Paeoniflorin abrogates DSS-induced colitis via a TLR4-dependent pathway

Tokishakuyakusan alleviates ultraviolet-induced skin pigmentation by decreasing the expression of melanogenesis-related enzymes

ETHNOPHARMACOLOGICAL RELEVANCE

Tokishakuyakusan (TSS), a traditional Kampo medicine, can effectively alleviate symptoms unique to women, such as menstrual pain and menopausal symptoms, and this effect is believed to be related to its ability to increase the secretion of female hormones. TSS is also believed to be effective against skin pigmentation. However, no studies have examined the effect of TSS on pigmentation.

AIM OF THE STUDY

In this study, we conducted basic research to determine the effects of TSS on pigmentation.

MATERIALS AND METHODS

Female HRM-2 mice were given free access to a normal diet or a TSS-containing diet for 7 weeks. For 3 weeks starting from the 4th week of treatment, the back of the skin was irradiated with ultraviolet (UV) light, and the melanin level was measured. The expression levels of melanogenesis-related genes and inflammatory markers in the skin were analyzed.

RESULTS

The melanin level in the skin of the mice exposed to UV radiation was approximately three times greater than that in the skin of the mice in the non-UV-irradiated group, confirming pigmentation due to UV irradiation. The protein expression levels of tyrosinase (Tyr), tyrosinase-related protein-1 (Tyrp1), and dopachrome tautomerase (Dct), which are important for melanin production, were significantly greater in the UV irradiation group than in the non-UV irradiation group. In contrast, the amount of skin melanin in the mice treated with TSS was significantly lower than that in the UV-irradiated group, and the expression levels of melanogenesis-related enzymes were also lower. Furthermore, TSS significantly decreased the expression of microphthalmia transcription factor (Mitf), a transcription factor for melanogenesis-related enzymes, and the inflammatory cytokines interleukin-1β and interleukin-6.

CONCLUSIONS

TSS inhibits melanin production in melanocytes by suppressing the increase in the expression of melanogenesis-related enzymes caused by UV irradiation. These findings suggested that this effect of TSS is exerted through the combined regulation of MITF expression and anti-inflammatory responses.

The Landscape of Gut Microbiota and Its Metabolites: A Key to Understanding the Pathophysiology of Pattern in Chinese Medicine

Liver Stagnation and Spleen Deficiency (LSSD) is a Chinese Medicine (CM) pattern commonly observed in gastrointestinal (GI) diseases, yet its biological nature remains unknown. This limits the global use of CM medications for treating GI diseases. Recent studies emphasize the role of gut microbiota and their metabolites in the pathogenesis and treatment of LSSD-associated GI diseases. There is increasing evidence supporting that an altered gut microbiome in LSSD patients or animals contributes to GI and extra-intestinal symptoms and affects the effectiveness of CM therapies. The gut microbiota is considered to be an essential component of the biological basis of LSSD. This study aims to provide an overview of existing research findings and gaps for the pathophysiological study of LSSD from the gut microbiota perspective in order to understand the relationship between the CM pattern and disease progression and to optimize CM-based diagnosis, prevention, and therapy.

Toll-like receptors in inflammatory bowel disease: A review of the role of phytochemicals

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic inflammation within the gastrointestinal tract with a remarkable impact on patients' quality of life. Toll-like receptors (TLR), as a key contributor of immune system in inflammation, has a critical role in the pathogenesis of IBD and thus, can be a suitable target of therapeutic agents. Medicinal plants have long been considered as a source of bioactive agents for different diseases, including IBD.

PURPOSE

This review discusses current state of the art on the role of plant-derived compounds for the management of IBD with a focus on TLRs.

METHODS

Electronic database including PubMed, Web of Science, and Scopus were searched up to January 2023 and all studies in which anticolitis effects of a phytochemical was assessed via modulation of TLRs were considered.

RESULTS

Different categories of phytochemicals, including flavonoids, lignans, alkaloids, terpenes, saccharides, and saponins have demonstrated modulatory effects on TLR in different animal and cell models of bowel inflammation. Flavonoids were the most studied phytochemicals amongst others. Also, TLR4 was the most important type of TLRs which were modulated by phytochemicals. Other mechanisms such as inhibition of pro-inflammatory cytokines, nuclear factor-κB pathway, nitric oxide synthesis pathway, cyclooxygenase-2, lipid peroxidation, as well as induction of endogenous antioxidant defense mechanisms were also reported for phytochemicals in various IBD models.

CONCLUSION

Taken together, a growing body of pre-clinical evidence support the efficacy of herbal compounds for the treatment of IBD via modulation of TLRs. Future clinical studies are recommended to assess the safety and efficacy of these compounds in human.

Chicoric acid enhances the antioxidative defense system and protects against inflammation and apoptosis associated with the colitis model induced by dextran sulfate sodium in rats

Although several anticolitic drugs are available, their application is associated with numerous side effects. Chicoric acid (CA) is a hydroxycinnamic acid found naturally in chicory (Cichorium intybus), purple coneflower (Echinacea purpurea), and basil with numerous health benefits, such as antioxidative and anti-inflammatory activities. Here, the potential anticolitic efficiency of CA against dextran sulfate sodium (DSS)-induced colitis in rats was examined in rats. Animals were randomly assigned to the following five groups: control, CA (100 mg/kg body weight), DSS [(DSS); 4% w/v], CA + DSS (100 mg/kg), and the 5-aminosalicylic acid (100 mg/kg) + DSS group. The obtained data revealed that CA significantly prevented the shortening of colon length. Meanwhile, the oxidative stress-related enzymes were increased, while malondialdehyde and nitric oxide, were markedly decreased significantly by CA. The results also indicated that CA administration decreased significantly the pro-apoptogenic indices (Bax and caspase-3) and enhanced significantly Bcl-2, the anti-apoptogenic protein. Moreover, DSS caused a significant elevation of pro-inflammatory mediators, including interleukin-1β, tumor necrosis factor-α, myeloperoxidase, cyclooxygenase II, prostaglandin E2, and peroxisome proliferator-activated receptor gamma. Interestingly, these changes were significantly decreased following the CA administration. At the molecular level, CA supplementation has increased significantly the expression level of nuclear factor erythroid 2-related factor-2 (Nrf2) and decreased the expressions of nitric oxide synthase and mitogen-activated protein kinase 14. CA has been determined to significantly lessen DSS-induced colitis by activating Nrf2 and its derived antioxidant molecules and suppressing inflammation and apoptosis cascades associated with the development of colitis; suggesting that CA could be used as an alternative naturally-derived anticolitic agent.

Natural products modulate NLRP3 in ulcerative colitis

Ulcerative colitis (UC) is a clinically common, progressive, devastating, chronic inflammatory disease of the intestine that is recurrent and difficult to treat. Nod-like receptor protein 3 (NLRP3) is a protein complex composed of multiple proteins whose formation activates cysteine aspartate protease-1 (caspase-1) to induce the maturation and secretion of inflammatory mediators such as interleukin (IL)-1β and IL-18, promoting the development of inflammatory responses. Recent studies have shown that NLRP3 is associated with UC susceptibility, and that it maintains a stable intestinal environment by responding to a wide range of pathogenic microorganisms. The mainstay of treatment for UC is to control inflammation and relieve symptoms. Despite a certain curative effect, there are problems such as easy recurrence after drug withdrawal and many side effects associated with long-term medication. NLRP3 serves as a core link in the inflammatory response. If the relationship between NLRP3 and gut microbes and inflammation-associated factors can be analyzed concerning its related inflammatory signaling pathways, its expression status as well as specific mechanism in the course of IBD can be elucidated and further considered for clinical diagnosis and treatment of IBD, it is expected that the development of lead compounds targeting the NLRP3 inflammasome can be developed for the treatment of IBD. Research into the prevention and treatment of UC, which has become a hotbed of research in recent years, has shown that natural products are rich in therapeutic means, and multi-targets, with fewer adverse effects. Natural products have shown promise in treating UC in numerous basic and clinical trials over the past few years. This paper describes the regulatory role of the NLRP3 inflammasome in UC and the mechanism of recent natural products targeting NLRP3 against UC, which provides a reference for the clinical treatment of this disease.

Terpenes: Modulating anti-inflammatory signaling in inflammatory bowel disease

Inflammatory Bowel Disease (IBD) are autoimmune diseases characterized by chronic intestinal inflammation. Considered a western disease, IBD incidence in newly developed countries is skyrocketing. Accordingly, global prevalence is steadily increasing. There are two major IBD phenotypes, ulcerative colitis (UC) and Crohn's disease (CD). UC manifests as uninterrupted inflammation localized in the colon and rectum. Meanwhile, CD presents as interrupted inflammation that can occur throughout the digestive tract. As a result, therapeutics have focused on anti-inflammatory approaches for its treatment. Unfortunately, only 50% of patients benefit from current Food and Drug Administration approved treatments, and all are associated with serious adverse effects. Thus, there is a need for safer and novel therapeutics to increase the efficacy in this population. One aspect that is critical in understanding IBD is how food and phytochemicals therein may be associated with modifying the pathogenesis of IBD. A variety of retrospective and prospective studies, and clinical trials have shown benefits of plant-rich diets on the prevention and symptomatic improvement of IBD. The Mediterranean diet is rich in vegetables, fruits, legumes, and herbs; and characterized by the abundance of anti-inflammatory phytochemicals. An understudied phytochemical class enriched in this diet is terpenes; isoprene-based molecules are widely available in Mediterranean herbs and citrus fruits. Various terpenes have been evaluated in different IBD models. However, some present contradictory or inconclusive results. Therefore, in this review we evaluated preclinical studies of terpenes modulating basic inflammatory signaling related to IBD.

