Natural Coumarin Derivatives Activating Nrf2 Signaling Pathway as Lead Compounds for the Design and Synthesis of Intestinal Anti-Inflammatory Drugs.

Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor related to stress response and cellular homeostasis that plays a key role in maintaining the redox system. The imbalance of the redox system is a triggering factor for the initiation and progression of non-communicable diseases (NCDs), including Inflammatory Bowel Disease (IBD). Nrf2 and its inhibitor Kelch-like ECH-associated protein 1 (Keap1) are the main regulators of oxidative stress and their activation has been recognized as a promising strategy for the treatment or prevention of several acute and chronic diseases. Moreover, activation of Nrf2/keap signaling pathway promotes inhibition of NF-κB, a transcriptional factor related to pro-inflammatory cytokines expression, synchronically promoting an anti-inflammatory response. Several natural coumarins have been reported as potent antioxidant and intestinal anti-inflammatory compounds, acting by different mechanisms, mainly as a modulator of Nrf2/keap signaling pathway. Based on in vivo and in vitro studies, this review focuses on the natural coumarins obtained from both plant products and fermentative processes of food plants by gut microbiota, which activate Nrf2/keap signaling pathway and produce intestinal anti-inflammatory activity. Although gut metabolites urolithin A and urolithin B as well as other plant-derived coumarins display intestinal anti-inflammatory activity modulating Nrf2 signaling pathway, in vitro and in vivo studies are necessary for better pharmacological characterization and evaluation of their potential as lead compounds. Esculetin, 4-methylesculetin, daphnetin, osthole, and imperatorin are the most promising coumarin derivatives as lead compounds for the design and synthesis of Nrf2 activators with intestinal anti-inflammatory activity. However, further structure-activity relationships studies with coumarin derivatives in experimental models of intestinal inflammation and subsequent clinical trials in health and disease volunteers are essential to determine the efficacy and safety in IBD patients.

Recent Advances in Herbal-Derived Products with Skin Anti-Aging Properties and Cosmetic Applications.

Although aesthetic benefits are a desirable effect of the treatment of skin aging, it is also important in controlling several skin diseases, mainly in aged people. The development of new dermocosmetics has rapidly increased due to consumers' demand for non-invasive products with lower adverse effects than those currently available on the market. Natural compounds of plant origin and herbal-derived formulations have been popularized due to their various safe active products, which act through different mechanisms of action on several signaling pathways for skin aging. Based on this, the aim of the review was to identify the recent advances in herbal-derived product research, including herbal formulations and isolated compounds with skin anti-aging properties. The studies evaluated the biological effects of herbal-derived products in in vitro, ex vivo, and in vivo studies, highlighting the effects that were reported in clinical trials with available pharmacodynamics data that support their protective effects to treat, prevent, or control human skin aging. Thus, it was possible to identify that gallic and ferulic acids and herbal formulations containing Thymus vulgaris, Panax ginseng, Triticum aestivum, or Andrographis paniculata are the most promising natural products for the development of new dermocosmetics with skin anti-aging properties.

Modulation of autophagy by an innovative phytocosmetic preparation (Myrothamnus flabelifolia and Coffea arabica) in human fibroblasts and its effects in a clinical randomized placebo-controlled trial.

