Select phytochemicals suppress human T-lymphocytes and mouse splenocytes suggesting their use in autoimmunity and transplantation

Eat4Genes: a bioinformatic rational gene targeting app and prototype model for improving human health

Introduction and aims

Dietary Rational Gene Targeting (DRGT) is a therapeutic dietary strategy that uses healthy dietary agents to modulate the expression of disease-causing genes back toward the normal. Here we use the DRGT approach to (1) identify human studies assessing gene expression after ingestion of healthy dietary agents with an emphasis on whole foods, and (2) use this data to construct an online dietary guide app prototype toward eventually aiding patients, healthcare providers, community and researchers in treating and preventing numerous health conditions.

Methods

We used the keywords "human", "gene expression" and separately, 51 different dietary agents with reported health benefits to search GEO, PubMed, Google Scholar, Clinical trials, Cochrane library, and EMBL-EBI databases for related studies. Studies meeting qualifying criteria were assessed for gene modulations. The R-Shiny platform was utilized to construct an interactive app called "Eat4Genes".

Results

Fifty-one human ingestion studies (37 whole food related) and 96 key risk genes were identified. Human gene expression studies were found for 18 of 41 searched whole foods or extracts. App construction included the option to select either specific conditions/diseases or genes followed by food guide suggestions, key target genes, data sources and links, dietary suggestion rankings, bar chart or bubble chart visualization, optional full report, and nutrient categories. We also present user scenarios from physician and researcher perspectives.

Conclusion

In conclusion, an interactive dietary guide app prototype has been constructed as a first step towards eventually translating our DRGT strategy into an innovative, low-cost, healthy, and readily translatable public resource to improve health.

The Anti-Inflammatory and Immunomodulatory Activities of Natural Products to Control Autoimmune Inflammation

Inflammation is an integral part of autoimmune diseases, which are caused by dysregulation of the immune system. This dysregulation involves an imbalance between pro-inflammatory versus anti-inflammatory mediators. These mediators include various cytokines and chemokines; defined subsets of T helper/T regulatory cells, M1/M2 macrophages, activating/tolerogenic dendritic cells, and antibody-producing/regulatory B cells. Despite the availability of many anti-inflammatory/immunomodulatory drugs, the severe adverse reactions associated with their long-term use and often their high costs are impediments in effectively controlling the disease process. Accordingly, suitable alternatives are being sought for these conventional drugs. Natural products offer promising adjuncts/alternatives in this regard. The availability of specific compounds isolated from dietary/medicinal plant extracts have permitted rigorous studies on their disease-modulating activities and the mechanisms involved therein. Here, we describe the basic characteristics, mechanisms of action, and preventive/therapeutic applications of 5 well-characterized natural product compounds (Resveratrol, Curcumin, Boswellic acids, Epigallocatechin-3-gallate, and Triptolide). These compounds have been tested extensively in animal models of autoimmunity as well as in limited clinical trials in patients having the corresponding diseases. We have focused our description on predominantly T cell-mediated diseases, such as rheumatoid arthritis, multiple sclerosis, Type 1 diabetes, ulcerative colitis, and psoriasis.

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.

Network medicine framework shows that proximity of polyphenol targets and disease proteins predicts therapeutic effects of polyphenols

Polyphenols, natural products present in plant-based foods, play a protective role against several complex diseases through their antioxidant activity and by diverse molecular mechanisms. Here we develop a network medicine framework to uncover mechanisms for the effects of polyphenols on health by considering the molecular interactions between polyphenol protein targets and proteins associated with diseases. We find that the protein targets of polyphenols cluster in specific neighbourhoods of the human interactome, whose network proximity to disease proteins is predictive of the molecule's known therapeutic effects. The methodology recovers known associations, such as the effect of epigallocatechin-3-O-gallate on type 2 diabetes, and predicts that rosmarinic acid has a direct impact on platelet function, representing a novel mechanism through which it could affect cardiovascular health. We experimentally confirm that rosmarinic acid inhibits platelet aggregation and α-granule secretion through inhibition of protein tyrosine phosphorylation, offering direct support for the predicted molecular mechanism. Our framework represents a starting point for mechanistic interpretation of the health effects underlying food-related compounds, allowing us to integrate into a predictive framework knowledge on food metabolism, bioavailability and drug interaction.

