Polysaccharides from Arctium lappa L.: Chemical structure and biological activity.

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.

Structure and antinociceptive effects of ß-D-glucans from Cookeina tricholoma.

Structurally different water-insoluble (1→3),(1→6) 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 (1→3)-linked ß-D-Glcp units O-6 substituted by side chains with different lengths of (1→6)-linked ß-d-Glcp units (ICW-Ct and IHW-Ct) or by a combination of (1→6)-linked ß-D-Glcp units and single units of ß-D-Glcp (IK2-Ct). ß-D-glucans with similar MW and showing only (1→6)-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.

Chemical characterization of heteropolysaccharides from green and black teas (Camellia sinensis) and their anti-ulcer effect.

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 (1→3)-ß-Galp, substituted at O-6 by (1→6)-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 (1→4)-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.

Arabinoxylan from Mucilage of Tomatoes (Solanum lycopersicum L.): Structure and Antinociceptive Effect in Mouse Models.

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 (1→4)-linked ß-d-Xylp units in the main chain, which carried a low proportion of branching (∼5.6%), 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.

Anti-inflammatory properties of the medicinal mushroom Cordyceps militaris might be related to its linear (1→3)-ß-D-glucan.

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 (1→3)-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-(1→3)-D-glucan, that seems to be the most potent anti-inflammatory compound present in the polysaccharide extracts of C. militaris. In vivo, ß-(1→3)-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-(1→3)-D-glucan.

Structural characterization and anti-inflammatory activity of a linear ß-D-glucan isolated from Pleurotus sajor-caju.

Glucans comprise an important class of polysaccharides present in basidiomycetes with potential biological activities. A (1 → 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.

Glucuronoarabinoxylan from coconut palm gum exudate: chemical structure and gastroprotective effect.

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 (1→4)-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.

Gastroprotective bio-guiding fractionation of hydro-alcoholic extracts from green- and black-teas (Camellia sinensis).

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.

Structure of a galactoarabinoglucuronoxylan from tamarillo (Solanum betaceum), a tropical exotic fruit, and its biological activity.

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 (1→5)-linked α-l-arabinofuranosyl units. Fractions designated as STK-1000R and PF contained galactoarabinoglucuronoxylans, with (1→4)-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 (∼20.0% and 36.5%, respectively), with side-chains formed by (1→5)-linked α-l-Araf residues and (1→4)-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.

Polysaccharide glucomannan isolated from Heterodermia obscurata attenuates acute and chronic pain in mice.

Glucomannan (GM) is a polysaccharide obtained from Heterodermia obscurata lichens. The present study was conducted to elucidate the antinociceptive effect of GM in behavioural models of acute and chronic pain in mice. GM reduced mechanical allodynia and the levels of interleukin 1-ß (IL-1ß) in spinal cord and nerve in the partial sciatic nerve ligation (PSNL) model. Systemic treatment with GM inhibited the nociception induced by intraplantar injection of glutamate and by intrathecal injection of N-methyl-d-aspartic acid (NMDA), (±)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (trans-ACPD), tumour necrosis factor α (TNF-α) and IL-1ß. Taken together, our data demonstrate that GM has significant antinociceptive effect in acute and chronic pain, suggesting a potential interest in the development of new clinically relevant drugs for the management of pain.

Agaricus bisporus fucogalactan: structural characterization and pharmacological approaches.

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 (1→6)-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.

Gastroprotective effect and structure of a rhamnogalacturonan from Acmella oleracea.

The plant Acmella oleracea (L.) R.K.Jansen (Asteraceae), locally known as jambu, is widely used in Legal Amazon in local dishes and in folk medicine. A polysaccharide (SC) was isolated from this plant, following aqueous extraction, which contained uronic acid, galactose, arabinose, rhamnose, and glucose in a 15:2:1:1:0.5 molar ratio and had a M(w) 226,000 g/mol. Methylation analysis and NMR spectroscopy indicated that SC is a rhamnogalacturonan composed of a long chain of →4)-6-OMe-α-D-GalpA-(1→, interspersed with some α-L-Rhap residues, partly substituted by side-chains of type II arabinogalactans. SC significantly inhibited ethanol-induced gastric ulcers in rats with an ED50 of 1.5 mg/kg, indicating that SC acts as gastroprotective agent.

In vivo/in vitro studies of the effects of the type II arabinogalactan isolated from Maytenus ilicifolia Mart. ex Reissek on the gastrointestinal tract of rats.

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.

Isolation of a gastroprotective arabinoxylan from sugarcane bagasse.