Treatment Effects of Natural Products on Inflammatory Bowel Disease In Vivo and Their Mechanisms: Based on Animal Experiments

Inflammatory bowel disease (IBD) is a chronic, non-specific inflammatory disease of the intestine that can be classified as ulcerative colitis (UC) and Crohn's disease (CD). Currently, the incidence of IBD is still increasing in developing countries. However, current treatments for IBD have limitations and do not fully meet the needs of patients. There is a growing demand for new, safe, and highly effective alternative drugs for IBD patients. Natural products (NPs) are used in drug development and disease treatment because of their broad biological activity, low toxicity, and low side effects. Numerous studies have shown that some NPs have strong therapeutic effects on IBD. In this paper, we first reviewed the pathogenesis of IBD as well as current therapeutic approaches and drugs. Further, we summarized the therapeutic effects of 170 different sources of NPs on IBD and generalized their modes of action and therapeutic effects. Finally, we analyzed the potential mechanisms of NPs for the treatment of IBD. The aim of our review is to provide a systematic and credible summary, thus supporting the research on NPs for the treatment of IBD and providing a theoretical basis for the development and application of NPs in drugs and functional foods.

Therapeutic potential of paeoniflorin in atherosclerosis: A cellular action and mechanism-based perspective

Epidemiological studies have shown that the incidence, prevalence and mortality of atherosclerotic cardiovascular disease (ASCVD) are increasing globally. Atherosclerosis is characterized as a chronic inflammatory disease which involves inflammation and immune dysfunction. P. lactiflora Pall. is a plant origin traditional medicine that has been widely used for the treatment of various diseases for more than a millennium in China, Japan and Korean. Paeoniflorin is a bioactive monomer extracted from P. lactiflora Pall. with anti-atherosclerosis effects. In this article, we comprehensively reviewed the potential therapeutic effects and molecular mechanism whereby paeoniflorin protects against atherosclerosis from the unique angle of inflammation and immune-related pathway dysfunction in vascular endothelial cells, smooth muscle cells, monocytes, macrophages, platelets and mast cells. Paeoniflorin, with multiple protective effects in atherosclerosis, has the potential to be used as a promising therapeutic agent for the treatment of atherosclerosis and its complications. We conclude with a detailed discussion of the challenges and future perspective of paeoniflorin in translational cardiovascular medicine.

Paeoniflorin alleviates inflammatory response in IBS-D mouse model via downregulation of the NLRP3 inflammasome pathway with involvement of miR-29a

Paeoniflorin has been traditionally used to treat pain and immunologic derangement in China. However, its detailed mechanism remains to be illuminated. We investigated the mechanism by which paeoniflorin alleviates the inflammatory response in a mouse model of irritable bowel syndrome with predominant diarrhea (IBS-D). C57BL/6 wild type (WT) and miR-29a knockout (KO) mice were randomly divided into control, model, rifaximin, and paeoniflorin groups (n = 7). IBS-D model was induced by single intracolonic instillation of 0.1 mL trinitro-benzene-sulfonic acid (TNBS, 50 mg/mL) combined with restraint stress for seven consecutive days. The treatment groups received rifaximin (100 mg/kg) and paeoniflorin (50 mg/kg) via intragastric administration for seven days, respectively. The results showed that the fecal water content, fecal pellet output, visceral sensitivity, and histopathological score after paeoniflorin treatment were lower than those of the model group in both WT and miR-29a KO mice (P < 0.05). In both lineage mice, damage was observed in the colon tissues of model group, while paeoniflorin treatment partially ameliorated the tissue damage. Serum levels of DAO, DLA, IL-1β, IL-18, TNF-α, and MPO were decreased after paeoniflorin treatment (P < 0.05), with miR-29a KO mice in a lower level compared with that of WT mice. RT-PCR showed that the relative expression of miR-29a, NF-κB (p65), NLRP3, ASC, caspase-1, IL-1β, and TNF-α was downregulated while NKRF was upregulated after paeoniflorin treatment (P < 0.05). Immunohistochemistry showed that intestinal epithelial protein levels of NLRP3, ASC, and caspase-1 decreased while those of Claudin-1 and ZO-1 increased in the paeoniflorin treatment group (P < 0.05). In general, compared with WT mice, NLRP3 inflammasome pathway targets was in much lower expression level than miR-29a KO mice. In conclusion, paeoniflorin could inhibit abnormal activation of the NLRP3 inflammasome pathway by inhibiting miR-29a in IBS-D, thereby relieving the inflammatory response of the intestinal mucosa and reconstructing the intestinal epithelial barrier.

Research trends in ulcerative colitis: A bibliometric and visualized study from 2011 to 2021

Background: Ulcerative colitis (UC) is an idiopathic inflammatory bowel disease with repeated relapses and remissions. Despite decades of effort, numerous aspects, including the initiating event and pathogenesis of UC, still remain ambiguous, which requires ongoing investigation. Given the mass of publications on UC, there are multidimensional challenges to evaluating the scientific impact of relevant work and identifying the current foci of the multifaceted disease. Accordingly, herein, we aim to assess the global growth of UC research production, analyze patterns of research areas, and evaluate trends in this area.

Methods: The Web of Science Core Collection of Clarivate Analytics was searched for articles related to UC published from 2011 to 2021. Microsoft Office Excel 2019 was used to visualize the number of publications over time. Knowledge maps were generated using CiteSpace and VOSviewer to analyze collaborations among countries, institutions, and authors and to present the journey of UC research as well as to reveal the current foci of UC research.

Results: A total of 5,088 publications were evaluated in the present study. China had the most publications (1,099, 22.5%). Univ Calif San Diego was the most productive institution (126, 2.48%). William J Sandborn published the greatest number of articles (100, 1.97%). Toshifumi Hibi was the most influential author in the field with a betweenness centrality of 0.53. Inflammatory bowel diseases was identified as the most prolific journal (379, 7.45%). Gastroenterology was the most co-cited journal (3,730, 4.02%). “Vedolizumab,” “tofacitinib,” “Faecalibacterium prausnitzii,” “fecal microbiota transplantation (FMT),” “toll-like receptor 4,” and “nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome” were considered the hot topics.

Conclusion: In UC research, manuscripts that had high impacts on the scientific community provided an evidence base. UC therapy has entered the era of personalized and precision therapy. As research on FMT, anti-integrin antibodies, Janus kinase inhibitors, and anti-tumor necrosis factor drugs continues to grow, their use in the clinical setting may also expand.

Holism of Chinese herbal medicine prescriptions for inflammatory bowel disease: A review based on clinical evidence and experimental research

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic nonspecific inflammatory disease that causes a heavy burden and lacks effective treatments. Chinese herbal medicine prescriptions (CHMPs), which are characterized by a synergistic usage of herbs, are widely used in the management of IBD. The molecular mechanisms of action of CHMP are still ambiguous as the canonical "one-compound-one-target" approach has difficulty describing the dynamic bioreactions among CHMP objects. It seems more flexible to define the holism of CHMP for IBD by employing high-throughput analysis. However, studies that discuss the development of CHMP in treating IBD in a holistic view are still lacking.

PURPOSE

This review appraised preclinical and clinical research to fully describe the anti-IBD capacity of CHMPs and discussed CHMPs' holistic characteristics that can contribute to better management of IBD.

METHODS & RESULTS

We screened clinical and preclinical references of CHMP being used as treatments for IBD. We discussed the complexity of IBD and the development of CHMP to present the sophistication of CHMP treatments. To describe the clinical effectiveness of CHMPs against IBD, we performed an umbrella review of CHMP-associated META analyses, in which 1174 records were filtered down to 12 references. Then, we discussed 14 kinds of CHMPs that had a long history of use and analyzed their mechanisms of action. Representative herbs were employed to provide a subordinate explanation for the whole prescription. As holism is the dominant characteristic of CHMPs, we explored applications of CHMPs for IBD with the help of omics, gut microbiome, and network pharmacology, which are potential approaches to a dynamic figure of bioactions of CHMPs.

CONCLUSION

This review is the first to discuss the potential of CHMPs to manage IBD in a holistic context and will provide inspiring explanations for CHMP applications for further product transformation and application to other diseases.

Potential Chemoprevention of Paeoniflorin in Colitis-associated Colorectal Cancer by Network Pharmacology, Molecular Docking, and In Vivo Experiment

Chronic inflammation plays a positive role in the development and progression of colitis-associated colorectal cancer (CAC). Medicinal plants and their extracts with anti-inflammatory and immunoregulatory properties may be an effective treatment and prevention strategy for CAC. This research aimed to explore the potential chemoprevention of paeoniflorin (PF) for CAC by network pharmacology, molecular docking technology, and in vivo experiments. The results showed that interleukin-6 (IL-6) is a key target of PF against CAC. In the CAC mouse model, PF increased the survival rate of mice and decreased the number and size of colon tumors. Moreover, reduced histological score of colitis and expression of Ki-67 and PCNA were observed in PF-treated mice. In addition, the chemoprevention mechanisms of PF in CAC may be associated with suppression of the IL-6/STAT3 signaling pathway and the IL-17 level. This research provides experimental evidence of potential chemoprevention strategies for CAC treatment.

