Inhibitory effect of carotenoids on the degranulation of mast cells via suppression of antigen-induced aggregation of high affinity IgE receptors

Screening of Prospective Antiallergic Compound as FcεRI Inhibitors and Its Antiallergic Efficacy Through Immunoinformatics Approaches

The occurrence of allergy, a type I hypersensitivity reaction, is rising exponentially all over the world. Sometimes, allergy proves to be fatal for atopic patients, due to the occurrence of anaphylaxis. This study is aimed to find an anti-allergic agent that can inhibit the binding of IgE to Human High Affinity IgE Receptor (FCεRI), thereby preventing the degranulation of mast cells. A considerable number of potential anti-allergic compounds were assessed for their inhibitory strength through ADMET studies. AUTODOCK was used for estimating the binding energy between anti-allergic compounds and FCεRI, along with the interacting amino acids. The docked pose showing favorable binding energy was subjected to molecular dynamics simulation study. Marrubiin, a diterpenoid lactone from Lamiaceae, and epicatechin-3-gallate appears to be effective in blocking the Human High Affinity IgE Receptor (FCεRI). This in-silico study proposes the use of marrubiin and epicatechin-3-gallate, in the downregulation of allergic responses. Due to the better inhibition constant, future direction of this study is to analyze the safety and efficacy of marrubiin in anti-allergic activities through in-vivo clinical human trials.

Fucoxanthin levels in maternal serum at birth and eczema risk in offspring in early childhood: A birth cohort study

BACKGROUND

Fucoxanthin, a marine xanthophyll carotenoid, has been shown to exert beneficial health effects. Cell-based and animal-based experimental studies have shown that fucoxanthin has the potential to mitigate eczema symptoms. Hence, we sought to assess whether fucoxanthinol 3-arachidate, a fucoxanthin metabolite, measured in maternal serum at birth is associated with eczema development during early childhood.

METHODS

Data from the 1989/1990 Isle of Wight birth cohort were analyzed. We focused on data obtained from the 1, 2, and 4 years follow-ups. Fucoxanthinol 3-arachidate was measured in maternal serum at the child's birth as abundance relative to the reference lipids. Eczema was ascertained according to parent-reported clinical history and characteristic morphology and distribution. Log-binomial regression models were used to estimate adjusted risk ratios (aRR) and their 95% confidence intervals (CI).

RESULTS

A total of 592 subjects (49.2% males and 50.8% females) were included in the current analysis. Associations between fucoxanthinol 3-arachidate levels and eczema risk during the first 4 years of life (longitudinal analysis) were evaluated using four modeling approaches, which showed higher fucoxanthinol 3-arachidate levels were associated with reduced eczema risk: (i) aRR_{per 10 unit increase}  = 0.88, 95% CI: 0.76-1.03; (ii) aRR_{>0 vs. =0}  = 0.67, 0.45-0.99; (iii) aRR_{≥2.3 vs. <2.3}  = 0.66, 0.44-0.98; and (iv) aRR_{tertile 3 vs. tertile 1}  = 0.65, 0.42-0.99.

CONCLUSION

Our findings suggest that increased fucoxanthinol 3-arachidate levels measured in maternal serum at the child's birth is associated with reduced eczema risk during the first 4 years of the offspring life.

Evaluation of You-Gui-Wan critical compounds inhibiting ALOX-5 and HDC gene expression in RBL-2H3 cells using a fractional factorial design

ETHNOPHARMACOLOGICAL RELEVANCE

The traditional Chinese medicine (TCM) You-Gui-Wan (YGW) has been used to treat asthma for hundreds of years.

AIM OF THE STUDY

YGW is composed of 10 types of medicinal materials. However, the immune mechanism of YGW in asthma treatment has not been elucidated. Therefore, this study investigated asthma symptoms attenuated by YGW and the underlying immune regulatory mechanism.

MATERIALS AND METHODS

Intratracheal (i.t.) stimulation of BALB/c mice with Dermatophagoides pteronyssinus (Der p) was performed once per week (40 μL, 2.5 μg/μL). For six consecutive weeks, different doses of YGW (0.2 g/kg and 0.5 g/kg) were orally administered 30 min before stimulation with Der p. After the last stimulation, airway hyperreactivity, lung gene expression, and total immunoglobulin E (IgE) in blood were evaluated using a whole-body plethysmograph system, real-time PCR, and ELISA, respectively. In addition, DNP-IgE/DNP-BSA was added to stimulate mast cells (RBL-2H3), and YGW or various compound compositions (Trial) were added to RBL-2H3 cells for 30 min to evaluate the effects of the drug on mast cell degranulation and on gene expression. JMP 5.1 software was used to design and analyze YGW's critical compounds by which it inhibited ALOX-5 and HDC gene expression in RBL-2H3 cells.

RESULTS

YGW significantly decreased serum total IgE levels and airway hyperresponsiveness in asthmatic mice. YGW also reduced the gene expression of IL-6, TNF-α, IL-4, IL-13, and COX-2 in the lungs of asthmatic mice and RBL-2H3 cells. YGW and the compound (Trial 21) present in YGW inhibited the gene expression of ALOX-5 and HDC in RBL-2H3 cells.

CONCLUSION

The experimental results indicate that YGW exhibits anti-airway hyperresponsiveness and specific immunomodulatory effects. In addition, YGW synergistically inhibits ALOX-5 and HDC gene expression in mast cells through a combination of 21 compounds, including luteolin, quercetin, and β-carotene.

Fucoxanthin Prevents the Ovalbumin-Induced Food Allergic Response by Enhancing the Intestinal Epithelial Barrier and Regulating the Intestinal Flora

This study aimed to determine whether fucoxanthin alleviated ovalbumin (OVA)-induced food allergy (FA) and explored the possible mechanisms. The results indicated that supplementation with fucoxanthin at 10.0-20.0 mg/kg per day for 7 weeks inhibited food anaphylaxis and the production of immunoglobulin (Ig) E, IgG, histamine, and related cytokines while alleviating allergic symptoms in sensitized mice. Fucoxanthin enhanced the intestinal epithelial barrier by up-regulating tight junction (TJ) protein expression and promoting regenerating islet-derived protein III-gamma (RegIIIγ) and secretory IgA (sIgA) secretion. In addition, fucoxanthin induced the secretion of anti-inflammatory factors (interleukin (IL)-10 and transforming growth factor β (TGF-β)) by regulatory T (Treg) cells and decreased the pro-inflammatory factor levels (IL-4, tumor necrosis factor-α (TNF-α), IL-17, and IL-1β), ameliorating intestinal inflammation. Compared with the model group, beneficial bacteria, such as Lactobacillaceae, increased in the intestinal flora, while pathogenic bacteria like Helicobacteraceae, Desulfovibrionaceae, and Streptococcaceae decreased. Therefore, fucoxanthin may effectively prevent FA by enhancing the intestinal epithelial barrier and reshaping the intestinal flora.

