The interplay of the inhibitory effect of nifuroxazide on NF-κB/STAT3 signaling attenuates acetic acid-induced ulcerative colitis in rats

A Traditional Chinese Medicine, Zhenqi Granule, Potentially Alleviates Dextran Sulfate Sodium-Induced Mouse Colitis Symptoms

Ulcerative colitis (UC) is an inflammatory bowel disease that causes chronic inflammation in the large intestine. The etiology of UC is complex and incompletely understood, with potential contributing factors including genetic susceptibility, environmental influences, immune dysregulation, and gut barrier dysfunction. Despite available therapeutic drugs, the suboptimal cure rate for UC emphasizes the necessity of developing novel therapeutics. Traditional Chinese Medicine (TCM) has attracted great interest in the treatment of such chronic inflammatory diseases due to its advantages, such as multi-targets and low side effects. In this study, a mouse model of Dextran Sulfate Sodium (DSS)-induced acute colitis was established and the efficacy of Zhenqi Granule, a TCM preparation composed of the extractives from Astragali Radix and Fructus Ligustri Lucidi, was evaluated. The results showed that treatment with Zhenqi Granule prior to or post-DSS induction could alleviate the symptoms of colitis, including weight loss, diarrhea, hematochezia, colon length shortening, and pathological damage of colon tissues of the DSS-treated mice. Further, network pharmacology analysis showed that there were 98 common targets between the active components of Zhenqi Granule and the targets of UC, and the common targets were involved in the regulation of inflammatory signaling pathways. Our results showed that Zhenqi Granule had preventive and therapeutic effects on acute colitis in mice, and the mechanism may be that the active components of Zhenqi Granule participated in the regulation of inflammatory response. This study provided data reference for further exploring the mechanism of Zhenqi Granule and also provided potential treatment strategies for UC.

Molecular mechanisms underlying methotrexate-induced intestinal injury and protective strategies

Methotrexate (MTX) is a folic acid reductase inhibitor that manages various malignancies as well as immune-mediated inflammatory chronic diseases. Despite being frequently prescribed, MTX's severe multiple toxicities can occasionally limit its therapeutic potential. Intestinal toxicity is a severe adverse effect associated with the administration of MTX, and patients are significantly burdened by MTX-provoked intestinal mucositis. However, the mechanism of such intestinal toxicity is not entirely understood, mechanistic studies demonstrated oxidative stress and inflammatory reactions as key factors that lead to the development of MTX-induced intestinal injury. Besides, MTX causes intestinal cells to express pro-inflammatory cytokines like interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α), which activate nuclear factor-kappa B (NF-κB). This is followed by the activation of the Janus kinase/signal transducer and activator of the transcription3 (JAK/STAT3) signaling pathway. Moreover, because of its dual anti-inflammatory and antioxidative properties, nuclear factor erythroid-2-related factor 2/heme oxygenase-1 (Nrf2/HO-1) has been considered a critical signaling pathway that counteracts oxidative stress in MTX-induced intestinal injury. Several agents have potential protective effects in counteracting MTX-provoked intestinal injury such as omega-3 polyunsaturated fatty acids, taurine, umbelliferone, vinpocetine, perindopril, rutin, hesperidin, lycopene, quercetin, apocynin, lactobacillus, berberine, zinc, and nifuroxazide. This review aims to summarize the potential redox molecular mechanisms of MTX-induced intestinal injury and how they can be alleviated. In conclusion, studying these molecular pathways might open the way for early alleviation of the intestinal damage and the development of various agent plans to attenuate MTX-mediated intestinal injury.

Nifuroxazide attenuates indomethacin-induced renal injury by upregulating Nrf2/HO-1 and cytoglobin and suppressing NADPH-oxidase, NF-κB, and JAK-1/STAT3 signals

Indomethacin (INDO) is an NSAID with remarkable efficacy and widespread utilization for alleviating pain. Nevertheless, renal function impairment is an adverse reaction linked to INDO usage. Nifuroxazide (NFX), an oral nitrofuran antibiotic, is frequently employed as an intestinal anti-infective agent. Our study aimed to investigate the renoprotective effects of NFX against INDO-induced nephrotoxicity and explore the protection mechanisms. Four groups of rats were allocated to (I) the normal control, (II) the NFX-treated (50 mg/kg), (III) INDO control (20 mg/kg), and (IV) NFX + INDO. NFX attenuates renal impairment in INDO-induced renal injury, proved by decreasing serum levels of urea, creatinine, uric acid, and NGAL while the albumin was elevated. NFX mitigates renal oxidative stress by decreasing MDA levels and restoring the antioxidants' GSH and SOD levels mediated by upregulating Nrf2, HO-1, and cytoglobin pathways. NFX mitigated renal inflammation and effectively decreased MPO, IL-1β, and TNF-α levels in the rat's kidney mediated by significant downregulation of NADPH-oxidase and NF-κB expression and suppression of JAK-1 and STAT3 phosphorylation. NFX mitigates renal apoptosis by decreasing the expression of cleaved caspase-3 expression. In conclusion, NFX treatment prevents INDO nephrotoxicity by regulating Nrf2/HO-1, cytoglobin, NADPH-oxidase, NF-κB, and JAK-1/STAT3 signals.

