Exploring Immune Modulatory Effects of Cyclotide-Enriched Viola tricolor Preparations.

Viola tricolor is a medicinal plant with documented application as an anti-inflammatory herb. The standard of care for the treatment of inflammatory bowel disease is immunosuppressive therapeutics or biologics, which often have undesired effects. We explored V. tricolor herbal preparations that are rich in an emerging class of phytochemicals with drug-like properties, so-called cyclotides. As an alternative to existing inflammatory bowel disease medications, cyclotides have immunomodulatory properties, and their intrinsic stability allows for application in the gastrointestinal tract, for instance, via oral administration. We optimized the isolation procedure to improve the yield of cyclotides and compared the cellular effects of violet-derived organic solvent-extracts, aqueous preparations, and an isolated cyclotide from this plant on primary human T lymphocytes and macrophages, i.e., cells that are crucial for the initiation and progression of inflammatory bowel disease. The hot water herbal decoctions have a stronger immunosuppressive activity towards proliferation, interferon-γ, and interleukin-21 secretion of primary human T cells than a DCM/MeOH cyclotide-enriched extract, and the isolated cyclotide kalata S appears as one of the active components responsible for the observed effects. This effect was increased by a longer boiling duration. In contrast, the DCM/MeOH cyclotide-enriched extract was more effective in reducing the levels of cytokines interleukin-6, interleukin-12, interleukin-23, tumor necrosis factor-α, and C - X-C motif chemokine ligand 10, secreted by human monocyte-derived macrophages. Defined cyclotide preparations of V. tricolor have promising pharmacological effects in modulating immune cell responses at the cytokine levels. This is important towards understanding the role of cyclotide-containing herbal drug preparations for future applications in immune disorders, such as inflammatory bowel disease.

An Overview on the Hallucinogenic Peyote and Its Alkaloid Mescaline: The Importance of Context, Ceremony and Culture.

Peyote (Lophophora williamsii) is a cactus that contains various biologically active alkaloids-such as pellotine, anhalonidine, hordenine and mescaline. Here, mescaline induces the psychoactive effects of peyote through the activation of the serotonin 5-HT2A receptor and the subsequent release of calcium (Ca2+) from the endoplasmic reticulum (ER). Moreover, an evaluation of the therapeutic benefits of mescaline is also currently the subject of research. It is important to consider that the outcome of taking a psychedelic drug strongly depends on the mindset of the recipient and the context (set and setting principle), including ceremonies and culture. This overview serves to summarise the current state of the knowledge of the metabolism, mechanism of action and clinical application studies of peyote and mescaline. Furthermore, the benefits of the potential of peyote and mescaline are presented in a new light, setting an example for combining a form of treatment embedded in nature and ritually enriched with our current highly innovative Western medicine.

Silicon Resorption from Equisetum arvense Tea - A Randomized, Three-Armed Pilot Study.

Equisetum arvense tea (TEA) contains high concentrations of silicon and has been used in folk medicine for the treatment of inflammatory ailments. We examined the resorption of silicon after TEA consumption. Safety and immunological effects were secondary outcomes. A monocentric, randomized, three-armed pilot study was conducted with 12 voluntary, healthy, male subjects. The study is registered in the German register for clinical trials (DRKS-ID: DRKS00016628). After a low silicon diet for 36 hours, 1000 mL TEA1 with approximately 200 000 µg silicon/L, TEA2 with approximately 750 000 µg silicon/L, or Si-low-Water (approximately 10 - 10 000 µg silicon/L as a control) were ingested on three consecutive days. Blood and urine samples were collected at baseline, day 1 examining silicon kinetics, day 3 examining silicon accumulation, and day 8 (safety, immunological parameters). Si-low-Water intake did not change silicon serum (Cmax 294 µg/L) or urine (19 000 µg/24 h) concentrations compared to baseline. Cmax was 2855 µg/L for TEA1 and 2498 µg/L for TEA2; tmax was 60 and 120 min, respectively. Silicon accumulation did not occur. Urine silica within 24 h (E24 h) was higher after TEA2 compared to TEA1 ingestion (142 000 vs. 109 000 µg/24 h). Serum silicon levels at t = 120 min differed significantly after intake of TEA2 or intake of Si-low-Water (p = 0.029). The immunological parameters did not show any significant changes indicating immunosuppressive effects in volunteers. TEA1 was well tolerated, while TEA2 caused diarrhoea in 4 subjects. Our investigations show that intake of TEA1 leads to significant rise in serum silicon concentration.