Lower concentrations of curcumin inhibit Her2-Akt pathway components in human breast cancer cells, and other dietary botanicals potentiate this and lapatinib inhibition

Her2-dependent breast cancer is treated with pharmacological drugs (eg, Herceptin, lapatinib) that target Her2 signaling. Curcumin has emerged as a potential co-treatment for this and other cancers, but prior studies have focused on non-attainable concentrations. Here we test the hypothesis that attainable in vivo levels of dietary curcumin can reduce Her2 signaling. Consistent with previous studies, higher dose curcumin (18 μmol/L) inhibits Her2-Akt pathway signaling (pHer2, total Her2 and pAkt levels) and cell growth using AU565 human breast cancer cells. We then examined lower, more physiologically relevant concentrations of curcumin, alone and in combination with other dietary botanicals (quercetin and OptiBerry fruit extract). At 4 μmol/L, curcumin reduced Her2 signaling, and even more when combined with quercetin or OptiBerry. At 1.5 μmol/L curcumin, pHer2 and Her2 (but not pAkt) were reduced, with all three pathway markers reduced more in the presence of quercetin. We also found that 1.5 μmol/L curcumin strongly potentiated lapatinib inhibition of Her2-Akt pathway signaling, and more so for pAkt, when combined with quercetin plus OptiBerry (CQO). Parallel analyses revealed cell growth inhibition at 18 and 4 μmol/L but not 1.5 μmol/L curcumin, and potentiation of 1.5 μmol/L curcumin growth arrest with other botanicals +/- lapatinib. These studies demonstrate that a physiological attainable level of curcumin (1.5 μmol/L) can reduce some components of the critical Her2-Akt pathway; that even more complete inhibition can be achieved by combination with other dietary botanicals; and that curcumin and other botanicals can potentiate the action of the Her2-cancer metastatic drug lapatinib, in turn suggesting the potential anti-cancer clinical use of these botanicals.

Involvement of heme oxygenase-1 in suppression of T cell activation by quercetin

AIM

Acute rejection is still a major problem in transplantation and one of the most important causes of late graft loss. Cyclosporine and tacrolimus are widely used for suppression of T cell function to avoid graft rejection, but long-term use of these compounds is associated with serious toxicities. Quercetin, a flavonoid found in fruits and vegetables, has been demonstrated to exhibit cytoprotective effects through the induction of heme oxygenase (HO) -1, an enzyme involved in heme catabolism. We hypothesized that quercetin induces HO-1 in T cells and suppresses T cell function via HO-1. In the present study, we showed that quercetin suppressed the A23187-mediated expression of interleukin (IL) -2 in T cells.

METHODS

Mouse splenocytes, enriched T cells, and EL4 cells, a mouse T cell line, were treated with quercetin, and then stimulated with A23187, a calcium ionophore, concanavalin A, or anti-CD3ε and anti-CD28 antibodies. Cell proliferation, expression of IL-2, calcium mobilization, apoptosis, cell cycle, and phosphorylation of extracellular signal-regulated kinase (ERK) were investigated.

RESULTS

Quercetin induced HO-1, and this induction of HO-1 was implicated in the suppression of IL-2 production. Furthermore, the induction of HO-1 by quercetin suppressed the influx of calcium ions, a known trigger of IL-2 production. Additionally, quercetin suppressed T cell proliferation through promotion of cell cycle arrest via HO-1 induction, but quercetin did not induce apoptosis. To investigate the role of the signal transduction pathway in quercetin's effect on cell proliferation, we evaluated the phosphorylation of ERK in T cells. Quercetin suppressed the A23187-mediated stimulation of ERK, an effect that was mediated through HO-1. These results suggested that HO-1 is involved in the suppressive effects of quercetin on T cell activation and proliferation.

CONCLUSION

Our findings indicate that the quercetin may be a promising candidate for inducing HO-1 in T cells, thereby facilitating immunosuppressive effects.

Functional characterization of a HD-ZIP IV transcription factor NtHDG2 in regulating flavonols biosynthesis in Nicotiana tabacum

The HD-ZIP Ⅳ transcription factors have been identified and functional characterized in many plant species. However, no tobacco HD-ZIP IV gene has been isolated, and it is not yet known whether HD-ZIP IV genes are involved in controlling flavonols accumulation in plants. Here, we cloned a HD ZIP gene named NtHDG2 from Nicotiana tabacum, which belongs to the class IV of HD-ZIP family, and the NtHDG2-GFP fusion protein is localized to the nucleus. We further observed that the flavonols contents in the NtHDG2 overexpression leaves increase to 1.9-4.5 folds of that in WT plants, but in the NtHDG2-RNAi plants the flavonols contents reduce to 20.9%-52.7% of that in WT plants. The transcriptions of one regulatory gene NtMYB12, and three structural genes (NtPAL, NtF3'H, NtF3GT), contributing to flavonols biosynthesis, were significantly induced by NtHDG2. However, the transcription level of NtNAC002, a flavonols biosynthesis repressor, was also significantly up-regulated in NtHDG2-overexpression lines, but significantly down-regulated in the RNAi lines, indicating that HDG2 regulates the synthesis of flavonols as a complex regulatory network. Moreover, ectopic expression of NtHDG2 gene promoted the transcription of several AP2/ERF genes, including NtERF1-5, NtERF109, NtDREB1, and NtCIPK11, which participate in regulating root development and resistance to abiotic stresses. Our findings reveal the new function of HD-ZIP IV transcription factors in flavonoids biosynthesis, and indicate that HD-ZIP IV members may play an important role in plant resistance to abiotic stress. The NtHDG2 gene provides a promising target for genetically manipulating to increase the amounts of flavonols in tobacco leaves.

