Berit Smestad Paulsen

Interaction Between Human Complement and a Pectin Type Polysaccharide Fraction, PMII, from the Leaves of Plantago major L.

The interaction between a pectin type polysaccharide fraction, PMII, isolated from the leaves of Plantago major, and human complement was tested in two different hemolytic complement‐fixation tests and in addition by two elisa methods detecting complement‐activation products. Sera were used as a complement source of 10 arbitrary human volunteers, individually and as a pool. The complement‐fixation tests were designed to measure the concentration of the pectin necessary to inhibit 50% of the hemolysis (ICH50). The elisa tests for complement‐activation products were measured in AU/mg using a fully activated serum as a standard. We observed a more than 200‐fold difference in ICH50 activity of the PMII pectin in one of the hemolytic tests by varying the individual sera used as complement‐source. On the other hand, the elisa complement‐activation tests showed no significant variation in activity of the PMII depending on the complement‐serum used. The level of antibodies against PMII detected in the complement‐sera did not correlate with the ICH50 activity of PMII. The results show that PMII is a potent complement activator with an activity of the same order of magnitude on a weight basis as that of aggregated human immunoglobulin (Ig)G. This activation leads to a complement consumption probably explaining the PMIIs effect in the complement‐fixation tests. PMII seems to be an activator both on the classical and the alternative pathway of activation. The results might be related to the reported wound‐healing effect of the leaves of Plantago major.

Extracellular carbohydrate polymers from five desert soil algae with different cohesion in the stabilization of fine sand grain

Extracellular polymeric substances (EPS) from four filamentous cyanobacteria Microcoleus vaginatus, Scytonema javanicum, Phormidium tenue and Nostoc sp. and a coccoid single-cell green alga Desmococcus olivaceus that had been separated from desert algal crusts of Tegger desert of China, were investigated for their chemical composition, structure and physical properties. The EPS contained 7.5‐ 50.3% protein (in polymers ranging from 14 to more than 200 kD, SDS-PAGE) and 16.2‐ 40.5% carbohydrate (110 ‐ 460 kD, GFC). 6 ‐ 12 kinds of monosaccharides, including 2-O-methyl rhamnose, 2-O-methyl glucose, and N-acetyl glucosamine were found. The main carbohydrate chains from M. vaginatus and S. javanicum consisted mainly of equal proportion of Man, Gal and Glc, that from P. tenue consisted mainly of arabinose, glucose and rhamnose. Arabinose was present in pyranose form, mainly a-L 1 ! 3 linked, with branches on C4 of almost half of the units. Glucose was responsible for the terminal units, in addition of having some units as b1 ! 3 and some asb1 ! 4 linked. Rhamnose was mainly 1 ! 3 linked with branches on C2 on half of the units. The carbohydrate polymer from D. olivaceus was composed mainly of b-1 ! 4 linked xylose, galactose and glucose. The galactose part was present both in b-pyranose and -furanose forms. Arabinose in a-L-furanose form was mainly present as 1 ! 2 and 1 ! 2, 5 linked units, rhamnose only as a 1 ! 3 and xylose as b 1 ! 4. The backbone of the polysaccharide from Nostoc sp. was composed of b-1 ! 4 linked xylose, galactose and glucose. Most of the glucose was branched on position C6, terminal glucose and 2-O-methyl glucose units are also present. The relationship between structure, physical properties and potential biological function is discussed. q 2003 Elsevier Ltd. All rights reserved.

Characterization of a biologically active pectin from Plantago major L.

Abstract PMII isolated from the leaves of Plantago major L. is a pectin type polysaccharide with anti-complementary activity. It is highly esterified and partly O-acetylated with regions of 1,4 linked polygalacturonic acid and at least two different hairy regions. The galactose side chains are linked to position 4 of rhamnose in the main chain. The structure of the galactan side chains is complex, but 1,3,6 linkages are dominating in one of the isolated hairy regions. Arabinose is attached to position 3 and 6 of galactose. In the other hairy region arabinose is attached to position 3 of galacturonic acid. De-esterification and de-acetylation do not alter the anti-complementary activity of PMII. Different parts of PMII were shown to have different activities. The smooth regions are only slightly active in contrast to the hairy regions which had significantly higher activity. The hairy regions of highest molecular weight (PVa) with 1,3,6 linked galactose side chains were found to be the most active fraction. The importance of arabinose for the activity seems to depend on the site of substitution. Removal of arabinose terminally linked to galactose increases the activity slightly while removal of arabinose linked to the galacturonic acid backbone decreases the activity.

