Peter Capek

Scavenging and antioxidant activities of immunomodulating polysaccharides isolated from Salvia officinalis L.

Crude polysaccharides, isolated from the aerial parts of sage (Salvia officinalis L.) by sequential extraction with water (A), hot ammonium oxalate (B), dimethyl sulfoxide (C), 1M (D) and 4M (E) potassium hydroxide solutions, and six ion-exchange fractions of A were examined for their ability to inhibit peroxidation of liposome lipid by hydroxyl radicals and to reduced DPPH radical content. The highest inhibition of liposome lipid peroxidation was found with crude polysaccharides A, B and D, antioxidant activities reached approximately 37%. The purified fractions A1 and A2 inhibited the liposome peroxidation to approximately 35%. However, the radical scavenging abilities of the most active crude polysaccharides A, B and C on DPPH radicals were found in the range 80-90%, while the most active purified fractions A3-A6 in three or fourfold doses achieved 75-92%. The least effective tested polysaccharides succeeded 20% inhibition using both methods.

Antitussive activity of polysaccharides isolated from the Malian medicinal plants.

From the leaves of popular Malian medicinal plants Trichilia emetica (TE) and Opilia celtidifolia (OC), and fruits of Crossopteryx febrifuga (CF) water and water-ethanol soluble polysaccharide materials were isolated. The results of chemical analysis of the crude polysaccharides showed the dominance of the arabinogalactan ( approximately 54%) and the rhamnogalacturonan ( approximately 30%) in T. emetica leaves, the arabinogalactan ( approximately 60%), the rhamnogalacturonan ( approximately 14%) and the glucuronoxylan ( approximately 14%) in O. celtidifolia leaves, and pectic type of polysaccharides ( approximately 75%) with a lower content of the arabinogalactan ( approximately 17%) in C. febrifuga fruits. The plant polysaccharides showed various biological effects on the citric acid-induced cough reflex and reactivity of airways smooth muscle in vivo conditions. T. emetica and O. celtidifolia polysaccharides possessed significant cough-suppressive effect on chemically induced cough. Furthermore, values of specific airways resistance pointed on bronchodilatory property of polysaccharides isolated from O. celtidifolia. However, the crude extract from C. febrifuga in the same dose as T. emetica and O. celtidifolia did not influence the experimentally induced cough as well as reactivity of airways smooth muscle despite of the fact that the water-ethanol extract is recommended for cough therapy in Mali in the form of syrup.

Polysaccharides from the roots of the marsh mallow (Althaea officinalis L., var. Rhobusta): structural features of an acidic polysaccharide

Abstract An acidic heteropolysaccharide isolated from the mucilage of the roots of the marsh mallow (Althaea officinalis L., var. Rhobusta) via its insoluble barium salt contained d -galactose, l -rhamnose, d -glucuronic acid, and d -galacturonic acid in the molar ratios 1.2:1.0:1.0:1.0. It was homogenous on free-boundary electrophoresis and in the anlytical ultracentrifuge, and it had M w = 26,700, M n = 23,900. Partial acid hydrolysis and analyses of the methylated and the methylated, carboxyl-reduced polysaccharide indicated that the polymer backbone is composed of (1→4)-linked d -galactopyranuronic acid and (1→2)-linked l -rhamnopyranose units in the ratio of 1:1. Each d -galacturonic unit carries a single β- d -glucopyranuronic residue linked to C-3, and each l -rhamnopyranose unit carries d -galactopyranose residues, mainly as non-reducing terminals linked to C-4. A smal number of presumably short chains of (1→4)-linked d -galactopyranose units are also involved in branching.

Possible mechanisms of dose-dependent cough suppressive effect of Althaea officinalis rhamnogalacturonan in guinea pigs test system.

