Novel agents in the future: Therapy beyond anti-TNF agents in inflammatory bowel disease

Synthesis and biological evaluation of chrysin derivatives containing α-lipoic acid for the treatment of inflammatory bowel disease

This study introduces newly discovered chrysin derivatives that show potential as candidate molecules for treating inflammatory bowel disease (IBD). Compound 4b, among the synthesized compounds, displayed significant inhibitory effects on monocyte adhesion to colon epithelium induced by TNF-α, with an IC50 value of 4.71 μM. Further mechanistic studies demonstrated that 4b inhibits the production of reactive oxygen species (ROS) and downregulates the expression of ICAM-1 and MCP-1, key molecules involved in monocyte-epithelial adhesion, as well as the transcriptional activity of NF-κB. In vivo experiments have shown that compound 4b exhibits a dose-dependent inhibition of 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in rats, thereby validating its effectiveness as a colitis inhibitor in animal models. These results indicate that 4b shows considerable promise as a therapeutic agent for managing IBD.

Comparative Study of Anti-Inflammatory Effect on DSS-Induced Ulcerative Colitis Between Novel Glycyrrhiza Variety and Official Compendia

Glycyrrhizae radix (GR), a plant commonly referred to as licorice, is used as a medicine and food worldwide. However, the utilization of GR from wild areas has caused desertification and a depletion of natural resources. Environmental restrictions and low productivity have limited plant cultivation. For this reason, an improved Glycyrrhiza variety, Wongam (WG), in cultivation and quality has been developed by Korea Rural Development Administration. To evaluate the equivalence of efficacy, several comparative studies between already-registered species and new cultivars have been conducted. This study evaluated the anti-inflammatory effect of WG extracts in a dextran sulfate sodium (DSS)-induced colitis model, in comparison to that of GR extracts. WG extract significantly improved the clinical signs of DSS-induced ulcerative colitis, including disease activity index, body weight loss, and colon length shortening, which was equivalent to the effect of GR. Furthermore, the fecal microbiota was analyzed by terminal restriction fragment length polymorphism. The composition of the fecal microbiota did not show a specific pattern based on experimental groups; however, a tendency toward an increase in the proportion of Lactobacillales was observed. These findings showed an equivalence of efficacy and the possible utilization of WG as a medicinal resource with already-registered species.

Bacterial biofilms in human gastrointestinal tract: An intricate balance between health and inflammatory bowel diseases

Inflammatory bowel disease (IBD) has been a worldwide health problem. It is characterized by severe intestinal inflammation due to immune responses against the gut microbes in genetically susceptible individuals. The understanding of gut microbiota for its composition and complex interaction in normal and diseased conditions has been assisted by the use of molecular, metagenomics and meta transcriptomics studies. The alteration of intestinal microbiota is the key determinant in the degree of inflammation caused and the prolonged course of disease. The relationship between luminal gut bacteria and innate immunity is also of prime significance. Such developments have further led to the search of specific (including bacteria and fungi) as a causative agent of IBD. Although detailed research has been done for the role of gut microbiota in IBD, molecular mechanisms and related gene expression are still not well understood in this disease, which hampers the generation of effective therapeutic agents for IBD. This paper assessed various factors contributing to IBD, genetic dysbiosis and pathogenic influence in the gut microbiota, interactions such as microbiome-host immune system interaction and microbe-microbe interactions involved in IBD, currently available IBD therapies, followed by a detailed review on bacterial infections that might be involved in IBD, globally and specifically in India.

Regulatory effects of glycyrrhizae radix extract on DSS-induced ulcerative colitis

BACKGROUND

Glycyrrhizae Radix (GR) is a Korean traditional herb medicine that is widely-used in clinical health care. The clinical functions of GR include relief of toxicity, anti-cancer, regulating blood cholesterol and anti-inflammation. This study investigated the role of GR on ulcerative colitis in a dextran sulfate sodium (DSS)-induced mouse model of colitis.

METHOD

Western blot analysis and enzyme-linked immunosorbent assay (ELISA) analyses were done on male BALB/c mice administered 5 % DSS during the experimental period. Ethanol extracts of GR were orally administered at same time daily to control mice. The severity of colitis was measured by body weight change and colon length.

RESULT

DSS-treated mice displayed weight loss and shortened colon length compared with control mice. Mice were administered GR showed less weight loss and longer colon length than the DSS-treated group. Inflammatory cytokines were decreased by GR treatment. Treatment also reduced DSS-induced microscopic damage to colon tissue. GR regulated the phosphorylation of transcription factors such as NF-κB p65 and IκB α.

