Lancemaside A inhibits lipopolysaccharide-induced inflammation by targeting LPS/TLR4 complex

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.

Real-World Study on Chai-Shi-Jie-Du Granules for the Treatment of Dengue Fever and the Possible Mechanisms Based on Network Pharmacology

Objectives

Traditional Chinese medicine (TCM) is a widely used method for treating dengue fever in China. TCM improves the symptoms of patients with dengue, but there is no standard TCM prescription for dengue fever. This real-world study aimed to evaluate the effects of Chai-Shi-Jie-Du (CSJD) granules for the treatment of dengue fever and the underlying mechanisms.

Methods

We implemented a multicenter real-world study, an in vitro assay and network pharmacology analysis. Patients from 5 hospitals in mainland China who received supportive western treatment in the absence or presence of CSJD were assigned to the control and CSJD groups between 1 August and 31 December 2019. Propensity score matching (PSM) was performed to correct for biases between groups. The clinical data were compared and analyzed. The antidengue virus activity of CSJD was tested in Syrian baby hamster kidney (BHK) cells using the DENV2-NGC strain. Network pharmacological approaches along with active compound screening, target prediction, and GO and KEGG enrichment analyses were used to explore the underlying molecular mechanisms.

Results

137 pairs of patients were successfully matched according to age, sex, and the time from onset to presentation. The time to defervescence (1.7 days vs. 2.5 days, P < 0.05) and the disease course (4.1 days vs. 6.1 days, P < 0.05) were significantly shorter in the CSJD group than those in the control group. CSJD showed no anti-DENV2-NGC virus activity in BHK cells. Network pharmacology analysis revealed 108 potential therapeutic targets, and the top GO and KEGG terms were related to immunity, oxidative stress response, and the response to lipopolysaccharide.

Conclusions

CSJD granules exhibit high potential for the treatment of dengue fever, and the therapeutic mechanisms involved could be related to regulating immunity, moderating the oxidative stress response, and the response to lipopolysaccharide.

Protective effects of different Bacteroides vulgatus strains against lipopolysaccharide-induced acute intestinal injury, and their underlying functional genes

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Different Bacteroides vulgatus strains have varying effects on inflammatory diseases.

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B. vulgatus FTJS7K1 was screened due to its role in alleviating inflammation.

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B. vulgatus FTJS7K1 can modulate gut microbial community.

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B. vulgatus FTJS7K1 can regulate the levels of related cytokines.

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The genes about SCFAs secretion are responsible for the anti-inflammatory effect.

Introduction

The roles of Bacteroides species in alleviating inflammation and intestinal injury has been widely demonstrated, but few studies have focused on the roles of Bacteroides vulgatus.

Objectives

In this study, four B. vulgatus strains were selected, based on their genomic characteristics, to assess their ability to alleviate lipopolysaccharide (LPS)-induced acute intestinal injury in C57BL/6J mice.

Methods

Alterations in the intestinal microbiota, intestinal epithelial permeability, cytokine level, short-chain fatty acid (SCFA) concentration, and immune responses were investigated following LPS-induced acute intestinal injury in C57BL/6J mice.

Results

Severe histological damage and a significant change in cytokine expression was observed in the mouse colon tissues 24 h after LPS administration. Oral administration of different B. vulgatus strains showed different effects on the assessed parameters of the mice; particularly, only the administration of B. vulgatus FTJS7K1 was able to protect the architectural integrity of the intestinal epithelium. B. vulgatus FTJS7K1 also negated the LPS-induced changes in cytokine mRNA expression in the colon tissues, and in the proportion of regulatory T cells in the mesenteric lymph node. Compared with the LPS group, the B. vulgatus FTJS7K1 group showed significantly increased abundance of Lactobacillus, Akkermansia, and Bifidobacterium, and decreased abundance of Faecalibaculum. The B. vulgatus FTJS7K1 group also showed significantly increased concentration of SCFAs in fecal samples. The results of genomic analysis showed that these protective roles of B. vulgatus FTJS7K1 may be mediated through specific genes associated with defense mechanisms and metabolism (e.g., the secretion of SCFAs).

Conclusions

Our findings suggest that the protective role of B. vulgatus FTJS7K1 appear to be via modulation of cytokine production in the colon tissue and regulation of the structure of the gut microbiota. These results provide support for the screening of the Bacteroides genus for next-generation probiotics.

Luteolin ameliorates lipopolysaccharide-induced microcirculatory disturbance through inhibiting leukocyte adhesion in rat mesenteric venules

Background

Microcirculatory disturbance is closely associated with multiple diseases such as ischemic and septic stroke. Luteolin (3,4,5,7-tetrahydroxyflavone) is a vascular protective flavonoid present in several dietary foods. However, how luteolin plays a role in microcirculatory disturbance is still unknown. The purpose of this study was to find out the influence of luteolin on the lipopolysaccharide (LPS)-induced microcirculatory disturbance, focusing on its effect on leukocyte adhesion and the underlying mechanism of this effect.

Methods

After injecting LPS into rats, we used an inverted intravital microscope to observe the velocity of red blood cells in venules, numbers of leukocytes adherent to and emigrated across the venular wall, hydrogen peroxide production in venular walls and mast cell degranulation. Intestinal microcirculation blood flow was measured by High-resolution Laser Doppler Perfusion Imaging. Histological changes of small intestine and mesenteric arteries were evaluated. Additionally, cell adhesion stimulated by LPS was tested on EA.hy926 and THP-1 cells. The production of pro-inflammatory cytokines, adhesion molecules and the activation of TLR4/Myd88/NF-κB signaling pathway were determined.