BACKGROUND: Autophagy is a natural and evolutionary mechanism that reduces cell toxic components and reutilizes metabolites to provide energy and renew cell function, which is linked to a wide range of age-related diseases, including those that affect the skin. Positive modulation of autophagy is useful to treat skin disorders and new active herbal products are potential candidates as autophagy modulators. AIMS: The present study aimed to evaluate the effects of a phytocosmetic formulation containing Myrothamnus flabellifolia leaf and Coffea arabica seed plant extracts (MflCas) on the ubiquitin-proteasome and autophagy markers in human dermal fibroblasts, and investigate its topical skin effects in a randomized, simple-blind, and placebo-controlled trial. METHODS: Human dermal fibroblasts were used to determine proteasome activity, protein carbonylation, LC3B protein, and lipofuscin production by luminescence and immune-enzymatic assays, and to determinate gene expression of autophagy biomarkers (Atg5, Atg7, EI24, EIF2A, Park2, foxo1, and mTOR) by RT-PCR. A clinical trial was conducted to evaluate the effects of MflCas on the hand, face, and forearms skin features after treatment by 56 days. RESULTS: Topical treatment with MflCas improved several skin features of volunteers, mainly skin aging and pigmentation signals. On the hand skin, MflCas 2% after 56 days of treatment, reduced the spots length (30.8%), skin contrast (42.2%), and increased skin homogeneity (63.2%) and skin lightening effect (1.4%). On the face skin, topical treatment after 56 days reduced the spots length (21.5%), wrinkles area (8.1%), and wrinkles volume (5.6%) with an increment in face skin homogeneity (59.5%). These effects were related to the ability of MflCas to reduce proteasome activity protein carbonylation, and lipofuscin level, increase LC3B production, downregulate Atg7 and mTOR genes, and upregulate Park2 gene expressions. CONCLUSIONS: The phytocosmetic preparation containing Myrothamnus flabellifolia leaf and Coffea arabica seed modulated ubiquitin-proteasome and autophagy process, representing an innovative and safe herbal preparation to improve skin features, mainly acting as skin anti-aging and lightening agent.

Coumarin Derivatives in Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a non-communicable disease characterized by a chronic inflammatory process of the gut and categorized into Crohn's disease and ulcerative colitis, both currently without definitive pharmacological treatment and cure. The unclear etiology of IBD is a limiting factor for the development of new drugs and explains the high frequency of refractory patients to current drugs, which are also related to various adverse effects, mainly after long-term use. Dissatisfaction with current therapies has promoted an increased interest in new pharmacological approaches using natural products. Coumarins comprise a large class of natural phenolic compounds found in fungi, bacteria, and plants. Coumarin and its derivatives have been reported as antioxidant and anti-inflammatory compounds, potentially useful as complementary therapy of the IBD. These compounds produce protective effects in intestinal inflammation through different mechanisms and signaling pathways, mainly modulating immune and inflammatory responses, and protecting against oxidative stress, a central factor for IBD development. In this review, we described the main coumarin derivatives reported as intestinal anti-inflammatory products and its available pharmacodynamic data that support the protective effects of these products in the acute and subchronic phase of intestinal inflammation.

A new phytocosmetic preparation from Thymus vulgaris stimulates adipogenesis and controls skin aging process: In vitro studies and topical effects in a double-blind placebo-controlled clinical trial.

BACKGROUND: The use of the injectable products for soft tissue augmentation and treatment of skin aging is an uncomfortable, invasive and related to several complications, and chronic reactions, mainly after long-term application. Efforts to develop new topically active anti-aging products with fewer adverse effects are a huge challenge that should be faced. AIMS: We evaluated the anti-aging effects of a phytocosmetic preparation containing Thymus vulgaris associated with lecithin (ThymLec) on the facial wrinkles, expression lines, and face oval remodeling using a double-blind placebo-controlled clinical trial and in vitro cell culture assays. METHODS: A clinical trial was conducted to evaluate the effects of ThymLec 2% on the area, length, and depth of the perioral and crow's feet wrinkles, nasolabial and smile lines, as well as face oval remodeling in female volunteers using a sophisticated Bio3D Structured-light Scanner. In the in vitro studies using 3T3-L1 mouse embryonic fibroblasts, adiponectin was measured by immunoenzymatic assay, adipogenesis by the AdipoRed reagent method, and the PPAR-γ expression by RT-PCR analysis. RESULTS: Topical treatment with ThymLec 2% reduced facial wrinkles and expression lines promoting a face oval remodeling. In the in vitro studies, ThymLec upregulated the PPAR-γ expression increasing adiponectin production and stimulating the adipogenesis process. CONCLUSIONS: The phytocosmetic preparation containing Thymus vulgaris and lecithin is an innovative and safe topical anti-aging product promoting fat tissue augmentation by adipogenesis stimulation via the upregulation of PPAR-γ expression and adiponectin production.