CONCLUSIONS

GR has beneficial effects in a colitis model. GR might be a useful herb medicine in the treatment of ulcerative colitis.

The intestinal microbiome, barrier function, and immune system in inflammatory bowel disease: a tripartite pathophysiological circuit with implications for new therapeutic directions

We discuss the tripartite pathophysiological circuit of inflammatory bowel disease (IBD), involving the intestinal microbiota, barrier function, and immune system. Dysfunction in each of these physiological components (dysbiosis, leaky gut, and inflammation) contributes in a mutually interdependent manner to IBD onset and exacerbation. Genetic and environmental risk factors lead to disruption of gut homeostasis: genetic risks predominantly affect the immune system, environmental risks predominantly affect the microbiota, and both affect barrier function. Multiple genetic and environmental 'hits' are likely necessary to establish and exacerbate disease. Most conventional IBD therapies currently target only one component of the pathophysiological circuit, inflammation; however, many patients with IBD do not respond to immune-modulating therapies. Hope lies in new classes of therapies that target the microbiota and barrier function.

Morin Attenuates Ovalbumin-Induced Airway Inflammation by Modulating Oxidative Stress-Responsive MAPK Signaling

Asthma is one of the most common inflammatory diseases characterized by airway hyperresponsiveness, inflammation, and remodeling. Morin, an active ingredient obtained from Moraceae plants, has been demonstrated to have promising anti-inflammatory activities in a range of disorders. However, its impacts on pulmonary diseases, particularly on asthma, have not been clarified. This study was designed to investigate whether morin alleviates airway inflammation in chronic asthma with an emphasis on oxidative stress modulation. In vivo, ovalbumin- (OVA-) sensitized mice were administered with morin or dexamethasone before challenge. Bronchoalveolar lavage fluid (BALF) and lung tissues were obtained to perform cell counts, histological analysis, and enzyme-linked immunosorbent assay. In vitro, human bronchial epithelial cells (BECs) were challenged by tumor necrosis factor alpha (TNF-α). The supernatant was collected for the detection of the proinflammatory proteins, and the cells were collected for reactive oxygen species (ROS)/mitogen-activated protein kinase (MAPK) evaluations. Severe inflammatory responses and remodeling were observed in the airways of the OVA-sensitized mice. Treatment with morin dramatically attenuated the extensive trafficking of inflammatory cells into the BALF and inhibited their infiltration around the respiratory tracts and vessels. Morin administration also significantly suppressed goblet cell hyperplasia and collagen deposition/fibrosis and dose-dependently inhibited the OVA-induced increases in IgE, TNF-α, interleukin- (IL-) 4, IL-13, matrix metalloproteinase-9, and malondialdehyde. In human BECs challenged by TNF-α, the levels of proteins such as eotaxin-1, monocyte chemoattractant protein-1, IL-8 and intercellular adhesion molecule-1, were consistently significantly decreased by morin. Western blotting and the 2',7'-dichlorofluorescein assay revealed that the increases in intracellular ROS and MAPK phosphorylation were abolished by morin, implying that ROS/MAPK signaling contributes to the relief of airway inflammation. Our findings indicate for the first time that morin alleviates airway inflammation in chronic asthma, which probably occurs via the oxidative stress-responsive MAPK pathway, highlighting a novel profile of morin as a potent agent for asthma management.

The Effect of Cigarette Smoke Exposure on the Development of Inflammation in Lungs, Gut and Joints of TNFΔARE Mice

The inflammatory cytokine TNF-α is a central mediator in many immune-mediated diseases, such as Crohn’s disease (CD), spondyloarthritis (SpA) and chronic obstructive pulmonary disease (COPD). Epidemiologic studies have shown that cigarette smoking (CS) is a prominent common risk factor in these TNF-dependent diseases. We exposed TNF^ΔARE mice; in which a systemic TNF-α overexpression leads to the development of inflammation; to 2 or 4 weeks of air or CS. We investigated the effect of deregulated TNF expression on CS-induced pulmonary inflammation and the effect of CS exposure on the initiation and progression of gut and joint inflammation. Upon 2 weeks of CS exposure, inflammation in lungs of TNF^ΔARE mice was significantly aggravated. However, upon 4 weeks of CS-exposure, this aggravation was no longer observed. TNF^ΔARE mice have no increases in CD4+ and CD8+ T cells and a diminished neutrophil response in the lungs after 4 weeks of CS exposure. In the gut and joints of TNF^ΔARE mice, 2 or 4 weeks of CS exposure did not modulate the development of inflammation. In conclusion, CS exposure does not modulate gut and joint inflammation in TNF^ΔARE mice. The lung responses towards CS in TNF^ΔARE mice however depend on the duration of CS exposure.