Topical pectins for the treatment of burn wounds]

The results of the burned wounds treatment with 1-2% solution of apple or beet pectins were analysed. The control results were examined at the same patients with symmetrical wounds treated by chlorhexidine, levomecol, furacillin liniment. Clinical evaluation demonstrated good tolerability of the treatment regime, absence of side effects and complications, inhibition of inflammation, acceleration of epithelisation of the burns II-IIIA class, allowed to diminish the preliminary period before autodermoplastic operation (burns of IIIB class), diminished microbial dissemination and dissemination with Pseudomonas aeruginosa. The best results were demonstrated when the pectins application was performed since the first day after the burned injury.     

Expanding roles for pectins in plant development

Pectins are complex cell wall polysaccharides important for many aspects of plant development. Recent studies have discovered extensive physical interactions between pectins and other cell wall components, implicating pectins in new molecular functions. Pectins are often localized in spatially‐restricted patterns, and some of these non‐uniform pectin distributions contribute to multiple aspects of plant development, including the morphogenesis of cells and organs. Furthermore, a growing number of mutants affecting cell wall composition have begun to reveal the distinct contributions of different pectins to plant development. This review discusses the interactions of pectins with other cell wall components, the functions of pectins in controlling cellular morphology, and how non‐uniform pectin composition can be an important determinant of developmental processes.     

Polypotency of the immunomodulatory effect of pectins

Pectins are the major component of plant cell walls, and they display diverse biological activities including immunomodulation. The pectin macromolecule contains fragments of linear and branched regions of polysaccharides such as homogalacturonan, rhamnogalacturonan-I, xylogalacturonan, and apiogalacturonan. These structural features determine the effect of pectins on the immune system. The backbones of pectic macromolecules have immunosuppressive activity. Pectins containing greater than 80% galacturonic acid residues were found to decrease macrophage activity and inhibit the delayed-type hypersensitivity reaction. Branched galacturonan fragments result in a biphasic immunomodulatory action. The branched region of pectins mediates both increased phagocytosis and antibody production. The fine structure of the galactan, arabinan, and apiogalacturonan side chains determines the stimulating interaction between pectin and immune cells. This review summarizes data regarding the relationship between the structure and immunomodulatory activity of pectins isolated from the plants of the European north of Russia and elucidates the concept of polypotency of pectins in native plant cell walls to both stimulate and suppress the immune response. The possible mechanisms of the immunostimulatory and anti-inflammatory effects of pectins are also discussed.     

Role of pectins in the complex treatment in patients in neurointensive care units]

Clinical and laboratory estimation of the efficacy of pectins in complex treatment of patients with intracranial hematoma was performed. It was shown that in the group of the patients treated with pectins vs the control group development of pyo-inflammatory infections was less frequent, the indices of the immunity status improved and a more rapid decrease of the intoxication and a more rapid normalization of the composition of various biotopes in the patients were observed.     

Identification of chemical constituents of tomato juice which affect the heat resistance of Lactobacillus fermentum

Pectins appear to be the main factors in tomato juice which are associated with the protection of Lactobacillus fermentum against destruction or injury by heat. Hydrolysis of pectins by enzymic action makes the cells more vulnerable to heat.     

Extraction and characterisation of very highly methylated pectins from lemon cell walls

Pectins were extracted either by water from extruded lemon fibre or by hot acid from the raw lemon fibre. The amount of water-soluble polysaccharides from lemon plant cell walls was greatly increased after extrusion-cooking. The pectins obtained by extraction with water from the extruded fibre and the pectins extracted from the raw material by hot acid were studied. The water-soluble pectins obtained after extrusion-cooking had the distinctive feature of being very highly (92%) methylated; they were also particularly rich in arabinose side-chains. High molecular weight material coming from the “hairy” regions was isolated after digestion by an endo-polygalacturonase. Methylation analysis revealed the presence in both pectins of fairly branched (1 → 5)-linked arabinans and arabinogalactans of type I and II side-chains.     