Fucoxanthin: A Promising Phytochemical on Diverse Pharmacological Targets

Fucoxanthin (FX) is a special carotenoid having an allenic bond in its structure. FX is extracted from a variety of algae and edible seaweeds. It has been proved to contain numerous health benefits and preventive effects against diseases like diabetes, obesity, liver cirrhosis, malignant cancer, etc. Thus, FX can be used as a potent source of both pharmacological and nutritional ingredient to prevent infectious diseases. In this review, we gathered the information regarding the current findings on antimicrobial, antioxidant, anti-inflammatory, skin protective, anti-obesity, antidiabetic, hepatoprotective, and other properties of FX including its bioavailability and stability characteristics. This review aims to assist further biochemical studies in order to develop further pharmaceutical assets and nutritional products in combination with FX and its various metabolites.

FcεRI: A Master Regulator of Mast Cell Functions

Mast cells (MCs) perform multiple functions thought to underlie different manifestations of allergies. Various aspects of antigens (Ags) and their interactions with immunoglobulin E (IgE) cause diverse responses in MCs. FcεRI, a high-affinity IgE receptor, deciphers the Ag–IgE interaction and drives allergic responses. FcεRI clustering is essential for signal transduction and, therefore, determines the quality of MC responses. Ag properties precisely regulate FcεRI dynamics, which consequently initiates differential outcomes by switching the intracellular-signaling pathway, suggesting that Ag properties can control MC responses, both qualitatively and quantitatively. Thus, the therapeutic benefits of FcεRI-targeting strategies have long been examined. Disrupting IgE–FcεRI interactions is a potential therapeutic strategy because the binding affinity between IgE and FcεRI is extremely high. Specifically, FcεRI desensitization, due to internalization, is also a potential therapeutic target that is involved in the mechanisms of allergen-specific immunotherapy. Several recent findings have suggested that silent internalization is strongly associated with FcεRI dynamics. A comprehensive understanding of the role of FcεRI may lead to the development of novel therapies for allergies. Here, we review the qualitatively diverse responses of MCs that impact the attenuation/development of allergies with a focus on the role of FcεRI toward Ag exposure.

Astaxanthin as a Novel Mitochondrial Regulator: A New Aspect of Carotenoids, beyond Antioxidants

Astaxanthin is a member of the carotenoid family that is found abundantly in marine organisms, and has been gaining attention in recent years due to its varied biological/physiological activities. It has been reported that astaxanthin functions both as a pigment, and as an antioxidant with superior free radical quenching capacity. We recently reported that astaxanthin modulated mitochondrial functions by a novel mechanism independent of its antioxidant function. In this paper, we review astaxanthin’s well-known antioxidant activity, and expand on astaxanthin’s lesser-known molecular targets, and its role in mitochondrial energy metabolism.

Comparison of the anticancer effect of microalgal oils and microalgal oil-loaded electrosprayed nanoparticles against PC-3, SHSY-5Y and AGS cell lines

Many of the bioactive substances used in pharmaceutical industry are easily affected by temperature, light and oxygen, and are easily degraded during storage and processing, and exhibit poor adsorption properties during digestion, which limits their direct use. Microalgae are rich in oils which have antimicrobial properties and antioxidants that attract attention in both food and pharmaceutical sectors in recent years. Studies to encapsulate bioactive compound-rich microalgae oils with nanotechnological approaches to improve the physical and chemical stability are relatively new, and it is promising to apply these approaches for pharmaceutical purposes. In this study, cytotoxic effects of oil extracts of Botryococcus braunii and Microcystis aeruginosa and their oil-loaded nanoparticles on L929 cell line, PC-3 prostate cell line, SHSY-5Y neuroblastoma cell line and AGS gastric adenocarcinoma cell line were investigated. The obtained extracts were found to have no cytotoxic effect on L929 cells. However, they showed cytotoxic effect on cancer cells. As for the nanoparticles; a gradual release was determined and the stability of the nanoparticle structure was shown. In the light of obtained findings, it was considered that nanoparticles produced with oil extracts of microalgae which have bioactive substances, have potential to be evaluated especially in pharmaceutical and cosmetic fields.

Carotenoids: Therapeutic Strategy in the Battle against Viral Emerging Diseases, COVID-19: An Overview

Carotenoids, a group of phytochemicals, are naturally found in the Plant kingdom, particularly in fruits, vegetables, and algae. There are more than 600 types of carotenoids, some of which are thought to prevent disease, mainly through their antioxidant properties. Carotenoids exhibit several biological and pharmaceutical benefits, such as anti-inflammatory, anti-cancer, and immunity booster properties, particularly as some carotenoids can be converted into vitamin A in the body. However, humans cannot synthesize carotenoids and need to obtain them from their diets or via supplementation. The emerging zoonotic virus severe acute respiratory syndrome coronavirus 2, which causes coronavirus disease 2019 (COVID-19), originated in bats, and was transmitted to humans. COVID-19 continues to cause devastating international health problems worldwide. Therefore, natural preventive therapeutic strategies from bioactive compounds, such as carotenoids, should be appraised for strengthening physiological functions against emerging viruses. This review summarizes the most important carotenoids for human health and enhancing immunity, and their potential role in COVID-19 and its related symptoms. In conclusion, promising roles of carotenoids as treatments against emerging disease and related symptoms are highlighted, most of which have been heavily premeditated in studies conducted on several viral infections, including COVID-19. Further in vitro and in vivo research is required before carotenoids can be considered as potent drugs against such emerging diseases.