Phytochemicals targeting Toll-like receptors 4 (TLR4) in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a collective term for inflammatory diseases including Crohn's disease and ulcerative colitis. Toll-like receptor 4 (TLR4) is thought to play a key role in the pathogenesis of IBD. Inhibition of TLR4 has been recognized as an effective target for the treatment of IBD. Many phytochemicals have been shown to have potential as new drugs for the treatment of IBD. This review surveyed the available literature and reports which focused on the in vivo effects of phytochemicals targeting TLR4 in different models of IBD, and clarified the significance of TLR4 as a current therapeutic target for IBD. Based on our review, we have concluded that phytochemicals targeting TLR4 are potentially effective candidates for developing new therapeutic drugs against IBD.

Chitin derivatives ameliorate DSS-induced ulcerative colitis by changing gut microbiota and restoring intestinal barrier function

Chitin derivatives (CDs), including chitosan (CS), chitooligosaccharides (COS), and glucosamine (GlcN), were administrated in dextran sodium sulfate (DSS)-induced ulcerative colitis (UC) mice. UC symptoms such as body weight loss, reduced food intake, and increased disease activity index were relieved (except GlcNL group). CDs (except GlcNL) exerted a strong protective effect on colon length and colonic structure. Treatment with CDs (except GlcNL) increased IL-10 level, reduced levels of IL-1β, IL-6, TNF-α, myeloperoxidase, and inducible nitric oxide synthase, and enhanced expression of tight junction proteins significantly. CDs (except GlcNL) significantly upregulated IκB-α level, and downregulated p65 and p38 phosphory lation and TLR-4 mRNA transcription level, indicating inhibition of TRL-4/NF-κB/MAPK signaling pathway activity. CD treatments increased relative abundance of gut microbiota, modulated its composition, and increased the concentrations of SCFAs. Our findings indicate that CDs exert an ameliorative effect on UC by change of gut microbiota composition and restoration of intestinal barrier function.

Picroside II alleviates DSS-induced ulcerative colitis by suppressing the production of NLRP3 inflammasomes through NF-κB signaling pathway

CONTEXT

Ulcerative colitis (UC) is a common acute or chronic intestinal disease with the imbalance of inflammation. Picroside II (P-II) exerts the protective role in various inflammation-related diseases. However, the effect of P-II on UC is still unclear.

OBJECTIVE

To explore the effect of P-II on UC and its potential mechanism.

MATERIALS AND METHODS

Human monocytic leukemia cell line THP-1 were treated with phorbol ester (PMA) to differentiate into macrophage. The differentiated THP-1 cells were hatched with LPS combined with ATP or Nigericin to activate the NLRP3 inflammasome in vitro. The UC model was constructed by injection of DSS into mice.

RESULTS

The maximum non-toxic concentration of P-II on THP-1 cells was 60 μM. LPS combined with ATP or Nigericin stimulated the production of IL-1β, which was antagonized by P-II treatment. Meanwhile, P-II administration interfered the aggregation of ASC and the assembly of NLRP3 inflammasomes. Also, P-II treatment reduced the LPS and ATP-induced elevation of the relative protein expression of NLRP3, pro-caspase-1, IL-1β and p-p65/p65, and the concentration of TNF-α and IL-6. Besides, the NF-κB specific inhibitor BAY-117082 notably repressed the LPS together with ATP-enhanced the relative protein expression of NLRP3, caspase-1 and IL-1β. Moreover, in vivo results showed that P-II relieved the DDS-induced UC, as evidenced by the improvement of mice weight, DAI and pathological scores. In addition, P-II treatment notably decreased DDS-promoted expression of NLRP3 inflammasomes and inflammatory factors in vivo.

CONCLUSION

P-II alleviated DSS-induced UC by repressing the production of NLRP3 inflammasomes via NF-κB signaling pathway.

Paeoniflorin ameliorates ischemic injury in rat brain via inhibiting cytochrome c/caspase3/HDAC4 pathway

Paeoniflorin (PF), a bioactive monoterpene glucoside, has shown a variety of pharmacological effects such as anti-inflammation and autophagy modulation etc. In this study, we investigated whether and how PF exerted a protective effect against ischemic brain injury in vivo and in vitro. Primary rat cortical neurons underwent oxygen/glucose deprivation/reperfusion (OGD/R) for 90 min. We showed that after OGD/R, a short fragment of histone deacetylase 4 (HDAC4) produced by caspase3-mediated degradation was markedly accumulated in the nucleus and the activity of caspase3 was increased. Treatment with PF (100 nM, 1 μM) significantly improved the viability of cortical neurons after OGD/R. Furthermore, PF treatment could maintain HDAC4 intrinsic subcellular localization and reduce the caspase3 activity without changing the HDAC4 at the transcriptional level. PF treatment significantly reduced OGD/R-caused inhibition of transcriptional factor MEF2 expression and increased the expression of downstream proteins such as GDNF, BDNF, and Bcl-xl, thus exerting a great anti-apoptosis effect as revealed by TUNEL staining. The beneficial effects of PF were almost canceled in HDAC4 (D289E)-transfected PC12 cells after OGD/R. In addition, PF treatment reduced the caspase9 activity, rescued the release of cytochrome c from mitochondria, and maintained the integrity of mitochondria membrane. We conducted in vivo experiments in 90-min-middle cerebral artery occlusion (MCAO) rat model. The rats were administered PF (20, 40 mg/kg, ip, 3 times at the reperfusion, 24 h and 48 h after the surgery). We showed that PF administration dose-dependently reduced infarction area, improved neurological symptoms, and maintained HDAC4 localization in rats after MCAO. These results demonstrate that PF is effective in protecting against ischemic brain injury and inhibit apoptosis through inhibiting the cytochrome c/caspase3/HDAC4 pathway.

Pharmacokinetic interaction between peimine and paeoniflorin in rats and its potential mechanism

CONTEXT

Peimine and paeoniflorin can be combined for the treatment of cough in paediatrics. The interaction during the co-administration could dramatically affect the bioavailability of drugs.

OBJECTIVE

The interaction between peimine and paeoniflorin was investigated in this study.

MATERIALS AND METHODS

The pharmacokinetics of paeoniflorin (20 mg/kg) with or without the coadministration of peimine (5 mg/kg for 10 days before paeoniflorin) was orally investigated in Sprague-Dawley rats (n = 6). The group without the peimine was set as the control group. The metabolic stability of paeoniflorin was studied in rat liver with microsomes. The effect of peimine on the absorption of paeoniflorin was investigated with Caco-2 cell monolayers.

RESULTS

The C_max (244.98 ± 10.95 vs. 139.18 ± 15.14 μg/L) and AUC_(0-t) (3295.92 ± 263.02 vs. 139.18 ± 15.14 h·μg/L) of paeoniflorin was increased by peimine. The t_1/2 was prolonged from 5.33 ± 1.65 to 14.21 ± 4.97 h and the clearance was decreased from 15.43 ± 1.75 to 4.12 ± 0.57 L/h/kg. Consistently, peimine increased the metabolic stability of paeoniflorin with rat liver microsomes with the increased t_1/2 (56.78 ± 2.62 vs. 26.33 ± 3.15 min) and the decreased intrinsic clearance (24.42 ± 3.78 vs. 52.64 ± 4.47 μL/min/mg protein). Moreover, the transportation of paeoniflorin was also inhibited by peimine as the efflux ratio decreased from 3.06 to 1.63.

DISCUSSION AND CONCLUSIONS

Peimine increased the systemic exposure of paeoniflorin through inhibiting the activity of CYP3A4 and P-gp. These results provide a reference for further in vivo studies in a broader population.

Alhagi pseudalhagi Extract Exerts Protective Effects Against Intestinal Inflammation in Ulcerative Colitis by Affecting TLR4-Dependent NF-κB Signaling Pathways

Alhagi pseudalhagi Desv. Extract (APE) is the major active fraction extracted from the aerial part of Alhagi pseudalhagi Desv. In view of its application in Uyghur medicine, it may be beneficial for the treatment of ulcerative colitis (UC). The aim of the present study was to investigate the possible beneficial effects of APE on UC mice and detect the possible mechanisms underlying these effects.