Structure and properties of pectin gels in plant cell walls

Abstract This review deals with recent advances in the structural characterization of pectins and the gels which they form, in relation to auxin-induced extension growth, the ripening of fruit, and cellular recognition. Pectins are block polysaccharides. Heavily branched, largely methyl-esterified blocks alternate with unbranched blocks of varying degrees of esterification. The unbranched, non-esterified blocks can aggregate through calcium binding to form the junction zones that hold a gel together. The aggregates are of two, or possibly four, chains at low calcium levels, and larger with excess calcium. The fall in wall pH during auxin-induced growth activates glycanase enzymes. These may attack some components of the pectic fraction, as well as xyloglucans. Pectin-bound calcium ions may be displaced but this probably has little effect on gel strength. Pectins may be cross-linked by diferulate esters when growth stops. The softening of ripe fruit is due to loss of cohesion in the pectin gel. In apples this results from replacement of the pectins by more esterified forms. In many other fruits it results from depolymerization by polygalacturonases, assisted by pectinesterases, so that the remaining segments are too short for effective calcium binding. Pectins have a further role in the recognition reactions between plant cells and some of their bacterial and fungal pathogens.     

Characterisation of pectin subunits released by an optimised combination of enzymes

Pectins from sugar beet, lime and apple were degraded by a rhamnogalacturonan hydrolase associated or not with pectin methylesterases and side chain degrading enzymes (galactanase and arabinanase). The composition of the enzymatic mixture was optimised by following the reaction by viscosimetric means. The reaction products were fractionated by ion exchange chromatography. Treatment with all the enzymes released four fractions: (1). 227-247 mg/g of initial pectins and corresponded to neutral sugars from the side chains; (2,3). represented together 184-220 mg/g of pectins and corresponded to rhamnogalacturonan; (4). 533-588 mg/g of pectins and corresponded to homogalacturonan. Lime pectins have the shortest rhamnogalacturonan regions. The molar masses of homogalacturonans were in the range of 16000-43400 g/mol according to the origin of pectins, corresponding to degrees of polymerisation of 85-250. The mode of action of the enzymes used is also discussed.     

The Functions of 4-α-glucanotransferases and their use for the Production of Cyclic Glucans

Chitosans and pectins are natural polysaccharides which show great potential in drug delivery systems.

Chitosans are a family of strongly polycationic derivatives of poly-N-acetyl-D-glucosamine. This positive charge is very important in chitosan drug delivery systems as it plays a very important role in mucoadhesion (adhesion to the mucosal surface). Other chitosan based drug delivery systems involve complexation with ligands to form chitosan nanoparticles with can be used to encapsulate active compounds.

Pectins are made of several structural elements the most important of which are the homogalacturonan (HG) and type I rhamnogalacturonan (RG-I) regions often described in simplified terms as the “smooth” and “hairy” regions respectively. Pectin HG regions consist of poly-glacturonic acid residues which can be partially methyl esterified. Pectins with a degree of methyl esterification (DM) > 50% are known as high methoxyl (HM) pectins and consequently low methoxyl (LM) pectins have a DM < 50%. Low methoxyl pectins are of particular interest in drug delivery as they can form gels with calcium ion (Ca^{2 +}) which has potential applications especially in nasal formulations.     

Interactions between apple (Malus x domestica Borkh.) polyphenols and cell walls modulate the extractability of polysaccharides