Studies on polysaccharides from three edible species of Nostoc (Cyanobacteria) with different colony morphologies: Comparison of monosaccharide compositions and viscosities of polysaccharides from field colonies and suspension cultures

Hot water‐soluble polysaccharides were extracted from field colonies and suspension cultures of Nostoc commune Vaucher, Nostoc flagelliforme Berkeley et Curtis, and Nostoc sphaeroides Kützing. Excreted extracellular polymeric substances (EPS) were isolated from the media in which the suspension cultures were grown. The main monosaccharides of the field colony polysaccharides from the three species were glucose, xylose, and galactose, with an approximate ratio of 2:1:1. Mannose was also present, but the levels varied among the species, and arabinose appeared only in N. flagelliforme. The compositions of the cellular polysaccharides and EPS from suspension cultures were more complicated than those of the field samples and varied among the different species. The polysaccharides from the cultures of N. flagelliforme had a relatively simple composition consisting of mannose, galactose, glucose, and glucuronic acid, but no xylose, as was found in the field colony polysaccharides. The polysaccharides from cultures of N. sphaeroides contained glucose (the major component), rhamnose, fucose, xylose, mannose, and galactose. These same sugars were present in the polysaccharides from cultures of N. commune, with xylose as the major component. Combined nitrogen in the media had no qualitative influence on the compositions of the cellular polysaccharides but affected those of the EPS of N. commune and N. flagelliforme. The EPS of N. sphaeroides had a very low total carbohydrate content and thus was not considered to be polysaccharide in nature. The field colony polysaccharides could be separated by anion exchange chromatography into neutral and acidic fractions having similar sugar compositions. Preliminary linkage analysis showed that 1) xylose, glucose, and galactose were 1→4 linked, 2) mannose, galactose, and xylose occurred as terminal residues, and 3) branch points occurred in glucose as 1→3,4 and 1→3,6 linkages and in xylose as a 1→3,4 linkage. The polymer preparations from field colonies had higher kinematic viscosities than those from correspondingsuspension cultures. The high viscosities of the polymers suggested that they might be suitable for industrial uses.

Ethnopharmacological survey of different uses of seven medicinal plants from Mali, (West Africa) in the regions Doila, Kolokani and Siby.

An ethnopharmacological survey was carried out to collect information on the use of seven medicinal plants in rural areas in the nearby regions of Bamako, Mali. The plants were Opilia celtidifolia, Anthocleista djalonensis, Erythrina senegalensis, Heliotropium indicum, Trichilia emetica, Piliostigma thonningii and Cochlospermum tinctoriumAbout 50 medical indications were reported for the use of these plants in traditional medicine. The most frequent ailments reported were malaria, abdominal pain and dermatitis. The highest number of usages was reported for the treatment of malaria (22%). The majority of the remedies were prepared from freshly collected plant material from the wild and from a single species only. They were mainly taken orally, but some applications were prepared with a mixture of plants or ingredients such as honey, sugar, salt, ginger and pepper. Decoction of the leaves was the main form of preparation (65%) and leaf powder was mostly used for the preparation of infusions (13%). The part of the plants most frequently used was the leaves. There was a high degree of informant consensus for the species and their medicinal indications between the healers interviewed.The results of this study showed that people are still dependent on medicinal plants in these rural areas of Mali.

Biologically active polysaccharides as possible lead compounds

Various carbohydrate polymers have during the last decades been shown to be responsible for biological effects, either by exhibiting the effect themselves or by inducing effects via complex reaction cascades. These are e.g. anti-inflammatory, immunostimulating, complement activation, antithrombotic, antidiabetic and infection protectant. Modern pharmaceutical industry has extensive research programs where the aim is to obtain information on traditional use of medicinal plants still being in use, and perform screening of these for the claimed biological activity and follow the isolation of chemical compounds with the relevant activity tests, but few of the programs focus on polysaccharides. Various plants have been used for treating wounds of different types, both internally and externally and bioassay guided isolation of active compounds in these plants showed that in many cases, polysaccharides were responsible for the biological activity. Many of these polysaccharide fractions have been shown to activate complement. The active compounds studied are often of the pectic type, but acetylated glucomannans and glucans are also among those having the same kind of effect and certain structure/activity relationships of these polysaccharides is discussed.Various carbohydrate polymers have during the last decades been shown to be responsible for biological effects, either by exhibiting the effect themselves or by inducing effects via complex reaction cascades. These are e.g. anti-inflammatory, immunostimulating, complement activation, antithrombotic, antidiabetic and infection protectant. Modern pharmaceutical industry has extensive research programs where the aim is to obtain information on traditional use of medicinal plants still being in use, and perform screening of these for the claimed biological activity and follow the isolation of chemical compounds with the relevant activity tests, but few of the programs focus on polysaccharides. Various plants have been used for treating wounds of different types, both internally and externally and bioassay guided isolation of active compounds in these plants showed that in many cases, polysaccharides were responsible for the biological activity. Many of these polysaccharide fractions have been shown to activate complement. The active compounds studied are often of the pectic type, but acetylated glucomannans and glucans are also among those having the same kind of effect and certain structure/activity relationships of these polysaccharides is discussed.

