Extra virgin olive oil and related by-products (Olea europaea L.) as natural sources of phenolic compounds for abdominal pain relief in gastrointestinal disorders in rats.

Management of abdominal pain, a common symptom of IBDs and IBS, is still a clinical problem. Extra virgin olive oil (EVOO), a main component of the Mediterranean diet, shows positive effects on chronic inflammation in IBDs. In this study, the effect of the oral administration of EVOO (3 mL) and two olive milling by-products, DPA (300 mg kg-1) and DRF (300 mg kg-1), on preventing the development of abdominal pain in a DNBS-induced colitis model in rats was evaluated. The doses were chosen with the aim of simulating a plausible daily intake in humans. DPA and EVOO treatments significantly reduced the abdominal viscero-motor response to colon-rectal distension at 2 and 3 mL of balloon distension volume, both 7 and 14 days after the DNBS-injection. DRF showed efficacy in the reduction of visceral hypersensitivity only with 3 mL balloon inflation. In awake animals, DPA and DRF reduced pain perception (evaluated as abdominal withdrawal reflex) with all balloon distension volumes, while EVOO was effective only with higher distension volumes. Fourteen days after the DNBS-injection, all samples reduced the macroscopic intestinal damage (quantified as the macroscopic damage score) also showing, at the microscopic level, a reduction of the inflammatory infiltrate (quantified by hematoxylin and eosin analysis), fibrosis (highlighted by picrosirius red staining), the increase in mast cells and their degranulation (analyzed by triptase immunohistochemistry). This is the first report on the promotion of abdominal pain relief in a rat model obtained administering EVOO and two derived by-products. Our results suggest a protective role of phenol-rich EVOO and milling by-products, which may be proposed as food ingredients for novel functional foods.

Black Raspberries and Protocatechuic Acid Mitigate DNFB-Induced Contact Hypersensitivity by Down-Regulating Dendritic Cell Activation and Inhibiting Mediators of Effector Responses.

Contact hypersensitivity (CHS) is the most common occupational dermatological disease. Dendritic cells (DCs) mediate the sensitization stage of CHS, while T-cells facilitate the effector mechanisms that drive CHS. Black raspberry (Rubus occidentalis, BRB) and BRB phytochemicals possess immunomodulatory properties, but their dietary effects on CHS are unknown. We examined the effects of diets containing BRB and protocatechuic acid (PCA, a constituent of BRB and an anthocyanin metabolite produced largely by gut microbes), on CHS, using a model induced by 2,4-dinitrofluorobenze (DNFB). Mice were fed control diet or diets supplemented with BRB or PCA. In vitro bone-marrow derived DCs and RAW264.7 macrophages were treated with BRB extract and PCA. Mice fed BRB or PCA supplemented diets displayed decreased DNFB-induced ear swelling, marked by decreased splenic DC accumulation. BRB extract diminished DC maturation associated with reduced Cd80 expression and Interleukin (IL)-12 secretion, and PCA reduced IL-12. Dietary supplementation with BRB and PCA induced differential decreases in IL-12-driven CHS mediators, including Interferon (IFN)-γ and IL-17 production by T-cells. BRB extracts and PCA directly attenuated CHS-promoting macrophage activity mediated by nitric oxide and IL-12. Our results demonstrate that BRB and PCA mitigate CHS pathology, providing a rationale for CHS alleviation via dietary supplementation with BRB or BRB derived anthocyanins.

Conjugated linoleic acid attenuates 2,4-dinitrofluorobenzene-induced atopic dermatitis in mice through dual inhibition of COX-2/5-LOX and TLR4/NF-κB signaling.

Conjugated linoleic acid (CLA), commonly found in beef, lamb and dairy products, has been reported to exhibit anti-inflammatory and antipruritus effects and to inhibit the release of chemical mediators such as histamine and eicosanoid in laboratory rodents. The chief objective of the study is to assess the efficacy of CLA on atopic dermatitis (AD) in mice and to explore possible mechanisms with CLA treatments. To develop a new therapy for AD, the anti-AD potential of CLA was investigated by inducing AD-like skin lesions in mice using 2,4-dinitrofluorobenzene. We evaluated dermatitis severity; histopathological changes; serum levels of T helper (Th) cytokines (interferon-γ, interleukin-4); changes in protein expression by western blotting and immunohistochemistry staining for cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), toll like receptor 4 (TLR-4), myeloid differentiation factor 88 (MyD88), nuclear factor-κB (NF-κB) and tumor necrosis factor α (TNF-α); and production of the proinflammatory lipid mediators, such as prostaglandin E2 and leukotriene B4, in the skin lesions. Treatment with CLA ameliorated the development of AD-like clinical symptoms and effectively inhibited epidermal hyperplasia and infiltration of mast cells and CD4+ T cells in the AD mouse skin. Total serum immunoglobulin E levels and the expression levels of Th1/Th2 cytokines and lipid mediators in dorsal skin were dramatically suppressed by CLA. Furthermore, CLA down-regulated the expressions of COX-2, 5-LOX, TLR4, MyD88, NF-κB and TNF-α. Taken together, our findings demonstrate the potential usefulness of CLA as an anti-inflammatory dietary supplement or drug for the prevention and management of AD skin diseases by modulating the COX-2/5-LOX and TLR4/MyD88/NF-κB signaling pathways.