Comprehensive insight into the pharmacology, pharmacokinetics, toxicity, detoxification and extraction of hypaconitine from Aconitum plants

ETHNOPHARMACOLOGICAL RELEVANCE

Hypaconitine (HA), a diterpenoid alkaloid, mainly derived from Aconitum plants such as Acoitum carmichaeli Debx. And Aconitum nagarum Stapf., has recently piqued significant interest among the scientific community given its multifaceted attributes including anti-inflammatory, anticancer, analgesic, and cardio-protective properties.

AIM OF THE STUDY

This review presents a comprehensive exploration of the research advancements regarding the traditional uses, pharmacology, pharmacokinetics, toxicity, and toxicity reduction of HA. It aims to provide a thorough understanding of HA's multifaceted properties and its potential applications in various fields.

MATERIALS AND METHODS

A systematic literature search was conducted using several prominent databases including PubMed, Web of Science, NCBI, and CNKI. The search was performed using specific keywords such as "hypaconitine," "heart failure," "anti-inflammatory," "aconite decoction," "pharmacological," "pharmacokinetics," "toxicity," "detoxification or toxicity reduction," and "extraction and isolation." The inclusion of these keywords ensured a comprehensive exploration of relevant studies and enabled the retrieval of valuable information pertaining to the various aspects of HA.

RESULTS

Existing research has firmly established that HA possesses a range of pharmacological effects, encompassing anti-cardiac failure, anti-inflammatory, analgesic, and anti-tumor properties. The therapeutic potential of HA is promising, with potential applications in heart failure, ulcerative colitis, cancer, and other diseases. Pharmacokinetic studies suggest that HA exhibits high absorption rates, broad distribution, and rapid metabolism. However, toxic effects of HA on the nerves, heart, and embryos have also been observed. To mitigate these risks, HA needs attenuation before use, with the most common detoxification methods being processing and combined use with other drugs. Extraction methods for HA most commonly include cold maceration, soxhlet reflux extraction, and ultrasonic-assisted extraction. Despite the potential therapeutic benefits of HA, further research is warranted to elucidate its anti-heart failure effects, particularly in vivo, exploring aspects such as in vivo metabolism, distribution, and metabolites. Additionally, the therapeutic effects of HA monomers on inflammation-induced diseases and tumors should be validated in a more diverse range of experimental models, while the mechanisms underlying the therapeutic effects of HA should be investigated in greater detail.

CONCLUSION

This review serves to emphasize the therapeutic potential of HA and highlights the crucial need to address its toxicity concerns before considering clinical application. Further research is required to comprehensively investigate the pharmacological properties of HA, with particular emphasis on its anti-cardiac failure and anti-inflammatory activities. Such research endeavors have the potential to unveil novel treatment avenues for a broad spectrum of diseases.

The enteroprotective effect of nifuroxazide against methotrexate-induced intestinal injury involves co-activation of PPAR-γ, SIRT1, Nrf2, and suppression of NF-κB and JAK1/STAT3 signals

Methotrexate (MTX) has long manifested therapeutic efficacy in several neoplastic and autoimmune disorders. However, MTX-associated intestinal toxicity restricts the continuation of treatment. Nifuroxazide (NIF) is an oral antibiotic approved for gastrointestinal infections as an effective antidiarrheal agent with a high safety profile. The current study was designed to explore the potential efficacy of NIF in alleviating intestinal toxicity associated with MTX chemotherapy with the elucidation of the proposed molecular mechanisms. Rats were administered NIF (50 mg/kg; p.o.) for ten days. On day five, a single i.p. injection of MTX (20 mg/kg) was given to induce intestinal intoxication. At the end of the experiment, duodenal tissue samples were isolated for biochemical, Western blotting, immunohistochemical (IHC), and histopathological analysis via H&E, PSA, and Alcian blue stains. NIF showed antioxidant enteroprotective effects against MTX intestinal intoxication through enhanced expression of the redox-sensitive signals of PPAR-γ, SIRT1, and Nrf2 estimated by IHC. Moreover, NIF down-regulated the pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), NF-κB protein expression, and the phosphorylation of JAK1/STAT3 proteins, leading to mitigation of intestinal inflammation. In accordance, the histological investigation revealed that NIF ameliorated the intestinal pathological changes, preserved the goblet cells, and reduced the inflammatory cells infiltration. Therefore, NIF could be a promising candidate for adjunctive therapy with MTX to mitigate the associated intestinal injury and increase its tolerability.