Results

The results showed luteolin significantly inhibited LPS-induced leukocyte adhesion, hydrogen peroxide production and mast cell degranulation, and increased intestinal microcirculation blood flow and ameliorated pathological changes in the mesenteric artery and the small intestine. Furthermore, luteolin inhibited the release of pro-inflammatory cytokines, the expression of TLR4, Myd88, ICAM-1, and VCAM-1, the phosphorylation of IκB-α and NF-κB/p65 in LPS stimulated EA.hy926.

Conclusions

Our findings revealed that it is likely that luteolin can ameliorate microcirculatory disturbance. The inhibitory effects of luteolin on the leukocyte adhesion stimulated by LPS, which participates in the development of microcirculatory disturbance, are mediated through the regulation of the TLR4/Myd88/NF-κB signaling pathway.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-020-03196-9.

OroxylinA reverses lipopolysaccharide-induced adhesion molecule expression and endothelial barrier disruption in the rat aorta

Vascular dysfunction plays a critical role in the pathogenesis of sepsis. We elucidated the mechanisms underlying the amelioration of lipopolysaccharide (LPS)-induced vascular inflammation by oroxylin A (OroA) post-treatment in rats. The animals were intraperitoneally injected with LPS (10 mg/kg) to induce systemic inflammation and intravenously (iv) administered OroA (15 mg/kg) 6 h after the LPS treatment. The assessments included biochemical changes in peripheral blood, vascular reactivity which was evaluated by blood-vessel myography, morphological/histological assessment of inflammation, toll-like receptor (TLR)-4-mediated interleukin-1-receptor-associated-kinase (IRAK)-4 activation, changes in adhesion molecule expression, and endothelial junctional stability in the aorta. LPS significantly enhanced the proinflammatory cytokine release, increased vascular cell adhesion molecule (VCAM)-1 expression, disrupted endothelial tight junction, reduced vascular endothelial barrier stability, and increased macrophage infiltration and accumulation in the aorta. All observed pathological changes and vascular inflammation were significantly reversed by the OroA post-treatment. Importantly, OroA suppressed the increased adhesion molecule expression and the endothelial barrier disruption by inhibiting LPS-activated IRAK-4-targeted inhibitory nuclear factor kappa B kinase (IKK) α/β complex phosphorylation, without directly affecting the interaction between LPS and TLR-4. Moreover, the iNOS activity induced by the LPS challenge was inhibited by the OroA pretreatment of the isolated aortic rings. These results suggest that OroA regulates the vascular tone by inhibiting vascular hyporeactivity caused by NO overproduction and reverses the endothelial barrier dysfunction and inflammation by inhibiting the IRAK-4-mediated IKKα/β phosphorylation. Overall, these findings suggest OroA administration as a potentially useful therapeutic approach for clinical interventions in septic shock.

Lancemaside A from Codonopsis lanceolata prevents hypertension by inhibiting NADPH oxidase 2-mediated MAPK signalling and improving NO bioavailability in rats

OBJECTIVES

This study investigated whether lancemaside A (LMA) can prevent hypertension and assessed the mechanisms of action of LMA in rats.

METHODS

Hypertension was induced by chronic immobilization stress and nicotine administration. Hypertensive vehicle rats were treated with LMA (1, 20, or 40 mg/kg) or nifedipine (10 mg/kg) as a positive control daily for 3 weeks.

KEY FINDINGS

In hypertensive vehicle rats, LMA dose-dependently reduced systolic blood pressure. LMA doses of 20 and 40 mg/kg reduced the aortic expression of nicotinamide adenine dinucleotide phosphate oxidase (NOX)2 (both P < 0.01), and 40 mg/kg LMA reduced serum malondialdehyde (P < 0.01). Serum nitrite levels were significantly higher in LMA treated rats than in hypertensive vehicle rats, with LMA doses of 20 and 40 mg/kg reducing the expression of endothelial nitric oxide synthase in rat aortas (P < 0.001 and P < 0.01, respectively). LMA also reduced the aortic levels of nuclear factor kappa B and the activation of the three isoforms of mitogen-activated protein kinase (MAPK).

CONCLUSIONS

Lancemaside A prevents hypertension in rats by inhibiting the activation of MAPK signalling and the impairment in nitric oxide bioavailability due to NOX2-mediated oxidative stress. Thus, LMA may act as a preventive agent for hypertension.

Lancemaside A, a major triterpene saponin of Codonopsis lanceolata enhances regulation of nitric oxide synthesis via eNOS activation

Background

Many studies on the effect of saponin-rich Codonopsis lanceolata as a bioactive source for improving physical health have been performed. C. lanceolata contains triterpenoid saponins, including lancemasides. These saponins are known to be particularly involved in the regulation of blood pressure or hypertension. This study investigated whether lancemaside A (LA), a major triterpenoid saponin from C. lanceolata, regulates nitric oxide (NO) production via the activation of endothelial NO synthase (eNOS) in human umbilical vein endothelial cells.

Methods

Upon separation with petroleum ether, ethyl acetate, and n-butanol, LA was found to be abundant in the n-butanol-soluble portion. For further purification of LA, HPLC was performed to collect fraction, and LA was identified using analysis of LC/MSMS and ¹³C-NMR values. In in vitro, the effects of LA on NO release mechanism in HUVECs were investigated by Griess assay, quantitative real-time reverse-transcription PCR, and Western blotting.