Bamboo salt suppresses skin inflammation in mice with 2, 4-dinitrofluorobenzene-induced atopic dermatitis.

Bamboo salt (BS) is a traditional Korean food, and has been reported to have anti-cancer, anti-inflammatory, and anti-metastatic effects. However, the anti-atopic dermatitis (AD) activity of BS has not been described yet. In the present study, we examined the preventive effect of BS on AD. The effect of oral administration of BS was tested in a 2, 4-dinitrofluorobenzene (DNFB)-induced AD animal model, by histological analysis, enzyme-linked immunosorbent assay, reverse transcription-polymerase chain reaction, caspase-1 assay, and Western blotting analysis. BS administration reduced the total clinical severity and scratching frequencies, compared with the AD group. In the serum of DNFB-induced AD mice, the levels of IgE, histamine, thymic stromal lymphopoietin (TSLP), interleukin (IL)-5, and IL-13 were significantly reduced by BS treatment. BS significantly reduced the protein and mRNA expression of TSLP, IL-6, and tumor necrosis factor-α in the AD skin lesions. BS markedly reduced the infiltration of inflammatory cells. Furthermore, the activation of caspase-1 was reduced by BS in the AD skin lesions. Our results suggested that BS should be considered as a candidate treatment for allergic inflammatory diseases including AD.

MicroRNA-21-Mediated Inhibition of Mast Cell Degranulation Involved in the Protective Effect of Berberine on 2,4-Dinitrofluorobenzene-Induced Allergic Contact Dermatitis in Rats via p38 Pathway.

The study aimed to investigate the effect of berberine on allergic contact dermatitis (ACD) in rats and explore its underlying mechanisms. Firstly, ACD model was established by sensitizing and challenging with 2,4-dinitrofluorobenzene (DNFB) topically, and the rats were treated with berberine. Ear swelling was assessed, and cytokine, IgE, and histamine productions were measured. The ear biopsies were obtained for histology analysis. Additionally, rat peritoneal mast cells (RPMCs) were isolated for detection of microRNA-21 (miR-21) expression, mitogen-activated protein kinase (MAPK) signaling, and MC degranulation. Lastly, RPMCs were transfected with miR-21 mimic or miR-21 inhibitor to investigate the relationship between miR-21 and p38 pathway in MC. Our results showed that berberine significantly attenuated ear swelling in DNFB-induced ACD (ACD vs high dose of berberine 0.48 ± 0.03 vs. 0.33 ± 0.03 mm, P < 0.01), inhibited inflammatory cell infiltration (86 ± 5.16 vs. 58 ± 4.32 cells/mm2, P < 0.01), reduced MC recruitment (61 ± 4.07 vs. 39 ± 3.42 mast cells/mm2, P < 0.01), as well as decreased inflammatory cytokine, IgE, and histamine productions (all P < 0.05). Berberine treatment inhibited miR-21 expression, suppressed ß-hexosaminidase and histamine release, and prevented p38 phosphorylation (all P < 0.05), which was abrogated by pretreatment with miR-21 overexpression. These findings indicate that miR-21-mediated inhibition of MC degranulation is involved in the anti-ACD effect of berberine via inhibiting p38 pathway, which provide a new insight into the immunopharmacological role of berberine and suggest its potential application for the treatment of allergic inflammation, such as ACD.

The solid-state fermentation of Artemisia capillaris leaves with Ganoderma lucidum enhances the anti-inflammatory effects in a model of atopic dermatitis.

