Enhanced Glucose Uptake in Human Liver Cells and Inhibition of Carbohydrate Hydrolyzing Enzymes by Nordic Berry Extracts.

A Western lifestyle with low physical activity and a diet rich in sugar, fat and processed food contribute to higher incidences of diabetes and obesity. Enhanced glucose uptake in human liver cells was observed after treatment with phenolic extracts from different Nordic berries. All berry extracts showed higher inhibition against α-amylase and α-glucosidase than the anti-diabetic agent acarbose. Total phenolic content and phenolic profiles in addition to antioxidant activities, were also investigated. The berries were extracted with 80% methanol on an accelerated solvent extraction system (ASE) and then purified by C-18 solid phase extraction (SPE). Among the ASE methanol extracts, black chokeberry, crowberry and elderberry extracts showed high stimulation of glucose uptake in HepG2 cells and also considerable inhibitory effect towards carbohydrate hydrolyzing enzymes. SPE extracts with higher concentrations of phenolics, resulted in increased glucose uptake and enhanced inhibition of α-amylase and α-glucosidase compared to the ASE extracts. Crowberry and cloudberry were the most potent 15-lipoxygenase inhibitors, while bog whortleberry and lingonberry were the most active xanthine oxidase inhibitors. These results increase the value of these berries as a component of a healthy Nordic diet and have a potential benefit against diabetes.

Tilia tomentosa pectins exhibit dual mode of action on phagocytes as ß-glucuronic acid monomers are abundant in their rhamnogalacturonans I.

Silver linden flowers contain different pectins (PSI-PSIII) with immunomodulating properties. PSI is a low-esterified pectic polysaccharide with predominant homogalacturonan region, followed by rhamnogalacturonan I (RGI) with arabinogalactan II and RGII (traces) domains. PSII and PSIII are unusual glucuronidated RGI polymers. PSIII is a unique high molecular weight RGI, having almost completely O-3 glucuronidated GalA units with >30% O-3 acetylation at the Rha units. Linden pectins induced reactive oxygen species (ROS) and NO generation from non-stimulated whole blood phagocytes and macrophages, resp., but suppressed OZP-(opsonized zymosan particles)-activated ROS generation, LPS-induced iNOS expression and NO production. This dual mode of action suggests their anti-inflammatory activity, which is known for silver linden extracts. PSI expressed the highest complement fixation and macrophage-stimulating activities and was active on intestinal Peyer's patch cells. PSIII was active on non-stimulated neutrophils, as it induced ß2-integrin expression, revealing that acetylated and highly glucuronidated RGI exhibits immunomodulating properties via phagocytes.

The common lavender (Lavandula angustifolia Mill.) pectic polysaccharides modulate phagocytic leukocytes and intestinal Peyer's patch cells.

Two pectic (chPS-L1, chPS-L2) and one polyphenolic (chPP-L) fractions were obtained from lavender flowers after boiling water extraction, exhaustive removing of alcohol-soluble molecules and SEC. chPS-L1 (52.4kDa) contains mainly low-acetylated and high-methoxylated homogalacturonans (HG), and smaller rhamnogalacturonan (RG) I backbone fragments rich in 1,3,5-branched arabinan and arabinogalactan (AG) II side chains. chPS-L2 (21.8kDa) contains predominantly similarly esterified HG, followed by RGI with AGII structures and RGII. The prevalence of catechin and epicatechin in chPP-L indicates that they form weak interactions with pectins. chPS-L1 and chPS-L2 enhanced ß2-integrin expression on neutrophils, inducing ROS generation and macrophage NO production. Both the effects on ß2-integrin and high complement fixation activity of chPS-L1 were proposed for its inhibitory action against PMA- and OZP-activated ROS formation. This, together with suppression of NO generation after co-stimulation with chPS-L1 and LPS, suggested anti-inflammatory activity of studied pectins. Lavender polysaccharides expressed intestinal Peyer's patch immunomodulating activity.