The rhamnogalacturonan, isolated from the roots of medicinal plant Althaea officinalis L., showed various biological effects on the citric acid-induced cough reflex and reactivity of airways smooth muscle in vitro and in vivo conditions. It possessed dose-dependent cough suppression effect comparable with opioid agonist codeine. However, reactivity of the airways smooth muscle, measured in vitro as well as in vivo conditions was not significantly affected by rhamnogalacturonan and thus bronchodilatory activity did not participate in the cough suppression effect of polysaccharide tested. Moreover, the cough suppression effect of the polymer was not significantly modified by pretreatment of K(+)(ATP) ion channels with selective antagonist and therefore activation of this type of ion channels is not involved in the mechanism of rhamnogalacturonan cough suppressive ability. On the contrary, pretreatment of animals with selective 5-HT(2) receptors antagonist significantly decreased rhamnogalacturonan antitussive efficacy. From this point of view it seems that the cough suppression effect of the polymer is associated with the serotonergic 5-HT(2) receptors function.

Antitussive and immunomodulating activities of instant coffee arabinogalactan-protein

A low molecular mass arabinogalactan-protein (AGP) composed of galactose and arabinose with a low protein content, isolated from the instant coffee powder of Coffea arabica beans, has been tested on antitussive (in vivo) and immunomodulating (ex vivo) activities. The results of antitussive tests revealed a significant dose dependant cough-suppressive effect of coffee AGP. It was observed 30 or 60 min after AGP administration and its efficacy lasted during the entire experiment course. Immunological tests showed that AGP affected some mediators of immunocompetent cells of immune system as TNF-α, IFN-γ and IL-2 cytokines. It seems that coffee AGP is a good inductor of both pro-inflammatory cytokines TNF-α and IFN-γ, however, less potent in TNF-α induction in comparison with that of β-D-glucan. Evident induction of TNF-α, IL-2 and IFN-γ cytokines, pro-TH1 polarization supports our conclusion about bio-immunological efficacy of AGP with an emphasis on the cellular immunity.

Structure of arabinogalactan oligosaccharides derived from arabinogalactan-protein of Coffea arabica instant coffee powder

Arabinogalactan-protein, previously isolated from instant coffee powder of Coffea arabica, has been subjected to partial mild acidic and enzymatic hydrolyses. Separation of obtained mixtures by size exclusion and HPLC chromatographies afforded series of oligosaccharides, structure of which were studied by NMR spectroscopy. Mild acidic hydrolysis afforded oligosaccharides without any αAraf substituent while after enzymatic hydrolysis αAraf was found in di-, tri-, and tetrasaccharides. In all cases αAraf was a terminal substituent linked separately to O3, O6, and to both, O3 and O6, of βGal residues. Identification of di-, tri-, and tetrasaccharides containing α-Araf enabled to distinguish in the (1)H NMR spectra αAraf signals linked to O6 and O3 of neighboring βGal unit. Composition of polymeric residues after enzymatic and mild acidic hydrolyses was also analyzed.

NMR structural study of fructans produced by Bacillus sp. 3B6, bacterium isolated in cloud water

Bacillus sp. 3B6, bacterium isolated from cloud water, was incubated on sucrose for exopolysaccharide production. Dialysis of the obtained mixture (MWCO 500) afforded dialyzate (DIM) and retentate (RIM). Both were separated by size exclusion chromatography. RIM afforded eight fractions: levan exopolysaccharide (EPS), fructooligosaccharides (FOSs) of levan and inulin types with different degrees of polymerization (dp 2-7) and monosaccharides fructose:glucose=9:1. Levan was composed of two components with molecular mass ~3500 and ~100kDa in the ratio 2.3:1. Disaccharide fraction contained difructose anhydride DFA IV. 1-Kestose, 6-kestose, and neokestose were identified as trisaccharides in the ratio 2:1:3. Fractions with dp 4-7 were mixtures of FOSs of levan (2,6-βFruf) and inulin (1,2-βFruf) type. DIM separation afforded two dominant fractions: monosaccharides with fructose: glucose ratio 1:3; disaccharide fraction contained sucrose only. DIM trisaccharide fraction contained 1-kestose, 6-kestose, and neokestose in the ratio1.5:1:2, penta and hexasaccharide fractions contained FOSs of levan type (2,6-βFruf) containing α-glucose. In the pentasaccharide fraction also the presence of a homopentasaccharide composed of 2,6-linked βFruf units only was identified. Nystose, inulin (1,2-βFruf) type, was identified as DIM tetrasaccharide. Identification of levan 2,6-βFruf and inulin 1,2-βFruf type oligosaccharides in the incubation medium suggests both levansucrase and inulosucrase enzymes activity in Bacillus sp. 3B6.