Artemisia capillaris, which belongs to the Asteraceae family and the genus Artemisia, has been reported to exert inhibitory effects on diabetes, cancer and inflammation. In this study, in order to enhance the bioactivity potential of the leaves of Artemisia by Ganoderma lucidum mycelium, we prepared aqueous samples of Artemisia capillaris (Ac) leaves, Ganoderma lucidum (Gl) and aqueous fractions produced by the solid fermentation of Ganoderma lucidum on Artemisia capillaris leaves (afAc/Gl). Thereafter, we evaluated whether these samples have potential to attenuate inflammation-related symptoms in an amimal model of 2,4-dinitrofluorobenzene (DNFB)-induced atopic dermatitis. We found that afAc/Gl exhibited enhanced anti-inflamamatory activity following the solid fermentation process when compared with Ac or Gl on ear thickness, ear epidermal thickness and eosinophil infiltration in the skin tissues. The expression of nitric oxide (NO) synthases (NOSs) was measured by immunohistochemical staining. The results revealed that afAc/Gl decreased endothelial NOS and inducible NOS expression compared with the DNFB group, while neuronal NOS expression was not altered. By comparing NO production, we found that as opposed to Ac, afAc/Gl has potential to inhibit atopic dermatitis-related symptoms during the inflammatory event. As regards matrix metalloproteinase (MMP) expression patterns, afAc/Gl exerted potent inhibitory activity on the mRNA expression of MMP-2, -7, -9, -12, -14 and -19. Taken together, these results suggest that the solid state fermentation of Ac by Gl is an effective strategy to obtaining useful ingredients which are converted into valuable compounds during an atopic inflammatory insult.

Grape-seed proanthocyanidins ameliorate contact hypersensitivity induced by 2,4-dinitrofluorobenzene (DNFB) and inhibit T cell proliferation in vitro.

Contact hypersensitivity (CHS) is a delayed-type hypersensitivity reaction which is mediated by hapten-specific T cells. Strong haptens, such as 2, 4-dinitrofluorobenzene (DNFB) can induce it. Grape seed proanthocyanidins extract (GSPs), which is an antioxidant derived from grape seeds, has been reported to possess a variety of potent properties. However, few reports demonstrated the effects of GSPs on contact hypersensitivity. Therefore, the present study was devised to describe the role of GSPs on a mouse model of experimental CHS induced by DNFB and try to explore the possible underlying mechanisms. We observed that, GSPs when orally administrated into the CHS mice, inhibited the aggravation of inflammation. After administration of GSPs, there was obvious fewer inflammatory cell infiltration in the inflamed ears. Ear swelling after challenge was significantly reduced. In addition, we investigated the effects of GSPs on T cells in vitro, which play critical role during the progress of CHS. It was found that GSPs inhibited proliferative activity of T cells by blocking the activation of mitogen-activated protein kinases (MAPK) and NF-кB signaling pathways. Collectively, these results showed that GSPs has protective effect on CHS induced by DNFB and it also could inhibit the proliferation ability of T cells in vitro, suggesting the potential of GSPs as new and effective compound for the treatment of T-cell mediated inflammatory diseases.

Mitigation of 2,4-dinitrofluorobenzene-induced atopic dermatitis-related symptoms by Terminalia chebula Retzius.

To evaluate whether an aqueous seed extract of Terminalia chebula Retzius inhibited development of atopy in vivo, we used a 2,4-dinitrofluorobenzene (DNFB)-induced animal model of atopic symptoms to investigate the effects of the extract. We measured CD4+ cell numbers by hematoxylin and eosin (H&E) staining, and determined the expression levels of matrix metalloproteinase (MMP)-9, interleukin (IL)-31, and T-bet genes, in this animal model. The data showed that a Terminalia chebula extract (100 µg/ml) exhibited strong anti-atopic activity, mediating a 52% reduction in the immune response, as measured by thickness of ear swelling, and resulting in decreased eosinophil levels in adjacent skin tissue. Collectively, the results indicate that a Terminalia chebula seed extract has potential for alleviation of atopy-like symptoms induced by DNFB in the mouse.

Effect of tiacrilast, a mast cell mediator-release inhibitor, on murine experimental contact dermatitis.

The effect of tiacrilast, a mast cell mediator-release inhibitor, was studied in dinitrofluorobenzene-induced allergic and croton oil- or dimethyl sulfoxide-induced irritant murine contact dermatitis. At 1% concentration, the compound significantly reduced the ear swelling in both allergic and irritant dermatitis and preserved the mast cell architecture on histopathology. These findings suggest that mast cells participate in the elicitation of murine contact dermatitis.