Methods: An acute UC model was established in mice using dextran sulfate sodium. Sixty mice were randomly divided into six groups: normal, UC model, sulfasalazine (200 mg/kg), high-dose APE (APE-H, 2.82 g/kg), middle-dose APE (APE-M, 1.41 g/kg), and low-dose APE (APE-L, 0.70 g/kg) groups. Drugs were administered by gavage for 10 days after the induction of colitis. Serum and colon tissue samples were collected from the mice during the experiment, and survival signs, body weight changes, disease activity index (DAI), colon length, and colon wet weight in mice were determined after the treatment. UC-induced damage, including inflammation and ulceration of colon mucosa, were observed by the naked eye as well as using hematoxylin and eosin staining (H&E) and scanning electron microscopy and scored according to Wallace and Keean’s criteria. We measured the levels of tumor necrosis factor α (TNF-α), interleukin (IL)-1β, IL-6, and IL-10 in the serum and colon tissues using ELISA. Additionally, the relative protein levels of toll-like receptor 4 (TLR₄), nuclear factor-kappa B p65 (NF-κB p65), phosphorylated NF-κB p65 at Ser536 (p-p65 Ser536), inhibitor kappa B-kinase ß (IK-Kβ), and phosphorylated IK-Kβ (Ser176/180) (p-IK-Kβ) in colonic mucosal epithelial tissues were detected using western blotting. The main functional components of APE were analyzed and confirmed by UPLC-MS/MS.

Results: APE treatment repaired the UC-induced colon mucosa injury, reduced the weight loss, attenuated DAI, colon macroscopic damage index, and histological inflammation, and significantly downregulated the levels of inflammatory markers, including TNF-α, IL-1β, and IL-6, in the serum and colon tissues. Additionally, APE treatment reduced the levels of TLR₄ and phosphorylation of p-NF-κB and p-IK-Kβ. The main components of APE are taxifolin, 3,5-dihydroxy-2-(4-hydroxyphenyl)-7-[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl) oxan-2-yl] oxychromen-4-one, hyperoside, rutin, kaempferol, isorhamnetin, 7,8-dihydroxyflavone, and kaempferide.

Conclusions: To the best of our knowledge, the present study is first to demonstrate that APE exerts a protective effect against intestinal inflammation in UC by affecting TLR₄-dependent NF-κB signaling pathways.

A recent update on the use of Chinese medicine in the treatment of inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is a chronic idiopathic disease that is characterized by inflammation of the gastrointestinal tract. Proper management of IBD requires both early diagnosis and novel therapies and management programs. Many reports have suggested that Chinese medicine has unique properties favorable to the treatment of IBD. However, there are no systematic analyses on this topic.

PURPOSE

This review summarizes recent studies that assessed the effects and mechanisms of Chinese medicine in the treatment of IBD in order to fully understand the advantages of Chinese medicine in the management of IBD.

METHODS

A literature search was conducted using peer-reviewed and clinical databases, including PubMed, Web of Science, ClinicalTrials.gov, MEDLINE, EMBASE, Springer LINK, Wan-fang database, the Chinese Biomedicine Database, and the China National Knowledge Infrastructure (CNKI). Keywords used were inflammatory bowel disease (including Ulcerative colitis or Crohn's disease) and Chinese medicine. All selected articles were from 1997 to 2021, and each were assessed critically for our exclusion criteria. Studies describing the pathogenesis of IBD, the effects and mechanisms of Chinese medicine in the treatment of IBD, in particular their roles in immune regulation, intestinal flora regulation, and improvement of intestinal barrier function, were included.

CONCLUSION

This review highlights recent progress in the use of Chinese medicine in the treatment of IBD. It also provides a reference for further evaluation and exploration of the potential of classical multi-herbal Chinese medicine in the treatment of IBD.

Novel kojic acid derivatives with anti-inflammatory effects from Aspergillus versicolor

Two novel kojic acid derivatives, kojicones A and B (1 and 2), along with the precursors kojic acid (3) and (2R,4R)-4-hydroxy-5-methoxy-2,4-dimethyl-2- [(2R)-2-methylbutyryloxy]-5-cyclohexen-1,3-dione (4), were isolated from a fungal strain Aspergillus versicolor. Their structures and absolute configurations were accurately confirmed by HRESIMS data, NMR analysis, and electronic circular dichroism (ECD) calculations. Kojicones A and B were the first examples of kojic acid adducts with cyclohexen-1,3-dione possessing unprecedented tricycle skeletons. Compounds 1-3 were found to have inhibition on the NO production of murine RAW 264.7 cells. They can also reduce the mRNA expression of four cytokines (IL-6, IL-1β, TNF-α, and iNOS) and promote the expression of IL-4 at 20 μM. Moreover, kojic acid (3) could treat the DSS (dextran sulfate sodium)-induced colitis on mice with the effectiveness similar to that of the positive control. The results suggested that kojic acid and its derivatives could be a promising anti-inflammatory source for the medicinal and cosmetic industry.

The Therapeutic Strategies for Uremic Toxins Control in Chronic Kidney Disease

Uremic toxins (UTs) are mainly produced by protein metabolized by the intestinal microbiota and converted in the liver or by mitochondria or other enzymes. The accumulation of UTs can damage the intestinal barrier integrity and cause vascular damage and progressive kidney damage. Together, these factors lead to metabolic imbalances, which in turn increase oxidative stress and inflammation and then produce uremia that affects many organs and causes diseases including renal fibrosis, vascular disease, and renal osteodystrophy. This article is based on the theory of the intestinal-renal axis, from bench to bedside, and it discusses nonextracorporeal therapies for UTs, which are classified into three categories: medication, diet and supplement therapy, and complementary and alternative medicine (CAM) and other therapies. The effects of medications such as AST-120 and meclofenamate are described. Diet and supplement therapies include plant-based diet, very low-protein diet, probiotics, prebiotics, synbiotics, and nutraceuticals. The research status of Chinese herbal medicine is discussed for CAM and other therapies. This review can provide some treatment recommendations for the reduction of UTs in patients with chronic kidney disease.

Paeoniflorin protects against dextran sulfate sodium (DSS)-induced colitis in mice through inhibition of inflammation and eosinophil infiltration

Ulcerative colitis (UC) is a type of inflammatory bowel disease (IBD) that causes inflammation and ulcers in the digestive tract. The treatment commonly includes anti-inflammatory agents like 5-aminosalicylic acid or corticosteroids or biologics for people with UC who are no longer responding to corticosteroids. The radices of Paeonia lactiflora Pall. or similar plants of the Paeonia genus have been used in Chinese medicine to treat certain diseases that resemble the symptoms of UC. Paeoniflorin, a terpenoid glycoside, is a major active component for the anti-inflammatory and antitumor activity. In this study, we evaluated the therapeutic effect of paeoniflorin (PF) against dextran sulfate sodium (DSS)-induced colitis in mice and found that PF exhibited protective activity against colitis. PF treatment suppressed NF-κB pathway activation, resulting down regulation of pro-inflammatory factor expression. In addition, we detected reduction in eosinophil-related chemokine gene expression and eosinophil infiltration. The treatment also reversed Treg cell population suppression. Although PF treatment did not block COX2 induction, the compound weakly inhibited COX2 activity in an enzymatic assay. Taken together, PF exerts its therapeutic activity against UC through inhibition of inflammation and eosinophil infiltration.

Pinocembrin alleviates ulcerative colitis in mice via regulating gut microbiota, suppressing TLR4/MD2/NF-κB pathway and promoting intestinal barrier

Pinocembrin, a plant-derived flavonoid, has a variety of pharmacological activities, including anti-infection, anti-cancer, anti-inflammation, cardiovascular protection, etc. However, the mechanism of pinocembrin on the anti-colitis efficacy remains elusive and needs further investigation. Here, we reported that pinocembrin eased the severity of dextran sulfate sodium (DSS)-induced colitis in mice by suppressing the abnormal activation of toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) signal pathway in vivo. In addition, the gut microbiota was disordered in DSS colitis mice, which was associated with a significant decrease in microbiota diversity and a great shift in bacteria profiles; however, pinocembrin treatment improved the imbalance of gut microbiota and made it similar to that in normal mice. On the other hand, in vitro, pinocembrin down-regulated the TLR4/NF-κB signaling cascades in lipopolysaccharide (LPS)-stimulated macrophages. At the upstream level, pinocembrin competitively inhibited the binding of LPS to myeloid differentiation protein 2 (MD2), thereby blocking the formation of receptor multimer TLR4/MD2·LPS. Furthermore, pinocembrin dose-dependently promoted the expression of tight junction proteins (ZO-1, Claudin-1, Occludin and JAM-A) in Caco-2 cells. In conclusion, our work presented evidence that pinocembrin attenuated DSS-induced colitis in mouse, at least in part, via regulating intestinal microbiota, inhibiting the over-activation of TLR4/MD2/NF-κB signaling pathway, and improving the barriers of intestine.

Si-Ni-San ameliorates chronic colitis by modulating type I interferons-mediated inflammation

BACKGROUND

Ulcerative colitis (UC) is a chronic relapsing inflammatory disease that markedly elevates the risk of colon cancers and results in disability. The disrupted immune homeostasis has been recognized as a predominant player in the pathogenesis of UC. However, the overall remission rate of current therapies based on immunoregulation is still unsatisfactory. Si-Ni-San (SNS) has been found effective in relieving UC through thousands of years of clinical practice, yet the specific mechanisms of the protective effect of SNS were not fully elucidated.

PURPOSE

We aim to investigate the therapeutic effects of SNS against the development of chronic colitis and the underlying mechanisms.

METHODS

We established a DSS-induced chronic experimental colitis mouse model to evaluate the effect of SNS. RNA-sequencing, bioinformatic analysis, and in vitro studies were performed to investigate the underlying mechanisms.

