The guggulsterone derivative GG-52 inhibits NF-κB signaling in bone marrow-derived dendritic cells and attenuates colitis in IL-10 knockout mice

Exploring the Promising Role of Guggulipid in Rheumatoid Arthritis Management: An In-depth Analysis

BACKGROUND

Guggulipid, an oleo-gum resin extracted from the bark of Commiphora wightii of the Burseraceae family, holds a significant place in Ayurvedic medicine due to its historical use in treating various disorders, including inflammation, gout, rheumatism, obesity, and lipid metabolism imbalances.

OBJECTIVE

This comprehensive review aims to elucidate the molecular targets of guggulipids and explore their cellular responses. Furthermore, it summarizes the findings from in-vitro, in-vivo, and clinical investigations related to arthritis and various inflammatory conditions.

METHODS

A comprehensive survey encompassing in-vitro, in-vivo, and clinical studies has been conducted to explore the therapeutic capacity of guggulipid in the management of rheumatoid arthritis. Various molecular pathways, such as cyclooxygenase-2 (COX-2), vascular endothelial growth factor (VEGF), PI3-kinase/AKT, JAK/STAT, nitric oxide synthase (iNOS), and NFκB signaling pathways, have been targeted to assess the antiarthritic and anti-inflammatory effects of this compound.

RESULTS

The research findings reveal that guggulipid demonstrates notable antiarthritic and anti-inflammatory effects by targeting key molecular pathways involved in inflammatory responses. These pathways include COX-2, VEGF, PI3-kinase/AKT, JAK/STAT, iNOS, and NFκB signaling pathways. in-vitro, in-vivo, and clinical studies collectively support the therapeutic potential of guggulipid in managing rheumatoid arthritis and related inflammatory conditions.

CONCLUSION

This review provides a deeper understanding of the therapeutic mechanisms and potential of guggulipid in the management of rheumatoid arthritis. The collective evidence strongly supports the promising role of guggulipid as a therapeutic agent, encouraging further research and development in guggulipid-based treatments for these conditions.

The role of guggulsterone on the NF-κB pathway in inflammatory bowel disease: preclinical evidence

Guggulsterone, a phytosterol in the herb Commiphora wightii (Arn.) Bhandari, has been used in the treatment of diseases such as hyperlipidemia, arthritis and atherosclerosis. It has attracted significant research interest because of its pharmacological properties, especially its anti-inflammatory nature. It can be used for the treatment of inflammatory bowel disease (IBD), a disease characterized by chronic inflammation and damage in the gastrointestinal tract. In various preclinical studies, it inhibited NF-κB, an important pathway in the pathophysiology of IBD. This review summarizes the preclinical studies on this topic for providing more insights to the mechanism by which guggulsterone exerts its effect.

Structure-activity relationship and mechanistic study on guggulsterone derivatives; Discovery of new anti-pancreatic cancer candidate

Pancreatic cancer is one of the deadliest types of malignancies. A new intervention aiming to combat pancreatic cancer is targeting its extra-ordinary ability to tolerate nutrition starvation, a phenomenon known as "Austerity". As a part of a research program aiming to develop a new-generation of anticancer agents, known as "anti-austerity agents", guggulsterone derivatives (GSDs) were identified as unique anti-austerity agents in terms of potency and selectivity. These agents are able to exert preferential cytotoxic activity only under nutrient-deprived conditions with little or no toxicity under normal conditions. In the present study, a library of 14 GSDs was synthesized and screened against PANC-1 human pancreatic cells. Among tested compounds, GSD-11 showed the most potent activity with PC₅₀ a value of 0.72 μM. It also inhibited pancreatic cancer cell migration and colony formation in a concentration-dependent manner. A mechanistic study revealed that this compound can inhibit the activation of the Akt/mTOR signaling pathway. Therefore, GSD-11 could be a promising lead compound for the anticancer drug discovery against pancreatic cancer.