Acidic polysaccharide complexes from purslane, silver linden and lavender stimulate Peyer's patch immune cells through innate and adaptive mechanisms.

Three polysaccharide complexes (PSCs) were isolated from the aerial parts of common purslane (Portulaca oleracea L.), and the flowers of common lavender (Lavandula angustifolia Mill.) and silver linden (Tilia tomentosa Moench) by boiling water extraction and ethanol precipitation. The chemical composition and immunomodulating effects of isolated PSCs were characterized. The chemical characterization revealed that the three samples contain mainly pectic polysaccharides. They exhibited ex vivo intestinal immunomodulating activity through the murine Peyer's patch-mediated bone marrow cell proliferation test at 100µg/ml concentration. At the same time, they stimulated ex vivo human blood T-cell populations (CD4+/CD25+ and CD8+/CD25+), phagocytic leukocytes (CD14+ and CD64+ cells) and induced IL-6 production from human white blood cells and Peyer's patch cells. The herbal PSCs stimulated ex vivo ROS production from whole blood phagocytes and showed unspecific in vitro anti-proliferative activity against normal and A549, HeLa and LS180 tumor cells. This is the first report on immunomodulating studies of linden flower pectins and chemical and biological activity characterization of lavender polysaccharides. Our study demonstrates that similarly to purslane, lavender and silver linden herbal materials contain immunomodulating polysaccharides that could be useful for support of compromised immune system.

Elderberry and Elderflower Extracts, Phenolic Compounds, and Metabolites and Their Effect on Complement, RAW 264.7 Macrophages and Dendritic Cells.

Modulation of complement activity and inhibition of nitric oxide (NO) production by macrophages and dendritic cells may have therapeutic value in inflammatory diseases. Elderberry and elderflower extracts, constituents, and metabolites were investigated for their effects on the complement system, and on NO production in lipopolysaccharide (LPS)-activated RAW 264.7 macrophages and murine dendritic D2SC/I cells. The EtOH crude extracts from elderberry and elderflower and the isolated anthocyanins and procyanidins possessed strong complement fixating activity and strong inhibitory activity on NO production in RAW cells and dendritic cells. Phenolic compounds in the range of 0.1-100 µM showed a dose-dependent inhibition of NO production, with quercetin, rutin, and kaempferol as the most potent ones. Among the metabolites, caffeic acid and 3,4-dihydroxyphenylacetic acid showed the strongest inhibitory effects on NO production in both cell lines, without having cytotoxic effect. Only 4-methylcatechol was cytotoxic at the highest tested concentration (100 µM). Elderberry and elderflower constituents may possess inflammatory modulating activity, which increases their nutritional value.

Phenolic Elderberry Extracts, Anthocyanins, Procyanidins, and Metabolites Influence Glucose and Fatty Acid Uptake in Human Skeletal Muscle Cells.

Uptake of glucose and fatty acids in skeletal muscle is of interest for type 2 diabetes treatment. The aim was to study glucose and fatty acid uptake in skeletal muscle cells, antioxidant effects, and inhibition of carbohydrate-hydrolyzing enzymes by elderberries. Enhanced glucose and oleic acid uptake in human skeletal muscle cells were observed after treatment with phenolic elderberry extracts, anthocyanins, procyanidins, and their metabolites. The 96% EtOH and the acidified MeOH extracts were highly active. Of the isolated substances, cyanidin-3-glucoside and cyanidin-3-sambubioside showed highest stimulation of uptake. Phloroglucinol aldehyde was most active among the metabolites. Isolated anthocyanins and procyanidins are strong radical scavengers and are good inhibitors of 15-lipoxygenase and moderate inhibitors of xanthine oxidase. As α-amylase and α-glucosidase inhibitors, they are considerably better than the positive control acarbose. The antidiabetic property of elderberry phenolics increases the nutritional value of this plant and indicates potential as functional food against diabetes.

Effect of Phenolic Compounds from Elderflowers on Glucose- and Fatty Acid Uptake in Human Myotubes and HepG2-Cells.

