Inibidores da Bomba de Prótons , Inibidores da Bomba de Prótons/farmacologia , Estômago/efeitos dos fármacos , Animais , Atropina/farmacologia , Baccharis/química , Betanecol/farmacologia , Relação Dose-Resposta a Droga , Feminino , Flores , Ácido Gástrico/metabolismo , Determinação da Acidez Gástrica , ATPase Trocadora de Hidrogênio-Potássio/metabolismo , Histamina/metabolismo , Luteolina/farmacologia , Omeprazol/farmacologia , Pentagastrina/farmacologia , Extratos Vegetais/farmacologia , Inibidores da Bomba de Prótons/isolamento & purificação , Ratos , Ratos Wistar , Estômago/enzimologiaRESUMO
Aquaporin (AQP) 3 expression is altered in inflammatory bowel diseases, although the exact mechanisms regulating AQP abundance are unclear. Although interferon gamma (IFNγ) is centrally involved in intestinal inflammation, the effect of this cytokine on AQP3 expression remains unknown. HT-29 human colonic epithelial cells were treated with IFNγ to assess AQP3 mRNA expression by real-time RT-PCR and functional protein expression through the uptake of radiolabelled glycerol. Transient knockdown of signal transducer and activator of transcription 1 (STAT1), STAT3, Sp1, and Sp3 were performed to determine the involvement of these transcription factors in the IFNγ-induced signalling cascade. AQP3 promoter regions involved in the response to IFNγ were assessed using a luciferase reporter system. Likewise, enteroids derived from human colonic biopsies were also treated with IFNγ to assess for changes in AQP3 mRNA expression. IFNγ decreased AQP3 mRNA expression in HT-29 cells in a time- and concentration-dependent manner and reduced functional AQP3 protein expression (decreased 3H-labelled glycerol uptake). IFNγ also reduced AQP3 expression in enteroids derived from human colonic biopsies. Knockdown of STAT1 partially prevented the IFNγ-induced downregulation of AQP3 expression, whereas STAT3 and Sp3 knockdowns resulted in increased baseline expression of AQP3 but did not alter IFNγ-induced downregulation. Constitutive transcription of AQP3 is downregulated by IFNγ as demonstrated using the luciferase reporter system, with Sp3 bound to the AQP3 promoter as shown by chromatin immunoprecipitation. AQP3 constitutive transcription in intestinal epithelial cells is downregulated by IFNγ. This response requires STAT1 that is postulated to drive the downregulation of AQP3 expression through increased acetylation or decreased deacetylation the AQP3 promoter, ultimately resulting in decreased constitutive transcription of AQP3. KEY MESSAGES: ⢠IFNγ suppresses the expression of AQP3 in intestinal epithelial cells. ⢠Proximal AQP3 promoter elements are sufficient to drive constitutive expression and mediate the IFNγ-induced downregulation of AQP3 mRNA expression. ⢠IFNγ-induced suppression of AQP3 is dependent upon STAT1 expression, but not STAT3, Sp1, or Sp3.
Assuntos
Aquaporina 3/genética , Interferon gama/farmacologia , Mucosa Intestinal/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Células HT29 , Humanos , Mucosa Intestinal/metabolismo , Transcrição Gênica/efeitos dos fármacosRESUMO
Structurally different water-insoluble (1â3),(1â6) ß-D-glucans were isolated from aqueous and alkaline extracts of the mushroom-forming ascomycete Cookeina tricholoma, a wild edible mushroom found in Brazilian Amazon forest. The structures showed different substitution patterns, which may influence their extractability and consequently their conformation in solution, and different MW (4.3×10(5)Da, 3.7×10(5)Da and 8.2×10(5)Da, for ICW-Ct, IHW-Ct and IK2-Ct, respectively). The main-chains are composed of (1â3)-linked ß-D-Glcp units O-6 substituted by side chains with different lengths of (1â6)-linked ß-d-Glcp units (ICW-Ct and IHW-Ct) or by a combination of (1â6)-linked ß-D-Glcp units and single units of ß-D-Glcp (IK2-Ct). ß-D-glucans with similar MW and showing only (1â6)-linked ß-D-Glcp units as side chains (ICW-Ct and IHW-Ct) showed significant inhibition of neurogenic pain, 69±11 and 57±11% at the dose of 10mgkg(-1), respectively, in the model of nociception induced by intraplantar injection of formalin.