Phytotherapy in Integrative Oncology-An Update of Promising Treatment Options.

Modern phytotherapy is part of today's conventional evidence-based medicine and the use of phytopharmaceuticals in integrative oncology is becoming increasingly popular. Approximately 40% of users of such phytopharmaceuticals are tumour patients. The present review provides an overview of the most important plants and nature-based compounds used in integrative oncology and illustrates their pharmacological potential in preclinical and clinical settings. A selection of promising anti-tumour plants and ingredients was made on the basis of scientific evidence and therapeutic practical relevance and included Boswellia, gingko, ginseng, ginger, and curcumin. In addition to these nominees, there is a large number of other interesting plants and plant ingredients that can be considered for the treatment of cancer diseases or for the treatment of tumour or tumour therapy-associated symptoms. Side effects and interactions are included in the discussion. However, with the regular and intended use of phytopharmaceuticals, the occurrence of adverse side effects is rather rare. Overall, the use of defined phytopharmaceuticals is recommended in the context of a rational integrative oncology approach.

Compounds from Toddalia asiatica: Immunosuppressant Activity and Absolute Configurations.

In a screening of an extract library from plants used in Traditional Chinese Medicine the MeOH extract of Toddalia asiatica inhibited proliferation of human primary T cells with an IC50 of 25.8 µg/mL. Activity in the extract was tracked by HPLC activity profiling, and a total of 15 compounds were characterized. Three compounds, toddalic acid (6) and both enantiomers (7a and 7b) of toddanolic acid (7), were new natural products, and two recently published compounds, (2'R)-toddalolactone 3'-O-ß-d-glucopyranoside (10) and (2'S)-toddalolactone 2'-O-ß-d-glucopyranoside (11), were described in detail for the first time. The absolute configurations of compounds 8, 9, 10, 12, 13, and 15 were determined by comparison of experimental and calculated ECD spectra. For glucosides 9 and 10, ECD data and chiral-phase HPLC of the aglycones after enzymatic hydrolysis confirmed the results. Nitidine chloride (4) inhibited proliferation of primary human T cells with an IC50 of 0.4 µM.

Hapalindoles from the Cyanobacterium Hapalosiphon sp. Inhibit T Cell Proliferation.

Novel immunomodulating agents are currently sought after for the treatment of autoimmune diseases and cancers. In this context, a screening campaign of a collection of 575 cyanobacteria extracts for immunomodulatory effects has been conducted. The screening resulted in several active extracts. Here we report the results of subsequent studies on an extract from the cyanobacterium Hapalosiphon sp. CBT1235. We identified 5 hapalindoles as the compounds responsible for the observed immunomodulatory effect. These indole alkaloids are produced by several strains of the cyanobacterial family Hapalosiphonaceae. They are known for their anti-infective, cytotoxic, and other bioactivities. Modulation of the activity of human immune cells has not yet been described. The immunomodulatory activity of the hapalindoles was characterized in vitro using flow cytometry-based measurements of T cell proliferation after carboxyfluorescein diacetate succinimidyl ester staining, and apoptosis and necrosis induction after annexin V/propidium iodide staining. The most potent compound, hapalindole A, reduced T cell proliferation with an IC50 of 1.56 µM, while relevant levels of apoptosis were measurable only at 10-fold higher concentrations. Hapalindole A-formamide and hapalindole J-formamide, isolated for the first time from a natural source, had much lower activity than the nonformylated derivatives while, at the same time, being less selective for antiproliferative over apoptotic effects.

Sesquiterpene Lactones from Artemisia argyi: Absolute Configuration and Immunosuppressant Activity.

