Evaluation of the therapeutic effects of mycophenolate mofetil targeting Nrf-2 and NLRP3 inflammasome in acetic acid induced ulcerative colitis in rats

The Dual Role of NRF2 in Colorectal Cancer: Targeting NRF2 as a Potential Therapeutic Approach

Colorectal cancer (CRC), as the third most common bisexual cancer worldwide, requires urgent research on its underlying mechanisms and intervention methods. NRF2 is an important transcription factor involved in the regulation of redox homeostasis, protein degradation, DNA repair, and other cancer processes, playing an important role in cancer. In recent years, the complex role of NRF2 in CRC has been continuously revealed: on the one hand, it exhibits a chemopreventive effect on cancer by protecting normal cells from oxidative stress, and on the other hand, it also exhibits a protective effect on malignant cells. Therefore, this article explores the dual role of NRF2 and its related signaling pathways in CRC, including their chemical protective properties and promoting effects in the occurrence, development, metastasis, and chemotherapy resistance of CRC. In addition, this article focuses on exploring the regulation of NRF2 in CRC ferroptosis, as well as NRF2 drug modulators (activators and inhibitors) targeting CRC, including natural products, compounds, and traditional Chinese medicine formulations.

The Multifaceted Roles of NRF2 in Cancer: Friend or Foe?

Physiological concentrations of reactive oxygen species (ROS) play vital roles in various normal cellular processes, whereas excessive ROS generation is central to disease pathogenesis. The nuclear factor erythroid 2-related factor 2 (NRF2) is a critical transcription factor that regulates the cellular antioxidant systems in response to oxidative stress by governing the expression of genes encoding antioxidant enzymes that shield cells from diverse oxidative alterations. NRF2 and its negative regulator Kelch-like ECH-associated protein 1 (KEAP1) have been the focus of numerous investigations in elucidating whether NRF2 suppresses tumor promotion or conversely exerts pro-oncogenic effects. NRF2 has been found to participate in various pathological processes, including dysregulated cell proliferation, metabolic remodeling, and resistance to apoptosis. Herein, this review article will examine the intriguing role of phase separation in activating the NRF2 transcriptional activity and explore the NRF2 dual impacts on tumor immunology, cancer stem cells, metastasis, and long non-coding RNAs (LncRNAs). Taken together, this review aims to discuss the NRF2 multifaceted roles in both cancer prevention and promotion while also addressing the advantages, disadvantages, and limitations associated with modulating NRF2 therapeutically in cancer treatment.

NLRP3 inhibitors: Unleashing their therapeutic potential against inflammatory diseases

The NOD-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasome has been linked to the release of pro-inflammatory cytokines and is essential for innate defence against infection and danger signals. These secreted cytokines improve the inflammatory response caused by tissue damage and associated inflammation. Consequently, the development of NLRP3 inflammasome inhibitors are viable option for the treatment of diverse inflammatory disorders. The significant anti-inflammatory effects of the NLRP3 inhibitors have severe side effects. Hence, the application of NLRP3 inhibitors against inflammatory disease has not yet been understood and most of the developed inhibitors are unsuccessful in clinical trials. The processes behind the NLRP3 complex, priming, and activation are the main emphasis of this review, which also covers therapeutical inhibitors of the NLRP3 inflammasome and potential therapeutic strategies for directing the NLRP3 inflammasome towards clinical development.

Dandelion polysaccharide treatment protects against dextran sodium sulfate-induced colitis by suppressing NF-κB/NLRP3 inflammasome-mediated inflammation and activating Nrf2 in mouse colon

The treatment of ulcerative colitis (UC) is still an intractable medical problem. Polysaccharides are promising candidates for the treatment of UC and have received widespread attention in recent years. The objective of this study was to explore the protective effect and underlying mechanism of dandelion polysaccharide (DP) on dextran sulfate sodium (DSS)-induced colitis in mice. Our results showed that oral administration of DP could dramatically alleviate colonic lesions, as evidenced by reduced DAI scores, shortening of colon length, and ameliorating pathologic abnormalities in colons. Additionally, the expressions of pro-inflammatory factors (TNF-α, IL-1β, and IL-6) and the infiltration of inflammation-regulation cells, marked by myeloperoxidase and F4/80, were also inhibited after DP treatment. Moreover, DP treatment also markedly suppressed the nuclear translocation of NF-κB-p65 and the activation of the NLRP3 inflammasome. Furthermore, DP also activated the Nrf2/HO-1 pathway and reduced the oxidative stress induced by DSS. Overall, these results suggest that DP could be a promising novel therapeutic approach for the treatment of UC.

Therapeutic interventions target the NLRP3 inflammasome in ulcerative colitis: Comprehensive study

One of the significant health issues in the world is the prevalence of ulcerative colitis (UC). UC is a chronic disorder that mainly affects the colon, beginning with the rectum, and can progress from asymptomatic mild inflammation to extensive inflammation of the entire colon. Understanding the underlying molecular mechanisms of UC pathogenesis emphasizes the need for innovative therapeutic approaches based on identifying molecular targets. Interestingly, in response to cellular injury, the NLR family pyrin domain containing 3 (NLRP3) inflammasome is a crucial part of the inflammation and immunological reaction by promoting caspase-1 activation and the release of interleukin-1β. This review discusses the mechanisms of NLRP3 inflammasome activation by various signals and its regulation and impact on UC.

Fingolimod ameliorates acetic acid-induced ulcerative colitis: An insight into its modulatory impact on pro/anti-inflammatory cytokines and AKT/mTOR signalling

BACKGROUND

Because of the approved immunomodulatory activities of fingolimod, the current study aimed at studying the curative potential of fingolimod against experimentally induced ulcerative colitis (UC) via modulating pro/anti-inflammatory cytokines release and AKT/mTOR signalling.