RESULTS

Our data demonstrated that SNS significantly ameliorated chronic experimental colitis via inhibiting the expression of genes associated with inflammatory responses. Interestingly, SNS significantly suppressed DSS-induced type I interferon (IFN) responses instead of directly downregulating the production of pro-inflammatory cytokines, such as Il-6. In vitro study further found that SNS selectively inhibited STING and RIG-I pathway-induced type I IFN responses by modulating TBK1- and IRF3-dependent signaling transduction. SNS also suppressed the expression of IFN-stimulated genes by directly inhibiting STAT1 and STAT2 activation.

CONCLUSION

Our study not only provides novel insights into the pathogenic role of type I IFN responses in colitis but also suggested that SNS or bioactive compounds derived from SNS may serve as novel therapeutic strategies for the treatment of UC via interfering type I IFN-mediated inflammation.

Paeoniflorin Enhances Endometrial Receptivity through Leukemia Inhibitory Factor

Despite advances in assisted reproductive technology, treatment for deficient endometrial receptivity is a major clinical unmet need. In our previous study, the water extract of Paeonia lactiflora Pall. enhanced endometrial receptivity in vitro and in vivo via induction of leukemia inhibitory factor (LIF), an interleukin (IL)-6 family cytokine. In the present study, we found that paeoniflorin, a monoterpene glycoside, is the major active compound of P. lactiflora. Paeoniflorin significantly improved the embryo implantation rate in a murine model of mifepristone (RU486)-induced implantation failure. In addition, paeoniflorin increased the adhesion of human trophectoderm-derived JAr cells to endometrial Ishikawa cells through the expression of LIF in vitro. Moreover, using the National Center for Biotechnology Information (NCBI) Gene Expression Omnibus (GEO) database of the human endometrium, we confirmed that LIF signaling is a key regulator for improving human endometrial receptivity. Therefore, these results suggest that paeoniflorin might be a potent drug candidate for the treatment of endometrial implantation failure by enhancing endometrial receptivity.

Anthocyanin-containing purple potatoes ameliorate DSS-induced colitis in mice

Ulcerative colitis (UC), a major form of inflammatory bowel disease (IBD), is on the rise worldwide. Approximately three million people suffer from IBD in the United States alone, but the current therapeutic options (e.g., corticosteroids) come with adverse side effects including reduced ability to fight infections. Thus, there is a critical need for developing effective, safe and evidence-based food products with anti-inflammatory activity. This study evaluated the antiinflammatory potential of purple-fleshed potato using a dextran sodium sulfate (DSS) murine model of colitis. Mice were randomly assigned to control (AIN-93G diet), P15 (15% purple-fleshed potato diet) and P25 (25% purple-fleshed potato diet) groups. Colitis was induced by 2% DSS administration in drinking water for six days. The results indicated that purple-fleshed potato supplementation suppressed the DSS-induced reduction in body weight and colon length as well as the increase in spleen and liver weights. P15 and P25 diets suppressed the elevation in the intestinal permeability, colonic MPO activity, mRNA expression and protein levels of pro-inflammatory interleukins IL-6 and IL-17, the relative abundance of specific pathogenic bacteria such as Enterobacteriaceae, Escherichia coli (E. coli) and pks⁺ E. coli, and the increased flagellin levels induced by DSS treatment. P25 alone suppressed the elevated systemic MPO levels in DSS-exposed mice, and elevated the relative abundance of Akkermansia muciniphila (A. muciniphila) as well as attenuated colonic mRNA expression level of IL-17 and the protein levels of IL-6 and IL-1β. Therefore, the purple-fleshed potato has the potential to aid in the amelioration of UC symptoms.

Protecting Intestinal Microenvironment Alleviates Acute Graft-Versus-Host Disease

Acute gut graft-versus-host disease (aGVHD) is a leading threat to the survival of allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. Abnormal gut microbiota is correlated with poor prognosis in allo-HSCT recipients. A disrupted intestinal microenvironment exacerbates dysbiosis in GVHD patients. We hypothesized that maintaining the integrity of the intestinal barrier may protect gut microbiota and attenuate aGVHD. This hypothesis was tested in a murine aGVHD model and an in vitro intestinal epithelial culture. Millipore cytokine array was utilized to determine the expression of proinflammatory cytokines in the serum. The 16S rRNA sequencing was used to determine the abundance and diversity of gut microbiota. Combining Xuebijing injection (XBJ) with a reduced dose of cyclosporine A (CsA) is superior to CsA alone in improving the survival of aGVHD mice and delayed aGVHD progression. This regimen also reduced interleukin 6 (IL-6) and IL-12 levels in the peripheral blood. 16S rRNA analysis revealed the combination treatment protected gut microbiota in aGVHD mice by reversing the dysbiosis at the phylum, genus, and species level. It inhibited enterococcal expansion, a hallmark of GVHD progression. It inhibited enterococcal expansion, a hallmark of GVHD progression. Furthermore, Escherichia coli expansion was inhibited by this regimen. Pathology analysis revealed that the combination treatment improved the integrity of the intestinal tissue of aGVHD mice. It also reduced the intestinal permeability in aGVHD mice. Besides, XBJ ameliorated doxorubicin-induced intestinal epithelial death in CCK-8 assay. Overall, combining XBJ with CsA protected the intestinal microenvironment to prevent aGVHD. Our findings suggested that protecting the intestinal microenvironment could be a novel strategy to manage aGVHD. Combining XBJ with CsA may reduce the side effects of current aGVHD prevention regimens and improve the quality of life of allo-HSCT recipients.

Zeolite-containing mixture alleviates microbial dysbiosis in dextran sodium sulfate-induced colitis in mice

Inflammatory bowel disease (IBD) is a multifactorial immunomodulatory disorder. In relative nosogenesis, gut microbiota has been the focus of research on IBD. In our previous study, we demonstrated the ameliorating effect of zeolite-containing mixture (Hydryeast®, HY) on dextran sodium sulfate (DSS)-induced colitis, through transcriptomics and proteomics. In the present study, we performed further investigation from the perspective of metagenomics using the gut microbiota. C57BL6 mice were provided an AIN-93G basal diet or a 0.8% HY-containing diet, and sterilized tap water for 11 days. Thereafter, colitis was induced by providing 1.5% (w/v) DSS-containing water for 9 days. DNA was extracted from the cecal contents and pooled into libraries in a single Illumina MiSeq run. The resulting sequences were analyzed using Quantitative Insights Into Microbial Ecology (QIIME) software. According to the alterations in the relative abundance of certain bacteria, and the related gene and protein expressions, HY supplementation could improve the gut microbiota composition, ameliorate the degree of inflammation, inhibit the colonic mucosal microbial growth, and, to some extent, promote energy metabolism in the colon compared with the DSS treatment. Thus, we believe that HY may be a candidate to prevent and treat IBD.

Ziyuglycoside II Inhibits Rotavirus Induced Diarrhea Possibly via TLR4/NF-κB Pathways

Rotavirus (RV) induced diarrhea has been a major reason affecting children healthy under 5 years old especially in developing countries. Although specific vaccines have preventive effects, antiviral therapy is essential for the diarrhea patients. Ziyuglycoside II is a traditional Chinese herb which has been proven to possess anti-virus effects. This study aimed to investigate the roles of Ziyuglycoside II in rotavirus-induced diarrhea and the underlying molecular mechanism. We found that normal MA104 cells treated with RV became swollen and gather together. However, Ziyuglycoside II treatment inhibited cell growth in a dose- and time dependent manner and suppressed RV replication. Moreover, Ziyuglycoside II reversed RV-induced downregulation of anti-inflammatory cytokine interleukin (IL)-10 and upregulation of pro-inflammatory factors, such as interferon-γ (IFN-γ), IL-1β, IL-6, and tumor necrosis factor (TNF-α). Moreover, Ziyuglycoside II administration and ribavirin blocked toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling pathway both in mRNA and protein level, which was paralleled with immunohistochemical assay. Additionally, Ziyuglycoside II administration improved diarrhea symptoms and decreased diarrhea scores. Ziyuglycoside II and ribavirin inhibited the apoptosis of small intestine epithelial cells induced by RV. Taken together, RV treatment induced diarrhea. Ziyuglycoside II administration inhibited TLR4/NF-κB pathway and inflammatory response and improved RV-induced diarrhea. The inhibitory effects of Ziyuglycoside II on RV-induced diarrhea predicted Ziyuglycoside II may be a promising drug for diarrhea.

Acacetin Ameliorates Experimental Colitis in Mice via Inhibiting Macrophage Inflammatory Response and Regulating the Composition of Gut Microbiota

Acacetin, a natural dietary flavonoid abundantly found in acacia honey and citrus fruits, reportedly exerts several biological effects, such as anti-tumor, anti-inflammatory, and anti-oxidative effects. However, the effects of acacetin on intestinal inflammation remain unclear. We sought to investigate whether acacetin ameliorates inflammatory bowel disease (IBD) in mice with dextran sulfate sodium (DSS)-induced ulcerative colitis (UC). Our results suggest that acacetin alleviates the clinical symptoms of DSS-induced colitis, as determined by body weight loss, diarrhea, colon shortening, inflammatory infiltration, and histological injury. Further studies showed that acacetin remarkably inhibited both the macrophage inflammatory response in vitro and levels of inflammatory mediators in mice with colitis. In addition, some features of the gut microbiota were disordered in mice with DSS-induced colitis, as evidenced by a significant reduction in microbiota diversity and a marked shift in bacterial profiles. However, acacetin treatment improved this imbalance and restored gut microbiota to levels that were similar to those in normal mice. In conclusion, our work presents evidence that acacetin attenuates DSS-induced colitis in mice, at least in part, by inhibiting inflammation and regulating the intestinal microbiota.