Type 2 diabetes (T2D) is manifested by progressive metabolic impairments in tissues such as skeletal muscle and liver, and these tissues become less responsive to insulin, leading to hyperglycemia. In the present study, stimulation of glucose and oleic acid uptake by elderflower extracts, constituents and metabolites were tested in vitro using the HepG2 hepatocellular liver carcinoma cell line and human skeletal muscle cells. Among the crude extracts, the 96% EtOH extract showed the highest increase in glucose and oleic acid uptake in human skeletal muscle cells and HepG2-cells. The flavonoids and phenolic acids contained therein were potent stimulators of glucose and fatty acid uptake in a dose-dependent manner. Most of the phenolic constituents and several of the metabolites showed high antioxidant activity and showed considerably higher α-amylase and α-glucosidase inhibition than acarbose. Elderflower might therefore be valuable as a functional food against diabetes.

RG-I regions from elderflower pectins substituted on GalA are strong immunomodulators.

Sambuci flos, also known as elderflower, has traditionally been used and is still in use for treatment of various types of illnesses related to the immune system such as cold, flu, fever and inflammation. Pectic polysaccharides from 50% EtOH, 50°C water and 100°C water extracts from elderflowers were treated with endo-α-d-(1-4)-polygalacturonase after previous de-esterification with the intention of isolating hairy regions and relate variation in structure to immunomodulating activity. High molecular weight sub-fractions (25-29kDa) and medium molecular weight sub-fractions (6-17kDa) were isolated after enzymatic treatment in addition to oligogalacturonides. Structural elucidation indicated that RG-I regions with AG-I and AG-II sidechains were the predominant structures in the high molecular weight sub-fractions, and two of three 1,4-linked GalA units in the rhamnogalacturonan backbone were branched in either position 2 or 3. The medium molecular weight sub-fractions had monomers and linkages typical for both RG-I and RG-II. The results showed that the high molecular RG-I containing polymers exhibit the highest dose-dependent complement fixing and macrophage stimulating activities.

Structural characterization of bioactive pectic polysaccharides from elderflowers (Sambuci flos).

Elderflowers have traditionally been used and are still used for its anti-inflammatory property. Traditionally elderflowers were used as remedies against cold, flu and diuretic. The aim of this study was to relate the structure of pectic-polysaccharides from elderflowers to immunomodulating properties. Purified fractions obtained by gelfiltration and ion exchange chromatography of 50% ethanol, 50°C water and 100°C water extracts exhibited strong complement fixating activity and macrophage stimulating activity. Reduced bioactivity was observed after removal of arabinose and 1,3,6-Gal linkages by weak acid hydrolysis. Enhanced bioactivity was observed after removal of estergroups by NaOH. Relating linkage analysis to the results of the bioactivity tests, led to the assumption that the branched moieties of the arabinogalactans linked to rhamnogalacturonan region, is important for the immunomodulating activity seen in elderflowers. No cytotoxity was observed.

Structure-activity relationship of immunomodulating pectins from elderberries.

The berries of Sambucus nigra have traditionally been used and are still used to treat respiratory illnesses such as cold and flu in Europe, Asia and America. The aim of this paper was to elucidate the structures and the immunomodulating properties of the pectic polymers from elderberries. All the purified fractions obtained from 50% ethanol, 50°C water and 100°C water extracts showed potent dose-dependent complement fixating activity and macrophage stimulating activity. The isolated fractions consisted of long homogalacturonan regions, in addition to arabinogalactan-I and arabinogalactan-II probably linked to a rhamnogalacturonan backbone. Reduced bioactivity was observed after reduction of Araf residues and 1→3,6 Gal by weak acid hydrolysis. The rhamnogalacturonan region in SnBe50-I-S3-I and SnBe50-I-S3-II showed higher activity compared to the native polymer, SnBe50-S3, after enzymatic treatment with endo-α-d-(1→4)-polygalacturonase. These results indicated that elderberries contained immunomodulating polysaccharides, where the ramified regions express the activities observed.