The potential of marine resources for retinal diseases: a systematic review of the molecular mechanisms

We rely on vision more than on any other sense to obtain information about our environment. Hence, the loss or even impairment of vision profoundly affects our quality of life. Diet or food components have already demonstrated beneficial effects on the development of retinal diseases. Recently, there has been a growing interest in resources from marine animals and plants for the prevention of retinal diseases through nutrition. Especially fish intake and omega-3 fatty acids have already led to promising results, including associations with a reduced incidence of retinal diseases. However, the underlying molecular mechanisms are insufficiently explained. The aim of this review was to summarize the known mechanistic effects of marine resources on the pathophysiological processes in retinal diseases. We performed a systematic literature review following the PRISMA guidelines and identified 107 studies investigating marine resources in the context of retinal diseases. Of these, 46 studies described the underlying mechanisms including anti-inflammatory, antioxidant, antiangiogenic/vasoprotective, cytoprotective, metabolic, and retinal function effects, which we critically summarize. We further discuss perspectives on the use of marine resources for human nutrition to prevent retinal diseases with a particular focus on regulatory aspects, health claims, safety, and bioavailability.

Dieckol isolated from a brown alga, Eisenia nipponica, suppresses ear swelling from allergic inflammation in mouse

We previously found a lipophilic fraction of the methanol/chloroform extract of a brown alga, Eisenia nipponica, that had an antiallergic effect in a murine ear swelling test. In this study, we purified the active component from the lipophilic fraction using high performance liquid chromatography and analyzed the mass and nuclear magnetic resonance spectra. This uncovered the phlorotannin dieckol, which exhibited antiallergic effects in an ear swelling test using mice sensitized by arachidonic acid, 12-O-tetradecanoylphorbol-13-acetate, and oxazolone. Mechanistic investigations indicated that dieckol suppressed degranulation, chemical mediator release, and the expression of mRNA such as cyclooxygenase-2, interleukin-6, and tumor necrosis factor-α in rat basophilic leukemia-2H3 cells. In summary, we isolated dieckol from E. nipponica and demonstrated its antiallergic mechanisms. PRACTICAL APPLICATIONS: As the incidence of allergies increases worldwide, so too does the demand for food components with antiallergic and anti-inflammatory properties. Given this trend, we focused on a brown alga that displays a variety of bioactivities. Here, we have isolated dieckol from the antiallergic lipophilic fraction of E. nipponica and found that it possesses diverse physiological activities that may prevent lifestyle-related diseases. Consequently, dieckol or the alga containing this phlorotannin could be used as a health food ingredient to combat not only allergies, but also variety of disorders including the undesirable effects of aging.

Ephedra Herb, Mao, Inhibits Antigen-Induced Mast Cell Degranulation by Induction of the Affinity Receptor for IgE Internalization

PURPOSE

Ephedra herb (Mao) exerts potent anti-allergic effects. This study aimed to examine the underlying mechanisms of Mao on allergic inflammation using in vitro cultured mast cells (MCs) and an in vivo model of MC-dependent anaphylaxis.

METHODS

Bone marrow-derived MCs (BMMCs) were presensitized with anti-2,4-dinitrophenol (DNP) immunoglobulin E (IgE) and challenged with antigens (Ag; DNP-human serum albumin). Degranulation responses and cell surface high-affinity receptor for IgE (FcεRI) expression were assessed with/without Mao treatment. Passive systemic anaphylaxis (PSA)-treated mice were administered Mao and the pathophysiological responses were evaluated.

RESULTS

Mao inhibited Ag-induced BMMC degranulation, but not polyclonal activation with phorbol 12-myristate 13-acetate (PMA) and ionomycin, indicating that Mao inhibits IgE-dependent activation of BMMCs. Mao-treated BMMCs exhibited significant reductions in expression of surface IgE and its receptor FcεRI. Analysis of subcellular localization revealed that Mao induces FcεRI internalization in BMMCs without degranulation. In the PSA mouse model, Mao administration prevented antigen-induced hypothermia. Mao administration significantly reduced cell surface expression of IgE-bound FcεRI on peritoneal MCs.

CONCLUSIONS

Mao induced FcεRI internalization in MCs, thereby inhibiting Ag-induced IgE-dependent degranulation. The inhibitory effects of Mao on MC degranulation may offer a novel therapeutic approach for allergic diseases.

Mast Cell Regulation and Irritable Bowel Syndrome: Effects of Food Components with Potential Nutraceutical Use

Mast cells are key actors in inflammatory reactions. Upon activation, they release histamine, heparin and nerve growth factor, among many other mediators that modulate immune response and neuron sensitization. One important feature of mast cells is that their population is usually increased in animal models and biopsies from patients with irritable bowel syndrome (IBS). Therefore, mast cells and mast cell mediators are regarded as key components in IBS pathophysiology. IBS is a common functional gastrointestinal disorder affecting the quality of life of up to 20% of the population worldwide. It is characterized by abdominal pain and altered bowel habits, with heterogeneous phenotypes ranging from constipation to diarrhea, with a mixed subtype and even an unclassified form. Nutrient intake is one of the triggering factors of IBS. In this respect, certain components of the daily food, such as fatty acids, amino acids or plant-derived substances like flavonoids, have been described to modulate mast cells' activity. In this review, we will focus on the effect of these molecules, either stimulatory or inhibitory, on mast cell degranulation, looking for a nutraceutical capable of decreasing IBS symptoms.

Therapeutic Efficacy of Antioxidants in Ameliorating Obesity Phenotype and Associated Comorbidities

Obesity has been a worldwide epidemic for decades. Despite the abundant increase in knowledge regarding the etiology and pathogenesis of obesity, the prevalence continues to rise with estimates predicting considerably higher numbers by the year 2030. Obesity is characterized by an abnormal lipid accumulation, however, the physiological consequences of obesity are far more concerning. The development of the obesity phenotype constitutes dramatic alterations in adipocytes, along with several other cellular mechanisms which causes substantial increase in systemic oxidative stress mediated by reactive oxygen species (ROS). These alterations promote a chronic state of inflammation in the body caused by the redox imbalance. Together, the systemic oxidative stress and chronic inflammation plays a vital role in maintaining the obese state and exacerbating onset of cardiovascular complications, Type II diabetes mellitus, dyslipidemia, non-alcoholic steatohepatitis, and other conditions where obesity has been linked as a significant risk factor. Because of the apparent role of oxidative stress in the pathogenesis of obesity, there has been a growing interest in attenuating the pro-oxidant state in obesity. Hence, this review aims to highlight the therapeutic role of antioxidants, agents that negate pro-oxidant state of cells, in ameliorating obesity and associated comorbidities. More specifically, this review will explore how various antioxidants target unique and diverse pathways to exhibit an antioxidant defense mechanism.