Results

Our results showed that NO production was efficiently improved by treatment with LA in a dose-dependent manner. In addition, the LA treatment resulted in extensive recovery of the NO production suppressed by the eNOS inhibitor, L-NAME, compared with that in the control group. Additionally, the level of eNOS mRNA was increased by this treatment in a dose-dependent manner. These results suggested that LA is an inducer of NO synthesis via eNOS mRNA expression. Also, the study indicated that LA is involved in activating the PI3K/Akt/eNOS signaling pathway.

Conclusion

These results suggested that LA is an inducer of NO synthesis via eNOS mRNA expression. Also, the study indicated that LA is involved in activating the PI3K/Akt/eNOS signaling pathway. These findings suggest the value of using LA as a component of functional foods and natural pharmaceuticals.

Electronic supplementary material

The online version of this article (10.1186/s12906-019-2516-6) contains supplementary material, which is available to authorized users.

Codonopsis lanceolata attenuates allergic lung inflammation by inhibiting Th2 cell activation and augmenting mitochondrial ROS dismutase (SOD2) expression

Allergic asthma is a chronic inflammatory disease induced by the inhalation of allergens, which trigger the activation of T helper type 2 (Th2) cells that release Th2 cytokines. Recently, herbal medicines are being considered a major source of novel agents to treat various diseases. In the present study, we evaluated the anti-asthmatic effects of a Codonopsis lanceolata extract (CLE) and the mechanisms involved in its anti-inflammatory effects. Treatment with CLE reduced infiltration of inflammatory cells, especially eosinophils, and the production of mucus in lung tissues. Levels of Th2 cytokines, such as IL-4, IL-5, and IL-13, and chemokines were also decreased following treatment with CLE. Moreover, Th2 cell proportion in vivo and differentiation in vitro were reduced as evidenced by the decreased expression of GATA3⁺. Furthermore, the expression of superoxide dismutase (SOD)2, a mitochondrial ROS (mROS) scavenger, was increased, which was related to Th2 cell regulation. Interestingly, treatment with CLE increased the number of macrophages in the lungs and enhanced the immune-suppressive property of macrophages. Our findings indicate that CLE has potential as a novel therapeutic agent to inhibit Th2 cell differentiation by regulating mROS scavenging.

Chemical constituents of the roots of Codonopsis lanceolata

A new phenylpropanoid (1), a new alkaloid (11), and a new natural polyacetylene (17), together with nine phenolic compounds (2-10), five alkaloids (12-16), three polyacetylenes (18-20), three triterpenoidal saponins (21-23), one phenylethanoid glycoside (24), and three hexyl glycosides (25-27) with previous known structures, were isolated from the roots of Codonopsis lanceolata. All of the isolates 1-27 were evaluated for their inhibitory effects on LPS-induced nitric oxide (NO) production in RAW 264.7 macrophages and cell viability in A2780 human ovarian cancer cells. Among the isolates, lancemasides A and B have a significant inhibitory effect on the production of NO in RAW264.7 cells (IC₅₀ values < 50 μM). In A2780 cells, lancemaside A exhibited the most potent inhibitory effect on cell viability. This is the first report on the pharmacological activities of lancemaside B (22).

Traditional uses, phytochemistry, pharmacology and toxicology of Codonopsis: A review

ETHNOPHARMACOLOGICAL RELEVANCE

Species of the genus Codonopsis are perennial herbs mainly distributed throughout East, Southeast and Central Asia. As recorded, they have been used as traditional Chinese medicines since the Qing Dynasty, where they were claimed for strengthening the spleen and tonifying the lung, as well as nourishing blood and engendering liquid. Some species are also used as food materials in southern China and Southeast Asia, such as tea, wine, soup, plaster, and porridge.

AIM OF THE REVIEW

The review aims to assess the ethnopharmacological uses, explicit the material basis and pharmacological action, promote the safety of medical use, and suggest the future research potentials of Codonopsis.

MATERIALS AND METHODS

Information on the studies of Codonopsis was collected from scientific journals, books, and reports via library and electronic data search (PubMed, Elsevier, Scopus, Google Scholar, Springer, Science Direct, Wiley, Researchgate, ACS, EMBASE, Web of Science and CNKI). Meanwhile, it was also obtained from published works of material medica, folk records, ethnopharmacological literatures, Ph.D. and Masters Dissertation. Plant taxonomy was confirmed to the database "The Plant List" (www.theplantlist.org).

RESULTS

Codonopsis has been used for medicinal purposes all around the world. Some species are also used as food materials in southern China and Southeast Asia. The chemical constituents of Codonopsis mainly are polyacetylenes, polyenes, flavonoids, lignans, alkaloids, coumarins, terpenoids, steroids, organic acids, saccharides, and so on. Extract of Codonopsis exhibit extensive pharmacological activities, including immune function regulation, hematopoiesis improvement, cardiovascular protection, neuroprotection, gastrointestinal function regulation, endocrine function regulation, cytotoxic and antibacterial effects, anti-aging and anti-oxidation, etc. Almost no obvious toxicity or side effect are observed and recorded for Codonopsis.

CONCLUSIONS

The traditional uses, phytochemistry, pharmacology and toxicology of Codonopsis are reviewed in this paper. Species of the genus have long been used as traditional medicines and food materials, they are reported with a large number of chemical constituents with different structures, extensive pharmacological activities in immune system, blood system, digestive system, etc. and almost no toxicity. More profound studies on less popular species, pharmacodynamic material basis and pharmacological mechanism, and quality assurance are suggested to be carried out to fulfil the research on the long-term clinical use and new drug research of Codonopsis.