Immunomodulating pectins from root bark, stem bark, and leaves of the Malian medicinal tree Terminalia macroptera, structure activity relations.

The root bark, stem bark, and leaves of Terminalia macroptera were sequentially extracted with ethanol, 50% ethanol-water, and 50°C water using an accelerated solvent extractor (ASE). Six bioactive purified pectic polysaccharide fractions were obtained from the 50°C crude water extracts after anion exchange chromatography and gel filtration. The root bark, stem bark, and leaves of T. macroptera were all good sources for fractions containing bioactive polysaccharides. The high molecular weight fraction 50WTRBH-I-I, being the most active fraction in the complement fixation test, has a highly ramified rhamnogalacturonan type I (RG-I) region with arabinogalactan type II (AG-II) side chains. The most abundant fractions from each plant part, 50WTRBH-II-I, 50WTSBH-II-I, and 50WTLH-II-I, were chosen for pectinase degradation. The degradation with pectinase revealed that the main features of these fractions are that of pectic polysaccharides, with hairy regions (RG-I regions) and homogalacturonan regions. The activity of the fractions obtained after pectinase degradation and separation by gel filtration showed that the highest molecular weight fractions, 50WTRBH-II-Ia, 50WTSBH-II-Ia, and 50WTLH-II-Ia, had higher complement fixation activity than their respective native fractions. These results suggest that the complement fixation activities of these pectins are expressed mainly by their ramified regions.

Structural features and complement fixing activity of polysaccharides from Codonopsis pilosula Nannf. var. modesta L.T.Shen roots.

Two pectic polysaccharides, 50 WCP-II-I and 100 WCP-II-I, were obtained from 50 and 100 °C water extracts of Codonopsis pilosula roots by ion exchange chromatography and gel filtration. The study of the sub-fractions obtained after pectinase degradation showed that the complement fixation activities of these pectins are expressed mainly by their ramified regions. The structure studies of native and sub-fractions showed the 50 WCP-II-I is a pectic polysaccharide, with long homogalacturonan regions (some of the galacturonic acid units were methyl esterified), interrupted by one short rhamnogalacturonan I (RG-I) region. The side chains of the RG-I region are arabinogalactan type I (AG-I) and type II (AG-II) attached on position 4 of rhamnose. The 100 WCP-II-I has two main ramified regions, one is galacturonan region with AG-I side chain on position 2 of GalA, and the other one is RG-I region with AG-II side chain on position 4 of Rha.

Immunomodulating activity of Aronia melanocarpa polyphenols.

The immunomodulating effects of isolated proanthocyanidin-rich fractions, procyanidins C1, B5 and B2 and anthocyanins of Aronia melanocarpa were investigated. In this work, the complement-modulating activities, the inhibitory activities on nitric oxide (NO) production in LPS-induced RAW 264.7 macrophages and effects on cell viability of these polyphenols were studied. Several of the proanthocyanidin-rich fractions, the procyanidins C1, B5 and B2 and the cyanidin aglycone possessed strong complement-fixing activities. Cyanidin 3-glucoside possessed stronger activity than the other anthocyanins. Procyanidins C1, B5 and B2 and proanthocyanidin-rich fractions having an average degree of polymerization (PD) of 7 and 34 showed inhibitory activities on NO production in LPS-stimulated RAW 264.7 mouse macrophages. All, except for the fraction containing proanthocyanidins with PD 34, showed inhibitory effects without affecting cell viability. This study suggests that polyphenolic compounds of A. melanocarpa may have beneficial effects as immunomodulators and anti-inflammatory agents.

Enzyme inhibition, antioxidant and immunomodulatory activities, and brine shrimp toxicity of extracts from the root bark, stem bark and leaves of Terminalia macroptera.