Effect of Carotenoids from Phaeodactylum tricornutum on Palmitate-Treated HepG2 Cells

Non-alcoholic fatty liver disease represents the most common liver disease and is characterized by an excess of lipid accumulation in hepatocytes, mainly stored as triglycerides. Phaeodactylum tricornutum is a marine microalga, which is rich in bioactive molecules known to be hepatoprotective, such as n-3 long-chain polyunsaturated fatty acids and fucoxanthin. The aim of this study was to investigate the effects of a carotenoid extract from P. tricornutum in a cellular model of non-alcoholic fatty liver disease induced by palmitate treatment. The combined effects of carotenoids and lipids, especially n-3 long-chain polyunsaturated fatty acids, were also investigated by using a total lipophilic extract. HepG2 cells were exposed for 24 h to 250 µM palmitate with or without the addition of carotenoid extract (6 μg/mL) or total lipophilic extract (100 μg/mL). The addition of carotenoid extract or total lipophilic extract prevented the accumulation of triglycerides, total cholesterol and cholesterol esters. The carotenoid extract and total lipophilic extract also decreased the mRNA expression levels of genes involved in lipogenesis (ACACA, FASN, SCD and DGAT1) and cholesterol esterification (ACAT1/SOAT1). In addition, the total lipophilic extract also downregulated the LXR/NR1H3 and SREBF1 genes, which are involved in lipogenesis regulation. By contrast, the carotenoid extract increased the mRNA level of CPT1A, a β-oxidation related gene, and reduced the lipid droplet accumulation. In conclusion, this study highlights the preventive effects against non-alcoholic fatty liver disease of the two microalga extracts.

Qi-Wei-Du-Qi-Wan and its major constituents exert an anti-asthmatic effect by inhibiting mast cell degranulation

ETHNOPHARMACOLOGICAL RELEVANCE

In Asia, Qi-Wei-Du-Qi-Wan (QWDQW) is a traditional Chinese medicine that has been used to treat chest tightness, cough, shortness of breath, night sweats, frequent urination and asthma. QWDQW is recorded in Yi Zong Yi Ren Pian (Medical Physician's Compilation), which was written by Yang Cheng Liu during the Qing Dynasty.

AIM OF THE STUDY

The traditional Chinese medicine QWDQW is composed of 7 ingredients and has been used in the treatment of asthma in Asia for hundreds of years. However, the mechanism through which QWDQW affects the immune system in the treatment of asthma is not known. Therefore, this study aimed to investigate whether QWDQW alleviates asthmatic symptoms in mice with chronic asthma induced by repeated stimulation with Dermatophagoides pteronyssinus (Der p) and to explore the underlying immune modulatory mechanism.

MATERIALS AND METHODS

BALB/c mice were stimulated intratracheally (i.t.) with Der p (40 μl, 2.5 μg/μl) once weekly for 6 weeks. Thirty minutes prior to Der p stimulation, the mice were treated with QWDQW (0.5 g/kg and 0.17 g/kg) orally. Three days after the last stimulation, the mice were sacrificed, and infiltration of inflammatory cells, lung histological characteristics, gene expression of lung and serum total IgE were assessed. In other experiments, RBL-2H3 cells were stimulated with DNP-IgE/DNP-BSA and then treated with QWDQW, quercetin, β-carotene, luteolin or a mixture of the three chemicals (Mix13) for 30 min, and the effects of the drugs on RBL-2H3 cell degranulation after DNP stimulation were determined.

RESULTS

QWDQW significantly reduced Der p-induced airway hyperreactivity (AHR) and decreased total serum IgE and Der p-specific IgE levels. Histopathological examination showed that QWDQW reduced inflammatory cell infiltration and sputum secretion from goblet cells in the lungs. Gene expression analysis indicated that QWDQW reduced overproduction of IL-12、IFN-γ、IL-13、IL-4、RNATES、Eotaxin and MCP-1in lung. Additionally, QWDQW and Mix13 suppressed DNP induced RBL-2H3 degranulation, and the effect was maximal when quercetin, β-carotene and luteolin were administered together.

CONCLUSION

These results indicate that QWDQW plays a role in suppressing excessive airway reaction and in specific immune modulation in a mouse model of chronic asthma and that QWDQW suppresses mast cell degranulation at defined doses of quercetin, β-carotene and luteolin.

Fucoxanthin Ameliorates Atopic Dermatitis Symptoms by Regulating Keratinocytes and Regulatory Innate Lymphoid Cells

Fucoxanthin (FX) is a xanthophyll that is contained abundantly in marine plants. The biological action of FX includes its antioxidant and anti-lipogenic activities, while the precise action of its mechanisms on skin cells has not yet been clarified. The current study examined the effect of FX in comparison with tacrolimus (TAC) on NC/Nga mice, which are an atopic dermatitis (AD) model. FX topical treatment dramatically ameliorated itching behavior over the TAC treatment, which was insufficient for improvement of AD symptoms. In Nc/Nga mice, FX or TAC applied to the skin inhibited eosinophil infiltration with decreased expression of Il-33. FX also stimulated Il-2, Il-5, Il-13, Il-10, and TGF-β expression levels, and Sca1⁺Il-10⁺TGF-β⁺ regulatory innate lymphoid cells (ILCreg) were dominantly observed in FX treated skin epidermal keratinocytes and dermal layers. This combined evidence demonstrated that FX exerts anti-inflammatory effects on keratinocytes and ameliorates AD symptoms by regulating ILCreg to normalize immune responses in an atopic dermatitis model.