Salvia miltiorrhiza stems and leaves total phenolic acids combination with tanshinone protect against DSS-induced ulcerative colitis through inhibiting TLR4/PI3K/AKT/mTOR signaling pathway in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Salvia miltiorrhiza Bge. as a traditional Asian medicinal plant, roots and rhizomes (Danshen) are used to treat chronic hepatitis and coronary heart disease. In recent years, the medicinal value of S. miltiorrhiza stems and leaves total phenolic acids extract (JF) similar to roots and rhizomes has received increasing attention. S. miltiorrhiza roots and rhizome tanshinone extract (DT) has a good anti-inflammatory effect.

AIM OF THE STUDY

To explore the therapeutic effect and possible molecular mechanisms of JF and DT alone or in combination on dextran sulfate sodium (DSS)-induced colitis mice.

MATERIALS AND METHODS

Colitis was induced by received 2% DSS in drinking water for 7 consecutive days. Then mice were administered orally for 7 days. Disease activity index (DAI) scores and body weight were recorded daily. After the end of the experiment, colon was removed, colon length was measured and histopathological analysis was performed. Inflammatory factors expression was determined by ELISA, its mRNA expression was detected by real-time quantitative PCR, and the expression of related proteins on TLR4/PI3K/AKT/mTOR signal was analyzed by Western blot.

RESULTS

Treatment with JF and DT alone or in combination reduced DAI scores, increase body weight, improved colon shortening, and decreased colon histology scores. In addition, the expression level of inflammatory factors was inhibited. The combination of JF and DT had a better inhibitory effect on inflammatory factors compared to JF alone. We also found that DT alone and JF combined with DT inhibited TLR4/PI3K/AKT/mTOR signaling-related proteins expression levels (including TLR4, p-PI3K p110α/PI3K p110α, p-AKT (ser473)/AKT, mTOR, p-mTOR, NF-κB p65), showing an effective anti-inflammatory effect.

CONCLUSIONS

We demonstrated for the first time that, JF and DT alone or in combination effectively ameliorated DSS-induced ulcerative colitis in mice, possibly by inhibiting the TLR4/PI3K/AKT/mTOR signaling pathway.

Toll-like receptor 4 (TLR4) antagonists as potential therapeutics for intestinal inflammation

Gastrointestinal inflammation is a hallmark of highly prevalent disorders, including cancer treatment-induced mucositis and ulcerative colitis. These disorders cause debilitating symptoms, have a significant impact on quality of life, and are poorly managed. The activation of toll-like receptor 4 (TLR4) has been proposed to have a major influence on the inflammatory signalling pathways of the intestinal tract. Inhibition of TLR4 has been postulated as an effective way to treat intestinal inflammation. However, there are a limited number of studies looking into the potential of TLR4 antagonism as a therapeutic approach for intestinal inflammation. This review surveyed available literature and reported on the in vitro, ex vivo and in vivo effects of TLR4 antagonism on different models of intestinal inflammation. Of the studies reviewed, evidence suggests that there is indeed potential for TLR4 antagonists to treat inflammation, although only a limited number of studies have investigated treating intestinal inflammation with TLR4 antagonists directly. These results warrant further research into the effect of TLR4 antagonists in the intestinal tract.

Targeting Mitogen-Activated Protein Kinases by Natural Products: A Novel Therapeutic Approach for Inflammatory Bowel Diseases

An increase in the prevalence of Inflammatory Bowel Diseases (IBD) as a multifactorial intestinal chronic inflammation as well as the absence of a certain cure, has created an innovative era in the management of IBD by molecule/pathway-based anti-inflammatory approaches. There are credible documentations that demonstrate Mitogen-Activated Protein Kinases (MAPK) acts as IBD regulator. Upon the activation of MAPK signalling pathway, the transcription and expression of various encoding inflammatory molecules implicated in IBD are altered, thereby exacerbating the inflammation development. The current pharmacological management of IBD, including drug and biological therapies are expensive, possess temporary relief and some adverse effects. In this context, a variety of dietary fruits or medicinal herbs have received worldwide attention versus the development of IBD. Infact, natural ingredients, such as Flavaglines, Fisetin, Myricitrin, Cardamonin, Curcumin, Octacosanol and Mangiferin possess protective and therapeutic effects against IBD via modulation of different segments of MAPK signaling pathway. This review paper calls attention to the role of MAPK signaling triggered by natural products in the prevention and treatment of IBD.

Paeoniflorin modulates gut microbial production of indole-3-lactate and epithelial autophagy to alleviate colitis in mice

BACKGROUND

Total glucosides of peony (TGP), extracted from the root and rhizome of Paeonia lactiflora Pall, has well-confirmed immunomodulatory efficacy in the clinic. However, the mechanism and active ingredients remain largely unclear.

HYPOTHESIS/PURPOSE

Our previous study revealed a low systemic exposure but predominant gut distribution of TGP components. The aim of this study was to investigate involvement of the gut microbiota in the immunoregulatory effects and identify the active component.

METHODS

Mice received 3% DSS to establish a model of colitis. The treatment group received TGP or single paeoniflorin (PF) or albiflorin (AF). Body weight, colon length, inflammatory and histological changes were assessed. Gut microbiota structure was profiled by 16s rRNA sequencing. Antibiotic treatment and fecal transplantation were used to explore the involvement of gut microbiota. Metabolomic assay of host and microbial metabolites in colon was performed.

RESULTS

TGP improved colonic injury and gut microbial dysbiosis in colitis mice, and PF was responsible for the protective effects. Fecal microbiota transfer from TGP-treated mice conferred resilience to colitis, while antibiotic treatment abrogated the protective effects. Both TGP and PF decreased colonic indole-3-lactate (ILA), a microbial tryptophan metabolite. ILA was further identified as an inhibitor of epithelial autophagy and ILA supplementation compromised the benefits of TGP.

CONCLUSION

Our findings suggest that TGP acts in part through a gut microbiota-ILA-epithelial autophagy axis to alleviate colitis.

Paeoniae radix alba polysaccharides obtained via optimized extraction treat experimental autoimmune hepatitis effectively

The extraction process of Paeoniae radix alba polysaccharides (PRAP) was optimized as the liquid-solid ratio of 10.65 mL/g, the extraction time of 2.10 h, and the 2 extraction repetitions through a response surface methodology. The chemical profiles of the obtained PRAP were characterized by measuring the contents of total carbohydrates, total phenolics, uronic acid and protein, and by analyzing the FT-IR spectrum and monosaccharide composition. To determine the therapeutic effects of PRAP on experimental autoimmune hepatitis (EAH), we established an EAH mice model. After treated with PRAP, liver and spleen injuries were reduced, and hepatocyte regeneration and liver function were improved. Further study of the mechanism by which PRAP treats EAH showed that PRAP significantly inhibited oxidative stress in the livers of EAH model mice. More importantly, PRAP inhibited immune inflammatory reactions in EAH model mice, including the hepatic infiltration of inflammatory CD4⁺ and CD8⁺ T cells, as well as overexpression of inflammatory cytokines IL-2, IL-6 and IL-10, via inhibition of the NF-κB signaling pathway.

Intestinal Anti-Inflammatory Activity of Terpenes in Experimental Models (2010-2020): A Review

Inflammatory bowel diseases (IBDs) refer to a group of disorders characterized by inflammation in the mucosa of the gastrointestinal tract, which mainly comprises Crohn’s disease (CD) and ulcerative colitis (UC). IBDs are characterized by inflammation of the intestinal mucosa, are highly debilitating, and are without a definitive cure. Their pathogenesis has not yet been fully elucidated; however, it is assumed that genetic, immunological, and environmental factors are involved. People affected by IBDs have relapses, and therapeutic regimens are not always able to keep symptoms in remission over the long term. Natural products emerge as an alternative for the development of new drugs; bioactive compounds are promising in the treatment of several disorders, among them those that affect the gastrointestinal tract, due to their wide structural diversity and biological activities. This review compiles 12 terpenes with intestinal anti-inflammatory activity evaluated in animal models and in vitro studies. The therapeutic approach to IBDs using terpenes acts basically to prevent oxidative stress, combat dysbiosis, restore intestinal permeability, and improve the inflammation process in different signaling pathways.

An In Vitro Verification of the Effects of Paeoniflorin on Lipopolysaccharide-Exposed Microglia

Background

The neuroprotective effects of Paeoniflorin (PF) are well known. Most of the evidence was verified in vivo. We attempted to perform an in vitro verification of the effects of PF in microglia.

Methods

A lipopolysaccharide- (LPS-) exposed microglia model was employed. An enzyme-linked immunosorbent assay was used to measure the levels of cytokines in the culture supernatants. A real-time polymerase chain reaction was performed to measure the mRNA expression of cytokines and M1- and M2-like genes. A western blot analysis was used to examine the expression of proteins associated with the nuclear factor-kappa B (NF-κB) signaling pathway.