Effects of quercetin and arginine on the nephrotoxicity and lipid peroxidation induced by gold nanoparticles in vivo

INTRODUCTION

This study aimed to evaluate the nephrotoxicity caused by gold nanoparticles (GNPs) and investigate the potential roles of quercetin (Qur) and arginine (Arg) in mitigating the inflammatory kidney damage and dysfunction and inhibiting the toxicity induced by GNPs in rats.

METHODS

Kidney function was assessed using various serum biomarkers, including blood urea nitrogen (BUN), uric acid (URIC), and creatinine (CR), while toxicity was evaluated by measuring the biomarkers glutathione (GSH) and malondialdehyde (MDA) in kidney tissues.

RESULTS

Administration of GNPs to the rats severely affected the serum kidney biomarkers, as confirmed by the notable increases in BUN, URIC, and CR. Substantial changes in the levels of the biomarkers MDA and GSH in the kidney tissues were also observed, with a reduced level of GSH and elevated MDA activity. The administration of Qur or Arg exerted a protective effect against GNP-induced inflammatory kidney damage and toxicity, but with different responses according to their evaluated normalized values.

CONCLUSION

This study demonstrates the beneficial effects of supplementation with Qur or Arg during the treatment with GNPs, potentially providing a powerful tool for cancer therapy.

Effects of a Standard American Diet and an anti-inflammatory diet in male and female mice

BACKGROUND

Obesity and chronic pain are prevalent concerns. Pain is frequently experienced in weight-bearing joints, but is common in other areas of the body as well, suggesting other factors. Poor diet often contributes to obesity and can directly influence the immune system. We have shown that poor diet prolongs recovery from inflammatory injury. Therefore, our goal was to determine whether poor-quality diet-induced consequences could be prevented or reversed by an anti-inflammatory diet (AID).

METHODS

A Standard American Diet (SAD) was developed to investigate the effects of poor diet on pain. The SAD includes amounts of refined sugar, carbohydrates and fats that better model the typical American diet, as compared to high-fat diets. We developed an AID to explore whether the effects of the SAD could reverse or whether the AID would enhance recovery prophylactically. The AID was developed using ingredients (epigallocatechin gallate, sulforaphane, resveratrol, curcumin and ginseng) with known anti-inflammatory properties. Following 15 weeks of diet [SAD, AID or regular (REG)] exposure, male and female mice underwent inflammatory injury, at which point some animals had their diets switched for the remainder of the study.

RESULTS

Animals who consumed the SAD showed longer recovery compared to the AID- and REG-fed animals. Animals switched off the SAD had faster recovery times, with AID-fed animals recovering as fast as REG-fed animals.

CONCLUSIONS

Poor diet prolonged recovery from inflammatory injury. Substitution of SAD with AID or REG promoted faster recovery. These findings suggest diet can be used as a non-pharmacological intervention following injury.

SIGNIFICANCE

Obesity may increase susceptibility to chronic pain often due to poor diet. Diet has potential to be used as treatment for pain. This study investigates the use of a novel translatable diet to act as a preventative (i.e. prior to surgery) or an intervention (i.e. following an injury).

The decrease in number of splenic lymphocytes in mice fed Rhodiola kirilowii during pregnancy and lactation concerns mainly CD19+ and CD4+ cells

In previous work we described the decline in the number of splenocytes of mice which during pregnancy and lactation were fed Rhodiola kirilowii. In this work we present the size of individual subpopulations of splenic lymphocytes in these mice. Experiments were performed on adult inbred female Balb/c mice, 8-9 weeks old, 20-22 g b.m., mated with adult males from the same strain. Females, from when the copulatory plug was noted up to the 28^th day after delivery, were supplemented daily with lyophilized aqueous (RKW) or 50% hydro-ethanolic (RKW-A) extract (20 mg/kg b.m.) dissolved in distilled water. Then, mice were euthanized, spleens dissected, cells counted and the total numbers of CD3+, CD19+, CD4+, CD8+ and CD335+ splenic lymphocytes were evaluated by cytometry.

The number of CD3+ lymphocytes per 1 g of splenic tissue was higher in RKW-A than in RKW spleens and did not differ from the control. The number of CD3+ lymphocytes in RKW spleens was lower than in the controls. The number of CD19+ and CD4+ cells was lower in both experimental groups than in the controls. The number of CD335+(NK) cells was lower in RKW spleens than in the control.