Xanthophyll: Health benefits and therapeutic insights

Xanthophylls constitute a major part of carotenoids in nature. They are an oxidized version of carotenoid. Xanthophyll has widely drawn scientists' attentions in terms of its functionality, bioavailability and diversity. An assortment of xanthophyll varieties includes lutein, zeaxanthin, β-cryptoxanthin, capsanthin, astaxanthin, and fucoxanthin. Chemically, lutein and zeaxanthin are dipolar carotenoids with hydroxyl groups at both ends of their molecules that bestow hydrophilic properties to them. Hydrophilic affinity in lutein and zeaxanthin makes better bioavailability in reaction with singlet oxygen in water phase, whereas non-polar carotenoids have shown to have less efficiency in scavenging free radicals. Xanthophylls have been studied for their effects in a wide variety of diseases including neurologic, ophthalmologic, oral, allergic and immune diseases. This review highlights pharmaco-pharmaceutical applications of xanthophylls as well asits drug interactions with beta-carotene. Different types of xanthophylls have been shown to have neuroprotective effects. Fucoxanthin demonstrated potent antiplasmodial activity. Lutein and zeaxanthin prevent the progression of age related macular degeneration. They have also demonstrated promising effects on uveitis, retinitis pigmentosa, scleritis, cataracts, glaucoma, retinal ischemia and choroideremia. Astaxanthin showed to have skin protecting effects against ultraviolet light injury. Astaxanthin have anti-allergic activity against the contact dermatitis especially to treat the patients having adverse reactions induced by steroids. Astaxanthin has been reported to exert beneficial effects in preventing oral lichen planus and early stage cancers. β-cryptoxanthin has been considered a good candidate for prevention of bone loss via osteoblastic bone formation and inhibiting osteoclastic bone resorption. There is also some concern that higher dose of xanthophylls may be linked to increased risk of skin cancer and gastric adenocarcinoma. However this increased risk was not statistically significant when adjusted for confounding factors. Further researches including clinical studies are needed to better evaluate the efficacy and safety of xanthophylls in prevention and treatment of different diseases.

Suppressive effect of ethanol extract from mango (Mangifera indica L.) peel on IgE production in vitro and in vivo

Immunoglobulin E (IgE) is involved in the onset of allergic reaction, and the suppression of IgE production leads to alleviation of allergic symptoms. We found that mango peel ethanol extract (MPE) significantly suppresses IgE production by human myeloma cell line U266 cells, suggesting that MPE has an anti-allergic effect by inhibiting the production of IgE. Although mangiferin is contained in mango, which suppresses IgE production by U266 cells, it was not contained in MPE. We investigated the suppressive effect of MPE in 2,4-dinitrofluorobenzene (DNFB)-induced allergic contact dermatitis model mice. The elevation of serum IgE level was significantly suppressed by oral administration of MPE. Intake of MPE also suppressed the expression level of IL-4 in the DNFB-challenged ears, suggesting that MPE suppresses the IL-4-mediated maturation into IgE-producing cells. Our findings indicate that MPE has a potential to alleviate the increase in serum IgE level that is feature of type I allergy.

Investigation of the effect of astaxanthin on alveolar bone loss in experimental periodontitis

BACKGROUND AND OBJECTIVE

Astaxanthin is a keto-carotenoid that has a strong antioxidant effect. The purpose of this study was to evaluate the effects of astaxanthin on alveolar bone loss and histopathological changes in ligature-induced periodontitis in rats.

MATERIAL AND METHODS

Wistar rats were divided into four experimental groups: non-ligated (C, n = 6); ligature only (L, n = 6); ligature and astaxanthin (1 mg/kg/day astaxanthin, AS1 group, n = 8); ligature and astaxanthin (5 mg/kg/day astaxanthin, AS5 group, n = 8). Silk ligatures were placed at the gingival margin of lower first molars of the mandibular quadrant. The study duration was 11 days and the animals were killed at the end of this period. Changes in alveolar bone levels were clinically measured and tissues were immunohistochemically examined, osteocalcin, bone morphogenic protein-2, inducible nitric oxide synthase, Bax and bcl-2 levels in alveolar bone and tartrate-resistant acid phosphatase-positive osteoclast cells, osteoblast and inflammatory cell counts were determined.

RESULTS

Alveolar bone loss was highest in the L group and the differences among the L, AS1 and AS5 groups were also significant (P < .05). Both doses of astaxanthin decreased tartrate-resistant acid phosphatase-positive+ osteoclast cell and increased osteoblast cell counts (P < .05). The inflammation in the L group was also higher than those of the C and AS1 groups were (P < .05) indicating the anti-inflammatory effect of astaxanthin. Although inducible nitric oxide synthase, osteocalcin, bone morphogenic protein-2 and bax staining percentages were all highest in the AS5 group and bcl-2 staining percentage was highest in the AS1 group, values were close to each other (P > .05).

CONCLUSION

Within the limits of this study, it can be suggested that astaxanthin administration may reduce alveolar bone loss by increasing osteoblastic activity and decrease osteoclastic activity in experimental periodontitis model.

Identification and biological activities of carotenoids from the freshwater alga Oedogonium intermedium

The chemical and biological properties of carotenoids in the freshwater alga Oedogonium intermedium were investigated in this study. Carotenoids were extracted from the alga by dichloromethane and purified by saponification. The carotenoid content was determined both spectrometrically and by HPLC, the carotenoids identified by HPLC-PDA-APCI-IT-TOF-MS and the extracts analysed for several health-related bioactivities. The crude and saponified extracts contained 3,411.2±20.7 and 2,929.6±5.9µg carotenoids/g dry algal biomass, respectively. Seven major carotenoids were identified, namely neoxanthin, 9'-cis-neoxanthin, loroxanthin, violaxanthin, lutein, α-carotene and β-carotene, which were present in similar amounts in the alga. Both the crude and saponified carotenoid extracts exhibited significant antioxidant activities as well as potent inhibitory effects against several metabolically important enzymes including α-amylase, α-glucosidase, pancreatic lipase and hyaluronidase, but they were poor inhibitors of angiotensin converting enzyme (ACE). Oedogonium could be an important new source of carotenoids, specifically loroxanthin, which is lacking in terrestrial plants.