Astragalin Inhibits Nuclear Factor-κB Signaling in Human Colonic Epithelial Cells and Attenuates Experimental Colitis in Mice

Background/Aims

Astragalin (kaempferol-3-O-β-D-glucoside) is a flavonoid isolated from the leaves of persimmon or Rosa agrestis. Astragalin exhibits various anti-inflammatory properties; however, little is known about its therapeutic potential for inflammatory bowel disease (IBD). This study aims to investigate the anti-inflammatory effect of astragalin via blockade of the nuclear factor κB (NF-κB) signaling pathway in human colonic epithelial cells and a murine colitis model.

Methods

HCT-116 and HT-29 human colonic epithelial cells were pretreated with astragalin and stimulated with tumor necrosis factor-α (TNF-α). Cell viability was assessed by the MTS assay. Real-time reverse transcription polymerase chain reaction was used to analyze the messenger RNA expression of the inflammatory cytokines interleukin (IL)-6 and IL-8. The effect of astragalin on the NF-κB pathway was evaluated by Western blot analysis of inhibitor of NF-κB alpha (IκBα) phosphorylation/degradation and by electrophoretic mobility shift assay. Dextran sulfate sodium (DSS)-induced acute murine colitis model was used for in vivo experiments.

Results

Astragalin strongly suppressed the expression of proinflammatory cytokines in human colonic epithelial cells in a dose-dependent manner. Western blot analysis showed that astragalin inhibited IκBα phosphorylation/degradation. Additionally, astragalin reduced the DNA binding activity of NF-κB. Astragalin alleviated colon shortening and improved the pathologic scores in DSS-induced acute murine colitis model. Furthermore, astragalin reduced the level of phosphorylated IκBα and decreased the production of the inflammatory cytokines IL-6, IL-8, and TNF-α in the DSS-treated colon mucosa.

Conclusions

Astragalin exerted an anti-inflammatory effect through NF-κB pathway inhibition and attenuated murine colitis. Astragalin is thus a potential therapeutic agent for IBD.

Novel Histone Deacetylase 6 Inhibitor CKD-506 Inhibits NF-κB Signaling in Intestinal Epithelial Cells and Macrophages and Ameliorates Acute and Chronic Murine Colitis

BACKGROUND

Selective blocking of HDAC6 has become a promising strategy in treating inflammatory bowel disease. CKD-506 is a novel isoform-selective inhibitor of histone deacetylase 6. The present study was performed to evaluate the effect of CKD-506 on the NF-κB signaling pathway in intestinal epithelial cells (IECs) and macrophages and on murine models of acute and chronic colitis.

METHODS

RAW264RAW264.7 murine macrophages and COLO 205 human IECs were pretreated with CKD-506 and then stimulated with lipopolysaccharides (LPS). Cytokine expression of TNF-α, interleukin (IL)-6, IL-8, and IL-10 was measured by ELISA. The effect of CKD-506 on NF-κB signaling was evaluated by Western blotting of IκBα phosphorylation/degradation and electrophoretic mobility shift assay. In vivo studies were performed using a dextran sulfate sodium (DSS)-induced acute colitis model, a chronic colitis model in IL-10 knockout mice, and an adoptive transfer model. Colitis was quantified by the disease activity index, colon length, and histopathologic evaluation.

RESULTS

CKD-506 suppressed the expression of pro-inflammatory cytokines such as IL-6, IL-8, and TNF-α in IECs and macrophages. CKD-506 strongly inhibited IκBα phosphorylation/degradation and the DNA-binding activity of NF-κB. Oral administration of CKD-506 attenuated DSS-induced acute colitis and chronic colitis in IL-10-/- and adoptive transfer models. CKD-506 ameliorated weight loss, disease activity, and histopathologic score in colitis mice and downregulated IκBα phosphorylation and pro-inflammatory cytokine production significantly.

CONCLUSIONS

CKD-506 blocked NF-κB signaling in IECs and macrophages and ameliorated experimental acute and chronic murine colitis models, which suggests that CKD-506 is a promising candidate for inflammatory bowel disease treatment as a small molecular medicine.

