Identification of Botanicals that Unmask ß-Glucan from the Cell Surface of an Opportunistic Fungal Pathogen.

Dectin-1 expressed on host immune cells recognizes ß-glucans within the cell walls of fungal pathogens and plays an important role in the clearance of fungal infections. However, because ß-glucan is masked by an outer layer of mannoproteins, fungal pathogens can evade detection by host immune cells. In this study, a microplate-based screen was developed to identify ß-glucan unmasking activity exhibited by botanicals. This screen measures the activity of a reporter gene in response to the transcriptional activation of NF-κB due to the interaction between ß-glucan on the fungal cell surface and Dectin-1 present on host immune cells. In this proof-of-concept study, we screened a collection of botanicals (10 plants and some of their reported pure compound actives) used in traditional medicine for their antifungal properties. Several hits were identified in samples that unmasked ß-glucan at sub-inhibitory concentrations. The hit samples were confirmed by fluorescent staining with a ß-glucan antibody, verifying that the samples identified in the screen did indeed unmask ß-glucan. These results indicate that the purported antifungal activities attributed to some botanicals may be due, at least in part, to the presence of compounds that exhibit ß-glucan unmasking activity. Enhanced exposure of cell wall ß-glucans would allow the host to build resilience against fungal infections by helping the immune system to detect the pathogen and mount a more effective clearance mechanism. This screen, together with direct killing/growth inhibition assays, may therefore serve as a valuable tool for substantiating the use of botanicals in preventing and/or treating fungal infections.

Immulina as an Immunostimulatory Supplement: Formulation and Pharmacological Studies.

Immulina is a commercially available extract of Arthrospira platensis enriched with bacterial lipoproteins that acts as a potent Toll-like receptor 2 agonist. However, the immunostimulatory effect of Immulina is not well understood in vivo. Here, to devise an Immulina formulation suitable for in vivo oral gavage dosing, Immulina nanosuspension was prepared and freeze-dried to yield lyophilized nano-Immulina, which had an average particle size of around 300 nm and fully retained the bioactivity as a Toll-like receptor 2 agonist. Compared to the regular Immulina powder, lyophilized nano-Immulina notably accelerated the dissolution in aqueous media. Immulina nanosuspension was found to stimulate the production of proinflammatory cytokines in murine bone marrow-derived dendritic cells and macrophages. The immune response to Immulina was investigated in healthy mice by longitudinally monitoring the phagocytic activity of circulating neutrophils as a surrogate marker. Following daily oral ingestion of Immulina nanosuspension (10 mg/mouse/day), the phagocytic activity of circulating neutrophils was significantly elevated, suggesting an important mechanism for Immulina to enhance innate immunity.

Is Baikiain in Tara Flour a Causative Agent for the Adverse Events Associated with the Recalled Frozen French Lentil & Leek Crumbles Food Product? - A Working Hypothesis.

The French Lentil & Leek Crumbles frozen food product was recently recalled due to reports of gastrointestinal issues. So far, 393 adverse illness complaints and 133 hospitalizations have been reported from consumption of this food, and the tara (Tara spinosa) protein flour ingredient is hypothesized to be responsible. A multipronged approach resulted in identification of (S)-(-)-baikiain in tara as a compound of interest due to its abundance, possible metabolic fate, and close resemblance to irreversible inhibitors of L-pipecolate oxidase. Oral administration of baikiain in ND4 mice showed a statistically significant increase in blood ALT levels and a reduction in liver GSH.

Utility of fatty acid profile and in vitro immune cell activation for chemical and biological standardization of Arthrospira/Limnospira.