A library of extracts from plants used in Chinese Traditional Medicine was screened for inhibition of T lymphocyte proliferation. An ethyl acetate extract from aerial parts of Artemisia argyi showed promising activity and was submitted to HPLC-based activity profiling to track the active compounds. From the most active time window, three guaianolides (1, 2, and 5) and two seco-tanapartholides (3 and 4) were identified and, in a less active time window, five new sesquiterpene lactones (8-11, 17), along with six known sesquiterpene lactones and two known flavonoids. The absolute configurations of compounds 1, 2, 5-10, 13-15, 17, and 18 were established by comparison of experimental with calculated electronic circular dichroism (ECD) spectra. For seco-tanapartholides B (3) and A (4), ECD yielded ambiguous results, and their absolute configurations were determined by comparing experimental and calculated vibrational circular dichroism (VCD) spectra. Compounds 1-5 showed significant, noncytotoxic inhibition of T lymphocyte proliferation, with IC50 values between 1.0 and 3.7 µM.

Impact of Green Tea Catechin ECG and Its Synthesized Fluorinated Analogue on Prostate Cancer Cells and Stimulated Immunocompetent Cells.

Among the known or suspected risk factors, inflammation plays an important role in infectious and non-infectious pathways leading to cancer. Green tea polyphenols have been associated with reducing inflammation and protection against carcinogenesis, especially in prostate cancer. While most of the research in this field, so far, has focussed on epigallocatechin-3-O-gallate only, we studied epicatechin-3-O-gallate, the second most abundant green tea polyphenol with essential therapeutic potential, to obtain a more detailed understanding of its anti-tumor and anti-inflammatory action. Furthermore, to improve the bioactivity of (-)-epicatechin-3-O-gallate, we synthesized a difluoro analogue, called (-)-5,7-difluoro-epicatechin-3-O-gallate. Both compounds reduced cell proliferation of human primary inflammatory lymphocytes in an apoptosis-specific fashion, while (-)-5,7-difluoro-epicatechin-3-O-gallate had a significantly higher activity compared to the natural product (-)-epicatechin-3-O-gallate. Treatment of low-metastatic LNCaP and high-metastatic PC-3 prostate cancer cells with (-)-epicatechin-3-O-gallate and (-)-5,7-difluoro-epicatechin-3-O-gallate demonstrated a dose-dependent inhibition of cell viability in the low micromolar range. These effects suggest that (-)-epicatechin-3-O-gallate and the more effective (-)-5,7-difluoro-epicatechin-3-O-gallate could be therapeutically used to inhibit tumorigenesis during initiation, promotion, and progression by diminishing the amount of inflammation due to a reduction of inflammatory lymphocytes. Further studies are needed to prove this in in vivo experiments.

Effects of Inonotus hispidus Extracts and Compounds on Human Immunocompetent Cells.

Inonotus hispidus is used as a traditional medicine in China. Previous investigations revealed promising immunomodulatory activity of fruit body extracts of I. hispidus. Bioactivity-guided fractionation showed that hispolon and hispidin were active substances.In this study, we analysed the effects of I. hispidus extract and selected constituents on different types of human immune cells and investigated the potential of I. hispidus extract as a medicinal mushroom. The influence of I. hispidus extract on activity and maturation of human T cells, purified natural killer cells, and dendritic cells was analysed using cytometric-based surface marker expression. The cell division characteristics of the activated T cells were assessed by membrane permeable dye, and the function of natural killer cells was investigated by a degranulation CD107a assay. Apoptosis induction was assessed by surface staining of phosphatidylserine, and camptothecin and cyclosporine A were used individually as controls. Phytochemical analysis, using TLC chromatograms and HPLC analysis, was conducted to characterise the I. hispidus extract. I. hispidus extract increased the activation and diminished the proliferation of activated human T cells in the presence of apoptosis. Natural killer cell activity and function were dose-dependently increased. Surface marker expression of dendritic cells demonstrated that I. hispidus extract has the potential to induce maturation. TLC and HPLC analyses showed that the extract contained hispidin and hispolon. Investigations using hispidin and hispolon demonstrated similar, albeit noncongruent, results with extracts on measured parameters.The results indicate that extracts from I. hispidus and their constituents, hispidin and hispolon, interfere with the function of multiple immune cells, thus providing a rationale for their potential as a medicinal mushroom.

Immunological evaluation of herbal extracts commonly used for treatment of mental diseases during pregnancy.