Fibroblast activation proteins-α suppress tumor immunity by regulating T cells and tumor-associated macrophages

Fibroblast activation protein-α (FAPα) is a type-II cell-surface-bound integral transmembrane serine protease and selectively overexpressed by tumor-associated stromal fibroblasts (TAFs), which are the main components in the tumor microenvironment, in >90% of malignant epithelial carcinomas. FAPα regulates the immunosuppression of tumor cells in the tumor microenvironment. Regulatory T cells (Tregs) and tumor-associated macrophages (TAMs) are the major immunosuppressive cells in the tumor microenvironment. However, the effect of FAPα on Tregs and TAMs is unknown. The non-enzymatic function of FAPα on Treg and TAM was investigated. In this study, we confirm that FAPα can promote the generation of Tregs and TAMs, which suggests that FAPα plays a immunosuppressive role in the tumor microenvironment and provides evidence for FAP α as a potent immunotherapeutic target for cancer.

Chemoprevention with isothiocyanates - From bench to bedside

Isothiocyanates (ITCs) are naturally occurring hydrolization products from glucosinolates (GLSs) in brassicaceae and in epidemiological studies their intake has been weakly to moderately inversely correlated with the risk of colorectal cancer, prostate cancer and lung cancer. Numerous preclinical studies demonstrate chemopreventive mode of actions of ITCs, mainly related to a.) detoxification (induction of phase II enzymes), b.) anti-inflammatory properties by down-regulation of NFkappaB activity, c.) cyclin-mediated cell cycle arrest and d.) epigenetic modulation by inhibition of histone deacetylase activity. First prospective clinical trials were promising in patients with risk of prostate cancer recurrence. The glutathione-S-transferase gene expression seems to play a major role in the individual susceptibility towards ITCs. Safety issues are widely unclear and should be more addressed in future studies because ITCs can, in low concentrations, compromise the function of human immune cells and might impair genome stability.

Screening and purification of catechins from underutilized tea plant parts and their bioactivity studies

Comparative investigation of major phytoconstituents was performed from various parts of tea plant viz. apical bud, subtending 1st-5th leaf, stem, coarse leaves, flowers, fruits and roots. From the results of comparative RP-HPLC-DAD analysis it was found that underutilized tea parts especially coarse leaves, flowers and fruits contains abundant amount of phenolics (17.5%) and catechins (4-5%). From these underutilized tea plant parts the catechins were extracted and purified and then screened for their anticancer, immunomodulatory effect and antimicrobial activity against food borne pathogens. The results showed that tea fruit extract exhibited higher toxicity against oral cancer cells and also promotes proliferation of mice splenocytes. The results of antimicrobial studies revealed the inhibitory effect of these extracts against both gram positive and gram negative bacteria. These investigations clearly demonstrated that the underutilized tea plant parts could act as economical and sustainable bioresource of functionally active constituents which further lead to the development of new cost-effective nutraceuticals and other formulations.

The genetic aspects of berries: from field to health

Berries are a relevant source of micronutrients and nonessential phytochemicals, such as polyphenol compounds, that play a synergistic and cumulative role in human health promotion. Several systematic analyses showed that berry phenolics are able to detoxify reactive oxygen and nitrogen species, blocking their production, to intervene in the cell cycle, participating in the transduction and expression of genes involved in apoptosis, and to repair oxidative DNA damage. As a consequence, the improvement of the nutritional quality of berries has become a new quality target of breeding and biotechnological strategies, to control or to increase the content of specific health-related compounds in fruits. This work reviews, on the basis of the in vitro and in vivo evidence, the main berries' phytochemical compounds and their possible mechanisms of action on pathways involved in several type of diseases, with particular attention to cancer, inflammation, neurodegeneration, diabetes and cardiovascular diseases.

A multi-targeted approach to suppress tumor-promoting inflammation

Cancers harbor significant genetic heterogeneity and patterns of relapse following many therapies are due to evolved resistance to treatment. While efforts have been made to combine targeted therapies, significant levels of toxicity have stymied efforts to effectively treat cancer with multi-drug combinations using currently approved therapeutics. We discuss the relationship between tumor-promoting inflammation and cancer as part of a larger effort to develop a broad-spectrum therapeutic approach aimed at a wide range of targets to address this heterogeneity. Specifically, macrophage migration inhibitory factor, cyclooxygenase-2, transcription factor nuclear factor-κB, tumor necrosis factor alpha, inducible nitric oxide synthase, protein kinase B, and CXC chemokines are reviewed as important antiinflammatory targets while curcumin, resveratrol, epigallocatechin gallate, genistein, lycopene, and anthocyanins are reviewed as low-cost, low toxicity means by which these targets might all be reached simultaneously. Future translational work will need to assess the resulting synergies of rationally designed antiinflammatory mixtures (employing low-toxicity constituents), and then combine this with similar approaches targeting the most important pathways across the range of cancer hallmark phenotypes.