Bidens pilosa (Black Jack) Standardized Extract Ameliorates Acute TNBS-induced Intestinal Inflammation in Rats.

Bidens pilosa is an herb popularly used to treat inflammation, hemorrhoids, fever, and gastric ulcers with reported pharmacological activities and chemical composition that sustain its selection as a potential intestinal anti-inflammatory product. Based on this, we examined the effects of a B. pilosa fatty acid-standardized supercritical preparation on the intestinal inflammatory process induced by trinitrobenzenesulphonic acid in rats, using either preventative or curative treatments. We also investigated the safety of plant extract by acute and sub-chronic toxicological analysis. The intestinal anti-inflammatory activity was related to modulation of the immune response, increasing IL-10 production and reducing IL-1ß, IL-6, and TNF-α level, the oxidative stress, and the MUC production in the inflamed colon. Optic, scanning, and transmission electron microscopy (TEM) analysis supported the beneficial effects promoted by B. pilosa, which were closely related to downregulation of heparanase, Hsp70, Mapk 3, and NF-κB signaling and with the presence of long-chain fatty acids in extract. Our data suggest that B. pilosa supercritical preparation is a chemically standardized preparation potentially useful as complementary intestinal anti-inflammatory agent to treat inflammatory bowel disease.

4-Methylesculetin, a natural coumarin with intestinal anti-inflammatory activity, elicits a glutathione antioxidant response by different mechanisms.

4-methylesculetin (4 ME) is a natural antioxidant coumarin with protective effects on the intestinal inflammation, in which oxidative stress plays a key role in its aetiology and pathophysiology. Based on this, we examined the antioxidant molecular mechanisms involved in the intestinal anti-inflammatory activity of the 4 ME. For this purpose, we investigated the effects of the 4 ME on the modulation of gene expression and antioxidant-related enzyme activities in TNBS model of intestinal inflammation as well as the molecular interaction between 4 ME and glutathione reductase. Our results showed that 4 ME modulated glutathione-related enzymes, mainly increasing glutathione reductase activity. These effects were related to upregulation of glutathione reductase and Nrf2 gene expression. Fluorescence and nuclear magnetic resonance data showed that interaction between 4 ME and glutathione reductase is collisional, hydrophobic and spontaneous, in which C4 methyl group is the second epitope most buried into glutathione reductase. Molecular modelling calculation showed Lys70-B, Arg81-A, Glu381-B, Asp443-A, Ser444-A, Glu447-B and Ser475-A participated in electrostatic interaction, Lys70-B, Glu381-B and Arg81-A acted in the hydrophobic interactions and Trp73, Phe377 and Ala446 are responsible for the hydrogen bonds. Based on this, our results showed 4 ME acted by different mechanisms to control oxidative stress induced by intestinal damage, controlling the imbalance between myeloperoxidase activity and glutathione production, upregulating the glutathione S-transferase and glutathione reductase activities, preventing the Nrf2 and glutathione gene expression downregulation with consequent glutathione maintenance. Finally, 4 ME interacted at molecular level with glutathione reductase, stabilizing its enzymatic activity and reducing oxidative stress to take place in intestinal inflammatory process.

Novel topical skin hydration agent containing Anadenanthera colubrina polysaccharide-standardized herbal preparation.