Results

We found that the administration of PF reversed the inflammatory response induced by LPS. It downregulated proinflammatory cytokines and upregulated anti-inflammatory cytokines. This, in turn, alleviated the oxidative injuries, downregulated the expression of M1-like genes, and upregulated the expression of M2-like genes. PF can also reverse the changes in proteins associated with the NF-κB signaling pathway induced by LPS.

Conclusions

We provided evidence obtained in vitro concerning the neuroprotective effects of PF via suppressing activation of microglia, which might be associated with the NF-κB signaling pathway. These findings contribute to obtaining a deeper understanding of PF, a potential new treatment for brain injuries.

Herbal pair Huangqin-Baishao: mechanisms underlying inflammatory bowel disease by combined system pharmacology and cell experiment approach

BACKGROUND

Inflammatory bowel disease (IBD) is a severe digestive system condition, characterized by chronic and relapsing inflammation of the gastrointestinal tract. Scutellaria baicalensis Georgi (Huangqin, HQ) and Paeonia lactiflora Pall (Baishao, BS) from a typical herbal synergic pair in traditional Chinese medicine (TCM) for IBD treatments. However, the mechanisms of action for the synergy are still unclear. Therefore, this paper aimed to predict the anti-IBD targets and the main active ingredients of the HQ-BS herbal pair.

METHODS

A systems pharmacology approach was used to identify the bioactive compounds and to delineate the molecular targets and potential pathways of HQ-BS herbal pair. Then, the characteristics of the candidates were analyzed according to their oral bioavailability and drug-likeness indices. Finally, gene enrichment analysis with DAVID Bioinformatics Resources was performed to identify the potential pathways associated with the candidate targets.

RESULTS

The results showed that, a total of 38 active compounds were obtained from HQ-BS herbal pair, and 54 targets associated with IBD were identified. Gene Ontology and pathway enrichment analysis yielded the top 20 significant results with 54 targets. Furthermore, the integrated IBD pathway revealed that the HQ-BS herbal pair probably acted in patients with IBD through multiple mechanisms of regulation of the nitric oxide biosynthetic process and anti-inflammatory effects. In addition, cell experiments were carried out to verify that the HQ-BS herbal pair and their Q-markers could attenuate the levels of nitric oxide (NO), prostaglandin E2 (PGE2), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) in lipopolysaccharide (LPS)-stimulated THP-1-derived macrophage inflammation. In particular, the crude materials exerted a much better anti-inflammatory effect than their Q-markers, which might be due to their synergistic effect.

CONCLUSION

This study provides novel insight into the molecular pathways involved in the mechanisms of the HQ-BS herbal pair acting on IBD.

The role of medicinal products in the treatment of inflammatory bowel diseases (IBD) through inhibition of TLR4/NF-kappaB pathway

Inflammatory bowel disease (IBD) is a lifelong and recurrent disease of the gastrointestinal tract that afflicts many people in the world. Growing evidence has currently indicated that dysfunction of immune system, particularly toll-like receptors 4 (TLR4) signaling pathway dysfunction plays a pivotal part in the pathogenesis of IBD. TLR4 signaling is involved both in the pathogenesis and in the efficacy of treatment of IBD. There are some medicinal products and herbal medicines, which their role in the treatment of IBD through modulation of TLR4 signaling has been implicated. The purpose of this review article is to summarize those medicinal products and herbal medicines.

p-Cymene and Rosmarinic Acid Ameliorate TNBS-Induced Intestinal Inflammation Upkeeping ZO-1 and MUC-2: Role of Antioxidant System and Immunomodulation

p-Cymene (p-C) and rosmarinic acid (RA) are secondary metabolites that are present in medicinal herbs and Mediterranean spices that have promising anti-inflammatory properties. This study aimed to evaluate their intestinal anti-inflammatory activity in the trinitrobenzene sulphonic acid (TNBS)-induced colitis model in rats. p-C and RA (25-200 mg/kg) oral administration reduced the macroscopic lesion score, ulcerative area, intestinal weight/length ratio, and diarrheal index in TNBS-treated animals. Both compounds (200 mg/kg) decreased malondialdehyde (MDA) and myeloperoxidase (MPO), restored glutathione (GSH) levels, and enhanced fluorescence intensity of superoxide dismutase (SOD). They also decreased interleukin (IL)-1β and tumor necrosis factor (TNF)-α, and maintained IL-10 basal levels. Furthermore, they modulated T cell populations (cluster of differentiation (CD)4+, CD8+, or CD3+CD4+CD25+) analyzed from the spleen, mesenteric lymph nodes, and colon samples, and also decreased cyclooxigenase 2 (COX-2), interferon (IFN)-γ, inducible nitric oxide synthase (iNOS), and nuclear transcription factor kappa B subunit p65 (NFκB-p65) mRNA transcription, but only p-C interfered in the suppressor of cytokine signaling 3 (SOCS3) expression in inflamed colons. An increase in gene expression and positive cells immunostained for mucin type 2 (MUC-2) and zonula occludens 1 (ZO-1) was observed. Altogether, these results indicate intestinal anti-inflammatory activity of p-C and RA involving the cytoprotection of the intestinal barrier, maintaining the mucus layer, and preserving communicating junctions, as well as through modulation of the antioxidant and immunomodulatory systems.

A review on the pharmacokinetics of paeoniflorin and its anti-inflammatory and immunomodulatory effects

Increasing pharmacological evidence supports that paeoniflorin, a water-soluble monoterpene glycoside isolated from Paeonia lactiflora Pall. (Shaoyao in Chinese), has a wide range of medicinal properties including anti-inflammatory, antioxidant, antithrombotic, anticonvulsive, analgesic, cardioprotective, neuroprotective, hepatoprotective, antidepressant-like, antitumoral, and immune-regulatory activities; as well as enhancing cognition and attenuating learning impairment. In addition to pharmacodynamic studies, information on pharmacokinetics is also significant for the further development and utilization of paeoniflorin. The present review focuses on the absorption, distribution, metabolism, and excretion of paeoniflorin, especially main pharmacological activities of paeoniflorin on inflammation and immune function. According to the findings obtained both in vitro and in vivo, a broad application prospect has been opened for paeoniflorin. However, further studies are needed to clarity the direct molecular mechanisms and key targets underlying the beneficial effects of paeoniflorin on inflammation and immunity.

Guizhi Fuling Capsule Exhibits Antidysmenorrhea Activity by Inhibition of Cyclooxygenase Activity

Guizhi Fuling capsule (GZFLc) is a modern preparation from traditional Chinese Medicine. Guizhi Fuling was first prescribed by Zhang Zhongjing almost two thousand years ago for the treatment of primary dysmenorrhea. It has also been used to treat uterine fibroids, dysfunctional uterine bleeding, and endometriosis. Although effective against dysmenorrhea clinically, there are limited information on the mechanism of its action. The major components responsible for the activity are not well defined. The aim of this study has been to elucidate a mechanism that may facilitate the development of a bioactivity-based assay for quality control during drug formulation and manufacturing. Using an oxytocin-induced mouse dysmenorrhea model, we showed that oral administration of GZFLc at 150 and 300 mg/kg, dosages relevant to clinic usages, significantly suppressed oxytocin-induced writhing response. The antidysmenorrhea effect was also demonstrated by a rotarod assay. We showed that GZFLc treatment significantly prolonged the hanging time of mice on the rotating rod. Histological studies showed that GZFLc treatment reduced lamina propria edema, while no effect on COX2 expression was detected. GZFLc instead exhibited direct inhibitory effect against COX2, a critical enzyme that catalyzes arachidonic acid conversion to prostaglandins. By HPLC profiling, we showed that paeoniflorin, paeonol, and cinnamaldehyde are the major components from the corresponding plants. At 5 and 10 mg/kg, both paeoniflorin and paeonol were active against induced dysmenorrhea. The study not only links GZFLc antidysmenorrhea activity to COX2 inhibition but also uncovers a mechanism of action by which an assay can be developed for bioefficacy evaluation of GZFLc.

Jiaweishaoyao Decoction Alleviates DSS-Induced Ulcerative Colitis via Inhibiting Inflammation

Purpose

Jiaweishaoyao decoction (JWSYD) is a traditional prescription of Chinese medicine that is initially used for the treatment of diarrhea. This study is aimed at investigating the effects of JWSYD on DSS-induced ulcerative colitis (UC).

Methods

DSS-induced UC mice and LPS-induced RAW264.7 cells were used as the UC model in vivo and in vitro. UC was assessed by body weight, disease activity index (DAI), colon length, spleen weight, and histopathological score (HE staining). The levels of TNF-α, IL-1β, and IL-6 were analyzed by ELISA and qRT-PCR. The levels of NLRP3 inflammasome- and NF-κB pathway-associated proteins were measured by western blot.