Apple polyphenol (procyanidin)–cell wall interactions were investigated and their impact on polysaccharide extractability were determined. Native and oxidised procyanidins with average degrees of polymerisation of 13 and 55 were incubated with cell walls. The effect of polyphenol oxidation was evaluated according to two designs: polyphenols were chemically oxidised either before or during interaction. The extent of procyanidin binding to cell walls was assessed by the weight increase of procyanidin–cell wall complexes as compared to weights of cell walls alone. Pectins and hemicelluloses were subsequently extracted from cell walls and from cell wall–procyanidin adducts using a chelating agent (ammonium oxalate), a pectin lyase treatment and NaOH.Weight increases of complexes ranged from 20% to 29%. Weight gains increased in the following order: native, pre-oxidised, simultaneously oxidised and bound procyanidins, these different fractions were, respectively, bound to cell walls. In presence of native procyanidins, oxalate extracted less pectins, and those pectins had lower degrees of methylation, as compared to cell walls alone. When cell walls were incubated with oxidised and oxidising procyanidins, even less pectins with lower degree of methylation were extracted. Major findings indicated that procyanidins mainly bound to pectins as compared to other cell wall compounds: (1) the procyanidin adsorption to cell walls limited the depolymerisation of pectins supposedly induced by pectin lyase. Thus less pectins were extracted but their degree of methylation increased, indicative of products of lysis of pectin lyase. (2) Hemicelluloses extracted using NaOH (4 M) were more abundant in pectins when oxidised or oxidising procyanidins were complexed rather than non complexed to cell walls.     

Immunocorrection with pentaglobin in wound infection and burn disease

Patients with wound infections and extended burns were treated with pentaglobin (Biotest-Pharma), a serum preparation containing high concentrations of immunoglobulin M. The use of the preparation at early stages after surgical operations in the patients with wound infections or at the beginning of active surgical treatment of the patients with burns decreased the terms of the body temperature normalization as well as normalization of the immunological, hematological and biochemical indices. The most pronounced efficacy of pentaglobin was observed in the patients with severe microbial toxemia. A scheme for pathogenetic immunocorrection of wound infections and burns was developed. It is based on simultaneous recording of intensity of immunological responses in peripheral blood and intensity of protective reactions in wound tissues.     

An array of possibilities for pectin

Pectins are a major component of plant cell walls and have numerous roles in plant growth and development. Extracted pectins are widely used as functional food ingredients in products including ice creams, jams, jellies and milk drinks. Although all are based on a galacturonan-rich backbone, pectins are an immensely diverse family of polysaccharides, the functional properties of which are dictated by their fine structures. Understanding the biological roles of pectins and optimizing their industrial usage requires a detailed knowledge of their diversity and spatial and temporal distributions, and microarray technology is a promising tool for high throughput pectin analysis. This article discusses the technical aspects of the production of pectin microarrays and explores their current and potential future uses in the context of recent work in the field.     

Degradation of different pectins by fungi: correlations and contrasts between the pectinolytic enzyme sets identified in genomes and the growth on pectins of different origin

ABSTRACT: BACKGROUND: Pectins are diverse and very complexe biomolecules and their structure depends on the plant species and tissue. It was previously shown that derivatives of pectic polymers and oligosaccharides from pectins have positive effects on human health. To obtain specific pectic oligosaccharides, highly defined enzymatic mixes are required. Filamentous fungi are specialized in plant cell wall degradation and some produce a broad range of pectinases. They may therefore shed light on the enzyme mixes needed for partial hydrolysis. RESULTS: The growth profiles of 12 fungi on four pectins and four structural elements of pectins show that the presence/absence of pectinolytic genes in the fungal genome clearly correlates with their ability to degrade pectins. However, this correlation is less clear when we zoom in to the pectic structural elements. CONCLUSIONS: This study highlights the complexity of the mechanisms involved in fungal degradation of complex carbon sources such as pectins. Mining genomes and comparative genomics are promising first steps towards the production of specific pectinolytic fractions.     

Reduced number of homogalacturonan domains in pectins of an Arabidopsis mutant enhances the flexibility of the polymer

Pectins are a family of highly complex multifunctional cell wall polysaccharides. Little is known on the relation between pectin structure, hydrodynamic properties, and cellular function. In this study, we took advantage of the Arabidopsis pectin mutant quasimodo2 (qua2), which specifically lacks half of its homogalacturonan blocks, to study the relationship between the amount of homogalacturonan blocks and the hydrodynamic properties of pectins. It was first shown that, in qua2 pectins, homogalacturonans had maintained the same size as those in the wild type. The persistence lengths of isolated homogalacturonan and rhamnogalacturonan-I blocks were then measured and it was shown that homogalacturonan was over 4-fold more rigid than rhamnogalacturonan-I. WT and qua2 pectins were next compared and it appeared that the specific reduction of the number of homogalacturonan blocks leads to an increased flexibility of qua2 pectins. These results show for the first time how mutant pectins can be used to demonstrate the opposite influence of rhamnogalacturonan-I and homogalacturonan blocks on the hydrodynamic properties of pectins.     