BACKGROUND: Hydration is an important factor to promote skin barrier function, metabolism, and appearance. In this process, the presence of aquaglyceroporins, envelope and lipid synthesis, and metabolism proteins are essential to provide greater corneocyte cohesion and to form a barrier avoiding transepidermal water loss. OBJECTIVE: We evaluated the effects of a new topical pigment-free agent containing an Anadenanthera colubrina polysaccharide-rich dermocosmetic preparation (ACP) on the aquaporin-3 (AQP-3), filaggrin (FLG), involucrin (INV), glucocerebrosidase (GBA), and elongation of very-long-chain fatty acid (ELOVL) proteins production in skin human fragments, as well as on the transepidermal water loss in a double-blind placebo-controlled clinical trial. METHODS: AQP3, FLG, INV, GBA, and ELOVL3 levels were measured by immunofluorescence analysis in human skin explants. Clinical trial was conducted to evaluate the effects of ACP 1% and ACP 3% on the transepidermal water loss (TEWL). RESULTS: Image and statistical analysis showed that ACP 3% significantly increased at 90% the expression of AQP3. Similarly, ACP 3% was able to promote a significant increase of 68% and 51% in FLG and INV, respectively. ACP 3% produced no effects on the GBA and ELOVL3 proteins. Transepidermal water loss was significantly reduced in human volunteers under treatment with ACP 1% and ACP 3%. CONCLUSION: ACP reduced transepidermal water loss in a clinical trial, promoting human skin hydration. These effects were related to modulation of the AQP3, FLG, and INV as evidenced by immunofluorescence assay. This way, A colubrina polysaccharide-rich phytopharmaceutical preparation is an effective additive product to skin hydration.

Changes in colonic contractility in response to inflammatory bowel disease: Long-term assessment in a model of TNBS-induced inflammation in rats.

AIMS: Inflammatory bowel disease is a chronic relapsing inflammation that affects the gastrointestinal tract, causing changes in colonic motility. The evolution of these changes is not completely understood and possibly related to symptoms that appear in different degrees of the intestinal inflammation. Therefore, our aim is evaluate during 14 days of assessment aspects of colonic contractility using 2,4,6-trinitrobenzenesulfonic acid (TNBS) model of inflammation in rats and associate the inflammatory process with colonic motility. METHODS: Contractility and inflammatory parameters were assessed in the same animal in six different moments: before intestinal inflammation induction, 2, 5, 8, 11, and 14 days after induction. The mechanical activity was determined by alternating current biosusceptometry (ACB) and subdivided into rhythmic propagating ripples (RPR) and rhythmic propulsive motor complexes (RPMC). We assessed inflammation by determining myeloperoxidase activity in feces. RESULTS: Transient and permanent changes were observed in colonic motility as a function of the inflammatory process evaluated through myeloperoxidase activity. We identified two contraction profiles: RPR and RPMC. The microscopic analysis demonstrated a depth of damage caused by an injury that was associated with changes in motility. CONCLUSIONS: We implemented a robust and adequate (specific) signal processing to quantify two measured colonic frequency patterns. Thus, we performed a detailed temporal analysis of the consequences of TNBS-induced inflammation on colonic motility in rats. Our approach enables further long-term assessments in the same animal with different mechanisms and duration of injury, remission, treatments and their motor consequences.

Sterol-standardized phytopharmaceutical from ground cherry: Corticoid-like properties on human keratinocytes and fibroblasts and its effects in a randomized double-blind placebo-controlled clinical trial.

BACKGROUND: Topical corticosteroids have been the most commonly prescribed drugs to treat skin inflammation, but their uses can lead to several adverse effects. Nowadays, new pharmacological strategies have been evaluated to improve dermatologic efficacy and reduce adverse effects, including natural products. OBJECTIVES: The aim of this study was to evaluate and compare the effects of a plant sterol standardized supercritical CO2 phytopharmaceutical of Physalis angulata L. with hydrocortisone on the immune and inflammatory mediators, and skin repair components production. Moreover, we studied effects of both products on the skin microcirculation and temperature in a double-blind placebo-controlled clinical trial. METHODS: Both products were evaluated on the immune (IL-6, IL-10, INF-γ, TNF-α, and IL-1α), inflammatory (COX-2, LOX, PLA2 , PGE2 , LTB4 , histamine, and NF-κB), and repair components (TGF-ß, GM-CSF, collagen, and GAG) production on human keratinocytes and fibroblast in non-stimulated and LPS-stimulated conditions. Indeed, in a randomized double-blind placebo-controlled clinical trial, we evaluated the effects of the both creams on the skin microcirculation and temperature using laser Doppler and infrared thermometer, respectively. RESULTS: Physalis angulata acted on the skin, modulating immune status and inflammatory response producing corticoid-like effects, but different of hydrocortisone, increased skin repair factors. The effects of phytopharmaceutical cream in the clinical trial promoted a better reduction in skin microcirculation and temperature than hydrocortisone. CONCLUSIONS: Taken together, the results indicate that sterol standardized CO2 supercritical preparation of P angulata is a new and innovative phytopharmaceutical with multiple pharmacological effects potentially useful as human skin protective product, particularly against cutaneous inflammatory disorders.