Results

JWSYD alleviated DSS-induced UC in respect to body weight, DAI, colon length, spleen weight, and histopathological score. JWSYD reduced the levels of TNF-α, IL-1β, and IL-6 in DSS-induced UC mice and the supernatants of LPS-induced RAW264.7 cells. JWSYD suppressed the protein levels of inflammasome-associated proteins, including NLRP3, ASC1, Procaspase-1, Cleaved caspase-1, and Cleaved IL-1β in DSS-induced UC mice and LPS-induced RAW264.7 cells. In addition, JWSYD suppressed the NF-κB pathway in vitro and in vivo.

Conclusion

JWSYD alleviated DSS-induced UC via inhibiting the NLRP3 inflammasome and NF-κB pathway.

Activation of PXR by Alpinetin Contributes to Abrogate Chemically Induced Inflammatory Bowel Disease

Alpinetin is a naturally occurring flavonoid from the ginger plants. We previously reported the identification of alpinetin as a ligand of human pregnane X receptor (hPXR). The current study investigated the role of alpinetin as a putative PXR activator in ameliorating chemically induced inflammatory bowel disease (IBD). We found that oral administration of alpinetin significantly alleviated the severity of dextran sulfate sodium (DSS)-induced colitis in mice by decreasing the inflammatory infiltration, the levels of the pro-inflammatory mediators, and the PXR target genes in the colon. In vitro, alpinetin blocked the nuclear translocation of p-p65 in lipopolysaccharide (LPS)-stimulated RAW264.7 macrophages. Further, alpinetin significantly upregulated PXR target genes and inhibited TNF-α-induced NF-κB-luciferase activity in LS174T colorectal cells; however, this regulatory effects were lost when cellular PXR gene was knocked down. In PXR transactivation assays, alpinetin increased both mouse and human PXR transactivation in a dose-dependent manner. Ligand occluding mutants, S247W/C284W and S247W/C284W/S208W, in hPXR-reporter assays, abrogated alpinetin-induced hPXR transactivation. Finally, alpinetin bound to the hPXR-ligand-binding domain (LBD) was confirmed by competitive ligand binding assay. The current study significantly extends prior observations by validating a PXR/NF-κB regulatory mechanism governing alpinetin's anti-inflammatory effects in a murine model of IBD.

Paeoniflorin alleviates lipopolysaccharide-induced disseminated intravascular coagulation by inhibiting inflammation and coagulation activation

Lipopolysaccharide (LPS) is a toxic component of the outer membrane of gram-negative bacteria that can activate the blood coagulation system, leading to disseminated intravascular coagulation (DIC). DIC is a syndrome characterized by thromboembolism and multiple organ failure. Herein, the beneficial effect of paeoniflorin (PF) on the alleviation of LPS-induced DIC was investigated with an experimental DIC mouse model. Briefly, mice were randomly divided into the following six groups: (1) control; (2) LPS; (3) heparin; (4) low-PF treatment; (5) medium-PF treatment; and (6) high-PF treatment. The histological morphology of the liver and kidney was observed, and the coagulation indicators (such as prothrombin time), function indicators (such as alanine transferase), and inflammatory factors (such as TNF-α) were detected. Additionally, an in vitro cell inflammation model using RAW 264.7 murine macrophages was established. Activation of the nuclear factor kappa B (NF-κB) signaling pathway and tumor necrosis factor-α (TNF-α) were determined by western blotting. Based on our findings, PF could significantly improve the histological morphology of the liver and kidney, indicating that PF protects the liver and kidney against damage induced by LPS. Additionally, PF improved the function and coagulation indicators and reduced the production of inflammatory factors. In vitro, PF inhibited the expression of TNF-α by suppressing NF-κB signaling pathway activation. Collectively, our findings support the hypothesis that PF has anti-inflammatory and anticoagulation effects for the alleviation of LPS-induced DIC. PF is thus a potential co-treatment option for DIC.

The natural flavonoid galangin ameliorates dextran sulphate sodium-induced ulcerative colitis in mice: Effect on Toll-like receptor 4, inflammation and oxidative stress

This study was carried out to investigate the potential therapeutic effect of galangin, a promising active principle of honeybee propolis, in dextran sulphate sodium (DSS)-induced colitis in mice. We explored the possible underlying mechanisms for galangin action and the therapeutic benefit of adding galangin to the standard therapy sulphasalazine. A galangin dose of 40 mg/kg was selected based on a preliminary dose-selection study for investigation in a 4-week cyclical model of DSS-induced colitis. Mice received 3% DSS in their drinking water during the first and third weeks and were administered the treatments (40 mg/kg galangin, 100 mg/kg sulphasalazine and a combination of 20 mg/kg galangin and 50 mg/kg sulphasalazine) daily starting from the second week. Galangin significantly ameliorated DSS-induced histopathological alterations and tissue injury, down-regulated Toll-like receptor 4 expression, suppressed NF-κB p65 activation, lowered inflammatory cytokine levels and demonstrated antioxidant effects. The combination of galangin and sulphasalazine at half doses yielded comparable results to either drug alone at full dose. This study highlights galangin as a promising therapy for colitis management.

Improvement of Oxazolone-Induced Ulcerative Colitis in Rats Using Andrographolide

Ulcerative colitis (UC) is usually accompanied with symptoms of abdominal pain, diarrhea, and bloody stool, which impair the quality of life of patients. Previous studies have shown that Andrographis paniculata extracts, which have andrographolide (AND) as their main compound, can relieve UC symptoms in patients. The aim of the study was to investigate the alleviating effect of AND on UC using the oxazolone (OXZ)-induced UC rat model. A total of 66 healthy male Sprague Dawley rats were used to evaluate the efficacy and mechanism of AND on UC (n = 11 per group) and grouped into control, model, SASP (sulfasalazine, positive control group, 500 mg/kg), AND-L (40 mg/kg), AND-M (80 mg/kg), and AND-H (120 mg/kg). The colonic disease activity index (DAI), colon length, spleen coefficient, pathological damage, and inflammation-related cytokine and protein expression levels were used as indices for evaluation. Results showed that the AND groups had reduced DAI and mortality, and significantly improved colon length and spleen coefficient compared with the model group. Furthermore, OXZ-induced histological injury was relieved significantly after AND treatment due to an improved crypt structure and reduced infiltration of inflammatory cells. Moreover, AND inhibited myeloperoxidase (MPO) activity and the secretion of interleukin-4 (IL-4), IL-13, and tumor necrosis factor α (TNF-α). The results of the anti-inflammatory mechanism revealed that AND blocked the signal transduction by reducing IL-4/IL-13 specific binding to IL-4 receptor (IL-4R) and inhibiting the phosphorylation of the signal transducer and activator of transcription 6 (p-STAT6). In conclusion, aside from natural plants, AND may be a candidate ingredient for UC therapy.

Paeoniflorin: a monoterpene glycoside from plants of Paeoniaceae family with diverse anticancer activities

OBJECTIVES

Paeoniflorin, a representative pinane monoterpene glycoside in plants of Paeoniaceae family, possesses promising anticancer activities on diverse tumours. This paper summarized the advance of Paeoniflorin on cancers in vivo and in vitro, discussed the related molecular mechanisms, as well as suggested some perspectives of the future investigations.

KEY FINDINGS

Anticancer activities of paeoniflorin have been comprehensively investigated, including liver cancer, gastric cancer, breast cancer, lung cancer, pancreatic cancer, colorectal cancer, glioma, bladder cancer and leukaemia. Furthermore, the potential molecular mechanisms corresponding to the antitumour effects of Paeoniflorin might be related to the following aspects: inhibition of tumour cell proliferation and neovascularization, induction apoptosis, and inhibition of tumour invasion and metastasis.

SUMMARY

Paeoniflorin has wide spectrum antitumour activities; however, in vivo and clinical investigations on antitumour effect of Paeoniflorin are lacking which should be focused on further studies. Our present review on antitumour effects of Paeoniflorin would be beneficial for the further molecular mechanisms study, candidate antitumour drug development and clinical research of Paeoniflorin in the future.

Paeoniflorin Alleviates H2O2-Induced Oxidative Injury Through Down-Regulation of MicroRNA-135a in HT-22 Cells

Paeoniflorin (PF) has been reported to possess neuroprotective influences on cognitive dysfunction illness. In current research, we attempted to probe into the protective influences of PF against H₂O₂-induced damage and the underlying regulating mechanisms on hippocampal HT-22 cells. HT-22 cells were pretreated with PF, and then induced by H₂O₂. Afterwards, the influences of PF pretreatment were examined using CCK-8 assay, apoptosis assay, western blot and ROS assay, respectively. In addition, the expression of microRNA-135a (miR-135a) was analyzed and altered by qRT-PCR and cell transfection, respectively. After overexpression of miR-135a, the effects of miR-135a mimic on cell functions were detected again. Moreover, influences of H₂O₂, PF and miR-135a overexpression on JAK2/STAT3 and ERK1/2 signal pathways were further investigated. Further experiments verified that PF pretreatment alleviated H₂O₂-induced oxidative stress through increasing cell viability, inhibiting cell apoptosis, reducing ROS generation and activating JAK2/STAT3 and ERK1/2 pathways. Besides, expression of miR-135a was declined by PF pretreatment. Whereas, miR-135a mimic abrogated the protective effects triggered by PF pretreatment. These results indicated that PF can alleviate H₂O₂-induced oxidative stress by down-regulation of miR-135a via activation of JAK2/STAT3 and ERK1/2 pathways.