Nonpsychotic mental diseases (NMDs) affect approximately 15% of pregnant women in the US. Herbal preparations are perceived a safe alternative to placenta-crossing antidepressants or benzodiazepines in the treatment of nonpsychotic mental diseases. But are these drugs really safe for mother and foetus? This question is of great relevance to physicians and patients. Therefore, this study investigates the influence of St. John's wort, valerian, hops, lavender, and California poppy and their compounds hyperforin and hypericin, protopine, valerenic acid, and valtrate, as well as linalool, on immune modulating effects in vitro. For this purpose a variety of methods was applied to assess the effects on viability and function of human primary lymphocytes. Viability was assessed via spectrometric assessment, flow cytometric detection of cell death markers and comet assay for possible genotoxicity. Functional assessment was conducted via flow cytometric assessment of proliferation, cell cycle and immunophenotyping. For California poppy, lavender, hops, and the compounds protopine and linalool, and valerenic acid, no effect was found on the viability, proliferation, and function of primary human lymphocytes. However, St. John's wort and valerian inhibited the proliferation of primary human lymphocytes. Hyperforin, hypericin, and valtrate inhibited viability, induced apoptosis, and inhibited cell division. Calculated maximum concentration of compounds in the body fluid, as well as calculated concentrations based on pharmacokinetic data from the literature, were low and supported that the observed effects in vitro would probably have no relevance on patients. In-silico analyses comparing the structure of studied substances with the structure of relevant control substances and known immunosuppressants revealed structural similarities of hyperforin and valerenic acid to the glucocorticoids. Valtrate showed structural similarities to the T cells signaling modulating drugs.

Potential benefits of Malva sylvestris in dry-eye disease pathology in vitro based on antioxidant, wound-healing and anti-inflammatory properties.

Dry eye disease (DED) is a common chronic ocular surface disease. Available therapies are effective but often associated with side effects. This study investigates the potential of a Malva sylvestris L. flower extract and two defined preparations, a mucilage and a polyphenol rich fraction, on cells that are essential for the DED pathology. Furthermore, single compounds were isolated and characterised out of the polyphenol fraction. The M. sylvestris extract and its two fractions reduced reactive oxygen species (ROS) in an ultraviolet-induced model and promoted wound healing capacity of HCE-T cells, but only the polyphenol fraction and the flower extract exhibited significant radical scavenging activity. The flower extract and the polyphenol fraction inhibited cytokine secretion (IL-6, TNF-α, IL-8) from HCE-T cells and THP-1 cells. In contrast, the mucilage fraction led to an increase in mediator secretion. The NF-κB activity and calcium influx in THP-1 and Jurkat cells, respectively was decreased by treatment with the flower extract and the polyphenol fraction, whereas the mucilage fraction had no influence on these parameters. Moreover, the flower extract and the mucilage fraction at low concentration could stimulate meibomian gland cells' lipid accumulation. The isolated single compounds showed no effect on analysed parameters, except a coumarin derivative and malvin which showed ROS inhibition effects.

Aryltetralin lignans from Hyptis brachiata inhibiting T lymphocyte proliferation.

Increased activation and proliferation of T lymphocytes plays an essential role in the development of chronic inflammation and autoimmune diseases. Currently used immunosuppressive drugs often do not provide long-lasting relief of symptoms and show a gradual loss of efficacy over time, and are accompanied by various side effects. Therefore, novel immunosuppressive lead substances are needed. For this purpose, an in-house library consisting of 600 extracts of plants from Panama was screened for inhibition of human T lymphocyte proliferation. As one of the hits, an ethyl acetate extract from the aerial parts of Hyptis brachiata (Lamiaceae) exhibited strong inhibitory effects. Subsequent investigation resulted in the isolation of seven aryltetralin lignans, five arylnaphthalene lignans, two flavonoids, three triterpenes, and cinnamyl cinnamate. Aryltetralin lignans inhibited T lymphocyte proliferation in a concentration-dependent manner without induction of apoptosis. No relevant inhibition was observed for the arylnaphthalene lignans, flavonoids, and triterpenes. Additional cell cycle arrest investigations revealed that isolated aryltetralin lignans potently inhibited cell division in G2/M phase similarly to podophyllotoxin. Multifluorescence panel analyses of the extract also showed weak suppressive effects on the production of IL-2 and TNF-α. Therefore, preparations made out of H. brachiata could be further explored as an interesting herbal alternative in the treatment of autoimmune diseases.

A cross-sectional study of nutritional status in healthy, young, physically-active German omnivores, vegetarians and vegans reveals adequate vitamin B12 status in supplemented vegans.