METHODS

UC was induced in rats by intracolonic instillation of acetic acid. Fingo (0.5 mg/kg/day, p.o.) was given for 8 consecutive days that started 48 h after UC induction.

RESULTS

Fingolimod increased body weight growth rate and colon body/weight and colon weight/length indices compared to the UC group. Fingolimod significantly decreased clinical evaluation score and macroscopic score compared to the UC group. The curative potential of fingolimod was further confirmed by histopathological examination revealing marked attenuation of mucosal injury and inflammatory cells infiltration. Fingolimod significantly decreased colon malondialdehyde content and increased colon glutathione contents compared to the UC group. Fingolimod also significantly decreased the expressions of pro-inflammatory cytokines interleukin-9 and T-helper 17 along with increasing the expression of anti-inflammatory interleukin-10 and transforming growth factor-β compared to the UC group. In addition, fingolimod decreased the expressions of AKT and mTOR compared to the UC group.

CONCLUSION

Fingolimod attenuated acetic acid-induced UC through its immunomodulatory effect by shifting the balance to favour anti-inflammatory cytokine production rather than pro-inflammatory cytokines and modulating the AKT/mTOR signalling.

Structural derivatization strategies of natural phenols by semi-synthesis and total-synthesis

Structural derivatization of natural products has been a continuing and irreplaceable source of novel drug leads. Natural phenols are a broad category of natural products with wide pharmacological activity and have offered plenty of clinical drugs. However, the structural complexity and wide variety of natural phenols leads to the difficulty of structural derivatization. Skeleton analysis indicated most types of natural phenols can be structured by the combination and extension of three common fragments containing phenol, phenylpropanoid and benzoyl. Based on these fragments, the derivatization strategies of natural phenols were unified and comprehensively analyzed in this review. In addition to classical methods, advanced strategies with high selectivity, efficiency and practicality were emphasized. Total synthesis strategies of typical fragments such as stilbenes, chalcones and flavonoids were also covered and analyzed as the supplementary for supporting the diversity-oriented derivatization of natural phenols.

A Novel Role of Dapagliflozin in Mitigation of Acetic Acid-Induced Ulcerative Colitis by Modulation of Monocyte Chemoattractant Protein 1 (MCP-1)/Nuclear Factor-Kappa B (NF-κB)/Interleukin-18 (IL-18)

Colon illnesses, particularly ulcerative colitis, are considered a major cause of death in both men and women around the world. The present study investigated the underlying molecular mechanisms for the potential anti-inflammatory effect of Dapagliflozin (DAPA) against ulcerative colitis (UC) induced by intracolonic instillation of 3% v/v acetic acid (AA). DAPA was administered to rats (1 mg/kg, orally) for two weeks during the treatment regimen. Interestingly, compared to the normal group, a marked increase in the index of colon/body weight, colon weight/colon length ratio, serum lactate dehydrogenase (LDH), and C-reactive protein (CRP), besides decrease in the serum total antioxidant capacity (TAC), were reported in the AA control group (p ˂ 0.05). Elevation in colon monocyte chemoattractant protein (MCP1), Interleukin 18 (IL-18), and inflammasome contents were also reported in the AA control group in comparison with the normal group. In addition, colon-specimen immunohistochemical staining revealed increased expression of nuclear factor-kappa B (NF-κB) and Caspase-3 with histopathological changes. Moreover, DAPA significantly (p ˂ 0.05) reduced the colon/body weight index, colon weight/colon length ratio, clinical evaluation, and macroscopic scoring of UC, and preserved the histopathological architecture of tissues. The inflammatory biomarkers, including colon MCP1, IL-18, inflammasome, Caspase-3, and NF-κB, were suppressed following DAPA treatment and oxidants/antioxidants hemostasis was also restored. Collectively, the present data demonstrate that DAPA represents an attractive approach to ameliorating ulcerative colitis through inhibiting MCP1/NF-κB/IL-18 pathways, thus preserving colon function. Antioxidant, anti-inflammatory, and anti-apoptotic properties of DAPA are implicated in its observed therapeutic benefits.

Protective effect of mirtazapine against acetic acid-induced ulcerative colitis in rats: Role of NLRP3 inflammasome pathway

AIMS

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that causes long-lasting inflammation on the innermost lining of the colon and rectum. Mirtazapine (MRT) is a well-known antidepressant that was proven to have anti-inflammatory activity; however, to date, its role has not been investigated in UC. The current study aimed to investigate the role and mechanism of MRT in UC.

MAIN METHOD

Acetic acid (AA) was used for UC induction, and sulfasalazine (SLZ) was used as a positive control. Rats were divided into five equal groups; as follows; normal control, AA, SLZ (received SLZ in a dose of 250 mg/kg for 14 days), MRT10 (received MRT in a dose of 10 mg/kg/day for 14 days), and MRT30 (received MRT in a dose of 30 mg/kg/day for 14 days) groups. Macroscopic and microscopic examinations together with oxidative stress parameters evaluation were done. NOD-like receptors-3 (NLRP3), caspase-1, TNF-α, and nuclear factor kappa B (NF-κB) expression together with interleukin (IL)-1β and IL-18 levels were examined.

KEY FINDING

MRT, in a dose-dependent manner, prevented the macroscopic and microscopic colonic damage and corrected the oxidative stress induced by AA. Moreover, MRT decreased the colonic tissue NLRP3 inflammasome, caspase-1, NF-κB, TNF-α expressions, IL-1β, and IL-18 levels that were elevated in colonic tissue by the AA.

SIGNIFICANCE

MRT has a dose-dependent protective effect against UC that was mediated mainly by its anti-inflammatory activity with modulation of NLRP3/caspase-1 inflammatory pathway.