Nectar Replaced by Volatile Secretion: A Potential New Role for Nectarless Flowers in a Bee-Pollinated Plant Species.

The presence of nectarless flowers in nectariferous plants is a widespread phenomenon in angiosperms. However, the frequency and distribution of nectarless flowers in natural populations, and the transition from nectariferous to nectarless flowers are poorly known. Variation in nectar production may affect mutualism stability, since energetic resource availability influences pollinators' foraging behavior. Here, we described the spatial and temporal nectar production patterns of Jacaranda oxyphylla, a bee-pollinated species that naturally presents nectarless flowers. Additionally, we compared nectariferous and nectarless floral disks in order to identify histological, subcellular and chemical changes that accompanied the loss of nectar production ability. For that we used standard methods for light and transmission electron microscopy, and gas chromatography coupled to mass spectrometry for chemical analyses. We verified that 47% of flowers did not produce nectar during the whole flower lifespan (nectarless flowers). We also observed remarkable inter-plant variation, with individuals having only nectarless flowers, others only nectariferous ones and most of them showing different proportions of both flower types, with variable nectar volumes (3-21 µl). Additionally, among nectariferous flowers, we registered two distinct rhythms of nectar production. 'Early' flowers produced nectar from 0 to 24 h, and 'late' flowers produced nectar from 24 to 48 h of anthesis. Although disks from nectariferous and nectarless flowers displayed similar histological organization, they differed strongly at subcellular level. Nectariferous ('early' and 'late') flowers exhibited a cellular apparatus typical of nectar secretion, while nectarless flowers exhibited osmophoric features. We found three aliphatic and one aromatic compound(s) that were detected in both the headspace of flowers and the disks of nectarless flowers, but not the disks of nectariferous flowers Although the remarkable variation in nectar availability may discourage pollinator visits, nectarless flowers might compensate it by producing volatile compounds that can be part of floral scent, acting as chemical attractants. Thus, nectarless flowers may be helping to maintain pollination in this scenario of trophic resource supply scarcity. We suggest that J. oxyphylla can be transitioning from a nectar-based pollination system to another resource-based or even to a deceit mechanism of pollination.

Experimental evidence of heparanase, Hsp70 and NF-κB gene expression on the response of anti-inflammatory drugs in TNBS-induced colonic inflammation.

AIM: Etiopathogenesis of inflammatory bowel disease is unclear and results from a complex interplay of genetic, microbial, environmental and immune factors. Elucidating the mechanisms that drive IBD depends on the detailed characterization of human inflammatory mediators in animal models. Therefore, we studied how intestinal inflammation affects heparanase, NF-κB and Hsp70 gene expression in rats, and if current intestinal anti-inflammatory drugs (sulphasalazine, prednisolone and azathioprine) act on these expressions. Moreover, we investigated the relationships among these genes with colonic cytokines levels (IL-1ß, TNF-α, IL-6, INF-γ and IL-10) and oxidative stress that have fundamental role in IBD. MATERIAL AND METHODS: Macroscopic parameters (diarrhea, extension of lesion, colonic weight/length ratio and damage score), biochemical markers (myeloperoxidase and alkaline phosphatase activities, and glutathione, IL-1ß, TNF-α, IL-6, INF-γ and IL-10 levels), gene expressions (heparanase, NF-κB and Hsp70), and microscopic evaluations (optic, electronic scanning and transmission microscopic) were performed in rats. KEY FINDINGS: Expression of heparanase, Hsp70 and NF-κB and oxidative stress were increased by inflammatory process and differentially modulated by sulphasalazine, prednisolone and azathioprine treatments. Protective effects of drugs were also related to differential modulation of cytokine changes induced by inflammatory process, showing different mechanisms to control inflammation. SIGNIFICANCE: Heparanase, NF-κB and Hsp70 gene expression participate in the inflammatory response induced by TNBS and represent pharmacological targets of the intestinal anti-inflammatory drugs. In addition, current drugs used to treat IBD (sulphasalazine, prednisolone and azathioprine) differentially modulate heparanase, NF-κB and Hsp70 gene expression, cytokine production and oxidative stress.