Googling the Guggul (Commiphora and Boswellia) for Prevention of Chronic Diseases

Extensive research during last 2 decades has revealed that most drugs discovered today, although costs billions of dollars for discovery, and yet they are highly ineffective in their clinical response. For instance, the European Medicines Agency has approved 68 anti-cancer drugs, and out of which 39 has reached the market level with no indication of increased survival nor betterment of quality of life. Even when drugs did improve survival rate compared to available treatment strategies, most of these were found to be clinically insignificant. This is a fundamental problem with modern drug discovery which is based on thinking that most chronic diseases are caused by alteration of a single gene and thus most therapies are single gene-targeted therapies. However, extensive research has revealed that most chronic diseases are caused by multiple gene products. Although most drugs designed by man are mono-targeted therapies, however, those designed by "mother nature" and have been used for thousands of years, are "multi-targeted" therapies. In this review, we examine two agents that have been around for thousands of years, namely "guggul" from Commiphora and Boswellia. Although we are all familiar with the search engine "google," this is another type of "guggul" that has been used for centuries and being explored for its various biological activities. The current review summarizes the traditional uses, chemistry, in vitro and in vivo biological activities, molecular targets, and clinical trials performed with these agents.

Intestinal alkaline phosphatase ameliorates experimental colitis via toll-like receptor 4-dependent pathway

Intestinal alkaline phosphatase (IAP) is an intestinal brush border enzyme which plays an important role in gut homeostasis and mucosal inflammation. However, the mechanism of the protective effect of IAP is not fully elucidated. The aim of the present study was to evaluate whether the protective effect of IAP on colitis is mediated via the toll-like receptor 4 (TLR4)/nuclear factor-kappa B (NF-κB) pathway. For in vitro analysis, peritoneal macrophages from the wild-type (WT) and TLR4-deficient (TLR4^-/-) C57BL/6 mice were used. IAP strongly inhibited the lipopolysaccharide (LPS)-induced production of tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) by suppressing the LPS-induced phosphorylation of IκBα and the DNA-binding activity of NF-κB in WT macrophages; however, the inhibitory effects mediated by IAP were reduced in the TLR4^-/- macrophages. For in vivo analysis, the protective mechanisms of IAP on dextran sulfate sodium (DSS)-induced colitis were evaluated using WT and TLR4^-/- mice. Although oral administration of IAP significantly attenuated the severity of colitis in both preventive and therapeutic models of WT mice, these protective effects were not significant in TLR4^-/- mice. When immunohistochemical analysis of IκBα was performed in the colitic tissues, the inhibitory effects of IAP on IκBα phosphorylation were also observed in the colon of WT mice, but these effects decreased in the colon of TLR4^-/- mice. In conclusion, the protective effects of IAP on colitis were mediated via the TLR4/NF-κB pathway. These results of this study shall be helpful in tailoring treatment against colitis using IAP.

Effect of Combinatory Treatment With Resveratrol and Guggulsterone on Mild Acute Pancreatitis in Mice

OBJECTIVES

This study was conducted to assess the preventive/therapeutic effects of combined administration of resveratrol and guggulsterone on cerulein-induced acute pancreatitis in mice.

METHODS

Acute pancreatitis was induced by intraperitoneal injection of cerulein in mice. Serum amylase assay and histology were performed to measure the severity of pancreatitis. Western blotting and multiplex cytokine/chemokine analysis were conducted to understand the action mechanisms of the reagents.

RESULTS

Serum amylase assay and histology revealed that the severity of acute pancreatitis was reduced by the combinatory treatment with resveratrol and guggulsterone, but the ratio of the band intensity implied that reduced nuclear factor-κB activation is primarily responsible for the effect. The reduced amounts of keratinocyte chemoattractant (chemokine [C-X-C motif] ligand 1), interferon gamma-induced protein 10 (C-X-C motif chemokine 10) and interleukin 6 expression in the sera could be involved in attenuated immune cell migration and reduced inflammation by these reagents.