Wound Healing Plants in Mali, the Bamako Region. An Ethnobotanical Survey and Complement Fixation of Water Extracts from Selected Plants

Identification of 123 species, belonging to 50 families, used for wound healing in the Bamako region of Mali, was performed in this study. The fifteen species that were most frequently cited by the traditional healers were subjected to chemical and biological studies. Water extracts were subjected to screening for effects on the human complement system in vitro. The monosaccharide composition and the total carbohydrate content of the extracts were also determined. All extracts showed effects on the complement system, but extracts from Biophytum petersianum Klotzsch., Pterocarpus erinaceus Poir, Podaxon aegyptiacus Mont., Stereospermum kunthianum Cham., and Ximenia americana L. had the highest activity. The content of carbohydrate in the extracts varied between 5% and 80% and most of them contained substantial amounts of the monosaccharides arabinose, rhamnose, galactose, glucose and galacturonic acid.

Polysaccharides from the roots of Entada africana Guill. et Perr., Mimosaceae, with complement fixing activity

Entada africana is a tree used in traditional medicine in Mali. The root is, for example, used for wound-healing. Since polysaccharides from other plants are thought to play a role in the wound-healing process, we wanted to study the polysaccharides present in the root of this species. The polysaccharides were extracted with water at 50 and 100 degrees C and were further separated by anion exchange chromatography. The acidic fractions were finally purified by affinity chromatography on a Con A column. The fraction denoted Ea100 acidic I had the highest activity in the complement fixation test system, while the other acidic fractions had minor activities and the neutral fractions were almost negative. Ea100 acidic I has a structure resembling the arabinogalactan-protein type II polymer, which also was demonstrated by the abilities to precipitate with the Yariv reagent. The biological activity was reduced considerably after removal of arabinofuranoside residues by weak acid hydrolysis. The main core of the other polysaccharides extracted with 100 degrees C were pectins resembling the rhamnogalacturonan type I. These fractions also contain arabinogalactan type II structures, shown by the formation of precipitates with the Yariv reagent.

RELATIVE INCREASE OF DEOXY SUGARS DURING MICROBIAL DEGRADATION OF AN EXTRACELLULAR POLYSACCHARIDE RELEASED BY A TROPICAL FRESHWATER THALASSIOSIRA SP. (BACILLARIOPHYCEAE)1

The aim of this study was to characterize the extracellular polysaccharides (EPS) released by a freshwater Thalassiosira sp. (Bacillariophyceae) and evaluate their degradation by heterotrophic microbial populations from the same habitat of Thalassiosira sp., a tropical eutrophic reservoir. The EPS were purified by anion exchange column chromatography, the monosaccharide composition was determined by GC, and the linkages of the monosaccharides by GC‐MS. The EPS is a mannose‐rich heteropolysaccharide composed of two different acidic fractions. Both of these fractions are composed of mannose, rhamnose, fucose, xylose, galactose, glucose, glucuronic acid, and N‐acetyl glucosamine but with different proportions. N‐acetyl galactosamine occurs only in fraction 1 and galacturonic acid only in fraction 2. We monitored the concentrations of the monosaccharides in the EPS during its degradation using pulse amperometric detection in an HPLC. The decay patterns of the monosaccharides were varied and the deoxy sugars, fucose and rhamnose, were degraded at a slower rate than the other components, increasing their relative concentrations and the hydrophobic feature of the EPS. The possibility of a selective degradation, which enhances the stickiness of the EPS, promoting transparent exopolymeric particles and aggregate formation, is discussed based on the literature data.

The malian medicinal plant Trichilia emetica; studies on polysaccharides with complement fixing ability

Trichilia emetica is a tree or bush that has many different traditional uses in Mali, amongst others the leaves have been used as a woundhealing remedy. As polysaccharides have been isolated from other plants that have a long tradition as woundhealing remedies, it was of interest to study the polysaccharides of T. emetica as well. The polysaccharides were extracted at 50 and 100 degrees C, and the polymeric material was separated into neutral and acidic polymers by anion exchange chromatography. The complement fixation ability of the different fractions was determined. The Acidic fraction 4 of the 100 degrees C extract was the most active, but most of the other fractions were also quite active. Structural studies showed that the most active fraction was a pectin of the rhamnogalacturonan type 1 with side chains of the arabinogalactan type II. Removal of terminal arabinofuranosides lead to a drop of the activity indicating that this structural unit may be involved in the bioactive site of the molecule.