Assuntos
Analgésicos/química , Ascomicetos/química , Polissacarídeos Fúngicos/química , Glucanos/química , Analgésicos/farmacologia , Animais , Feminino , Polissacarídeos Fúngicos/farmacologia , Glucanos/farmacologia , Camundongos , Nociceptividade/efeitos dos fármacosRESUMO
In order to obtain polysaccharides from green and black teas (Camellia sinensis), commercial leaves were submitted to infusion and then to alkaline extraction. The extracts were fractionated by freeze-thawing process, giving insoluble and soluble fractions. Complex arabinogalactan protein from the soluble fractions of both teas (GTPS and BTPS) were determined by methylation analysis and (1)H/(13)C-HSQC spectroscopy, showing a main chain of (1â3)-ß-Galp, substituted at O-6 by (1â6)-linked ß-Galp with side chains of α-Araf and terminal units of α-Araf, α-Fucp and α-Rhap. A highly branched heteroxylan from the insoluble fractions (GTPI and BTPI) showed in methylation analysis and (1)H/(13)C-HSQC spectroscopy the main chain of (1â4)-ß-Xylp, substituted in O-3 by α-Araf, ß-Galp and α-Glcp units. Evaluating their gastroprotective activity, the fractions containing the soluble heteropolysaccharides from green (GTPS) and black teas (BTPS) reduced the gastric lesions induced by ethanol. Furthermore, the fraction of insoluble heteropolysaccharides of green (GTPI) and black (BTPI) teas also protected the gastric mucosa. In addition, the maintenance of gastric mucus and reduced glutathione (GSH) levels was involved in the polysaccharides gastroprotection.
Assuntos
Camellia sinensis/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Chá/química , Úlcera/tratamento farmacológico , Ácido Acético/efeitos adversos , Animais , Etanol/efeitos adversos , Feminino , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Glutationa/metabolismo , Folhas de Planta/química , Polissacarídeos/isolamento & purificação , Polissacarídeos/uso terapêutico , Ratos , Ratos Wistar , Solubilidade , Úlcera/induzido quimicamente , Úlcera/metabolismo , Úlcera/patologiaRESUMO
Tomato is a known functional food due to its content of bioactive compounds. Herein, polysaccharides were extracted from mucilage of tomatoes, and a purified fraction (PTOK) was analyzed by sugar composition, methylation, and NMR spectroscopy analysis. The results showed the presence of an arabinoxylan, having (1â4)-linked ß-d-Xylp units in the main chain, which carried a low proportion of branching (â¼5.6%), at O-2 and O-3 position, with side chains constituted by single Araf or Xylp units. Intraperitoneal administration of the arabinoxylan in mice significantly reduced the number of abdominal constrictions induced by 0.6% acetic acid and the inflammatory phase of nociception induced by 2.5% formalin, indicating that it had an antinociceptive effect on inflammatory pain models, amplifying the biological role displayed by arabinoxylans in the diet. Furthermore, this study reports the presence of an arabinoxylan in a dicotyledon plant, and also it is the first study of polysaccharides from mucilage of tomatoes.
Assuntos
Analgésicos/administração & dosagem , Dor/tratamento farmacológico , Extratos Vegetais/administração & dosagem , Polissacarídeos/administração & dosagem , Solanum lycopersicum/química , Xilanos/administração & dosagem , Analgésicos/química , Animais , Modelos Animais de Doenças , Humanos , Camundongos , Extratos Vegetais/química , Polissacarídeos/química , Xilanos/químicaRESUMO
The plant Arctium lappa L. is popularly used to relieve symptoms of inflammatory disorders. A crude polysaccharide fraction (SAA) resulting of aqueous extraction of A. lappa leaves showed a dose dependent anti-edematogenic activity on carrageenan-induced paw edema, which persisted for up to 48h. Sequential fractionation by ultrafiltration at 50kDa and 30kDa cut-off membranes yielded three fractions, namely RF50, RF30, and EF30. All these maintained the anti-edematogenic effect, but RF30 showed a more potent action, inhibiting 57% of the paw edema at a dose of 4.9mg/kg. The polysaccharide RF30 contained galacturonic acid, galactose, arabinose, rhamnose, glucose, and mannose in a 7:4:2:1:2:1 ratio and had a Mw of 91,000g/mol. Methylation analysis and NMR spectroscopy indicated that RF30 is mainly constituted by a type I rhamnogalacturonan branched by side chains of types I and II arabinogalactans, and arabinan.