Codonopsis lanceolata extract prevents hypertension in rats

BACKGROUND

Codonopsis lanceolata, a plant with antioxidant, anti-cancer, anti-inflammatory and blood lipid improving effects, has been widely used as a therapeutic agent in traditional medicine.

PURPOSE

The present study investigated the ability of an ethanol extract of Codonopsis lanceolata (ECL) to prevent hypertension in hypertensive rats.

METHODS

Rats were orally administered daily doses of 0 mg/kg, 200 mg/kg and 400 mg/kg ECL for 3 weeks. As a positive control, rats were orally administered 10 mg/kg/day nifedipine. Hypertension was induced by immobilization stress for 2 h/day and by administration of 0.8 mg/kg/day nicotine for 3 weeks, followed by injection of 3 mg/kg nicotine on the day of sacrifice. Blood pressure and heart rate were measured using a volume pressure recording system. Vasoconstriction and vasodilation of aortic cross sections were measured with a physiological recorder. Neutrophil counts in bronchoalveolar lavage fluid were estimated with an automated cell counter.

RESULTS

Treatment with both dosages of ECL significantly reduced systolic blood pressure (SBP) in hypertensive rats. Both doses of ECL tended to increase ACh- and SNP-induced vascular relaxation in hypertensive rats. Treatment with 200 mg/kg ECL significantly reduced neutrophil in hypertensive rats.

CONCLUSIONS

These results suggest that ECL is effective in reducing SBP and inflammation in hypertensive conditions.

Codonopsis lanceolata Water Extract Increases Hepatic Insulin Sensitivity in Rats with Experimentally-Induced Type 2 Diabetes

We examined the mechanisms and efficacy of Codonopsis lanceolata water extract (CLW) for treating type 2 diabetic (T2DM) symptoms. Partial pancreatectomized (Px) rats, a non-obese T2DM model, were provided high fat diets containing cellulose (control), 0.3% (CLW-L) or 1% CLW (CLW-H) for eight weeks. The positive control group was provided with rosiglitazone (20 mg/kg bw/day). The control group had lower epididymal fat masses than the CLW and the positive control groups, possibly due to urinary glucose loss, although CPT-1 and SIRT-1 expression was higher in the CLW group. CLW-H significantly reduced serum glucose levels and urinary glucose loss compared to the untreated control. The improvement of glucose utilization was associated with a higher fat mass in the CLW-H and positive control groups. Glucose-stimulated insulin secretion was higher in the untreated control than other groups and CLW tightly regulated insulin secretion as much as the positive control, and it was much tighter than the untreated control. Glucose infusion rates were higher during the hyperinsulinemic euglycemic clamp in the CLW and positive controls than the untreated control, and liver glucose outputs were lower during basal and hyperinsulinemic conditions in the CLW and positive control groups than the untreated control group. The increased hepatic insulin sensitivity was associated with enhanced insulin signaling in CLW (pAkt➔pGSK-1β). In conclusion, CLW consumption effectively alleviated diabetic symptoms by improving insulin sensitivity, potentiating hepatic insulin signaling and tightly regulating the insulin secretion capacity in non-obese T2DM rats.

Kinases as Novel Therapeutic Targets in Asthma and Chronic Obstructive Pulmonary Disease

Multiple kinases play a critical role in orchestrating the chronic inflammation and structural changes in the respiratory tract of patients with asthma and chronic obstructive pulmonary disease (COPD). Kinases activate signaling pathways that lead to contraction of airway smooth muscle and release of inflammatory mediators (such as cytokines, chemokines, growth factors) as well as cell migration, activation, and proliferation. For this reason there has been great interest in the development of kinase inhibitors as anti-inflammatory therapies, particular where corticosteroids are less effective, as in severe asthma and COPD. However, it has proven difficult to develop selective kinase inhibitors that are both effective and safe after oral administration and this has led to a search for inhaled kinase inhibitors, which would reduce systemic exposure. Although many kinases have been implicated in inflammation and remodeling of airway disease, very few classes of drug have reached the stage of clinical studies in these diseases. The most promising drugs are p38 MAP kinases, isoenzyme-selective PI3-kinases, Janus-activated kinases, and Syk-kinases, and inhaled formulations of these drugs are now in development. There has also been interest in developing inhibitors that block more than one kinase, because these drugs may be more effective and with less risk of losing efficacy with time. No kinase inhibitors are yet on the market for the treatment of airway diseases, but as kinase inhibitors are improved from other therapeutic areas there is hope that these drugs may eventually prove useful in treating refractory asthma and COPD.

Houttuyniacordata Thunb. polysaccharides ameliorates lipopolysaccharide-induced acute lung injury in mice

ETHNOPHARMACOLOGICAL RELEVANCE

Houttuynia cordata (HC) has been used as a folk therapy to treat pulmonary infections. This study aimed to determine the role and mechanism of action of polysaccharides isolated from HC (HCP) in lipopolysaccharide (LPS)-induced ALI in the mice.

MATERIALS AND METHODS

LPS was delivered by the intratracheal route to Balb/c mice 2h before HCP (40, 80 and 160mg/kg) administration.