BACKGROUND/OBJECTIVE: Plant-based diets reduce the risk of cardiovascular disease but also increase the risk of certain micronutrient deficiencies, particularly, of vitamin B12 (B12). The extent to which the unsupervised use of oral nutrient supplements is sufficient to prevent these deficiencies is not well established. We analyzed nutrient intake, laboratory biomarkers, supplementation behavior, and B12 status adequacy amongst young, healthy, physically active omnivores, lacto-ovo-vegetarians and vegans from Germany. METHODS: We recruited 115 participants (n = 40 omnivores; n = 37 lacto-ovo-vegetarians, and n = 38 vegans) with comparable age, sex, marital status, physical activity and educational levels through online advertisements and local newspapers in Freiburg, Germany. RESULTS: Energy intake and macronutrient distribution were comparable across diets. Major differences included intake of fiber, cholesterol, and several vitamins. Vegans had the lowest intake of B12 from foods (0.43 (0.58) µg/d), compared to omnivores (2.14 (2.29) µg/d) and lacto-ovo-vegetarians (0.98 (1.34) µg/day). Multivariate analysis of 36 blood biomarkers revealed that three major classes of biomarkers contributed the most to the clustering of individuals by dietary group, namely, biomarkers of B12 status (B12, holoTC, Hcy), iron (iron, ferritin, transferrin) and lipid metabolism (vitamin A, HDL, LDL, total cholesterol, TAG). This suggests that nutrients that modify the metabolic pathways represented by these biomarkers have the most penetrating effect on health status across diets. Analysis of B12 status (including 4cB12) revealed adequacy in omnivores and vegans, and a poorer B12 status amongst lacto-ovo-vegetarians. Fewer lacto-ovo-vegetarians used B12 supplements compared to vegans (51% versus 90%). CONCLUSIONS: Even amongst homogeneously healthy Germans, each diet manifested with measurable differences in dietary intakes and biomarkers of health. Plant-based diets, in particular the vegan diet, exhibited the most favorable patterns of lipid metabolism and glycemic control, but the lowest food intake of B12. Supplementation of healthy vegans with B12 (median 250 µg B12/day, over 2 years) secured an adequate B12 status that was comparable to that of healthy omnivores.Clinical Trial Registry: German Clinical Trial register number: DRKS00027425.

Plant-based diets, in particular the vegan diet, exhibited the most favorable patterns of lipid metabolism and glycemic control, but the lowest food intake of B12.Analysis of B12 status (including 4cB12) revealed adequacy in omnivores and vegans, and a poorer B12 status amongst lacto-ovo-vegetarians.Supplementation with B12 (median 250 µg B12/day, over 1 year) in healthy physically-active vegans secured an adequate B12 status that was comparable to that of healthy omnivores.

A conserved enzyme of smut fungi facilitates cell-to-cell extension in the plant bundle sheath.

Smut fungi comprise one of the largest groups of fungal plant pathogens causing disease in all cereal crops. They directly penetrate host tissues and establish a biotrophic interaction. To do so, smut fungi secrete a wide range of effector proteins, which suppress plant immunity and modulate cellular functions as well as development of the host, thereby determining the pathogen's lifestyle and virulence potential. The conserved effector Erc1 (enzyme required for cell-to-cell extension) contributes to virulence of the corn smut Ustilago maydis in maize leaves but not on the tassel. Erc1 binds to host cell wall components and displays 1,3-ß-glucanase activity, which is required to attenuate ß-glucan-induced defense responses. Here we show that Erc1 has a cell type-specific virulence function, being necessary for fungal cell-to-cell extension in the plant bundle sheath and this function is fully conserved in the Erc1 orthologue of the barley pathogen Ustilago hordei.

Ipecac root extracts and isolated circular peptides differentially suppress inflammatory immune response characterised by proliferation, activation and degranulation capacity of human lymphocytes in vitro.