Assuntos
Arctium/química , Polissacarídeos/química , Polissacarídeos/farmacologia , Animais , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Fracionamento Químico , Cromatografia em Gel , Edema/tratamento farmacológico , Edema/patologia , Feminino , Camundongos , Monossacarídeos/análise , Polissacarídeos/uso terapêutico , Espectroscopia de Prótons por Ressonância MagnéticaRESUMO
The Ascomycete Cordyceps militaris, an entomopathogenic fungus, is one of the most important traditional Chinese medicines. Studies related to its pharmacological properties suggest that this mushroom can exert interesting biological activities. Aqueous (CW and HW) and alkaline (K5) extracts containing polysaccharides were prepared from this mushroom, and a ß-D-glucan was purified. This polymer was analysed by GC-MS and NMR spectrometry, showing a linear chain composed of ß-D-Glcp (1â3)-linked. The six main signals in the 13C-NMR spectrum were assigned by comparison to reported data. The aqueous (CW, HW) extracts stimulated the expression of IL-1ß, TNF-α, and COX-2 by THP-1 macrophages, while the alkaline (K5) extract did not show any effect. However, when the extracts were added to the cells in the presence of LPS, K5 showed the highest inhibition of the pro-inflammatory genes expression. This inhibitory effect was also observed for the purified ß-(1â3)-D-glucan, that seems to be the most potent anti-inflammatory compound present in the polysaccharide extracts of C. militaris. In vivo, ß-(1â3)-D-glucan also inhibited significantly the inflammatory phase of formalin-induced nociceptive response, and, in addition, it reduced the migration of total leukocytes but not the neutrophils induced by LPS. In conclusion, this study clearly demonstrates the anti-inflammatory effect of ß-(1â3)-D-glucan.
Assuntos
Anti-Inflamatórios/farmacologia , Produtos Biológicos/farmacologia , Cordyceps/química , beta-Glucanas/farmacologia , Anti-Inflamatórios/química , Produtos Biológicos/química , Ciclo-Oxigenase 2/metabolismo , Humanos , Interleucina-1beta/metabolismo , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Proteoglicanas , Fator de Necrose Tumoral alfa/metabolismo , beta-Glucanas/químicaRESUMO
Glucans comprise an important class of polysaccharides present in basidiomycetes with potential biological activities. A (1 â 3)-ß-D-glucan was isolated from Pleurotus sajor-caju via extraction with hot water followed by fractionation by freeze-thawing and finally by dimethyl sulfoxide extraction. The purified polysaccharide showed a (13)C-NMR spectrum with six signals consisting of a linear glucan with a ß-anomeric signal at 102.8 ppm and a signal at 86.1 ppm relative to O-3 substitution. The other signals at 76.2, 72.9, 68.3, and 60.8 ppm were attributed to C5, C2, C4, and C6, respectively. This structure was confirmed by methylation analysis, and HSQC studies. The ß-d-glucan from P. sajor-caju presented an immunomodulatory activity on THP-1 macrophages, inhibited the inflammatory phase of nociception induced by formalin in mice, and reduced the number of total leukocytes and myeloperoxidase levels induced by LPS. Taken together, these results demonstrate that this ß-d-glucan exhibits a significant anti-inflammatory activity.
Assuntos
Anti-Inflamatórios/química , Inflamação/induzido quimicamente , Polissacarídeos/química , beta-Glucanas/química , Animais , Anti-Inflamatórios/administração & dosagem , Dimetil Sulfóxido/química , Formaldeído/toxicidade , Imunomodulação/efeitos dos fármacos , Inflamação/tratamento farmacológico , Macrófagos/efeitos dos fármacos , Camundongos , Nociceptividade/efeitos dos fármacos , Pleurotus/química , Polissacarídeos/administração & dosagem , Proteoglicanas , beta-Glucanas/administração & dosagemRESUMO
Hydro-alcoholic extracts from leaves of Camellia sinensis (green- and black-tea leaves) were submitted to a fractionation, promoting the compound separation according to their polarity, and analyzed by ultra-high performance liquid chromatography-mass spectrometry. A wide range of compounds could be identified, such as catechins and their gallate (esters) or oxidation derivatives (theaflavins), glycosylated flavonoids and other phenolics, as well as lipids, saponins and alkaloids. Also have been developed, via bio-guided examination, the gastroprotective property of the compounds identified. The samples were assayed using the model of acute gastric lesions induced in rats by ethanol. Hydro-alcoholic extracts of green-tea and black-tea protected the gastric mucosa with ED50=3.6 and 10.2mg/kg, respectively, with participation of gastric mucus and reduced glutathione (GSH). The ethyl acetate fraction from green-tea and aqueous fraction from black-tea were, respectively, 6 and 10 times more effectiveness than the initial extracts. Moreover, the epigallocatechin gallate (EGCG, 0.204mg/kg), a main component of ethyl acetate fraction from green tea, reduced the gastric lesion by 56% and restored the mucus levels, however the rutin (0.0133mg/kg), a flavonoid found in the most active fraction of black-tea, was less significant at the natural concentrations. These results have confirmed that the different compounds present in green- and black-tea hydro-alcoholic extracts and partitioned fractions produce relevant gastroprotection mainly via maintenance of the protective factors, mucus and GSH.