RESULTS

The number of total cells, protein and tumor necrosis factor-α (TNF-α) concentrations in bronchoalveolar lavage fluid, the wet/dry weight ratio (w/d) of lungs and pulmonary pathology of each mouse were analyzed, it was found that HCP significantly alleviated ALI induced by LPS. Moreover, in lungs of mice, it was found that the infiltration of inflammatory cells, the expression of Toll-like receptor 4 and complement deposition were significantly decreased by HCP treatment. In vitro assays showed that C5a, a complement activation product, induced significant macrophage migration and treatment with HCP prevented it. The in vitro results also proved that LPS increased nitric oxide and pro-inflammatory cytokines (TNF-α, interleukin-6, and interleukin-1β) production, and HCP antagonized these effects of LPS. It was also found that HCP alone augmented secretion of some pro-inflammatory cytokines.

CONCLUSION

These results indicate that HCP may alleviate LPS induced lung inflammatory injury, which may be associated with its inhibitory effect on the over activation of complement and macrophages. This suggests a potential role to treat ALI.

Active components alignment of Gegenqinlian decoction protects ulcerative colitis by attenuating inflammatory and oxidative stress

ETHNOPHARMACOLOGICAL RELEVANCE

Gegenqinlian Decoction (GQD) has been used as a folk remedy for gastrointestinal diseases in China over thousands of years. It has significant treatment efficacy for patients with inflammatory bowel disease (IBD). We analyzed and showed that the active components alignment of Gegenqinlian Decoction (ACAG) possesses broad pharmacological effects including analgesic, antipyretic, anti-inflammatory, antibacterial, antiviral and antidiarrhea, as well as the effect of adjusting gastrointestinal function in our preliminary experiments. However, the exact molecular mechanisms on how ACAG exerts these pharmacological effects still remain elusive. In the present study, the plausible pharmacological effects of ACAG on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis were investigated.

MATERIALS AND METHODS

Male Sprague-Dawley (SD) rats with TNBS/ethanol-induced colitis were used. The colonic wet weight, macroscopic and histological colon injury, superoxide dismutase (SOD), malonyldialdehyde (MDA), and inducible nitric oxide synthase (iNOS) activity were observed. Pro-inflammation cytokines were determined by ELISA methods, semi-quantitative RT-PCR and Immuno-histochemistry.

RESULTS

We showed administration of ACAG was able to improve colitis. This was manifested by a decreased in the score of macroscopic and histological colonic injury, by lowered colonic wet weight, accompanied by significant increased of SOD activity, and decreased of MDA and iNOS activities. The treatment also significantly reduced tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) levels in colon and serum as well as the colonic mRNA levels for several inflammatory cytokines such as inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), macrophage inflammatory protein-2 (MIP-2), intercellular adhesion molecule-1 (ICAM-1) and toll-like receptor 2, 4 (TLR2, TLR4). In addition, we also showed that ACAG was able to inhibit the activation and translocation of transcription factors, nuclear factor kappaBp65 (NF-κBp65) in colon.

CONCLUSIONS

Our results suggest that ACAG exhibits protective effect in TNBS-induced ulcerative colitis. We postulate that this might be due to its modulation of oxidant/anti-oxidant balance, downregulation of productions, expressions of pro-inflammatory cytokines and inhibition of NF-κBp65 signal transduction pathways.

Diallyl trisulfide exerts anti-inflammatory effects in lipopolysaccharide-stimulated RAW 264.7 macrophages by suppressing the Toll-like receptor 4/nuclear factor-κB pathway

Diallyl trisulfide (DATS; di‑2‑propen‑1‑yl trisulfide) is an organic polysulfide compound found in garlic and other allium vegetables. Although certain studies have demonstrated that DATS possesses strong anti‑inflammatory activity, the underlying molecular mechanisms remain largely unresolved. In the present study, the anti‑inflammatory potential of DATS was investigated using the murine macrophage RAW 264.7 cell model. At non‑toxic concentrations, DATS inhibited the production of nitric oxide (NO) and prostaglandin E2 by inhibiting inducible NO synthase and cyclooxygenase‑2 expression at the transcriptional level in lipopolysaccharide (LPS)‑activated RAW 264.7 macrophages. DATS attenuated the release of the pro‑inflammatory cytokines, tumor necrosis factor‑α and interleukin‑1β, by inhibiting mRNA expression, respectively. DATS also suppressed LPS‑induced DNA‑binding activity of nuclear factor‑κB (NF‑κB), as well as the nuclear translocation of the NF‑κB p65, which correlated with the inhibitory effects of DATS on inhibitor κB (IκB) degradation. In addition, DATS was observed to significantly suppress LPS‑induced Toll‑like receptor 4 (TLR4) and myeloid differentiation factor 88 expression and the binding of LPS to macrophages, indicating the antagonistic effect of DATS against TLR4. Furthermore, blocking TLR4 signaling with the specific TLR4 signaling inhibitor, CLI‑095, increased the anti‑inflammatory potential of DATS in LPS‑stimulated RAW 264.7 macrophages. These data demonstrate that DATS may attenuate the initiation of LPS‑mediated intracellular signaling cascades by suppressing activation of NF‑κB and by inhibiting binding of LPS to TLR4 on macrophages.