CONCLUSIONS

Combinatory treatment with resveratrol and guggulsterone marginally reduced cerulein-induced mild acute pancreatitis in mice.

Nimbolide Inhibits Nuclear Factor-КB Pathway in Intestinal Epithelial Cells and Macrophages and Alleviates Experimental Colitis in Mice

Nimbolide is a limonoid extracted from neem tree (Azadirachta indica) that has antiinflammatory properties. The effect of nimbolide on the nuclear factor-kappa B (NF-κB) pathway in intestinal epithelial cells (IECs), macrophages and in murine colitis models was investigated. The IEC COLO 205, the murine macrophage cell line RAW 264.7, and peritoneal macrophages from interleukin-10-deficient (IL-10^-/- ) mice were preconditioned with nimbolide and then stimulated with tumor necrosis factor-α (TNF-α) or lipopolysaccharide. Dextran sulfate sodium-induced acute colitis model and chronic colitis model in IL-10^-/- mice were used for in vivo experiments. Nimbolide significantly suppressed the expression of inflammatory cytokines (IL-6, IL-8, IL-12, and TNF-α) and inhibited the phosphorylation of IκBα and the DNA-binding affinity of NF-κB in IECs and macrophages. Nimbolide ameliorated weight loss, colon shortening, disease activity index score, and histologic scores in dextran sulfate sodium colitis. It also improved histopathologic scores in the chronic colitis of IL-10^-/- mice. Staining for phosphorylated IκBα was significantly decreased in the colon tissue after treatment with nimbolide in both models. Nimbolide inhibits NF-κB signaling in IECs and macrophages and ameliorates experimental colitis in mice. These results suggest nimbolide could be a potentially new treatment for inflammatory bowel disease. Copyright © 2016 John Wiley & Sons, Ltd.

Guggulsterone and Its Role in Chronic Diseases

Guggulsterone is a plant sterol derived from gum resin of Commiphora wightii. The gum resin from guggul plants has been used for thousand years in Ayurveda to treat various disorders, including internal tumors, obesity, liver disorders, malignant sores and ulcers, urinary complaints, intestinal worms, leucoderma, sinuses, edema, and sudden paralytic seizures. Guggulsterone has been identified a bioactive components of this gum resin. This plant steroid has been reported to work as an antagonist of certain nuclear receptors, especially farnesoid X receptor, which regulates bile acids and cholesterol metabolism. Guggulsterone also mediates gene expression through the regulation of transcription factors, including nuclear factor-kappa B and signal transducer and activator of transcription 3, which plays important roles in the development of inflammation and tumorigenesis. Guggulsterone has been shown to downregulate the expression of proteins involved in anti-apoptotic, cell survival, cell proliferation, angiogenic, metastatic, and chemoresistant activities in tumor cells. This review aimed to clarify the cell signal pathways targeted by guggulsterone and the bioactivities of guggulsterone in animal models and humans.

Phytosterol nanoparticles with reduced crystallinity generated using nanoporous starch aerogels

Phytosterol nanoparticles with reduced crystallinity were generated by impregnation of the phytosterols into nanoporous starch aerogels using supercritical carbon dioxide.

Phytochemicals and their potential usefulness in inflammatory bowel disease

Inflammatory bowel disease (IBD) is a chronic inflammatory condition of the gastrointestinal tract with unclear etiology, namely ulcerative colitis and Crohn's disease. Various drug therapies including aminosalicylates and immunomodulators have been approved for use; they have shown to produce diverse side effects. To overcome these limitations of the current therapeutics for IBD, extensive research is underway to identify drugs that are effective and free of undesirable side effects. Recently, various naturally occurring phytochemicals that cover a wide range of chemical entities such as polyphenols, terpeniods, flavonoids, and alkaloids have received attention as alternative candidates for IBD therapy. These phytochemicals act by modulating the immune response, various transcription factors, or reduce cytokine secretion. This review summarizes the findings of recent studies on phytochemicals as therapeutic agents in the management of IBD.