Broad targeting of angiogenesis for cancer prevention and therapy

Deregulation of angiogenesis – the growth of new blood vessels from an existing vasculature – is a main driving force in many severe human diseases including cancer. As such, tumor angiogenesis is important for delivering oxygen and nutrients to growing tumors, and therefore considered an essential pathologic feature of cancer, while also playing a key role in enabling other aspects of tumor pathology such as metabolic deregulation and tumor dissemination/metastasis. Recently, inhibition of tumor angiogenesis has become a clinical anti-cancer strategy in line with chemotherapy, radiotherapy and surgery, which underscore the critical importance of the angiogenic switch during early tumor development. Unfortunately the clinically approved anti-angiogenic drugs in use today are only effective in a subset of the patients, and many who initially respond develop resistance over time. Also, some of the anti-angiogenic drugs are toxic and it would be of great importance to identify alternative compounds, which could overcome these drawbacks and limitations of the currently available therapy. Finding “the most important target” may, however, prove a very challenging approach as the tumor environment is highly diverse, consisting of many different cell types, all of which may contribute to tumor angiogenesis. Furthermore, the tumor cells themselves are genetically unstable, leading to a progressive increase in the number of different angiogenic factors produced as the cancer progresses to advanced stages. As an alternative approach to targeted therapy, options to broadly interfere with angiogenic signals by a mixture of non-toxic natural compound with pleiotropic actions were viewed by this team as an opportunity to develop a complementary anti-angiogenesis treatment option. As a part of the “Halifax Project” within the “Getting to know cancer” framework, we have here, based on a thorough review of the literature, identified 10 important aspects of tumor angiogenesis and the pathological tumor vasculature which would be well suited as targets for anti-angiogenic therapy: (1) endothelial cell migration/tip cell formation, (2) structural abnormalities of tumor vessels, (3) hypoxia, (4) lymphangiogenesis, (5) elevated interstitial fluid pressure, (6) poor perfusion, (7) disrupted circadian rhythms, (8) tumor promoting inflammation, (9) tumor promoting fibroblasts and (10) tumor cell metabolism/acidosis. Following this analysis, we scrutinized the available literature on broadly acting anti-angiogenic natural products, with a focus on finding qualitative information on phytochemicals which could inhibit these targets and came up with 10 prototypical phytochemical compounds: (1) oleanolic acid, (2) tripterine, (3) silibinin, (4) curcumin, (5) epigallocatechin-gallate, (6) kaempferol, (7) melatonin, (8) enterolactone, (9) withaferin A and (10) resveratrol. We suggest that these plant-derived compounds could be combined to constitute a broader acting and more effective inhibitory cocktail at doses that would not be likely to cause excessive toxicity. All the targets and phytochemical approaches were further cross-validated against their effects on other essential tumorigenic pathways (based on the “hallmarks” of cancer) in order to discover possible synergies or potentially harmful interactions, and were found to generally also have positive involvement in/effects on these other aspects of tumor biology. The aim is that this discussion could lead to the selection of combinations of such anti-angiogenic compounds which could be used in potent anti-tumor cocktails, for enhanced therapeutic efficacy, reduced toxicity and circumvention of single-agent anti-angiogenic resistance, as well as for possible use in primary or secondary cancer prevention strategies.

Synergistic radiation protective effect of purified Auricularia auricular-judae polysaccharide (AAP IV) with grape seed procyanidins

The aim of this study was to investigate the synergistic antioxidant potential and protective effect of grape seed procyanidins (GSP) in combination with Auricularia auricular-judae polysaccharides (AAP IV) on radiation injury in splenocytes. Rat splenocyte irradiation resulted in significantly higher apoptosis rate, malondialdehyde (MDA) (p < 0.005), reactive oxygen species (ROS) (p < 0.01); cell viability, total superoxide dismutase (T-SOD) (p < 0.01), catalase (CAT) (p < 0.01), glutathione peroxidase (GSH-PX) (p < 0.05), activity and glutathione (GSH) (p < 0.01) levels were significantly reduced, compared with the control group. "GSP + AAP IV" treatment of rat splenocytes at doses of "GSP (0.3 μg/mL) + AAP IV (50 μg/mL)" displayed higher radioprotective and antioxidative effects than the administration of either GSP or AAP IV, as evident by lower levels of MDA (p < 0.001) concentration, as well as higher cell viability and T-SOD (p < 0.05), CAT (p < 0.005), GSH-PX (p < 0.01) and GSH content compared to the radiation group. In addition, in vivo studies have shown that "GSP + AAP IV" significantly ameliorated the decrease of spleen index (p < 0.005) and spleen GSH (p < 0.005) levels and significantly inhibited the increase of MDA (p < 0.005) levels of spleen with radiation-induced damage, compared with the non-treated group. The in vivo and in vitro results suggested that GSP and AAP IV have a synergistic protective effect against radiation-induced injury by improving the antioxidant and immunomodulation activities.