Commercially cultivated Limnospira (species formerly classified to genus Arthrospira) is a popular food/supplement consumed by millions of people worldwide for health benefits. The objective of the current research was to advance the standardization technology for Limnospira. Quantitative methods were established to detect fatty acids as potential chemical markers and immune-enhancing activity. Analysis of 20 different batches of biomass obtained from one commercial grower demonstrated that there was a statistically significant relationship between the sum of two fatty acids (linoleic and γ-linolenic) and Toll-like receptor (TLR)2/TLR1-dependent activation (R2 = 0.48, p = 0.0007). Investigation of 12 biomass samples sourced from growers in 10 different countries demonstrated that fatty acid content was again significantly correlated with biological activity (R2 = 0.72, p = 0.0005) and the content of fatty acids varied by twofold and activity by 12.5-fold. This large variation between different samples confirms the need to use the present standardization methods to ensure consistent and properly characterized biomass for consumers and for future scientific research.

Macrophage activation by edible mushrooms is due to the collaborative interaction of toll-like receptor agonists and dectin-1b activating beta glucans derived from colonizing microorganisms.

Research supports the theory that the microbiome of plants and mushrooms produce potent activators of pathogen recognition receptors which are principal contributors to the stimulation of macrophages. We have previously reported that the in vitro macrophage stimulatory activity of water-soluble extracts from 13 different types of edible mushrooms is predominantly due to bacterial components originating from the naturally occurring bacterial communities within these materials. The purpose of the current study was to further investigate the bacterial-dependent activity of the water-soluble extracts and assess whether these 13 types of mushrooms contain water-insoluble beta glucans that activate the dectin-1b signaling pathway. Activity of the water-soluble extracts was predominantly due to Toll-like receptor 2 (TLR2) and TLR4 agonists. For dectin-1b-dependent activity (indicative of water-insoluble beta glucans), culinary mushrooms (Agaricus bisporus varieties) were essentially inactive, whereas most of the medicinal mushrooms (Lentinula edodes, Grifola frondosa, Hypsizygus marmoreus varieties, Flammulina velutipes) exhibited potent activation. A. bisporus samples with no detectable dectin-1b-dependent activity had yeast colony forming units that were 687 times lower than L. edodes exhibiting high activity, indicating that the active insoluble beta glucans are derived from colonizing yeast. In addition, co-stimulation of macrophages with the TLR agonists and insoluble beta glucan was found to result in a synergistic enhancement of in vitro cytokine production. Taken together, these findings indicate that the in vitro macrophage activating potential of edible mushrooms is due to the collaborative interaction of water-soluble TLR agonists (derived from colonizing bacteria) and water-insoluble beta glucans (derived from colonizing yeast).

Plant microbiome-dependent immune enhancing action of Echinacea purpurea is enhanced by soil organic matter content.

We previously demonstrated that extracts from Echinacea purpurea material varied substantially in their ability to activate macrophages in vitro and that this variation was due to differences in their content of bacterial components. The purpose of the current study was to identify soil conditions (organic matter, nitrogen, and moisture content) that alter the macrophage activation potential of E. purpurea and determine whether these changes in activity correspond to shifts in the plant-associated microbiome. Increased levels of soil organic matter significantly enhanced macrophage activation exhibited by the root extracts of E. purpurea (p < 0.0001). A change in soil organic matter content from 5.6% to 67.4% led to a 4.2-fold increase in the macrophage activation potential of extracts from E. purpurea. Bacterial communities also differed significantly between root materials cultivated in soils with different levels of organic matter (p < 0.001). These results indicate that the level of soil organic matter is an agricultural factor that can alter the bacterial microbiome, and thereby the activity, of E. purpurea roots. Since ingestion of bacterial preparation (e.g., probiotics) is reported to impact human health, it is likely that the medicinal value of Echinacea is influenced by cultivation conditions that alter its associated bacterial community.

Bacterial components are the major contributors to the macrophage stimulating activity exhibited by extracts of common edible mushrooms.