Products for the treatment of inflammatory bowel disease: a patent review (2013 - 2014).

INTRODUCTION: Inflammatory bowel disease (IBD) consists of Crohn's disease, ulcerative colitis and an unspecific IBD. The unclear etiology of IBD is a limiting factor that complicates the development of new pharmacological treatments and explains the high frequency of refractory patients to current drugs, including both conventional and biological therapies. In view of this, recent progress on the development of novel patented products to treat IBD was reviewed. AREAS COVERED: Evaluation of the patent literature during the period 2013 - 2014 focused on chemical compounds, functional foods and biological therapy useful for the treatment of IBD. EXPERT OPINION: Majority of the patents are not conclusive because they were based on data from unspecific methods not related to intestinal inflammation and, when related to IBD models, few biochemical and molecular evaluations that could be corroborating their use in human IBD were presented. On the other hand, methods and strategies using new formulations of conventional drugs, guanylyl cyclase C peptide agonists, compounds that influence anti-adhesion molecules, mAbs anti-type I interferons and anti-integrin, oligonucleotide antisense Smad7, growth factor neuregulin 4 and functional foods, particularly fermented wheat germ with Saccharomyces cerevisiae, are promising products for use in the very near future.

Photoprotective and antioxidant effects of Rhubarb: inhibitory action on tyrosinase and tyrosine kinase activities and TNF-α, IL-1α and α-MSH production in human melanocytes.

BACKGROUND: Exposure to ultraviolet (UV) radiation causes various forms of acute and chronic skin damage, including immunosuppression, inflammation, premature aging and photodamage. Furthermore, it induces the generation of reactive oxygen species, produces proinflammatory cytokines and melanocyte-stimulating hormone (MSH) and increases tyrosinase activity. The aim of this study was to evaluate the potential photoprotective effects of Rheum rhaponticum L. rhizome extract on human UV-stimulated melanocytes. METHODS: The effects of Rheum rhaponticum rhizome extract on tyrosine kinase activity, and on interleukin-1α (IL-1α), tumour necrosis factor α (TNF-α), and α-MSH production in human epidermal melanocytes were evaluated under UV-stimulated and non-stimulated conditions. Antioxidant activity was evaluated by lipid peroxidation and 1,1-dyphenyl-2-picryl-hydrazyl (DPPH) assays, while anti-tyrosinase activity was evaluated by the mushroom tyrosinase method. RESULTS: Rheum rhaponticum L. rhizome extract showed in vitro antioxidant properties against lipid peroxidation, free radical scavenging and anti-tyrosinase activities, and inhibited the production of IL-1α, TNF-α, α-MSH, and tyrosine kinase activity in melanocytes subjected to UV radiation. CONCLUSIONS: These results support the inclusion of Rheum rhaponticum L. rhizome extract into cosmetic, sunscreen and skin care products for the prevention or reduction of photodamage.

Dietary intervention with green dwarf banana flour (Musa sp AAA) prevents intestinal inflammation in a trinitrobenzenesulfonic acid model of rat colitis.

