The Regulatory Effects of Licochalcone A on the Intestinal Epithelium and Gut Microbiota in Murine Colitis

Traditional Chinese medicine treats ulcerative colitis by regulating gut microbiota, signaling pathway and cytokine: Future novel method option for pharmacotherapy

Background

Ulcerative colitis (UC) is a chronic non-specific inflammatory disease with intestinal tract as the main site. The pathogenic of UC has not yet been clarified, and multiple mechanisms can lead to the pathogenesis of UC. Traditional Chinese medicine (TCM) offers an opportunity for UC treatment. TCM has become the preferred treatment for UC with characteristics of multiple targets, multiple pathways and high safety. This review attempted to summarize the characteristics of TCM (compound prescriptions, single Chinese herbs, and active ingredients) for UC treatment and discussed their pathogenesis based on analyzing the UC-related gut microbiota, signaling pathway and cytokine. In order to provide more systematic and diverse reference for TCM in the prevention and treatment of UC, and provide theoretical reference for clinical treatment of UC.

Materials and methods

The information was acquired from different databases, including Web of Science, PubMed, CNKI, Wanfang, and VIP databases. We then focused on the recent research progress in UC treatment by TCM. Finally, the deficiencies and future perspectives are proposed.

Results

Modern pharmacological studies have shown that the compound prescriptions (strengthening spleen, clearing heat and removing dampness, clearing heat and removing toxin), single Chinese herbs (replenishing Qi, clearing heat, tonifying blood, etc.), and active ingredients (alkaloids, polysaccharides, flavonoids, polyphenols, terpenes, etc.) have an efficiency in UC treatment by regulating gut microbiota, signaling pathway and cytokine.

Conclusions

TCM can achieve its purpose of UC prevention and treatment by acting in multiple ways, and TCM deserves further research and development in this field.

Manipulating Microbiota in Inflammatory Bowel Disease Treatment: Clinical and Natural Product Interventions Explored

Inflammatory bowel disease (IBD) is a complex multifactorial chronic inflammatory disease, that includes Crohn's disease (CD) and ulcerative colitis (UC), having progressively increasing global incidence. Disturbed intestinal flora has been highlighted as an important feature of IBD and offers promising strategies for IBD remedies. A brief overview of the variations occurring in intestinal flora during IBD is presented, and the role of the gut microbiota in intestinal barrier maintenance, immune and metabolic regulation, and the absorption and supply of nutrients is reviewed. More importantly, we review drug research on gut microbiota in the past ten years, including research on clinical and natural drugs, as well as adjuvant therapies, such as Fecal Microbiota Transplantation and probiotic supplements. We also summarize the interventions and mechanisms of these drugs on gut microbiota.

Licochalcone A protects against LPS-induced inflammation and acute lung injury by directly binding with myeloid differentiation factor 2 (MD2)

BACKGROUND AND PURPOSE

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is a challenging clinical syndrome that leads to various respiratory sequelae and even high mortality in patients with severe disease. The novel pharmacological strategies and therapeutic drugs are urgently needed. Natural products have played a fundamental role and provided an abundant pool in drug discovery.

EXPERIMENTAL APPROACH

A compound library containing 160 natural products was used to screen potential anti-inflammatory compounds. Mice with LPS-induced ALI was then used to verify the preventive and therapeutic effects of the selected compounds.

KEY RESULTS

Licochalcone A was discovered from the anti-inflammatory screening of natural products in macrophages. A qPCR array validated the inflammation-regulatory effects of licochalcone A and indicated that the potential targets of licochalcone A may be the upstream proteins in LPS pro-inflammatory signalling. Further studies showed that licochalcone A directly binds to myeloid differentiation factor 2 (MD2), an assistant protein of toll-like receptor 4 (TLR4), to block both LPS-induced TRIF- and MYD88-dependent pathways. LEU61 and PHE151 in MD2 protein are the two key residues that contribute to the binding of MD2 to licochalcone A. In vivo, licochalcone A treatment alleviated ALI in LPS-challenged mice through significantly reducing immunocyte infiltration, suppressing activation of TLR4 pathway and inflammatory cytokine induction.

CONCLUSION AND IMPLICATIONS

In summary, our study identified MD2 as a direct target of licochalcone A for its anti-inflammatory activity and suggested that licochalcone A might serve as a novel MD2 inhibitor and a potential drug for developing ALI/ARDS therapy.

Chalcones and Gastrointestinal Cancers: Experimental Evidence

Colorectal (CRC) and gastric cancers (GC) are the most common digestive tract cancers with a high incidence rate worldwide. The current treatment including surgery, chemotherapy or radiotherapy has several limitations such as drug toxicity, cancer recurrence or drug resistance and thus it is a great challenge to discover an effective and safe therapy for CRC and GC. In the last decade, numerous phytochemicals and their synthetic analogs have attracted attention due to their anticancer effect and low organ toxicity. Chalcones, plant-derived polyphenols, received marked attention due to their biological activities as well as for relatively easy structural manipulation and synthesis of new chalcone derivatives. In this study, we discuss the mechanisms by which chalcones in both in vitro and in vivo conditions suppress cancer cell proliferation or cancer formation.

