In Vitro TNF-α Inhibition Elicited by Extracts from Echinodorus grandiflorus Leaves and Correlation with Their Phytochemical Composition.

This study aimed to evaluate the effect of various extracts and fractions obtained from Echinodorus grandiflorus leaves on tumor necrosis factor-α release by lipopolysaccharide-stimulated THP-1 cells, as well as to look at the association between bioactivity and phytochemical composition. To this end, a high-performance liquid chromatography with diode-array detection method was developed and validated, enabling the quantification of seven compounds in E. grandiflorus extracts and fractions. All of these samples showed antitumor necrosis factor-α activity, however, extracts prepared from 50% EtOH, water and dichloromethane, and a flavonoid-rich fraction elicited the most potent responses. trans-Aconitic acid and isoorientin were the major compounds in some preparations. Polynomial regression analysis showed the association between the contents of swertiajaponin, swertisin, trans-aconitic, and chicoric acids with the antitumor necrosis factor-α activity of the extracts and fractions. None of the compounds tested alone abolished tumor necrosis factor-α release completely, however, some extracts and fractions reached this result, suggesting a synergistic effect between the constituents. Therefore, it is clearly shown that the species E. grandiflorus has significant in vitro antitumor necrosis factor-α activity, a promising characteristic that deserves further investigations in the search for new anti-inflammatory agents from plants.

Evaluation of the Wound Healing Properties of Hancornia speciosa Leaves.

The leaves of Hancornia speciosa Gomes (Apocynaceae), a medicinal species found in the Brazilian cerrado biome, are traditionally used to treat wounds and inflammatory disorders. The goal of the present study was to investigate the in vitro wound healing properties of ethanolic extract of H. speciosa leaves and its isolated compounds, using the scratch assay, and to evaluate their effects on the release of the pro-inflammatory cytokine tumor necrosis factor (TNF-α) by lipopolysaccharide (LPS)-stimulated human acute monocytic (THP-1) cells. H. speciosa ethanolic extract significantly increased (42.8% ± 5.4 at 25 µg/mL) cell migration and proliferation of fibroblasts compared with control cells, as well as the isolated compounds bornesitol (80.8% ± 5.1) and quinic acid (69.1% ± 6.2), both assayed at 50 µM. TNF-α release by LPS-stimulated THP-1 cells was significantly reduced by the ethanolic extract (62.9% ± 8.2, i.e. 1791.1 ± 394.7 pg/mL) at 10 µg/mL, bornesitol (48.9% ± 0.9, i.e. 2461.6 ± 43.1 pg/mL) at 50 µM, and quinic acid (90.2% ± 3.4, i.e. 473.5 ± 164.4 pg/mL) and rutin (82.4% ± 5.6, i.e. 847.0 ± 271.8 pg/mL) at 10 µM. These results provided evidences to support the traditional use of H. speciosa leaves to treat wounds and inflammatory disorders.

Prolonged ingestion of ovalbumin diet by Ova sensitized mice suppresses mBSA-induced arthritis.

Concomitant chronic diseases are a common finding in clinics and may consist in a major issue in therapeutics. Here, we investigated whether prolonged ingestion of ovalbumin (Ova) by sensitized mice would reduce the severity of an associated concurrent immunomediated condition such as antigen-induced arthritis (AIA). AIA was induced by administration of methylated bovine albumin (mBSA) into the knee joints of previously immunized mice, and evaluated by articular leukocyte trafficking and levels of cytokines (TNF-α, IL-1ß) and chemokine (CXCL-1) in the periarticular tissue. Continuous Ova feeding by Ova sensitized mice decreased serum levels of anti-Ova IgE, and led to a significant suppression of leukocyte adhesion and infiltration into synovial tissue and cavity. Also, a marked cytokine reduction was observed, suggesting that prolonged ingestion of ovalbumin by sensitized mice suppresses specific IgE production with concomitant reduction in peripheral T cells, which may impact in the pathogenesis of AIA, a non-related condition.

Food components and the immune system: from tonic agents to allergens.