Lancemaside A from Codonopsis lanceolata modulates the inflammatory responses mediated by monocytes and macrophages

In this study, we aimed to examine the cellular and molecular mechanisms of lancemaside A from Codonopsis lanceolata (Campanulaceae) in the inflammatory responses of monocytes (U937 cells) and macrophages (RAW264.7 cells). Lancemaside A significantly suppressed the inflammatory functions of lipopolysaccharide- (LPS-) treated RAW264.7 cells by suppressing the production of nitric oxide (NO), the expression of the NO-producing enzyme inducible NO synthase (iNOS), the upregulation of the costimulatory molecule CD80, and the morphological changes induced by LPS exposure. In addition, lancemaside A diminished the phagocytic activity of RAW264.7 cells and boosted the neutralizing capacity of these cells when treated with the radical generator sodium nitroprusside (SNP). Interestingly, lancemaside A strongly blocked the adhesion activity of RAW264.7 cells to plastic culture plates, inhibited the cell-cell and cell-fibronectin (FN) adhesion of U937 cells that was triggered by treatment with an anti-β1-integrin (CD29) antibody and immobilized FN, respectively. By evaluating the activation of various intracellular signaling pathways and the levels of related nuclear transcription factors, lancemaside A was found to block the activation of inhibitor of κB kinase (IKK) and p65/nuclear factor- (NF-) κB. Taken together, our findings strongly suggest that the anti-inflammatory function of lancemaside A is the result of its strong antioxidative and IKK/NF-κB inhibitory activities.

Anti-inflammatory effects of genistein via suppression of the toll-like receptor 4-mediated signaling pathway in lipopolysaccharide-stimulated BV2 microglia

Genistein, a principal soy isoflavone, has received considerable attention as a protein kinase inhibitor. Although some studies have demonstrated that genistein possesses anti-inflammatory effects, the molecular mechanisms of genistein-mediated anti-inflammatory potential are unclear in microglial cells. In this study, we determined whether genistein attenuates pro-inflammatory responses in lipopolysaccharide (LPS)-stimulated BV2 microglia and attempted to establish the possible mechanisms. Our results indicated that genistein inhibited the production of nitric oxide (NO) and prostaglandin E2 at non-toxic concentrations by inhibiting inducible NO synthase and cyclooxygenase-2 expression. The increased release and expression of inflammatory cytokines, including interleukin-1β, tumor necrosis factor-α, by LPS, were markedly reduced by genistein. Genistein also attenuated LPS-induced reactive oxygen species generation and LPS-mediated nuclear translocation of nuclear factor-kappa B (NF-κB), associated with blocking degradation of the inhibitor of NF-κB-α. Furthermore, genistein potently suppressed binding of LPS to the microglial cell surface, indicating the antagonistic effect of genistein against toll like receptor 4 (TLR4), and inhibited LPS-induced TLR4 and myeloid differentiation factor 88 expression. In addition, blocking TLR4 signaling using the specific TLR4 signaling inhibitor CLI-095 increased the anti-inflammatory potential of genistein in BV2 microglia. Our data indicate that genistein may attenuate the initiation of intracellular signaling cascades by LPS through inhibiting NF-κB activation by inhibiting the binding of LPS to TLR-4 on microglial cells.

Protective effect of naringenin against experimental colitis via suppression of Toll-like receptor 4/NF-κB signalling

Naringenin, one of the most abundant flavonoids in citrus, grapefruits and tomatoes, has been used as a traditional anti-inflammatory agent for centuries. However, the molecular mechanism of naringenin in intestinal inflammation remains unknown so far. The present study investigated a molecular basis for the protective effect of naringenin in dextran sulphate sodium-induced murine colitis. Pre-administration of naringenin significantly reduced the severity of colitis and resulted in down-regulation of pro-inflammatory mediators (inducible NO synthase (iNOS), intercellular adhesion molecule-1 (ICAM-1), monocyte chemoattractant protein-1 (MCP-1), cyclo-oxygenase-2 (Cox2), TNF-α and IL-6 mRNA) in the colon mucosa. The decline in the production of pro-inflammatory cytokines, specifically TNF-α and IL-6, correlated with a decrease in mucosal Toll-like receptor 4 (TLR4) mRNA and protein. Phospho-NF-κB p65 protein was significantly decreased, which correlated with a similar decrease in phospho-IκBα protein. Consistent with the in vivo results, naringenin exposure blocked lipopolysaccharide-stimulated nuclear translocation of NF-κB p65 in mouse macrophage RAW264.7 cells. In addition, in vitro NF-κB reporter assays performed on human colonic HT-29 cells exposed to naringenin demonstrated a significant inhibition of TNF-α-induced NF-κB luciferase expression. Thus, for the first time, the present study indicates that targeted inhibition of the TLR4/NF-κB signalling pathway might be an important mechanism for naringenin in abrogating experimental colitis.

Lancemaside A inhibits microglial activation via modulation of JNK signaling pathway

Microglial activation plays an important role in neurodegenerative diseases. Thus, controlling microglial activation is considered to be a promising therapeutic target for neurodegenerative diseases. In the present study, we found that lancemaside A, a triterpenoid saponin isolated from Codonopsislanceolata, inhibited iNOS and proinflammatory cytokines in LPS-stimulated BV2 microglial cells. By analyzing molecular mechanisms underlying the anti-inflammatory effects of lancemaside A, we found that lancemaside A selectively inhibited LPS-induced JNK phosphorylation among the three types of MAP kinases. A JNK-specific inhibitor, SP600125, like lancemaside A, significantly inhibited not only NO, TNF-α, and IL-6 productions, but also NF-κB and AP-1 activities, suggesting that JNK inhibition is largely involved in the anti-inflammatory mechanism of lancemaside A. Interestingly, both the lancemaside A and SP600125 inhibited ROS production by suppressing the expression and/or phosphorylation of NADPH oxidase subunit proteins, such as p47(phox), p67(phox), and gp91(phox). The antioxidant effects of lancemaside A and SP600125 appear to be related with an increase of hemeoxygenase-1 expression by both agents. Finally, we demonstrated the neuroprotective effects of lancemaside A and SP600125 in microglia-neuron coculture systems. Collectively, our data suggest that JNK pathway plays a key role mediating anti-inflammatory effects of lancemaside A in LPS-stimulated microglia.