The role and mechanism of flavonoid herbal natural products in ulcerative colitis

Ulcerative colitis (UC) is a chronic inflammatory disease of the intestine that presents clinically with abdominal pain, mucopurulent stools, and posterior urgency. The lesions of UC are mainly concentrated in the rectal and colonic mucosa and submucosa. For patients with mild to moderate UC, the best pharmacological treatment includes glucocorticoids, immunosuppressants, antibiotics, and biologics, but the long-term application can have serious toxic side effects. Currently, nearly 40% of UC patients are treated with herbal natural products in combination with traditional medications to reduce the incidence of toxic side effects. Flavonoid herbal natural products are the most widely distributed polyphenols in plants and fruits, which have certain antioxidant and anti-inflammatory activities. Flavonoid herbal natural products have achieved remarkable efficacy in the treatment of UC. The pharmacological mechanisms are related to anti-inflammation, promotion of mucosal healing, maintenance of intestinal immune homeostasis, and regulation of intestinal flora. In this paper, we summarize the flavonoid components of anti-ulcerative colitis and their mechanisms reported in the past 10 years, to provide a basis for rational clinical use and the development of new anti-ulcerative colitis drugs.

Cymbopogon citratus (DC.) Stapf aqueous extract ameliorates loperamide-induced constipation in mice by promoting gastrointestinal motility and regulating the gut microbiota

Slow transit constipation (STC) is the most common type of functional constipation. Drugs with good effects and few side effects are urgently needed form the treatment of STC. Cymbopogon citratus (DC.) Stapf (CC) is an important medicinal and edible spice plant. The wide range of biological activities suggested that CC may have laxative effects, but thus far, it has not been reported. In this study, the loperamide-induced STC mouse model was used to evaluate the laxative effect of the aqueous extract of CC (CCAE), and the laxative mechanism was systematically explored from the perspectives of the enteric nervous system (ENS), neurotransmitter secretion, gastrointestinal motility factors, intestinal inflammation, gut barrier and gut microbiota. The results showed that CCAE not only decreased the serum vasoactive intestinal polypeptide (VIP), induced nitric oxide synthases (iNOS), and acetylcholinesterase (AchE) in STC mice but also increased the expression of gastrointestinal motility factors in colonic interstitial cells of Cajal (ICCs) and smooth muscle cells (SMCs), thereby significantly shortening the defecation time and improving the gastrointestinal transit rate. The significantly affected gastrointestinal motility factors included stem cell factor receptor (c-Kit), stem cell factor (SCF), anoctamin 1 (Ano1), ryanodine receptor 3 (RyR3), smooth muscle myosin light chain kinase (smMLCK) and Connexin 43 (Cx43). Meanwhile, CCAE could repair loperamide-induced intestinal inflammation and intestinal barrier damage by reducing the expression of the pro-inflammatory factor IL-1β and increasing the expression of the anti-inflammatory factor IL-10, chemical barrier (Muc-2) and mechanical barrier (Cldn4, Cldn12, Occludin, ZO-1, and ZO-2). Interestingly, CCAE could also partially restore loperamide-induced gut microbial dysbiosis in various aspects, such as microbial diversity, community structure and species composition. Importantly, we established a complex but clear network between gut microbiota and host parameters. Muribaculaceae, Lachnospiraceae and UCG-010 showed the most interesting associations with the laxative phenotypes; several other specific taxa showed significant associations with serum neurotransmitters, gastrointestinal motility factors, intestinal inflammation, and the gut barrier. These findings suggested that CCAE might promote intestinal motility by modulating the ENS-ICCs-SMCs network, intestinal inflammation, intestinal barrier and gut microbiota. CC may be an effective and safe therapeutic choice for STC.

Quercetin Reduces Inflammation and Protects Gut Microbiota in Broilers

The aim of this study was to investigate the effects of quercetin on inflammatory response and intestinal microflora in broiler chicken jejuna. A total of 120 broiler chickens were allocated into 3 groups: saline-challenged broilers fed a basal diet (CTR group), lipopolysaccharide (LPS)-challenged broilers fed a basal diet (L group) and LPS-challenged broilers fed a basal diet supplemented with 200 mg/kg quercetin (LQ group). Our results showed that LPS significantly increased expression of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-8, interferon (IFN)-γ, toll-like receptor (TLR)-4, Bax, Caspase-3 and diamine oxidase activity (DAO), and decreased expression of zona occludens-1 (ZO-1), Occludin and Bcl-2 in the jejunum, while dietary quercetin prevented the adverse effects of LPS injection. LPS injection significantly decreased the number of Actinobacteria, Armatimonadetes and Fibrobacteriae at the phylum level when compared to the CTR group. Additionally, at genus level, compared with the CTR group, the abundance of Halomonas, Micromonospora, Nitriliruptor, Peptococcus, Rubellimicrobium, Rubrobacter and Slaclda in L group was significantly decreased, while dietary quercetin restored the numbers of these bacteria. In conclusion, our results demonstrated that dietary quercetin could alleviate inflammatory responses of broiler chickens accompanied by modulating jejunum microflora.