The intestinal mucosa is the major site of contact with antigens, and it houses the largest lymphoid tissue in the body. In physiological conditions, microbiota and dietary antigens are the natural sources of stimulation for the gut-associated lymphoid tissues (GALT) and for the immune system as a whole. Germ-free models have provided some insights on the immunological role of gut antigens. However, most of the GALT is not located in the large intestine, where gut microbiota is prominent. It is concentrated in the small intestine where protein absorption takes place. In this review, we will address the involvement of food components in the development and the function of the immune system. Studies in mice have already shown that dietary proteins are critical elements for the developmental shift of the immature neonatal immune profile into a fully developed immune system. The immunological effects of other food components (such as vitamins and lipids) will also be addressed. Most of the cells in the GALT are activated and local pro-inflammatory mediators are abundant. Regulatory elements are known to provide a delicate yet robust balance that maintains gut homeostasis. Usually antigenic contact in the gut induces two major immune responses, oral tolerance and production of secretory IgA. However, under pathological conditions mucosal homeostasis is disturbed resulting in inflammatory reactions such as food hypersensitivity. Food allergy development depends on many factors such as genetic predisposition, biochemical features of allergens, and a growing array of environmental elements. Neuroimmune interactions are also implicated in food allergy and they are examples of the high complexity of the phenomenon. Recent findings on the gut circuits triggered by food components will be reviewed to show that, far beyond their role as nutrients, they are critical players in the operation of the immune system in health and disease.

Experimental food allergy leads to adipose tissue inflammation, systemic metabolic alterations and weight loss in mice.

To investigate the consequences of food allergy in adipose tissue and metabolism, we used a murine model in which mice have been sensitized subcutaneously with ovalbumin and further received antigen-containing diet. Allergic mice presented a significant weight loss 7 days after oral challenge with a concomitant decrease in epididymal adipose tissue mass. This decrease was associated with increased lipolysis and local inflammation. In adipose tissue of allergic mice there were increased leukocyte rolling and adhesion in the microvasculature, increased number of leukocytes in the tissue, especially macrophages (F4/80(+) cells) and increased pro-inflammatory cytokines levels, including TNF-α, IL-6 and CCL2. In addition, we observed low serum concentrations of triglyceride, glucose, total cholesterol and free fatty acids in the allergic mice. Our results suggest that the induction of food allergy in mice leads to adipose tissue inflammation and systemic metabolic alterations that contribute to the weight loss observed.

Aqueous extract of brazilian green propolis: primary components, evaluation of inflammation and wound healing by using subcutaneous implanted sponges.

Propolis is a chemically complex resinous bee product which has gained worldwide popularity as a means to improve health condition and prevent diseases. The main constituents of an aqueous extract of a sample of green propolis from Southeast Brazil were shown by high performance liquid chromatography/mass spectroscopy/mass spectroscopy to be mono- and di-O-caffeoylquinic acids; phenylpropanoids known as important constituents of alcohol extracts of green propolis, such as artepillin C and drupanin were also detected in low amounts in the aqueous extract. The anti-inflammatory activity of this extract was evaluated by determination of wound healing parameters. Female Swiss mice were implanted subcutaneously with polyesther-polyurethane sponge discs to induce wound healing responses, and administered orally with green propolis (500 mg kg(-1)). At 4, 7 and 14 days post-implantation, the fibrovascular stroma and deposition of extracellular matrix were evaluated by histopathologic and morphometric analyses. In the propolis-treated group at Days 4 and 7 the inflammatory process in the sponge was reduced in comparison with control. A progressive increase in cell influx and collagen deposition was observed in control and propolis-treated groups during the whole period. However, these effects were attenuated in the propolis-treated group at Days 4 and 7, indicating that key factors of the wound healing process are modulated by propolis constituents.

Prolonged antigen ingestion by sensitized mice ameliorates airway inflammation.

Food allergy frequently precedes or coexists with respiratory allergy, and although restriction of contacts with the allergen is the elected clinical procedure, oral immunotherapy (OIT) has proven to be surprisingly efficient in clinical trials. We investigated whether prolonged restriction and voluntary exposure of previously sensitized (immunized) mice to ovalbumin (OVA) in the drinking water would alter subsequent responses to bronchial (aerosol) challenge with OVA. We found a significant suppression of bronchial inflammation, with marked reduction of eosinophils. IL-4, CCL-2, and CCL-11 are not associated with elevation in IL-10 production or Foxp3 expression, with only minor digestive symptoms.

Role of IL-4 in aversion induced by food allergy in mice.

To ascertain the role of IL-4 in aversion to antigen induced by food allergy, wild type and IL-4 deficient BALB/c mice were sensitized with ovalbumin and challenged orally with egg white. Sensitized wild type mice had increased production of IL-4 by spleen and mesenteric lymph node cells in vitro, higher levels of serum anti-ovalbumin IgE and IgG1, aversion to ingestion of the antigen and loss of body weight after continuous oral challenge. Intestinal changes in wild type sensitized mice included eosinophil infiltration and increased mucus production. The IL-4 deficiency impaired the development of food allergy and the aversion to antigen, suggesting the involvement of the antigen specific antibodies. When IL-4 deficient mice received serum from sensitized wild type donors, the aversion was restored. These results indicate that production of IL-4 and specific IgE/IgG1 antibodies correlate with aversion to antigen induced by food allergy in mice.