Lancemaside A isolated from Codonopsis lanceolata and its metabolite echinocystic acid ameliorate scopolamine-induced memory and learning deficits in mice

The rhizome of Codonopsis lanceolata (family Campanulaceae), which contains lancemaside A as a main constituent, has been used as herbal medicine to treat inflammation, insomnia, and hypomnesia. Lancemaside A and echinocystic acid, which is its metabolite by intestinal microflora, potently inhibited acetylcholinesterase activity in a dose-dependent manner, with IC₅₀ value 13.6 μM and 12.2 μM, respectively. Its inhibitory potency is comparable with that of donepezil (IC₅₀=10.9 μM). Lancemaside A and echinocystic acid significantly reversed scopolamine-induced memory and learning deficits on passive avoidance task. Lancemaside A orally administered 5h before treatment with scopolamine reversed scopolamine-induced memory and learning deficits more potently than one orally administered 1h before. Echinocystic acid more potently reversed it than lancemaside A. Lancemaside A and echinocystic acid significantly reversed scopolamine-induced memory and learning deficits on the Y-maze and Morris water maze tasks. Lancemaside A and echinocystic acid also increased the expression of brain-derived neurotrophic factor (BDNF) and phosphorylated cAMP response element binding protein (p-CREB). Based on these findings, orally administered lancemaside A may be metabolized to echinocystic acid, which may be absorbed into the blood and ameliorate memory and learning deficits by inhibiting AChE activity and inducing BDNF and p-CREB expressions.

Pleckstrin homology domain of Akt kinase: a proof of principle for highly specific and effective non-enzymatic anti-cancer target

While pharmacological inhibition of Akt kinase has been regarded as a promising anti-cancer strategy, most of the Akt inhibitors that have been developed are enzymatic inhibitors that target the kinase active site of Akt. Another key cellular regulatory event for Akt activation is the translocation of Akt kinase to the cell membrane from the cytoplasm, which is accomplished through the pleckstrin homology (PH) domain of Akt. However, compounds specifically interacting with the PH domain of Akt to inhibit Akt activation are currently limited. Here we identified a compound, lancemaside A (LAN-A), which specifically binds to the PH domain of Akt kinase. First, our mass spectra analysis of cellular Akt kinase isolated from cells treated with LAN-A revealed that LAN-A specifically binds to the PH domain of cellular Akt kinase. Second, we observed that LAN-A inhibits the translocation of Akt kinase to the membrane and thus Akt activation, as examined by the phosphorylation of various downstream targets of Akt such as GSK3β, mTOR and BAD. Third, in a co-cultured cell model containing human lung epithelial cancer cells (A549) and normal human primary lung fibroblasts, LAN-A specifically restricts the growth of the A549 cells. LAN-A also displayed anti-proliferative effects on various human cancer cell lines. Finally, in the A549-luciferase mouse transplant model, LAN-A effectively inhibited A549 cell growth with little evident cytotoxicity. Indeed, the therapeutic index of LAN-A in this mouse model was >250, supporting that LAN-A is a potential lead compound for PH domain targeting as a safe anti-cancer Akt inhibitor.

Echinocystic acid ameliorates lung inflammation in mice and alveolar macrophages by inhibiting the binding of LPS to TLR4 in NF-κB and MAPK pathways

Orally administered lancemaside A, which is isolated from Codonopsis lanceolata (family Campanulaceae), showed anti-colitic effect in mice. However, its metabolite echinocystic acid was absorbed into the blood. Therefore, its anti-inflammatory effects were investigated in lipopolysaccharide (LPS)-stimulated alveolar macrophages in vitro and acute lung injury in vivo. Alveolar macrophages from mice were stimulated with LPS and were treated with echinocystic acid. Acute lung injury was induced by intratracheal administration of LPS in mice. Mice were treated with echinocystic acid or dexamethasone. Echinocystic acid potently suppressed the production of the pro-inflammatory cytokines, TNF-α and IL-1β, as well as of the activations of NF-κB and MAPKS, in LPS-stimulated alveolar macrophages. Echinocystic acid also down-regulated the production of inflammatory markers, which included inducible nitric oxide synthase and cyclooxygenase-2, as well as the inflammatory mediators, nitric oxide and prostaglandin E(2), in LPS-stimulated alveolar macrophages. Echinocystic acid also inhibited the activation of IL-1 receptor-associated kinases, and the activation of mitogen-activated protein kinases in LPS-stimulated alveolar macrophages. Furthermore, echinocystic acid potently inhibited the interaction between LPS and TLR4 in alveolar macrophages transfected with or without MyD88 siRNA, although it did not inhibit the binding in the macrophages transfected with TLR4 siRNA. Echinocystic acid suppressed LPS-induced acute lung inflammation in mice, as well as the expression of pro-inflammatory cytokines, such as IL-1β and TNF-α, and their transcription factor, NF-κB. On the basis of these findings, echinocystic acid, a metabolite of lancemaside A, may express anti-inflammatory effects by inhibiting the binding of LPS to TLR4 on macrophages.