Recent studies have indicated that a major contributor to the innate immune enhancing properties of some medicinal plants is derived from the cell wall components of bacteria colonizing these plants. The purpose of the current study was to assess if the bacteria present within edible and medicinal mushrooms substantially contribute to the innate immune stimulating potential of these mushrooms. Whole mushrooms from thirteen types of edible fungi and individual parts from Agaricus bisporus were analyzed for in vitro macrophage activation as well as bacterial lipopolysaccharides (LPS) content, cell load, and community composition. Substantial variation between samples was observed in macrophage activation (over 500-fold), total bacterial load (over 200-fold), and LPS content (over 10 million-fold). Both LPS content (ρ = 0.832, p < 0.0001) and total bacterial load (ρ = 0.701, p < 0.0001) correlated significantly with macrophage activation in the whole mushroom extracts. Extract activity was negated by treatment with NaOH, conditions that inactivate LPS and other bacterial components. Significant correlations between macrophage activation and total bacterial load (ρ = 0.723, p = 0.0001) and LPS content (ρ = 0.951, p < 0.0001) were also observed between different tissues of Agaricus bisporus. Pseudomonas and Flavobacterium were the most prevalent genera identified in the different tissue parts and these taxa were significantly correlated with in vitro macrophage activation (ρ = 0.697, p < 0.0001 and ρ = 0.659, p = 0.0001, respectively). These results indicate that components derived from mushroom associated bacteria contribute substantially to the innate immune enhancing activity exhibited by mushrooms and may result in similar therapeutic actions as reported for ingestion of bacterial preparations such as probiotics.

Activities and Prevalence of Proteobacteria Members Colonizing Echinacea purpurea Fully Account for Macrophage Activation Exhibited by Extracts of This Botanical.

Evidence supports the theory that bacterial communities colonizing Echinacea purpurea contribute to the innate immune enhancing activity of this botanical. Previously, we reported that only about half of the variation in in vitro monocyte stimulating activity exhibited by E. purpurea extracts could be accounted for by total bacterial load within the plant material. In the current study, we test the hypothesis that the type of bacteria, in addition to bacterial load, is necessary to fully account for extract activity. Bacterial community composition within commercial and freshly harvested (wild and cultivated) E. purpurea aerial samples was determined using high-throughput 16S rRNA gene pyrosequencing. Bacterial isolates representing 38 different taxa identified to be present within E. purpurea were acquired, and the activity exhibited by the extracts of these isolates varied by over 8000-fold. Members of the Proteobacteria exhibited the highest potency for in vitro macrophage activation and were the most predominant taxa. Furthermore, the mean activity exhibited by the Echinacea extracts could be solely accounted for by the activities and prevalence of Proteobacteria members comprising the plant-associated bacterial community. The efficacy of E. purpurea material for use against respiratory infections may be determined by the Proteobacterial community composition of this plant, since ingestion of bacteria (probiotics) is reported to have a protective effect against this health condition.

Oral administration of a Spirulina extract enriched for Braun-type lipoproteins protects mice against influenza A (H1N1) virus infection.

A growing body of research indicates that oral administration of bacteria (such as probiotics) can exhibit a protective effect against influenza A (H1N1) viral infection in mice. In the present study, we used a mouse model to examine whether oral administration of Immulina(®), a commercial extract from the cyanobacteria Arthrospira (Spirulina) platensis, can reduce the severity of illness resulting from influenza A (H1N1) viral infection. The main active compounds within Immulina(®) are bacterial Braun-type lipoproteins that activate innate immune cells through a toll-like receptor (TLR) 2-dependent pathway. Mice that were fed Immulina(®) for 30 days before and 21 days after infection with influenza A (H1N1) virus exhibited a statistically significant reduction in the severity of infection. Compared to the control group, Immulina(®)-fed mice exhibited less weight loss, increased appetite, decreased clinical signs of disease, and lower lung histopathology scores. The results from the present study adds to the increasing evidence that oral administration of bacterial components that activate innate immune cells, whether derived from a bacterial preparation (probiotics or cyanobacteria) or from plant material containing endophytic bacteria, can exhibit a protective effect against influenza A (H1N1) viral infection.

Total bacterial load within Echinacea purpurea, determined using a new PCR-based quantification method, is correlated with LPS levels and in vitro macrophage activity.