Dietary products are among the therapeutic approaches used to modify intestinal microflora and to promote protective effects during the intestinal inflammatory process. Because the banana plant is rich in resistant starch, which is used by colonic microbiota for the anaerobic production of the short-chain fatty acids that serve as a major fuel source for colonocytes: first, green dwarf banana flour produces protective effects on the intestinal inflammation acting as a prebiotic and, second, combination of this dietary supplementation with prednisolone presents synergistic effects. For this, we used the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. Our results revealed that the protective effect produced by a combination of 10% green dwarf banana flour with prednisolone was more pronounced than those promoted by a single administration of prednisolone or a diet containing 10% or 20% banana flour. This beneficial effect was associated with an improvement in the colonic oxidative status because the banana flour diet prevented the glutathione depletion and inhibited myeloperoxidase activity and lipid peroxidation. In addition, the intestinal anti-inflammatory activity was associated with an inhibition of alkaline phosphatase activity, a reduction in macroscopic and microscopic scores, and an extension of the lesions. In conclusion, the dietary use of the green dwarf banana flour constitutes an important dietary supplement and complementary medicine product to prevention and treatment of human inflammatory bowel disease.

Suppression of TNBS-induced colitis in rats by 4-methylesculetin, a natural coumarin: comparison with prednisolone and sulphasalazine.

The aim of the present study was to compare the effects of the 4-methylesculetin with those produced by prednisolone and sulphasalazine and to elucidate the mechanisms involved in its action. Colitis was induced in rat by instillation of trinitrobenzenesulphonic acid (TNBS). The colon damage was evaluated using macroscopic, microscopic and biochemical analysis. In addition, in vitro studies were performed to evaluate cytokine production in cell cultures using the murine macrophage cell line RAW264.7, mouse splenocytes and the human colonic epithelial cell line Caco-2. 4-Methylesculetin produced a reduction of the macroscopic damage score and the recovery of the intestinal cytoarchitecture. These effects were associated with a prevention of the GSH depletion and an inhibition in AP activity. After colitis relapse, 4-methylesculetin improved the colonic inflammatory status as evidenced by histological findings, with a reduction in apoptosis, as well as biochemically by inhibition of colonic myeloperoxidase, alkaline phosphatase and metalloproteinase 9 activities. Paired with this inhibitive activity, there was a decrease in malondialdehyde content and in IL-1ß levels. In vitro assays revealed that 4-methylesculetin promoted an inhibition in IL-1ß, IL-8, IL-2 and IFN-γ production in cell cultures. In conclusion, 4-methylesculetin showed similar efficacy to that obtained with either prednisolone or sulphasalazine, both in the acute phase of colitis as well as following a curative protocol. The intestinal anti-inflammatory activity by 4-methylesculetin is likely related to its ability in reduce colonic oxidative stress and inhibit pro-inflammatory cytokine production.

Dietary polydextrose prevents inflammatory bowel disease in trinitrobenzenesulfonic acid model of rat colitis.

Inflammatory bowel disease (IBD) is a multifactorial intestinal disorder that involves interactions among the immune system, genetic susceptibility, and environmental factors, especially the bacterial flora. Polydextrose, a polysaccharide constituted by 90% nondigestible and nonabsorbable soluble fibers, has several physiological effects consistent with those of dietary fibers, including proliferation of colon microflora. Because sulfasalazine presents serious side effects through long-term use at high doses, the aim of the present study was to evaluate the preventative effect of polydextrose on trinitrobenzenesulfonic acid-induced intestinal inflammation and its effects on the intestinal anti-inflammatory activity of sulfasalazine. Results indicated that polydextrose and its association with sulfasalazine present an anti-inflammatory effect that reduces myeloperoxidase activity, counteracts glutathione content, and promotes reductions in lesion extension and colonic weight/length ratio.

Intestinal anti-inflammatory activity of esculetin and 4-methylesculetin in the trinitrobenzenesulphonic acid model of rat colitis.