Circular peptides are attractive lead compounds for drug development; this study investigates the immunomodulatory effects of defined root powder extracts and isolated peptides (called cyclotides) from Carapichea ipecacuanha (Brot.) L. Andersson ('ipecac'). Changes in the viability, proliferation and function of activated human primary T cells were analysed using flow cytometry-based assays. Three distinct peptide-enriched extracts of pulverised ipecac root material were prepared via C18 solid-phase extraction and analysed by reversed-phase HPLC and mass spectrometry. These extracts induced caspase 3/7 dependent apoptosis, thus leading to a suppressed proliferation of activated T cells and a reduction of the number of cells in the G2 phase. Furthermore, the stimulated T cells had a lower activation potential and a reduced degranulation capacity after treatment with ipecac extracts. Six different cyclotides were isolated from C. ipecacuanha and an T cell proliferation inhibiting effect was determined. Furthermore, the degranulation capacity of the T cells was diminished specifically by some cyclotides. In contrast to kalata B1 and its analog T20K, secretion of IL-2 and IFN- γ was not affected by any of the caripe cyclotides. The findings add to our increased understanding of the immunomodulating effects of cyclotides, and may provide a basis for the use of ipecac extracts for immunomodulation in conditions associated with an exessive immune responses.

Immunosuppressive activity of non-psychoactive Cannabis sativa L. extract on the function of human T lymphocytes.

BACKGROUND: Cannabis sativa L. extracts (CSE) are used for treating inflammatory conditions, but little is known about their immunomodulatory effects. We investigated a novel CSE with high (14%) CBD and low (0.2%) THC concentration in comparison with pure CBD on primary human lymphocytes. METHODS: Proliferation, cell cycle distribution, apoptosis/necrosis and viability were analysed with standard methods. Genotoxicity was evaluated with the comet-assay. The effect on T lymphocyte activation was evaluated via CD25/CD69 marker expression, degranulation assays and the production of cytokines. The influence on the transcription factors was analysed using Jurkat reporter cell lines. Specific CB2 receptor antagonist SR144528 and TRPV1 receptor antagonist A78416B were used to study the involvement of CB2 or TRPV1 receptors. RESULTS: CSE inhibited the proliferation of activated T lymphocytes in a dose-dependent manner without inducing apoptosis, necrosis, or affecting cell viability and DNA integrity. The inhibitory effect was mediated via the suppression of T lymphocytes activation, particularly by the suppression of CD25 surface marker expression. Furthermore, CSE interferes with the functionality of the T lymphocytes, as indicated by inhibition of degranulation, IL-2, and IFN-γ production. AP-1-and-NFAT-reporter activation was reduced implicating an AP-1-and-NFAT-mediated mode of action. The effects were in part reversed by SR144528 and A78416B, showing that the effects were mainly mediated by CB2 and TRPV1 receptors. CONCLUSION: CSE and CBD have immunomodulatory effects and interfere with the activation and functionality of T lymphocytes. A comparison between CSE and CBD suggests that the immunosuppressive effect of CSE is mostly due to the effect of CBD.

A Vegan Diet Is Associated with a Significant Reduction in Dietary Acid Load: Post Hoc Analysis of a Randomized Controlled Trial in Healthy Individuals.

The composition of diet strongly affects acid-base homeostasis. Western diets abundant in acidogenic foods (meat and cheese) and deficient in alkalizing foods (fruits and vegetables) increase dietary acid load (DAL). A high DAL has been associated with numerous health repercussions, including cardiovascular disease and type-2-diabetes. Plant-based diets have been associated with a lower DAL; however, the number of trials exploring this association is limited. This randomized-controlled trial sought to examine whether an isocaloric vegan diet lowers DAL as compared to a meat-rich diet. Forty-five omnivorous individuals were randomly assigned to a vegan diet (n = 23) or a meat-rich diet (n = 22) for 4 weeks. DAL was determined using potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores at baseline and after 3 and 4 weeks, respectively. After 3 weeks, median PRAL (-23.57 (23.87)) and mean NEAPR (12.85 ± 19.71) scores were significantly lower in the vegan group than in the meat-rich group (PRAL: 18.78 (21.04) and NEAPR: 60.93 ± 15.51, respectively). Effects were mediated by a lower phosphorus and protein intake in the vegan group. Our study suggests that a vegan diet is a potential means to reduce DAL, whereas a meat-rich diet substantially increases the DAL burden.

Immunosuppressant flavonoids from Scutellaria baicalensis.