Biobrane versus 1% silver sulfadiazine in second-degree pediatric burns

Partial-thickness burns in children have been treated for many years by daily, painful tubbing, washing, and cleansing of the burn wound, followed by topical application of antimicrobial creams. Pain and impaired wound healing are the main problems. We hypothesized that the treatment of second-degree burns with Biobrane is superior to topical treatment. Twenty pediatric patients were prospectively randomized in two groups to compare the efficacy of Biobrane versus 1% silver sulfadiazine. The rest of the routine clinical protocols were followed in both groups. Demographic data, wound healing time, length of hospital stay, pain assessments and pain medication requirements, and infection were analyzed and compared. Main outcome measures included pain, pain medication requirements, wound healing time, length of hospital stay, and infection. The application of Biobrane to partial-thickness burns proved to be superior to the topical treatment. Patients included in the biosynthetic temporary cover group presented with less pain and required less pain medication. Length of hospital stay and wound healing time were also significantly shorter in the Biobrane group. None of the patients in either group presented with wound infection or needed skin autografting. In conclusion, the treatment of partial-thickness burns with Biobrane is superior to topical therapy with 1% silver sulfadiazine. Pain, pain medication requirements, wound healing time, and length of hospital stay are significantly reduced.     

Itraconazole (Orungal) in the treatment of mycotic infections in oncologic patients]

Clinical and microbiological activity of itraconazole (Orungal, solution for oral use, "Janssen-Cilag") for treatment of oncological patients with inhospital infections associated with candida was evaluated. The trial included 50 patients with oncological pathology of respiratory tract, as representatives of risk group for candida contamination. Two groups of patients were formed: when candida contamination was proved patients of the test group were treated by antifungal agent itraconazole (Orungal, "Janssen-Cilag"). Patients in control group were treated by fluconazole (Diflazon, "KRKA") according to standard therapy regime. When no clinical efficacy was achieved patients in both groups were treated by amphotericin B (Fungizone, "Bristol-Myers Squibb"). Clinical efficacy was demonstrated at 13 patients and microbiological efficacy (pathogen elimination) at 12 patient of 14 of itraconazole group. Clinical efficacy was demonstrated at 9 patients and microbiological efficacy at 7 of 11 patients of fluconazole group. Treatment with amphotericin B was effective at all 4 patients treated with this antibiotic, microbiological effect was demonstrated for 3 patients of the group. Frequency of side effects was significantly less in itraconazole group. The course price was also significantly lower at itraconazole group. All this data are important for elaboration of optimal pharmaco economic policy regarding inhospital infections at critical care units.     

Feruloylated pectic substances from sugar-beet pulp

Pectins have been isolated from an ethanol-insoluble residue of sugar-beet pulp by sequential extraction with water, oxalate, hot dilute acid, andcold dilute alkali in yields of 2.2, 0.53, 20, and 11%, respectively. They were purified by chromatography on DEAE-cellulose at pH 4.8,or by precipitation with copper sulphate (alkali-soluble pectin). The pectins had fairly low molecular weights, a high degree of acetylation, and relatively high contents of neutral sugars, but there were clear differences beteen the four fractions. The main neutral sugars in each pectin were arabinose and galactose, and rhamnose, fucose, xylose, mannose, and glucose were also present. The fractions were homogeneous in ion-exchange and gel-filtration chromatography. Polyphenols (1–2%) and possibly proteins (3–6%) were associated with the purified pectins. In addition, feruloyl groups (up to 0.6%) were linked mainly to the acid-soluble and alkali-soluble pectins.     