Clostridium difficile infection aggravates colitis in interleukin 10-deficient mice

AIM: To investigate the effect of Clostridium difficile (C. difficile) infection in an interleukin 10-deficient (IL-10^-/-) mouse model of inflammatory bowel disease.

METHODS: Bone marrow-derived dendritic cells isolated from wild type (WT) and IL-10^-/-mice were stimulated for 4 h with C. difficile toxin A (200 μg/mL), and gene expression of interferon (IFN)-γ, IL-12 and IL-23 was determined by real-time reverse transcription polymerase chain reaction. WT and IL-10^-/- mice (n = 20 each) were exposed to an antibiotic cocktail for three days and then were injected with clindamycin (i.p.). Mice (n = 10 WT, 10 IL-10^-/-) were then challenged with oral administration of C. difficile (1 × 10⁵ colony forming units of strain VPI 10463). Animals were monitored daily for 7 d for signs of colitis. Colonic tissue samples were evaluated for cytokine gene expression and histopathologic analysis.

RESULTS: C. difficile toxin A treatment induced IFN-γ gene expression to a level that was significantly higher in BDMCs from IL-10^-/- compared to those from WT mice (P < 0.05). However, expression of IL-12 and IL-23 was not different among the groups. Following C. difficile administration, mice developed diarrhea and lost weight within 2-3 d. Weight loss was significantly greater in IL-10^-/- compared to WT mice (P < 0.05). C. difficile infection induced histopathologic features typical of colitis in both IL-10^-/- and WT mice. The histopathologic severity score was significantly higher in the IL-10^-/- than in WT mice (mean ± standard error; 5.50 ± 0.53 vs 2.44 ± 0.46; P < 0.05). This was accompanied by a significantly greater increase in IFN-γ gene expression in colonic tissues from IL-10^-/- than from WT mice challenged with C. difficile (P < 0.05).

CONCLUSION: These results indicate that colitis is more severe after C. difficile infection in IL-10^-/-mice, and that IFN-γ expression is involved in this process.

Ursolic acid inhibits nuclear factor-κB signaling in intestinal epithelial cells and macrophages, and attenuates experimental colitis in mice

AIMS

Ursolic acid (UA), a natural pentacyclic triterpenoid acid, has been reported to show immunomodulatory activity. This study investigated the effects of UA on nuclear factor-kappa B (NF-κB) signaling in cells and experimental murine colitis.

MAIN METHODS

Human intestinal epithelial cells (IECs) COLO 205 and peritoneal macrophages from IL-10-deficient (IL-10(-/-)) mice were pretreated with UA and then stimulated with tumor necrosis factor-α (TNF-α) and lipopolysaccharide (LPS), respectively. The expression of pro-inflammatory cytokines was determined by real-time RT-PCR and ELISA. The effect of UA on NF-κB signaling was examined by immunoblot analysis to detect IκBα phosphorylation/degradation and electrophoretic mobility shift assay to assess the DNA binding activity of NF-κB. For in vivo studies, dextran sulfate sodium (DSS)-induced acute colitis in C57BL/6 wild-type mice and chronic colitis in IL-10(-/-) mice were treated with or without UA. Colitis was quantified by histopathologic evaluation. Immunohistochemical staining for phosphorylated IκBα was performed in the colonic tissue.

KEY FINDINGS

UA significantly inhibited the production of pro-inflammatory cytokines, IκBα phosphorylation/degradation and NF-κB DNA binding activity in both IEC and IL-10(-/-) peritoneal macrophages stimulated with TNF-α and LPS, respectively. UA significantly reduced the severity of DSS-induced murine colitis, as assessed by the disease activity index, colon length, and histopathology. UA also significantly ameliorated the severity of colitis in IL-10(-/-) mice. Furthermore, UA suppressed IκBα phosphorylation in the colonic tissue.

SIGNIFICANCE

UA inhibits NF-κB activation in both IECs and macrophages, and attenuates experimental murine colitis. These results suggest that UA is a potential therapeutic agent for inflammatory bowel disease.