Caloric restriction favorably impacts metabolic and immune/inflammatory profiles in obese mice but curcumin/piperine consumption adds no further benefit

Background

Obesity is associated with low-grade inflammation and impaired immune response. Caloric restriction (CR) has been shown to inhibit inflammatory response and enhance cell-mediated immune function. Curcumin, the bioactive phenolic component of turmeric spice, is proposed to have anti-obesity and anti-inflammation properties while piperine, another bioactive phenolic compound present in pepper spice, can enhance the bioavailability and efficacy of curcumin. This study sought to determine if curcumin could potentiate CR’s beneficial effect on immune and inflammatory responses in obesity developed in mice by feeding high-fat diet (HFD).

Methods

Mice were fed a HFD for 22 wk and then randomized into 5 groups: one group remained on HFD ad libitum and the remaining 4 groups were fed a 10% CR (reduced intake of HFD by 10% but maintaining the same levels of micronutrients) in the presence or absence of curcumin and/or piperine for 5 wk, after which CR was increased to 20% for an additional 33 wk. At the end of the study, mice were sacrificed, and spleen cells were isolated. Cells were stimulated with T cell mitogens, anti-CD3/CD28 antibodies, or lipopolysaccharide to determine T cell proliferation, cytokine production, and CD4⁺ T cell subpopulations.

Results

Compared to HFD control group, all CR mice, regardless of the presence of curcumin and/or piperine, had lower body weight and fat mass, lower levels of blood glucose and insulin, and fewer total spleen cells but a higher percentage of CD4⁺ T cells. Additionally, they demonstrated lower production of pro-inflammatory cytokines IL-1β and TNF-α, a trend toward lower IL-6, and lower production of PGE₂, a lipid molecule with pro-inflammatory and T cell-suppressive properties. Mice with CR alone had higher splenocyte proliferation and IL-2 production, but this effect of CR was diminished by spice supplementation. CR alone or in combination with spice supplementation had no effect on production of cytokines IL-4, IL-10, IFN-γ, and IL-17, or the proportion of different CD4⁺ T cell subsets.

Conclusion

CR on an HFD favorably impacts both metabolic and immune/inflammatory profiles; however, the presence of curcumin and/or piperine does not amplify CR’s beneficial effects.

Effect of tocopherol on biochemical blood parameters in pleuritis-induced rats treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin

The aim of this study was to evaluate the effect of tocopherol on pleuritis-induced rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Rats were treated with a single TCDD dose of 5 μg/kg body weight (b.w.) and then for 3 weeks they were daily supplemented with tocopherol at a dose of 30 mg/kg b.w. The inflammation was initiated by intrapleural injection of a single dose of 1% carrageenin solution in a volume of 0.15 ml. Changes in biochemical blood parameters were measured three times at the 24th, 72nd and 120th hour of pleuritis and the blood was collected from 20 animals of each group of rats (group with the control inflammation; group treated with TCDD and with control inflammation; group treated with TCDD, supplemented with tocopherol and with the inflammation). The following biochemical parameters were measured: tumor necrosis factor (TNF), interleukin-1 (IL-1), IL-2, IL-4, IL-6, procollagen, telopeptide, fibrinogen, cholesterol, urea, creatinine, aspartate aminotransferase (AspAT) and alanine aminotransferase (AlAT). Daily supplementation of tocopherol caused significant changes in the level of TNF, IL-1, IL-4, IL-6, urea, creatinine, AspAT and AlAT. According to the results of these studies, we suggest that tocopherol supplementation in high doses could act as a protective treatment to improve liver metabolism.

Oenothein B, a cyclic dimeric ellagitannin isolated from Epilobium angustifolium, enhances IFNγ production by lymphocytes

Oenothein B is a polyphenol isolated from Epilobium angustifolium and other plant sources, which has been reported to exhibit immunomodulatory properties. Oenothein B is known to activate myeloid cells and induce the production of IL-1 and other cytokines. However, its effects on lymphocytes are unknown. In this report, we show that oenothein B stimulated innate lymphocytes, including bovine and human γδ T cells and NK cells, resulting in either increased CD25 and/or CD69 expression. We also demonstrate that oenothein B enhanced the production of interferon-γ (IFNγ) by bovine and human NK cells alone and in combination with interleukin-18 (IL-18), a response not observed with other commonly studied polyphenols. Furthermore, we demonstrate that oenothein B enhanced the production of IFNγ by human T cells. Since IFNγ contributes to antitumor, antibacterial, and antiviral cell responses, these data suggest an additional mechanism that could account, at least in part, for the immune enhancing properties of oenothein B.