Coumarins comprise a broad class of phenolic compounds that influences the formation and scavenging of reactive oxygen species and the processes involving free radical-mediated injury. In light of the antioxidant and anti-inflammatory properties of esculetin and 4-methylesculetin, the aim of this study was to investigate the effects of these compounds in an experimental model of rat colitis induced by trinitrobenzenesulphonic acid (TNBS). For this purpose, macroscopic (diarrhoea, extension of lesion, colonic weight/length ratio and damage score) and biochemical parameters (myeloperoxidase, alkaline phosphatase and glutathione) were evaluated. Our results reveal that these compounds, particularly 4-methylesculetin, may be effective for the treatment of intestinal inflammatory bowel disease. In the acute colitis model, esculetin promoted a reduction in the extension of the lesion accompanied by a reduction in the incidence of diarrhoea and restoration of the glutathione content. Similar effects were produced by the administration of 4-methylesculetin, which also inhibited the myeloperoxidase and alkaline phosphatase activities in the acute intestinal inflammatory process and in the model of colitis relapse. The effect of the esculetin and 4-methylesculetin on the inflammatory process may be related to their antioxidant and anti-inflammatory properties, as observed in this study. The evidence for better effects of 4-methylesculetin in comparison to those demonstrated by esculetin in both experimental settings could be attributed to the presence of the methyl group at C-4 of 4-methylesculetin.

Preventative effects of lactulose in the trinitrobenzenesulphonic acid model of rat colitis.

AIMS: Lactulose is a drug used as a laxative that has been shown to promote the growth of lactobacilli and bifidobacteria, acting as a prebiotic and with a potential beneficial effect in inflammatory bowel disease. The present study describes the preventive antiinflammatory activity of lactulose in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. METHODS: Rats were rendered colitic by a colonic instillation of 10 mg of TNBS dissolved in 0.25 mL of 50% ethanol. One group of colitic rats received lactulose, which was incorporated in the drinking water (2.5% wt/vol) for 2 weeks before TNBS instillation, and colonic damage was evaluated 1 week after colitis induction. Different biochemical markers of colonic inflammation were assayed: myeloperoxidase activity, glutathione content, tumor necrosis factor alpha, leukotriene B4 levels, and colonic inducible nitric oxide synthase expression. In addition, bacterial counts (for lactobacilli and bifidobacteria) were performed in colonic contents from colitic rats. RESULTS: The results show that lactulose exerted a preventive antiinflammatory effect in this model of rat colitis, as evidenced by a significant reduction of myeloperoxidase activity and by a decrease of both colonic tumor necrosis factor alpha and leukotriene B4 production. This effect was also characterized by an inhibition of colonic inducible nitric oxide synthase expression, which is unregulated as a consequence of the inflammatory status. This beneficial effect was associated with increased levels of lactobacilli and bifidobacteria species in colonic contents in comparison with untreated colitic rats. CONCLUSION: In conclusion, the intestinal antiinflammatory effect of lactulose could be related to its prebiotic properties, supporting its potential use in human inflammatory bowel disease.

Intestinal anti-inflammatory activity of paepalantine, an isocoumarin isolated from the capitula of Paepalanthus bromelioides, in the trinitrobenzenesulphonic acid model of rat colitis.

The preventative intestinal anti-inflammatory activity of paepalantine, an isocoumarin isolated from the capitula of Paepalanthus bromelioides, was tested in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. This was performed in two different experimental settings, i. e. when the colonic mucosa is intact or when the mucosa is in process of recovery after an initial insult. The results obtained revealed that the paepalantine pretreatment, at doses of 5 and 10 mg/kg, significantly attenuated the colonic damage induced by TNBS in both situations, as it was evidenced both histologically and biochemically. This beneficial effect was associated with an improvement in the colonic oxidative status, since paepalantine prevented the glutathione depletion that occurred as a consequence of the colonic inflammation. In addition, the intestinal anti-inflammatory effect exerted by this isocoumarin was associated with an inhibition of colonic nitric oxide activity, which is upregulated as a consequence of the inflammatory process. In conclusion, the preventative effect exerted by paepalantine in the TNBS model of rat colitis is probably related with its antioxidant properties.