A novel arctigenin-containing latex glove prevents latex allergy by inhibiting type I/IV allergic reactions

The present study aimed at developing a natural compound with anti-allergic effect and stability under latex glove manufacturing conditions and investigating whether its anti-allergic effect is maintained after its addition into the latex. The effects of nine natural compounds on growth of the RBL-2H3 cells and mouse primary spleen lymphocytes were determined using MTT assay. The compounds included glycyrrhizin, osthole, tetrandrine, tea polyphenol, catechin, arctigenin, oleanolic acid, baicalin and oxymatrine. An ELISA assay was used for the in vitro anti-type I/IV allergy screening; in this process β-hexosaminidase, histamine, and IL-4 released from RBL-2H3 cell lines and IFN-γ and IL-2 released from mouse primary spleen lymphocytes were taken as screening indices. The physical stability of eight natural compounds and the dissolubility of arctigenin, selected based on the in vitro pharnacodynamaic screening and the stability evaluation, were detected by HPLC. The in vivo pharmacodynamic confirmation of arctigenin and final latex product was evaluated with a passive cutaneous anaphylaxis (PCA) model and an allergen-specific skin response model. Nine natural compounds showed minor growth inhibition on RBL-2H3 cells and mouse primary spleen lymphocytes. Baicalin and arctigenin had the best anti-type I and IV allergic effects among the natural compounds based on the in vitro pharmacodynamic screening. Arctigenin and catechin had the best physical stability under different manufacturing conditions. Arctigenin was the selected for further evaluation and proven to have anti-type I and IV allergic effects in vivo in a dose-dependent manner. The final product of the arctigenin-containing latex glove had anti-type I and IV allergic effects in vivo which were mainly attributed to arctigenin as proved from the dissolubility results. Arctigenin showed anti-type I and IV allergic effects in vitro and in vivo, with a good stability under latex glove manufacturing conditions, and a persistent anti-allergic effect after being added into the latex to prevent latex allergy.

Modulación de la respuesta alérgica por los carotenoides de la dieta

<p>Los carotenoides son pigmentos isoprenoides que están presentes de manera natural y en altas concentraciones en la mayoría de alimentos vegetales —entre ellos, aguacate, papaya, tomate y zanahoria—, pero también encontrados como aditivos y colorantes en diversos productos cárnicos, aceites vegetales, salsas, aderezos, harinas, entre otros. En los últimos años, algunos estudios han descrito que los carotenoides de la dieta participan en varios procesos fisiopatológicos, incluyendo la respuesta inmune de tipo alérgico. Las tasas de prevalencia para este tipo de enfermedades han incrementado de manera alarmante durante las últimas cinco décadas en todo el mundo, a la vez que varios factores e hipótesis se han planteado tratando de explicar este fenómeno: uno de ellos es la hipótesis de la dieta, la cual plantea que la composición de varios micro y macronutrientes de la alimentación, así como los cambios en los patrones dietarios, influirían en tal problemática. Evidencia epidemiológica y básica experimental emergente señala que los carotenoides de la dieta participan en la regulación de la inflamación alérgica, y por ello se postulan como coadyuvantes en la terapia de tales padecimientos. En el presente artículo se revisará el estado del arte en relación a los efectos de los carotenoides de la dieta sobre la patología alérgica.</p>

Marine Carotenoids against Oxidative Stress: Effects on Human Health

Carotenoids are lipid-soluble pigments that are produced in some plants, algae, fungi, and bacterial species, which accounts for their orange and yellow hues. Carotenoids are powerful antioxidants thanks to their ability to quench singlet oxygen, to be oxidized, to be isomerized, and to scavenge free radicals, which plays a crucial role in the etiology of several diseases. Unusual marine environments are associated with a great chemical diversity, resulting in novel bioactive molecules. Thus, marine organisms may represent an important source of novel biologically active substances for the development of therapeutics. In this respect, various novel marine carotenoids have recently been isolated from marine organisms and displayed several utilizations as nutraceuticals and pharmaceuticals. Marine carotenoids (astaxanthin, fucoxanthin, β-carotene, lutein but also the rare siphonaxanthin, sioxanthin, and myxol) have recently shown antioxidant properties in reducing oxidative stress markers. This review aims to describe the role of marine carotenoids against oxidative stress and their potential applications in preventing and treating inflammatory diseases.

Fucoxanthin: A Promising Medicinal and Nutritional Ingredient

Fucoxanthin, an allenic carotenoid, can be isolated from edible brown seaweeds. Recent studies have reported that fucoxanthin has many physiological functions and biological properties, such as antiobesity, antitumor, antidiabetes, antioxidant, anti-inflammatory, and hepatoprotective activities, as well as cardiovascular and cerebrovascular protective effects. Therefore, fucoxanthin can be used as both medicinal and nutritional ingredient to prevent and treat chronic diseases. Although fucoxanthin possesses many medicinal ingredient and nutritional qualities, studies indicated that its structure was unstable. In this paper, we consulted the current documents and reviewed structural properties and factors affecting the stability of fucoxanthin. We also reported the metabolism, safety, pharmacological activities, and the methods of improving the bioavailability of fucoxanthin. Based on these studies providing essential background knowledge, fucoxanthin can be developed into marine drugs and nutritional products.

Anti-obesity activity of the marine carotenoid fucoxanthin

Nowadays the global tendency towards physical activity reduction and an augmented dietary intake of fats, sugars and calories is leading to a growing propagation of overweight, obesity and lifestyle-related diseases, such diabetes, hypertension, dyslipidemia and metabolic syndrome. In particular, obesity, characterized as a state of low-level inflammation, is a powerful determinant both in the development of insulin resistance and in the progression to type 2 diabetes. A few molecular targets offer hope for anti-obesity therapeutics. One of the keys to success could be the induction of uncoupling protein 1 (UCP1) in abdominal white adipose tissue (WAT) and the regulation of cytokine secretions from both abdominal adipose cells and macrophage cells infiltrated into adipose tissue. Anti-obesity effects of fucoxanthin, a characteristic carotenoid, exactly belonging to xanthophylls, have been reported. Nutrigenomic studies reveal that fucoxanthin induces UCP1 in abdominal WAT mitochondria, leading to the oxidation of fatty acids and heat production in WAT. Fucoxanthin improves insulin resistance and decreases blood glucose levels through the regulation of cytokine secretions from WAT. The key structure of anti-obesity effect is suggested to be the carotenoid end of the polyene chromophore, which contains an allenic bond and two hydroxyl groups. Fucoxanthin, which can be isolated from edible brown seaweeds, recently displayed its many physiological functions and biological properties. We reviewed recent studies and this article aims to explain essential background of fucoxanthin, focusing on its promising potential anti-obesity effects. In this respect, fucoxanthin can be developed into promising marine drugs and nutritional products, in order to become a helpful functional food.