Effects of extraction condition on structural features and anticoagulant activity of F. vesca L. conjugates.

From the air-dried Wild strawberry (Fragaria vesca L., family Rosaceae) leaves five water-soluble glycoconjugates Fv I-V by different extraction conditions have been isolated. Effects of extraction steps/agents on chemical composition and anticoagulant activity of Fv I-V were examined. Dark brown F. vesca conjugates Fv I-V were recovered in 4.5-8.4% yields, based on dry herb. Isolates were composed of carbohydrate, phenolic and protein components. Fv I-V displayed on HPLC broad molecule-mass distribution patterns with dominance of low molecule-masses 9-14 kDa. Their carbohydrate parts revealed high hexuronic acids content (35-60%) while the dominant neutral sugars - galactose, arabinose and rhamnose were found in lower amounts and indicated the presence of rhamnogalacturonans associated with arabinogalactans in all F. vesca preparations. In all Fv I-V isolates high polyphenolic contents were determined, whereas proteins were found in low amounts only. In in vitro experiments on human pooled plasma Fv I-V showed at higher concentrations complete inhibition of plasma clot formation and the most active conjugates in aPTT, PT and TT tests were shown to be Fv I and Fv III, containing the highest amounts of phenolics.

Structural analysis and anti-obesity effect of a pectic polysaccharide isolated from Korean mulberry fruit Oddi (Morus alba L.)

A water-soluble polysaccharide JS-MP-1 was isolated from Korean mulberry fruits Oddi (Morus alba L.). Sugar linkage analysis and NMR data confirmed that it is a rhamnogalacturonan type I (RG I) polymer carrying arabinan and arabinogalactan (AG II) side chains. JS-MP-1 reduced dose-dependently the viability of 3T3-L1 pre-adipocyte cells, significantly stimulated the cleavage of caspases 9 and 3 and poly (ADP-ribose) polymerase (PARP) and decreased the ratio of Bcl-2 to Bax expression level that led to mitochondrial dysfunction and apoptosis in pre-adipocyte cells. The apoptotic death was mediated by stimulation of MAPKs (ERK and p38) signalling pathway. These results suggest that JS-MP-1 is able to reduce the number of fat cells and the mass of adipose tissue via inhibition of pre-adipocyte proliferation and thus JS-MP-1 itself or a crude aqueous Oddi extract containing this polysaccharide can be used as functional ingredient of health-beneficial food supplements for the treatment or prevention of obesity disorders.

Structural features and in vivo antitussive activity of the water extracted polymer from Glycyrrhiza glabra

Antitussive drugs are amongst the most widely used medications worldwide; however no new class of drugs has been introduced into the market for many years. Herein, we have analyzed the water-extracted polymeric fraction (WE) of Glycyrrhiza glabra. This arabinogalactan protein enriched fraction, ≥ 85% of which gets precipitated with Yariv reagent, consisted mainly of 3- and 3,6-linked galactopyranosyl, and 5- and 3,5-linked arabinofuranosyl residues. Peroral administration of this polymer in a dose of 50mg/kg body weight decreases the number of citric acid induced cough efforts in guinea pigs more effectively than codeine. It does not induce significant change in the values of specific airway resistance or provoked any observable adverse effects.