Saponins from soy bean and mung bean inhibit the antigen specific activation of helper T cells by blocking cell cycle progression

Treatment of helper T (Th) cells with saponins from soy bean and mung bean prevented their activation by inhibiting cell proliferation and cytokine secretion. However, the saponins did not affect the expression of major histocompatibility complex class II (A(b)) and co-stimulatory molecule (CD86) on professional antigen-presenting cells. Instead, the saponins directly inhibited Th cell proliferation by blocking the G(1) to S phase cell cycle transition. Moreover, blocking of the cell cycle by the saponins was achieved by decreased expression of cyclin D1 and cyclin E, and constitutive expression of p27(KIP1). Saponins also increased stability of p27(KIP1) in Th cells after antigenic stimulation.

Grape seed proanthocyanidins inhibit angiogenesis via the downregulation of both vascular endothelial growth factor and angiopoietin signaling

Vascular endothelial growth factor (VEGF)/VEGF receptor 2 and angiopoietin 1/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 signaling pathways regulate different, but complementary, aspects of blood vessel growth in tumors. Simultaneous inhibition of both pathways not only exhibits additive antiangiogenic effects but also overcomes the resistance to anti-VEGF therapy. Grape seed proanthocyanidins (GSPs) are widely consumed dietary supplements with antiangiogenic activity. However, the molecular mechanisms underlying their antiangiogenic action have not been fully understood. We hypothesized that GSPs modulate multiple signaling pathways to exhibit antiangiogenic effects. In the present study, we aimed to test this hypothesis by examining the effects of GSPs on human microvascular endothelial cell-1 and chick chorioallantoic membrane. Our results showed that GSPs inhibited the migration, matrix metalloproteinase-2 and -9 secretion, and tube formation of human microvascular endothelial cell-1 in vitro in a dose-dependent manner. In addition, chick chorioallantoic membrane angiogenesis assay showed that GSPs inhibited neovascularization in a dose-dependent manner. Furthermore, we demonstrated that GSPs inhibited the phosphorylation of VEGF receptor 2 and tyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 as well as downstream signaling component extracellular signal-regulated kinase 1/2. In summary, these data suggest that GSPs inhibit both VEGF and angiopoietin 1 signaling to execute the antiangiogenic effects and indicate that GSPs could be developed as a pharmacologically safe chemopreventive agent against cancer.

Role of quercetin and arginine in ameliorating nano zinc oxide-induced nephrotoxicity in rats

BACKGROUND

Nanoparticles are small-scale substances (<100 nm) with unique properties. Therefore, nanoparticles pose complex health risk implications. The objective of this study was to detect whether treatment with quercetin (Qur) and/or arginine (Arg) ameliorated nephrotoxicity induced by two different doses of nano zinc oxide (n-ZnO) particles.

METHOD

ZnO nanoparticles were administered orally in two doses (either 600 mg or 1 g/Kg body weight/day for 5 conscutive days) to Wister albino rats. In order to detect the protective effects of the studied antioxidants against n-ZnO induced nepherotoxicity, different biochemical parameters were investigated. Moreover, histopathological examination of kidney tissue was performed.

RESULTS

Nano zinc oxide-induced nephrotoxicity was confirmed by the elevation in serum inflammatory markers including: tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6); and C-reactive protein (CRP). Moreover, immunoglobulin (IGg), vascular endothelium growth factor (VEGF), and nitric oxide (NO) were significantly increased in rat serum. Serum urea and creatinine levels were also significantly increased in rats intoxicated with n-ZnO particles compared with the control group. Additionally, a significant decrease in the non-enzymatic antioxidant reduced glutathione (GSH) was shown in kidney tissues and serum glucose levels were increased. These biochemical findings were supported by a histopathological examination of kidney tissues, which showed that in the animals that received a high dose of n-ZnO, numerous kidney glomeruli underwent atrophy and fragmentation. Moreover, the renal tubules showed epithelial desquamation, degeneration and necrosis. Some renal tubules showed casts in their lumina. Severe congestion was also observed in renal interstitium. These effects were dose dependent. Cotreatment of rats with Qur and/or Arg along with n-ZnO significantly improved most of the deviated tested parameters.

CONCLUSIONS

The data show that Qur has a beneficial effect against n-ZnO oxidative stress and related vascular complications. Also, its combination with Arg proved to be even more effective in ameliorating nano zinc oxide nephrotoxicity.

Dietary agents in cancer prevention: an immunological perspective

Skin cancer is the most common form of cancer diagnosed in the United States. Exposure to solar ultraviolet (UV) radiations is believed to be the primary cause for skin cancer. Excessive UV radiation can lead to genetic mutations and damage in the skin's cellular DNA that in turn can lead to skin cancer. Lately, chemoprevention by administering naturally occurring non-toxic dietary compounds has proven to be a potential strategy to prevent the occurrence of tumors. Attention has been drawn toward several natural dietary agents such as resveratrol, one of the major components found in grapes, red wines, berries and peanuts, proanthocyanidins from grape seeds, (-)-epigallocatechin-3-gallate from green tea, etc. However, the effect these dietary agents have on the immune system and the immunological mechanisms involved therein are still being explored. In this review, we shall focus on the role of key chemopreventive agents on various immune cells and discuss their potential as antitumor agents with an immunological perspective.