ETHNOPHARMACOLOGICAL RELEVANCE: The root bark, stem bark and leaves of Terminalia macroptera have been traditionally used against a variety of ailments such as wounds, hepatitis, malaria, fever, cough, and diarrhea as well as tuberculosis and skin diseases in African folk medicine. Boiling water extracts of Terminalia macroptera, administered orally, are the most common preparations of this plant used by the traditional healers in Mali. This study aimed to investigate the inhibition of the activities of α-glucosidase, 15-lipoxygenase and xanthine oxidase, DPPH scavenging activity, complement fixation activity and brine shrimp toxicity of different extracts obtained by boiling water extraction (BWE) and by ASE (accelerated solvent extraction) with ethanol, ethanol-water and water as extractants from different plant parts of Terminalia macroptera. MATERIALS AND METHODS: 27 different crude extracts were obtained by BWE and ASE from root bark, stem bark and leaves of Terminalia macroptera. The total phenolic and carbohydrate contents, enzyme inhibition activities (α-glucosidase, 15-lipoxygenase and xanthine oxidase), DPPH scavenging activity, complement fixation activity and brine shrimp toxicity of these extracts were evaluated. Principal component analysis (PCA) was applied for total biological activities evaluation. RESULTS: Several of the extracts from root bark, stem bark and leaves of Terminalia macroptera obtained by BWE and ASE showed potent enzyme inhibition activities, radical-scavenging properties and complement fixation activities. None of the extracts are toxic against brine shrimp larvae in the test concentration. Based on the results from PCA, the ASE ethanol extracts of root bark and stem bark and the low molecular weight fraction of the 50% ethanol-water extract of leaves showed the highest total biological activities. The boiling water extracts were less active, but the bark extracts showed activity as α-glucosidase inhibitors and radical scavengers, the leaf extract being less active. CONCLUSION: The observed enzyme inhibition activities, radical scavenging properties and complement fixation activities may explain some of the traditional uses of this medicinal tree, such as in wound healing and against diabetes.

Complement fixing polysaccharides from Terminalia macroptera root bark, stem bark and leaves.

The root bark, stem bark and leaves of Terminalia macroptera were sequentially extracted with ethanol, 50% ethanol-water, and 50 °C and 100 °C water using an accelerated solvent extractor. Ten bioactive purified polysaccharide fractions were obtained from those crude extracts after anion exchange chromatography and gel filtration. The polysaccharides and their native extracts were characterized with respect to molecular weight, chemical compositions and effects in the complement assay. The chemical compositions showed that the polysaccharides are of pectic nature. The results indicated that there was no great difference of the complement fixation activities in the crude extracts from the different plant parts when extracting with the accelerated solvent extraction system. The purified polysaccharide fractions 100WTSBH-I-I and 100WTRBH-I-I isolated from the 100 °C water extracts of stem and root bark respectively, showed the highest complement fixation activities. These two fractions have rhamnogalacturonan type I backbone, but only 100WTSBH-I-I contains side chains of both arabinogalactan type I and II. Based on the yield and activities of the fractions studied those from the root bark gave highest results, followed by those from leaves and stem bark. But in total, all plant materials are good sources for fractions containing bioactive polysaccharides.

Complement activity of polysaccharides from three different plant parts of Terminalia macroptera extracted as healers do.