Our previous studies indicate that the majority of in vitro monocyte/macrophage activation exhibited by extracts of Echinacea depends on bacterial components. In the present study, total bacterial load was determined within E. purpurea samples and ranged from 6.4 × 10(6) to 3.3 × 10(8) bacteria/g of dry plant material. To estimate total bacterial load, we developed a PCR-based quantification method that circumvents the problems associated with nonviable/nonculturable cells (which precludes using plate counts) or the coamplification of mitochondrial or chloroplast DNA with the use of universal bacterial primers (which precludes the use of qPCR). Differences in total bacterial load within Echinacea samples were strongly correlated with the activity (NF-κB activation in THP-1 cells) and content of bacterial lipopolysaccharides within extracts of this plant material. These results add to the growing body of evidence that bacteria within Echinacea are the main source of components responsible for enhancing innate immune function.

Enhancement of natural killer cell activity in healthy subjects by Immulina®, a Spirulina extract enriched for Braun-type lipoproteins.

Immulina®, a commercial extract of Arthrospira (Spirulina) platensis is a potent activator of THP-1 monocytes and CD4+ T cells IN VITRO and enhances several immunological functions in mice. We further characterized Immulina® by determining that Braun-type lipoproteins are responsible for a major portion of the IN VITRO monocyte activation exhibited by this material. In order to understand the effect of Immulina® on NK cell activity, a pilot study was conducted on ten healthy North American individuals who supplemented their diet with Immulina® (400 mg/day) for seven days. We observed a 40% average increase in the killing of K562 tumor cells by NK cells (p < 0.01) after Immulina® supplementation. In a separate placebo-controlled, crossover study involving 11 healthy Danish subjects, we observed increased mRNA expression of the NK cell marker NKG2D by 37% (p = 0.02) and by 55% (p = 0.0003) after administration of Immulina® (200 mg and 400 mg per day, respectively) for seven days. The mRNA expression of the NK- and T-cell marker perforin increased by 75% (p = 0.008) after administration of 400 mg Immulina® per day. Both markers displayed significant dose-dependent effects (p = 0.0003 and p = 0.02, respectively). The ratio between CD56 (bright) and CD56 (dim) NK cells was not affected by Immulina® administration. In summary, two independent studies showed enhancement of NK cell activity following administration of Immulina® for seven days.

Variability in in vitro macrophage activation by commercially diverse bulk echinacea plant material is predominantly due to bacterial lipoproteins and lipopolysaccharides.

We previously reported that the majority of in vitro monocyte/macrophage activation exhibited by extracts of Echinacea and other botanicals depends upon bacterial lipopolysaccharides and Braun-type bacterial lipoproteins. We determined the contribution made by these bacterial components to the overall immune-enhancing activity detected in E. purpurea and E. angustifolia bulk root and aerial material obtained from six major growers/suppliers in North America. Substantial variation in activity (up to 200-fold) was observed in extracts of these materials when tested in two monocyte/macrophage cell lines. The majority of activity was negated by treatment with agents that target bacterial lipoproteins (lipoprotein lipase) and lipopolysaccharides (polymyxin B). Experiments comparing the activity of freeze-dried, freshly harvested Echinacea plants to those harvested and dried using various commercially relevant conditions suggest that postharvesting procedures do not substantially contribute to the variation observed in the commercial material.

The majority of in vitro macrophage activation exhibited by extracts of some immune enhancing botanicals is due to bacterial lipoproteins and lipopolysaccharides.