A nonimmunosuppressant approach on Asia psoriasis subjects: 5-year followup and 11-year data analysis

Mono- or combine immunosuppressants are commonly used for psoriasis; however the side effect caused by potent systemic immunosuppressants frequently incurred; moreover the inflammation flares up shortly after immunosuppressants are discontinued. An alternative nonimmunosuppressive therapy was introduced to psoriasis subjects. A retrospective observational study consisted of 1583 psoriasis patients who were treated with Herose Psoria capsule 1440 mg three times daily at two clinical centres, one in China, the other in Singapore, from 1 January 2000 to 1 January 2011. Psoriasis lesion evolution was photographed at monthly visit, and efficacy and safety were assessed using psoriasis area severity index PASI score grading, renal and liver function testing, and adverse event reporting and supplemented by information obtained during targeted telephone interviews. The effectiveness of Herose on psoriasis was inversely associated to prior immunosuppressants exposure (r = 0.9154), significant improvements occurred in non-immunosuppressants subjects, and complete clearance was achieved in 8 months (87.5%, 14 of 16); the wavelike evolution of psoriatic lesion appeared in prior immunosuppressants subjects.

Natural isothiocyanates: genotoxic potential versus chemoprevention

Isothiocyanates, occurring in many dietary cruciferous vegetables, show interesting chemopreventive activities against several chronic-degenerative diseases, including cancer, cardiovascular diseases, neurodegeneration, diabetes. The electrophilic carbon residue in the isothiocyanate moiety reacts with biological nucleophiles and modification of proteins is recognized as a key mechanism underlying the biological activity of isothiocyanates. The nuclear factor-erythroid-2-related factor 2 system, which orchestrates the expression of a wide array of antioxidant genes, plays a role in the protective effect of isothiocyanates against almost all the pathological conditions reported above. Recent emerging findings suggest a further common mechanism. Chronic inflammation plays a central role in many human diseases and isothiocyanates inhibit the activity of many inflammation components, suppress cyclooxygenase 2, and irreversibly inactivate the macrophage migration inhibitory factor. Due to their electrophilic reactivity, some isothiocyanates are able to form adducts with DNA and induce gene mutations and chromosomal aberrations. DNA damage has been demonstrated to be involved in the pathogenesis of various chronic-degenerative diseases of epidemiological relevance. Thus, the genotoxicity of the isothiocyanates should be carefully considered. In addition, the dose-response relationship for genotoxic compounds does not suggest evidence of a threshold. Thus, chemicals that are genotoxic pose a greater potential risk to humans than non-genotoxic compounds. Dietary consumption levels of isothiocyanates appear to be several orders of magnitude lower than the doses used in the genotoxicity studies and thus it is highly unlikely that such toxicities would occur in humans. However, the beneficial properties of isothiocyanates stimulated an increase of dietary supplements and functional foods with highly enriched isothiocyanate concentrations on the market. Whether such concentrations may exert a potential health risk cannot be excluded with certainty and an accurate evaluation of the toxicological profile of isothiocyanates should be prompted before any major increase in their consumption be recommended or their clinical use suggested.

Distinct combinatorial effects of the plant polyphenols curcumin, carnosic acid, and silibinin on proliferation and apoptosis in acute myeloid leukemia cells

Acute myeloid leukemia (AML) is a malignancy without effective treatment for most patients. Here we demonstrate that combinations of the dietary plant polyphenols--curcumin and carnosic acid--at noncytotoxic concentrations of each agent, produced a synergistic antiproliferative effect and a massive apoptotic cell death in HL-60 and KG-1a human AML cells. In contrast, combinations of curcumin and another plant polyphenol silibinin had a predominantly additive cytostatic effect, without pronounced cytotoxicity. Neither polyphenol combination affected viability of normal human fibroblasts or proliferating and nonproliferating blood cells. Early stage of curcumin/carnosic acid-induced apoptosis was associated with cleavage (activation) of caspase-8, caspase-9, and caspase-3 and the proapoptotic protein Bid, but not with oxidative stress or altered levels of other Bcl-2 family proteins (Bcl-2, Bcl-xl, Mcl-1, Bax, and Bak). Inhibitors of caspase-8 and caspase-9 markedly attenuated apoptosis, indicating the involvement of both extrinsic and intrinsic apoptotic pathways. Caspase-8 inhibition abrogated Bid cleavage and strongly reduced caspase-9 activation, suggesting that the cross-talk mechanism mediated by caspase-8-dependent Bid cleavage can contribute to the activation of the intrinsic apoptotic pathway by curcumin + carnosic acid. Collectively, these results suggest a mechanistic basis for the potential use of dietary plant polyphenol combinations in the treatment and prevention of AML.