RESUMO
A glucuronoarabinoxylan (CNAL) was extracted with 1% aq. KOH (25°C) from Cocos nucifera gum exudate. It had a homogeneous profile on HPSEC-MALLS-RI (Mw 4.6 × 10(4)g/mol) and was composed of Fuc, Ara, Xyl, GlcpA (and 4-O-GlcpA) in a 7:28:62:3 molar ratio. Methylation data showed a branched structure with 39% of non-reducing end units, 3-O-substituted Araf (8%), 3,4-di-O- (15%), 2,4-di-O- (5%) and 2,3,4-tri-O-substituted Xylp units (17%). The anomeric region of CNAL (13)C NMR spectrum contained 9 signals, indicating a complex structure. The main chain of CNAL was characterized by analysis of a Smith-degraded polysaccharide. Its (13)C NMR spectrum showed 5 main signals at δ 101.6, δ 75.5, δ 73.9, δ 72.5, and δ 63.1 that were attributed to C-1, C-4, C-3, C-2 and C-5 of (1â4)-linked ß-Xylp-main chain units, respectively. CNAL exhibited gastroprotective effect, by reducing gastric hemorrhagic lesions, when orally administered (1 and 3mg/kg) to rats prior to ethanol administration.
Assuntos
Cocos/química , Citoproteção/efeitos dos fármacos , Gomas Vegetais/química , Estômago/efeitos dos fármacos , Xilanos/química , Xilanos/farmacologia , Animais , Feminino , Peso Molecular , Ratos , Ratos Wistar , Xilanos/isolamento & purificaçãoRESUMO
Tamarillo (Solanum betaceum) is a tropical exotic fruit whose polysaccharides were extracted from the ripe pulp. After various purification steps, homogeneous fractions (designated PTW, STK-1000R and PF) were analyzed by sugar composition, HPSEC, methylation and NMR spectroscopy analysis. The results showed that the fraction PTW consisted of a linear arabinan with (1â5)-linked α-l-arabinofuranosyl units. Fractions designated as STK-1000R and PF contained galactoarabinoglucuronoxylans, with (1â4)-linked ß-d-Xylp residues in the backbone, carrying branches exclusively at O-2. The polysaccharide in STK-1000R is less branched than that in the PF fraction (â¼20.0% and 36.5%, respectively), with side-chains formed by (1â5)-linked α-l-Araf residues and (1â4)-linked α-d-GlcpA residues and with non-reducing end units formed by α-l-Araf, ß-Arap, ß-d-Galp, α-d-GlcpA and 4-O-Me-α-d-GlcpA. Intraperitoneal administration of the STK-1000R fraction in mice significantly reduced the number of abdominal constrictions induced by 0.6% acetic acid and the inflammatory phase of nociception induced by 2.5% formalin, indicating that that fraction has an antinociceptive effect on inflammatory pain models.
Assuntos
Frutas/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Polissacarídeos/química , Polissacarídeos/farmacologia , Solanum/química , Animais , Sequência de Carboidratos , Cólica/tratamento farmacológico , Feminino , Humanos , Camundongos , Dados de Sequência Molecular , Estrutura Molecular , Nociceptividade/efeitos dos fármacos , Extratos Vegetais/isolamento & purificação , Polissacarídeos/isolamento & purificaçãoRESUMO
The fucogalactan from Agaricus bisporus (EFP-Ab) obtained on aqueous extraction followed by purification had M(w) 37.1 × 10(4)g mol(-1) relative to a (1â6)-linked α-D-Galp main-chain partially methylated at HO-3, and partially substituted at O-2 by nonreducing end-units of α-L-Fucp or ß-d-Galp. EFP-Ab also inhibited significantly the neurogenic and inflammatory phases of formalin-induced licking, however, the antinociceptive effect was more pronounced against the inflammatory phase with ID(50) of 36.0 (25.8-50.3)mg kg(-1). In addition, EFP-Ab decreased the lethality induced by CLP. Its administration reduced the late mortality rate by 40%, prevented neutrophil accumulation in lungs and markedly decreased iNOS and COX-2 protein expression by ileum cells. These data show for the first time that EFP-Ab has significant anti-sepsis, antinociceptive and anti-inflammatory actions, which seems to be related to the decreased iNOS and COX-2 expression. Collectively, the present results demonstrate that EFP-Ab could constitute an attractive molecule of interest for the development of new drugs.