After industrial processing, one-third of sugarcane culms is converted into residual bagasse. The xylan-rich hemicellulose components of the bagasse were extracted with hot aqueous alkali (AX-CRUDE). Approximately 82% of the extracted hemicelluloses was precipitated with ethanol (AX-PET). Both AX-CRUDE and AX-PET contained an arabinoxylan as confirmed by 13C NMR and methylation analysis. Fraction AX-PET was fed to female Wistar rats with ethanol-induced gastric lesions. Oral administrations of 30, 100, and 300 mg/kg reduced the gastric lesion area by over 50%, and replenished ethanol-induced depletion of glutathione. The polysaccharide also increased mucus production by over 70%, indicating its cytoprotective action on experimentally induced gastric ulcers. These findings are significant, since a biologically active compound can be extracted in high yields from an abundant, readily available residue.

Chemical structure and selected biological properties of a glucomannan from the lichenized fungus Heterodermia obscurata.

Successive aqueous and alkaline extraction of the thallus of the lichenized fungus Heterodermia obscurata provided a highly branched glucomannan fraction (GM), whose chemical structure was determined. This was based on monosaccharide composition, methylation, partial acid hydrolysis, and NMR spectroscopic analysis. It consisted of a main chain of (1→6)-linked α-D-mannopyranosyl units, almost all being substituted at O-2 with α-D-glucopyranosyl, α-D-mannopyranosyl, and 4-O-substituted α-D-mannopyranosyl groups. Intra-peritoneal administration of this GM induced a marked and dose-dependent inhibition of acetic acid-induced visceral pain with an ID(50) of 0.6 (0.2-2.0) mg/kg and inhibition of 88±4%. It also reduced leukocyte migration by 58±4%, but did not alter plasmatic extravasation to the peritoneal cavity. The results suggest that the glucomannan from the H. obscurata might have potential for antinociceptive and anti-inflammatory utilization.

Host-mineral trioxide aggregate inflammatory molecular signaling and biomineralization ability.

INTRODUCTION: The biological processes underlying the ability of mineral trioxide aggregate (MTA) to promote hard-tissue deposition and wound healing remain unclear. To further study these processes, specific signaling molecules related to the inflammatory response and the biomineralization process were analyzed to assess host-MTA interactions in vivo. METHODS: For cytokine level quantification and immunohistochemical analysis, human dentin tubes were filled with ProRoot MTA (Dentsply, Tulsa Dental, OK) or kept empty and were implanted in subcutaneous tissues in the backs of mice. Dentin tubes were retrieved and subsequently observed using a scanning electron microscope. RESULTS: MTA induced a time-dependent proinflammatory cytokine up-regulation up to 3 days. Immunohistochemical analyses showed an up-regulated expression of myeloperoxidase, nuclear factor-kappa B, activating protein-1, cyclooxygenase-2, inducible nitric oxide synthase, and vascular endothelial growth factor on day 1. Scanning electron microscopic examination revealed the presence of apatite-like clusters on collagen fibrils over the surface of tubes containing MTA. With the increase in time after implantation, a more extensive mineralization showing a compact layer of apatite was observed. CONCLUSION: MTA induced a proinflammatory and pro-wound healing environment. The biomineralization process occurred simultaneously at the biomaterial-dentin-tissue interface, with the acute inflammatory response. This promoted the integration of the biomaterial into the environment.

Structure of Agaricus spp. fucogalactans and their anti-inflammatory and antinociceptive properties.

Fucogalactans from Agaricus brasiliensis (EPF-Ab) and A. bisporus var. hortensis (EPF-Ah) were prepared via by aqueous extraction and a purification procedure. EPF-Ab had M(w) 19.4 x 10(3)g/mol and EPF-Ah M(w) 31.1 x 10(3)g/mol. EPF-Ab had a (1-->6)-linked alpha-D-Galp main-chain partially substituted in O-2 by non-reducing end-units of alpha-L-Fucp. EPF-Ah had a similar main-chain with O-2 substitution, but was partially methylated at HO-3, as well as having 2.5% non-reducing end-units of beta-D-Gal. In mice, EPF-Ab gave 39% antinociceptive inhibition (ID(50)>100mg/kg) and no anti-inflammatory activity. EPF-Ah also gave an inhibition of 39% at ID(50) 0.33 mg/kg and also inhibited by 61% (ID(50) 5.0mg/kg) total cell migration and by 32% peritoneal capillary permeability, which is related to the anti-inflammatory effect. The small differences in chemical structure in these polysaccharides thus modified their biological activities.

Anti-inflammatory and analgesic properties in a rodent model of a (1-->3),(1-->6)-linked beta-glucan isolated from Pleurotus pulmonarius.

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.

Inhibition of H+/K+ ATPase in the gastroprotective effect of Baccharis illinita DC.

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.

Gastroprotective activity of the chloroform extract of the roots from Arctium lappa L.

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.