Hydroxytyrosol and oleuropein of olive oil inhibit mast cell degranulation induced by immune and non-immune pathways

The aim of this study was to determine whether hydroxytyrosol and oleuropein, the major phenols found in olives and olive oil, inhibit mast cell activation induced by immune and non-immune pathways. Purified peritoneal mast cells were preincubated in the presence of test compounds (hydroxytyrosol or oleuropein), before incubation with concanavalin A, compound 48/80 or calcium ionophore A23187. Dose-response and time-dependence studies were carried out. Comparative studies with sodium cromoglycate, a classical mast cell stabilizer, were also made. After incubation the supernatants and pellets were used to determine the β-hexosaminidase content by colorimetric reaction. The percentage of β-hexosaminidase release in each tube was calculated and taken as a measure of mast cell activation. Other samples of cell pellets were used for cell viability studies by the trypan blue dye exclusion test, or fixed for light and electron microscopy. Biochemical and morphological findings of the present study showed for the first time that hydroxytyrosol and oleuropein inhibit mast cell degranulation induced by both immune and non-immune pathways. These results suggest that olive phenols, particularly hydroxytyrosol and oleuropein, may provide insights into the development of useful tools for the prevention and treatment of mast cell-mediated disorders.

Siphonaxanthin, a green algal carotenoid, as a novel functional compound

Siphonaxanthin is a specific keto-carotenoid in green algae whose bio-functional properties are yet to be identified. This review focuses on siphonaxanthin as a bioactive compound and outlines the evidence associated with functionality. Siphonaxanthin has been reported to potently inhibit the viability of human leukemia HL-60 cells via induction of apoptosis. In comparison with fucoxanthin, siphonaxanthin markedly reduced cell viability as early as 6 h after treatment. The cellular uptake of siphonaxanthin was 2-fold higher than fucoxanthin. It has been proposed that siphonaxanthin possesses significant anti-angiogenic activity in studies using human umbilical vein endothelial cells and rat aortic ring. The results of these studies suggested that the anti-angiogenic effect of siphonaxanthin is due to the down-regulation of signal transduction by fibroblast growth factor receptor-1 in vascular endothelial cells. Siphonaxanthin also exhibited inhibitory effects on antigen-induced degranulation of mast cells. These findings open up new avenues for future research on siphonaxanthin as a bioactive compound, and additional investigation, especially in vivo studies, are required to validate these findings. In addition, further studies are needed to determine its bioavailability and metabolic fate.

Identification and evaluation of anti-inflammatory compounds from Kaempferia parviflora

The rhizome of Kaempferia parviflora has been used in traditional Thai medicine. In this study, we identified and compared specific compounds from the hexane extract of K. parviflora with those from other Zingiberaceous plants by using gas chromatography–mass spectrometry. We identified 5,7-dimethoxyflavone (DMF), 5-hydroxy-3,7,3′,4′-tetramethoxyflavone (TMF), estimated 3,5,7-trimethoxyflavone, 5-hydroxy-7,4′-dimethoxyflavone, 3,5,7,4′-tetramethoxyflavone, and investigated their anti-inflammatory effects in rat basophilic leukemia (RBL-2H3) cells stimulated with an IgE antigen or a calcium ionophore. We found that DMF and TMF more potently inhibited antigen-induced degranulation than did nobiletin, a well-known anti-inflammatory agent. In addition, compared to RBL-2H3 cells stimulated with a calcium ionophore, those treated with DMF and TMF showed more marked inhibition of the degranulation and the production and mRNA expression of inflammatory mediators. These results suggest that DMF and TMF inhibit an early step in the high-affinity IgE receptor signaling cascade rather than intracellular calcium release and protein kinase C activation.

Peridinin from the marine symbiotic dinoflagellate, Symbiodinium sp., regulates eosinophilia in mice

Peridinin and fucoxanthin, which are natural carotenoids isolated from a symbiotic dinoflagellate, Symbiodinium sp., and a brown alga, Petalonia fascia, respectively, were compared for inhibitory effects on delayed-type hypersensitivity in mice. The number of eosinophils at the site of inflammation and in peripheral blood was compared for the administration of peridinin and fucoxanthin applied by painting and intraperitoneally. Peridinin, but not the structurally-related fucoxanthin, significantly suppressed the number of eosinophils in both the ear lobe and peripheral blood. Furthermore, peridinin applied topically, but not administered intraperitoneally, suppressed the level of eotaxin in the ears of sensitized mice. Fucoxanthin weakly suppressed the concentration of eotaxin in ears only by intraperitoneal administration. Although both carotenoids inhibited the migration of eosinophils toward eotaxin, the inhibitory effect of peridinin was higher than that of fucoxanthin. Peridinin may be a potential agent for suppressing allergic inflammatory responses, such as atopic dermatitis, in which eosinophils play a major role in the increase of inflammation.

Immunomodulation of mast cells by nutrients

In the past decades an increasing prevalence of allergic disorders was observed in industrialized countries. Thus, it is necessary to develop adequate therapeutic and preventive strategies. Many of the conservative strategies possess diverse harmful side effects. Therefore agents with fewer side effects and a better compliance among afflicted patients would be of interest. Especially substances with natural origin acting immunomodulatory on mast cells - the key effector cells of allergic diseases - could be used. Among them there are components of the daily diet such as distinct fatty acids and amino acids as well as a range of secondary plant substances such as carotenoids, flavonoids and spices. These nutritional substances could be applied as nutraceuticals in the therapy of mast cell associated diseases. Many of these substances show inhibitory influences on the release of prestored mast cell mediators such as histamine or de novo expression of mast cell mediators such as cytokines and eicosanoids which are involved in the pathogenesis of mast cell associated inflammatory conditions like allergic reactions.