Some plants used in Traditional Chinese Medicine serve as treatment for disease states where a suppression of the cellular immune response is desired. However, the compounds responsible for the immunosuppressant effects of these plants are not necessarily known. The immunosuppressant compounds in the roots of Scutellaria baicalensis, one of the most promising plants identified in a previous screening, were tracked by HPLC activity profiling and concomitant on-line spectroscopic analysis. Compounds were then isolated by preparative chromatography, and structures elucidated by spectroscopic methods. Twelve flavonoids (5-16) were identified from the active time windows, and structurally related flavones 2, 4, and 17, and flavanones 1 and 3 were isolated from adjacent fractions. All flavonoids possessed an unusual substitution pattern on the B-ring, with an absence of substituents at C-3 and C-4. Compounds 11, 13, 14, and 16 inhibited T-cell proliferation (IC50 values at 12.1-39 µM) at non-cytotoxic concentrations. The findings may support the use of S. baicalensis in disorders where a modulation of the cellular immune response is desirable.

Boswellia carteri extract and 3-O-acetyl-alpha-boswellic acid suppress T cell function.

Resins from various Boswellia species have a long track record in different cultures as a treatment for inflammatory diseases. This study was designed to provide evidence for the anti-inflammatory capacity and medicinal use of Boswellia carteri (Burseraceae). A dichloromethane (DCM) extract of B. carteri gum resin and isolated compounds thereof were immunologically characterized. Flow cytometric-based analysis was performed to investigate the impact of B. carteri extract on proliferation, viability, and function of anti-CD3 and anti-CD28 activated human primary T cells. The secretion level of IL-2 and IFN-γ was determined by a bead array-based flow cytometric technique. HPLC-based activity profiling of the B. carteri extract identified active compounds. The impact of B. carteri extract and isolated compounds on the IL-2 transcription factor activity was addressed using specially designed Jurkat reporter cells. The extract of B. carteri suppressed the proliferation of human primary T lymphocytes in vitro in a concentration-dependent manner, without inducing cytotoxicity. Thereby, the B. carteri extract further reduced the degranulation capacity and cytokine secretion of stimulated human T cells. Transcription factor analysis showed that the immunosuppressive effects of the extract are based on specific NFAT-conditioned suppression within T cell signaling. Through HPLC-based activity profiling of the extract, 3-O-acetyl-alpha-boswellic acid was identified as the compound responsible for the NFAT-based mechanism. The recent study presents a scientific base for the immunosuppressive effects of B. carteri gum resin extract including a mode-of-action via the NFAT-conditioned suppression of T lymphocyte proliferation. The immunosuppressive effects of 3-O-acetyl-alpha-boswellic acid are depicted for the first time.

Vegan diet reduces neutrophils, monocytes and platelets related to branched-chain amino acids - A randomized, controlled trial.

BACKGROUND: Vegan diet (VD) has improved inflammatory activity in patients with rheumatoid arthritis (RA) in several small controlled trials. The underlying mechanism remains widely unclear. We investigated the effect of a VD in comparison to a meat-rich diet (MD) on markers of inflammation (which have been shown to be relevant in patients with RA) in healthy volunteers. METHODS: 53 healthy, omnivore subjects were randomized to a controlled VD (n = 26) or MD (n = 27) for 4 weeks following a pre-treatment phase of a one week controlled mixed diet. Primary parameters of interest were sialylation of immunoglobulins, percentage of regulatory T-cells and level of interleukin 10 (IL10). Usual care immune parameters used in patients with RA and amino acid serum levels as well as granulocytes and monocytes colony stimulating factor (GM-CSF) serum levels were secondary parameters. RESULTS: In the VD group, total leukocyte, neutrophil, monocyte and platelet counts decreased and after four weeks they were significantly lower compared to the MD group (ANCOVA: leukocytes p = 0.003, neutrophils p = 0.001, monocytes p = 0.032, platelets p = 0.004). Leukocytes, neutrophils, monocytes, and platelets correlated with each other and likewise conform with serum levels of branched-chain amino acids, which were significantly lower in the VD compared to the MD group. The primary parameters did not differ between the groups and BMI remained stable in the two groups. CONCLUSION: Four weeks of a controlled VD affected the number of neutrophils, monocytes and platelets but not the number or function of lymphocytes. The relation with branched-chain amino acids and GM-CSF suggests a mode of action via the mTOR signaling pathway. REGISTERED AT: http://www.drks.de (German Clinical Trial register) at DRKS00011963.