We have identified potent monocyte/macrophage activating bacterial lipoproteins within commonly used immune enhancing botanicals such as Echinacea, American ginseng and alfalfa sprouts. These bacterial lipoproteins, along with lipopolysaccharides, were substantially more potent than other bacterially derived components when tested in in vitro monocyte/macrophage activation systems. In experiments using RAW 264.7 and mouse peritoneal macrophages the majority (85-98%) of the activity within extracts from eight immune enhancing botanicals was eradicated by treatment with agents (lipoprotein lipase and polymyxin B) known to target these two bacterial components. Alfalfa sprouts exhibited the highest activity of those botanicals tested but the appearance of this activity during the germination of surface sterilized seeds was abolished by the presence of antibiotics. These studies indicate that the majority of the in vitro macrophage activating properties in extracts from these botanicals can be attributed to the presence of lipoproteins and lipopolysaccharides derived from bacteria and that bacterial endophytes may be a significant source of these components.

Toll-like receptor 2-dependent activation of monocytes by Spirulina polysaccharide and its immune enhancing action in mice.

We reported previously that a high molecular weight polysaccharide fraction (Immulina) from Spirulina was a potent activator of NF-kappa B and induced both IL-1 beta and TNF-alpha mRNAs in THP-1 human monocytes. In the present study, we show that NF-kappa B activation by Immulina is suppressed by antibodies to CD14 and TLR2 but not by antibodies to TLR4. Similarly, NF-kappa B directed luciferase expression was enhanced by Immulina treatment when cells were co-transfected with vectors expressing proteins supporting TLR2- (CD14 and TLR2) but not TLR4-(CD14, TLR4, and MD-2) dependent activation. Mice that consumed a chemically defined chow mixed with an extract containing Immulina exhibited changes in several immune parameters. The ex vivo production of IgA and IL-6 from Peyer's patch cells was enhanced 2-fold and interferon-gamma production from spleen cells was increased 4-fold in Immulina-treated mice. The enhanced production of these factors was most notable with mice that had consumed this extract for 4 or 5 days. These studies shed light on how Immulina activates cells of the innate immune system and suggests that oral consumption of this polysaccharide can enhance components within both the mucosal and systemic immune systems.

Melanin: dietary mucosal immune modulator from Echinacea and other botanical supplements.

The agents responsible for the therapeutic effects of many botanical supplements have not been established in spite of their popularity. Here we show that melanin is a previously unrecognized immunostimulatory compound that is a major component of botanicals traditionally used to enhance immune function. While melanin is present in commonly consumed vegetables, its specific activity is several orders of magnitude less than melanin extracted from these botanicals. The major reason that this agent has eluded detection is its solvent-specific requirement for extraction/solubility. Melanin activates NF-kappa B in monocytes in vitro through a toll-like receptor 2-dependent process. Ingestion of melanin by mice for four days increases production ex vivo of interferon-gamma by spleen cells and IgA and interleukin-6 by Peyer's patch cells. The identification of this new class of mucosal immune stimulants will allow further characterization of botanical products and advances our understanding of the basis for their traditional use.

Lowering cortisol and CVD risk in postmenopausal women: a pilot study using the Transcendental Meditation program.

Unlike younger women, the risk of cardiovascular disease in older women matches or exceeds that of men. Excessive cortisol may play a role in this increased risk. Here we explore the possibility that the Transcendental Meditation (TM) program may reduce the cortisol response to a metabolic stressor as a way of reducing disease risk in older women. Data from 16 women who were long-term practitioners of transcendental meditation (mean = 23 y) were compared with data from 14 control women matched for age (mean = 75 y, range = 65-92 y). Data on demographics, disease symptoms, and psychological variables were collected, and cortisol response to a metabolic stressor (75 g of glucose, orally) was examined in saliva and urine. Pre-glucose levels of salivary cortisol were identical for the two groups. Post-glucose cortisol rose faster in the controls and was significantly higher than that in the TM women (P < 1 3 10(-4)). Urinary excretion of cortisol during this period was 3 times higher in controls than in the TM women (2.4 +/- 0.17 and 0.83 +/- 0.10 microg/h, respectively; P = 2 x 10(-4)). In addition, the number of months practicing transcendental meditation was inversely correlated with CVD risk factors. Lower cortisol response to metabolic challenge may reflect improved endocrine regulation relevant to the disease-preventing effects of transcendental meditation in older women.