Dietary intervention with narrow-leaved cattail rhizome flour (Typha angustifolia L.) prevents intestinal inflammation in the trinitrobenzenesulphonic acid model of rat colitis

Background

Inflammatory bowel disease (IBD) is a chronic inflammation of the intestinal epithelium that is driven by the intestinal immune system, oxidative stress and the loss of tolerance to the luminal microbiota. The use of dietary products containing ingredients such as fibres and carbohydrates and/or antioxidant compounds have been used as a therapeutic strategy for intestinal diseases because these products are considered effective in the modulation of the immune system and colonic microbiota. We investigated the beneficial effects of cattail rhizome flour (Typha angustifolia L.) in the trinitrobenzenesulphonic acid (TNBS) model of rat colitis. In addition, we investigated the effects of cattail rhizome flour on the intestinal anti-inflammatory activity of prednisolone, which is a reference drug that is used for treatment of human IBD.

Methods

The present study included the preparation of flour from rhizomes of cattail (Typha angustifolia L.); an evaluation of the qualitative phytochemical profile of cattail rhizomes; an evaluation of the efficacy of cattail rhizome flour in TNBS-induced rat colitis; an evaluation of the synergistic effects of cattail rhizome flour on the intestinal anti-inflammatory activity of prednisolone; and macroscopic, clinical, biochemical, histopathological and microbiological studies to assess the healing effects of cattail rhizome flour and its synergistic effects in TNBS-induced rat colitis. The data were analysed by ANOVA, Kruskal-Wallis and χ² tests.

Results

We tested several concentrations of cattail rhizome flour and found that dietary supplementation with 10% cattail rhizome flour showed the best effects at reducing the extension of the lesion, the colon weight ratio, adherences to adjacent organs and diarrhoea. These effects were related to inhibition of myeloperoxidase (MPO) and alkaline phosphatase (AP) activities and an attenuation of glutathione (GSH) depletion. The 10% cattail rhizome flour was as effective as prednisolone, and no synergistic effects were observed. Saponins, flavonoids and coumarins were detected in the rhizome flour. No changes were observed in the total number of lactic bacteria after dietary supplementation with cattail rhizome flour.

Conclusions

Dietary supplementation with 10% cattail rhizome flour and its combination with prednisolone prevent TNBS-induced colonic damage in rats, but no synergistic effects were observed. The prevention of TNBS-induced colon damage was associated with an improvement in intestinal oxidative stress, which likely resulted from the antioxidant properties of the active compounds detected in the cattail rhizome. This protective effect was not related to an improvement in lactic bacteria counts.

Lactobacillus johnsonii HY7042 ameliorates Gardnerella vaginalis-induced vaginosis by killing Gardnerella vaginalis and inhibiting NF-κB activation

Hydrogen peroxide-producing lactic acid bacteria (LAB) were isolated from women's vaginas and their anti-inflammatory effects against Gardnerella vaginalis-induced vaginosis were examined in β-estradiol-immunosuppressed mice. Oral and intravaginal treatment with five LABs significantly decreased viable G. vaginalis numbers in vaginal cavities and myeloperoxidase activity in mouse vaginal tissues. Of the LABs examined, Lactobacillus johnsonii HY7042 (LJ) most potently inhibited G. vaginalis-induced vaginosis. This LAB also inhibited the expressions of IL-1β, IL-6, TNF-α, COX-2, and iNOS, and the activation of NF-κB in vaginal tissues, but increased IL-10 expression. Orally administered LJ (0.2×10(8) CFU/mouse) also inhibited the expression of TNF-α by 91.7% in β-estradiol-immunosuppressed mice intraperitoneally injected with LPS. However, it increased IL-10 expression by 63.3% in these mice. Furthermore, LJ inhibited the expressions of the pro-inflammatory cytokines, TNF-α and IL-1β, and the activation of NF-κB in lipopolysaccharide-stimulated peritoneal macrophages. LJ also killed G. vaginalis attached with and without HeLa cells. These findings suggest that LJ inhibits bacterial vaginosis by inhibiting the expressions of COX-2, iNOS, IL-1β, and TNF-α by regulating NF-κB activation and by killing G. vaginalis, and that LJ could ameliorate bacterial vaginosis.

Novel PI3K/Akt inhibitors screened by the cytoprotective function of human immunodeficiency virus type 1 Tat

The PI3K/Akt pathway regulates various stress-related cellular responses such as cell survival, cell proliferation, metabolism and protein synthesis. Many cancer cell types display the activation of this pathway, and compounds inhibiting this cell survival pathway have been extensively evaluated as anti-cancer agents. In addition to cancers, several human viruses, such as HTLV, HPV, HCV and HIV-1, also modulate this pathway, presumably in order to extend the life span of the infected target cells for productive viral replication. The expression of HIV-1 Tat protein exhibited the cytoprotective effect in macrophages and a human microglial cell line by inhibiting the negative regulator of this pathway, PTEN. This cytoprotective effect of HIV-1 appears to contribute to the long-term survival and persistent HIV-1 production in human macrophage reservoirs. In this study we exploited the PI3K/Akt dependent cytoprotective effect of Tat-expressing CHME5 cells. We screened a collection of compounds known to modulate inflammation, and identified three novel compounds: Lancemaside A, Compound K and Arctigenin that abolished the cytoprotective phenotype of Tat-expressing CHME5 cells. All three compounds antagonized the kinase activity of Akt. Further detailed signaling studies revealed that each of these three compounds targeted different steps of the PI3K/Akt pathway. Arctigenin regulates the upstream PI3K enzyme from converting PIP2 to PIP3. Lancemaside A1 inhibited the movement of Akt to the plasma membrane, a critical step for Akt activation. Compound K inhibited Akt phosphorylation. This study supports that Tat-expressing CHME5 cells are an effective model system for screening novel PI3K/Akt inhibitors.