The effect of intestinal alkaline phosphatase on intestinal epithelial cells, macrophages and chronic colitis in mice

AIMS

Intestinal alkaline phosphatase (IAP) is an intestinal brush border enzyme that is shown to function as a gut mucosal defense factor, but its defensive mechanism remains unclear. The aims of this study were to evaluate the effect of IAP on intestinal epithelial cells and macrophages, and on chronic colitis in interleukin-10-deficient (IL-10(-/-)) mice.

MAIN METHODS

Human intestinal epithelial cells COLO 205 and peritoneal macrophages from IL-10(-/-) mice were pretreated with IAP and then stimulated with lipopolysaccharide (LPS). IL-8 secretion from COLO205 cells and TNF-α, IL-6, IL-12 from peritoneal macrophages were measured by ELISA. Electrophoretic mobility shift assay was used to assess the DNA binding activity of NF-κB and IκBα phosphorylation/degradation was evaluated by immunoblot assay in COLO 205. For the in vivo study, colitis was induced in IL-10(-/-) mice with piroxicam, the mice were then treated with 100 or 300 units of IAP by oral gavage for 2 weeks. Colitis was quantified by histopathologic scoring, and the phosphorylation of IκBα in the colonic mucosa was assessed using immunohistochemistry.

KEY FINDINGS

IAP significantly inhibited LPS-induced inflammatory cytokine production in both IECs and peritoneal macrophages. IAP also attenuated LPS-induced NF-κB binding activity and IκBα phosphorylation/degradation in IECs. Oral administration of IAP significantly reduced the severity of colitis and down-regulated colitis-induced IκBα phosphorylation in IL-10(-/-) mice.

SIGNIFICANCE

IAP may inhibit the activation of intestinal epithelial cells and peritoneal macrophages, and may attenuate chronic murine colitis. This finding suggests that IAP supplementation is a potential therapeutic option for inflammatory bowel disease.

Enalapril inhibits nuclear factor-κB signaling in intestinal epithelial cells and peritoneal macrophages and attenuates experimental colitis in mice

AIMS

Enalapril, an angiotensin-converting enzyme (ACE) inhibitor, has pleiotropic effects such as anti-inflammatory effects. This study investigated the effect of enalapril on the nuclear factor-kappa B (NF-κB) pathway and on experimental colitis.

MAIN METHODS

The human intestinal epithelial cell (IEC) line COLO 205 and peritoneal macrophages from C57BL/6 wild-type mice and IL-10-deficient (IL-10(-/-)) mice were prepared and subsequently stimulated with lipopolysaccharide (LPS) alone or LPS plus enalapril. The effect of enalapril on NF-κB signaling was examined by western blotting to detect IκBα phosphorylation/degradation; an electrophoretic mobility shift assay (EMSA) to assess the DNA binding activity of NF-κB; and ELISAs to qualify IL-8, TNF-α, IL-6, and IL-12 production. In in vivo studies, dextran sulfate sodium (DSS)-induced acute colitis in wild-type mice and chronic colitis in IL-10(-/-) mice were treated with or without enalapril. Colitis was quantified by histologic scoring, and the phosphorylation of IκBα in the colonic mucosa was assessed using immunohistochemistry.

KEY FINDINGS

Enalapril significantly inhibited LPS-induced IκBα phosphorylation/degradation, NF-κB binding activity, and pro-inflammatory cytokine production in both IEC and peritoneal macrophages. The administration of enalapril significantly reduced the severity of colitis, as assessed based on histology in both murine colitis models. Furthermore, in colon tissue, the up-regulation of IκBα phosphorylation with colitis induction was attenuated in enalapril-treated mice.

SIGNIFICANCE

Enalapril may block the NF-κB signaling pathway, inhibit the activation of IECs and macrophages, and attenuate experimental murine colitis by down-regulating IκBα phosphorylation. These findings suggest that enalapril is a potential therapeutic agent for inflammatory bowel disease.