Streptochlorin suppresses allergic dermatitis and mast cell activation via regulation of Lyn/Fyn and Syk signaling pathways in cellular and mouse models

Allergic diseases are chronic inflammatory conditions with specific immune and inflammatory mechanisms. Scientific interest in understanding the mechanisms and discovering novel agents for the prevention and treatment of allergic disease is increasing. Streptochlorin, a small compound derived from marine actinomycete possesses anti-angiogenic and anti-tumor activities. However, the anti-allergic effects and underlying mechanisms remain to be elucidated. In the present study, we investigated the effect of streptochlorin on allergic responses in vitro and in vivo. Streptochlorin inhibited degranulation and production of tumor necrosis factor-α and IL-4 by antigen-stimulated mast cells. Streptochlorin also inhibited the phosphorylation of Akt and the mitogen-activated protein kinases (MAPKs), including p38, ERK, and JNK. Further, streptochlorin reduced the phosphorylation of Syk in RBL-2H3 cells and inhibited the activity of Lyn and Fyn. Furthermore, administration of streptochlorin suppressed the allergic reactions in both passive cutaneous anaphylaxis reaction and 2, 4-dinitrofluorobenzene (DNFB)-induced allergic dermatitis in mice model. Considering the data obtained, we report for the first time that streptochlorin possess anti-allergic properties. The underlying mechanism of streptochlorin in exhibiting potent anti-allergic activity might be through the inhibition of the Lyn/Fyn and Syk signaling pathways.

Plastids of marine phytoplankton produce bioactive pigments and lipids

Phytoplankton is acknowledged to be a very diverse source of bioactive molecules. These compounds play physiological roles that allow cells to deal with changes of the environmental constrains. For example, the diversity of light harvesting pigments allows efficient photosynthesis at different depths in the seawater column. Identically, lipid composition of cell membranes can vary according to environmental factors. This, together with the heterogenous evolutionary origin of taxa, makes the chemical diversity of phytoplankton compounds much larger than in terrestrial plants. This contribution is dedicated to pigments and lipids synthesized within or from plastids/photosynthetic membranes. It starts with a short review of cyanobacteria and microalgae phylogeny. Then the bioactivity of pigments and lipids (anti-oxidant, anti-inflammatory, anti-mutagenic, anti-cancer, anti-obesity, anti-allergic activities, and cardio- neuro-, hepato- and photoprotective effects), alone or in combination, is detailed. To increase the cellular production of bioactive compounds, specific culture conditions may be applied (e.g., high light intensity, nitrogen starvation). Regardless of the progress made in blue biotechnologies, the production of bioactive compounds is still limited. However, some examples of large scale production are given, and perspectives are suggested in the final section.

The anti-apoptotic effect of fucoxanthin on carbon tetrachloride-induced hepatotoxicity

This study evaluated the anti-apoptotic activity of fucoxanthin in carbon tetrachloride (CCl(4))-induced hepatotoxicity. An in vitro study using the 3-(4,5-dimethylthiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay clearly demonstrated an attenuation of CCl(4)-induced hepatotoxicity with fucoxanthin. This effect was dose-dependent; 25 µM was more effective than 10 µM of fucoxanthin for attenuating the hepatotoxicity induced by 5 mM of CCl(4). Acute CCl(4)-hepatotoxicity in rats, with numerous cells positive for the terminal deoxynucleotidyl - transferase (TdT) -mediated deoxyuridine triphosphate-digoxigenin (dUTP) nick-end labeling (TUNEL) stain were seen in the pericentral area of the hepatic lobule. Oral pretreatment of CCl(4)- injected rats with fucoxanthin significantly reduced hepatocyte apoptosis. Fucoxanthin was immunohistochemically shown to increase heme oxygenase-1 expression in the cultured liver cells of Hc cells and TRL1215 cells. By oral pretreatment of CCl(4)-injected rats with fucoxanthin, the hepatic heme oxygenase-1 protein levels were significantly increased compared to those not pretreated with fucoxanthin. Heme oxygenase-1 mRNA expression after CCl(4 )injection was higher in the CCl(4)+fucoxanthin group than in the CCl(4 )group, although the difference was not significant. The findings suggest that fucoxanthin attenuates hepatocyte apoptosis through heme oxygenase-1 induction in CCl(4)-induced acute liver injury.

The inhibitory activity of atractylenolide Ш, a sesquiterpenoid, on IgE-mediated mast cell activation and passive cutaneous anaphylaxis (PCA)

ETHNOPHARMACOLOGICAL RELEVANCE

AT Ш, a sesquiterpenoid, is the major component of Atractylodes japonica Koidz that has been used as a traditional oriental medicine.

AIM OF THE STUDY

We investigated the anti-allergic activity of AT Ш and its mechanism of action.

MATERIALS AND METHODS

The released amount of β-hexosaminidase in mast cells, a key parameter of degranulation, was measured. Anti-allergic potential of AT Ш was evaluated using passive cutaneous anaphylaxis in vivo. The anti-allergic mechanism of AT Ш was investigated by immunoblotting analysis, RT-PCR and measurement of [Ca(2+)]i in mast cells.

RESULTS

AT Ш significantly inhibited IgE/Ag-mediated degranulation with an IC(50) value (36 ± 4 μM) in RBL-2H3 cells without affecting cell viability. It also suppressed IgE/Ag-mediated passive cutaneous anaphylaxis (PCA) response with an ED(50) value (65 ± 41 mg/kg) in vivo. AT Ш suppressed the production of interleukin (IL-4) and tumor necrosis factor (TNF)-alpha mRNAs more potent than the Src-family kinase inhibitor PP2 in RBL-2H3 cells at all concentrations. In order to elucidate the anti-allergic mechanisms of AT Ш in mast cells, we examined the activated levels of signaling molecules. AT Ш inhibited the phosphorylation of Lyn, Fyn, Syk, LAT, PLCγ, Gab2, Akt, p38, and JNK kinases expression. IgE/Ag-mediated [Ca(2+)]i elevation was significantly inhibited by AT Ш.

CONCLUSIONS

Our study suggests that AT Ш might be used as a therapeutic agent for allergic diseases.