Evidence for in vitro binding of pectin side chains to cellulose

Pectins of varying structures were tested for their ability to interact with cellulose in comparison to the well-known adsorption of xyloglucan. Our results reveal that sugar beet (Beta vulgaris) and potato (Solanum tuberosum) pectins, which are rich in neutral sugar side chains, can bind in vitro to cellulose. The extent of binding varies with respect to the nature and structure of the side chains. Additionally, branched arabinans (Br-Arabinans) or debranched arabinans (Deb-Arabinans; isolated from sugar beet) and galactans (isolated from potato) were shown bind to cellulose microfibrils. The adsorption of Br-Arabinan and galactan was lower than that of Deb-Arabinan. The maximum adsorption affinity of Deb-Arabinan to cellulose was comparable to that of xyloglucan. The study of sugar beet and potato alkali-treated cell walls supports the hypothesis of pectin-cellulose interaction. Natural composites enriched in arabinans or galactans and cellulose were recovered. The binding of pectins to cellulose microfibrils may be of considerable significance in the modeling of primary cell walls of plants as well as in the process of cell wall assembly.     

Cellular localization and levels of pectins and arabinogalactan proteins in olive (Olea europaea L.) pistil tissues during development: implications for pollen–pistil interaction

Cell wall components in the pistil are involved in cell–cell recognition, nutrition and regulation of pollen tube growth. The aim of this work was to study the level, whole-organ distribution, and subcellular localization of pectins and arabinogalactan proteins (AGPs) in the olive developing pistil. Western blot analyses and immunolocalization with fluorescence and electron microscopy were carried out using a battery of antibodies recognizing different types of pectin epitopes (JIM7, JIM5, LM5, and LM6) and one anti-AGPs antibody (JIM13). In the olive pistil, highest levels of acid esterified and de-esterified pectins were observed at pollination. Moreover, pollination was accompanied by a slight decrease of the galactose-rich pectins pool, whereas arabinose-rich pectins were more abundant at that time. An increased expression of AGPs was also observed during pollination, in comparison to the pistil at the pre-anthesis stage. After pollination, the levels of pectins and AGPs declined significantly. Inmunofluorescence localization of pectins showed their different localization in the olive pistil. Pectins with galactose residues were located mainly in the cortical zones of the pistil, similar to the neutral pectins, which were found in the parenchyma and epidermis. In turn, the neutral pectins, which contain arabinose residues and AGPs, were localized predominantly in the stigmatic exudate, in the cell wall of secretory cells of the stigma, as well as in the transmitting tissue of the pistil during the pollination period. The differences in localization of pectins and AGPs are discussed in relation to their roles during olive pistil developmental course.     

Enzymic and chemical degradation and the fine structure of pectins from sugar-beet pulp

Pectins sequentially extracted from sugar-beet pulp with water (WSP), oxalate (OXP), hot acid (HP), and cold alkali (OHP) have been degraded variously by base-catalysed β-elimination, de-esterification, endopectin lyase, pectin methyl esterase, endopolygalacturonase, and endopectate lyase. The products were studied mainly by chromatography on Sephadex G-100. The pectins contain various amounts of degradation-resistant (hairy) fragments in which the molar ratios of neutral sugar residues to galacturonic acid residues were 4.8, 4.6, 3.8, and 3.7 for WSP, OXP, HP, and OHP, respectively. The molar ratios of rhamnose residues to galacturonic acid residues in these fragments were 0.15, 0.20, 0.38 and 0.35, respectively. The pectins also contained sequences of galacturonic acid residues with relatively little neutral sugar residues attached (smooth fragments). Methyl ester and acetyl groups were distributed fairly regularly along the smooth fragments. Evidence is presented for an association of oligogalacturonic acids with the hairy fragments under the conditions of gel chromatography. Feruloyl groups are located in the hairy fragments. Other phenolic compounds, associated with the purified pectins, appear not to be covalently linked.