ETHNOPHARMACOLOGICAL RELEVANCE: Water decoctions of the root bark, stem bark and leaves of Terminalia macroptera are used by traditional healers in Mali to cure a wide range of illnesses, such as wounds, hepatitis, malaria, fever, cough and diarrhea as well as tuberculosis. Plant polysaccharides isolated from crude water extracts have previously shown effects related to the immune system. The aims of this study are comparing the properties of the polysaccharides among different plant parts, as well as relationship between chemical characteristics and complement fixation activities when the plant material has been extracted as the traditional healers do, with boiling water directly. MATERIALS AND METHODS: Root bark, stem bark and leaves of Terminalia macroptera were extracted by boiling water, and five purified polysaccharide fractions were obtained by anion exchange chromatography and gel filtration. Chemical compositions were determined by GC of the TMS derivatives of the methyl-glycosides and the linkage determined after permethylation and GC-MS of the derived partly methylated alditol acetates. The bioactivity was determined by the complement fixation assay of the crude extracts and purified fractions. RESULTS: The acidic fraction TRBD-I-I isolated from the root bark was the most active of the fractions isolated. Structural studies showed that all purified fractions are of pectic nature, containing rhamnogalacturonan type I backbone. Arabinogalactan type II side chains were present in all fractions except TRBD-I-II. The observed differences in complement fixation activities among the five purified polysaccharide fractions are probably due to differences in monosaccharide compositions, linkage types and molecular sizes. CONCLUSION: The crude extracts from root bark and stem bark have similar total activities, both higher than those from leaves. The root bark, leaves and stem bark are all good sources for fractions containing bioactive polysaccharides. But due to sustainability, it is prefer to use leaves rather than the other two plant parts, and then the dosage by weight must be higher when using leaves.

Polysaccharides with immunomodulating properties from the bark of Parkia biglobosa.

The bark of Parkia biglobosa is used in traditional medicine to cure a wide range of illnesses. Polysaccharides were extracted from the bark with 50% ethanol-water, 50°C and 100°C water, and seven active fractions obtained by anion exchange chromatography and gel filtration. The complement fixation and macrophage stimulating activities of the different fractions were determined. The acidic fractions PBEII-I and PBEII-IV were the most active in the complement fixation assay, but the other fractions were also potent compared to the positive control BPII from Biophytum petersianum. Fractions PBEII-I and PBEII-IV were also the most potent fractions in stimulating macrophages to release nitric oxide. Structural studies showed that PBEII-I and PBEII-IV were pectic type polysaccharides, containing arabinogalactan type II structures. The observed differences in biological activities among the seven purified polysaccharide sub-fractions are probably due to differences in monosaccharide compositions, linkage types and molecular sizes.

Effects of Aronia melanocarpa constituents on biofilm formation of Escherichia coli and Bacillus cereus.

Many bacteria growing on surfaces form biofilms. Adaptive and genetic changes of the microorganisms in this structure make them resistant to antimicrobial agents. Biofilm-forming organisms on medical devices can pose serious threats to human health. Thus, there is a need for novel prevention and treatment strategies. This study aimed to evaluate the ability of Aronia melanocarpa extracts, subfractions and compounds to prevent biofilm formation and to inhibit bacterial growth of Escherichia coli and Bacillus cereus in vitro. It was found that several aronia substances possessed anti-biofilm activity, however, they were not toxic to the species screened. This non-toxic inhibition may confer a lower potential for resistance development compared to conventional antimicrobials.

Extracts, anthocyanins and procyanidins from Aronia melanocarpa as radical scavengers and enzyme inhibitors.

Extracts, subfractions, isolated anthocyanins and isolated procyanidins B2, B5 and C1 from the berries and bark of Aronia melanocarpa were investigated for their antioxidant and enzyme inhibitory activities. Four different bioassays were used, namely scavenging of the diphenylpicrylhydrazyl (DPPH) radical, inhibition of 15-lipoxygenase (15-LO), inhibition of xanthine oxidase (XO) and inhibition of α-glucosidase. Among the anthocyanins, cyanidin 3-arabinoside possessed the strongest and cyanidin 3-xyloside the weakest radical scavenging and enzyme inhibitory activity. These effects seem to be influenced by the sugar units linked to the anthocyanidin. Subfractions enriched in procyanidins were found to be potent α-glucosidase inhibitors; they possessed high radical scavenging properties, strong inhibitory activity towards 15-LO and moderate inhibitory activity towards XO. Trimeric procyanidin C1 showed higher activity in the biological assays compared to the dimeric procyanidins B2 and B5. This study suggests that different polyphenolic compounds of A. melanocarpa can have beneficial effects in reducing blood glucose levels due to inhibition of α-glucosidase and may have a potential to alleviate oxidative stress.