Anti-aging effect of nifuroxazide on skin changes of aged male rat models via modulating immunoreactivity of IL-6/NF-κB/Caspase-3

PURPOSE

To evaluate nifuroxazide's (NIF's) anti-aging characteristics in a skin-aging rat model for the first time in order to create effective preventive measures and anti-aging skin therapies.

MATERIALS AND METHODS

Thirty randomly selected aged male rats were assorted into three equal groups; aged control group, treated NIF I, aged rats were treated with NIF (10mg/kg, orally once daily for 14 consecutive days), and treated NIF II, aged rats were treated with NIF (20mg/kg, orally once daily for 14 consecutive days). Skin samples were obtained from the dorsal skin of the aged male rats and processed for tissue biochemical MDA, histological (Hx&E and Masson's Trichrome stains), and immunohistochemical (IL-6, NF-κB, and caspase-3) analysis.

RESULTS

Group I aged male albino rat skin illustrated evident distorted epidermis and dermis, disorganization of collagen fibers with marked multiple spaces of collagen fibers loss in the dermis, marked reduction of total epidermal thickness and mean area percent of collagen fibers, elevated tissue MDA level and strong positive IL-6, NF-κB, and caspase-3 immune reaction. The anti-aging benefits of NIF on skin aging are demonstrated by a marked improvement in histological alterations in the form of a well-organized epidermis and dermis, most collagen fibers in the dermis appear closely packed, significant elevation of total epidermal thickness and mean area percent of collagen fibers, a significant decrease of tissue MDA level, and immunoexpression of the inflammatory markers, IL-6, and NF-κB, and the apoptotic marker caspase-3.

CONCLUSIONS

This study found that group III, which received 20mg/kg of NIF, experienced more pronounced and noticeable improvements in skin aging than group II, which received 10mg/kg of NIF.

Pharmacological updates of nifuroxazide: Promising preclinical effects and the underlying molecular mechanisms

Nifuroxazide (NFX) is a safe nitrofuran antibacterial drug used clinically to treat acute diarrhea and infectious traveler diarrhea or colitis. Recent studies revealed that NFX displays multiple pharmacological effects, including anticancer, antioxidant, and anti-inflammatory effects. NFX has potential roles in inhibiting thyroid, breast, lung, bladder, liver, and colon cancers and osteosarcoma, melanoma, and others mediated by suppressing STAT3 as well as ALDH1, MMP2, MMP9, Bcl2 and upregulating Bax. Moreover, it has promising effects against sepsis-induced organ injury, hepatic disorders, diabetic nephropathy, ulcerative colitis, and immune disorders. These promising effects appear to be mediated by suppressing STAT3 as well as NF-κB, TLR4, and β-catenin expressions and effectively decreasing downstream cytokines TNF-α, IL-1β, and IL-6. Our review summarizes the available studies on the molecular biological mechanisms of NFX in cancer and other diseases and it is recommended to translate the studies in experimental animals and cultured cells and repurpose NFX in various diseases for scientific evidence based on human studies.

Imatinib mitigates experimentally-induced ulcerative colitis: Possible contribution of NF-kB/JAK2/STAT3/COX2 signaling pathway

RATIONALE

Ulcerative colitis (UC) is a chronic immune-mediated disease characterized by recurrent inflammation, damage, and alteration of the large intestine's mucosal and submucosal surfaces. The purpose of this research was to evaluate the impact of tyrosine kinase inhibitor (imatinib) on experimentally induced UC in rats via acetic acid (AA).

METHODS

Male rats were randomly assigned to four groups: control, AA, AA + imatinib (10 mg/kg), and AA + imatinib (20 mg/kg). Imatinib (10 and 20 mg/kg/day) was orally supplied by oral syringe for one week before induction of UC. On the eighth day, Rats received enemas containing a 4 % solution of acetic acid to induce colitis. One day after inducing colitis, rats were euthanized and their colons were subjected to morphological, biochemical, histological, and immunohistochemical analysis.

RESULTS

Imatinib pretreatment significantly decreased macroscopic and histological damage scores, decreased disease activity index as well as colon mass index. In addition, imatinib successfully lowered the levels of malondialdehyde (MDA) in colonic tissues and enhanced superoxide dismutase activity (SOD) and glutathione content (GSH). Imatinib also reduced colonic levels of inflammatory interleukins (IL-23, IL-17, IL-6), JAK2 and STAT3. Furthermore, imatinib suppressed nuclear transcription factor kappa B (NF-kB/p65) level, and COX2 expression in colonic tissues.

SIGNIFICANCE

Imatinib may be a viable therapy option for UC as it halts the interaction network of NF-kB/JAK2/STAT3/COX2 signaling pathway.

Sophorolipids produced by Yarrowia lipolytica grown on Moringa oleifera oil cake protect against acetic acid-induced colitis in rats: impact on TLR-4/p-JNK/NFκB-p65 pathway

OBJECTIVES

Toll-like receptor-4 (TLR-4) activation plays a major role in triggering oxidative stress (OS) and inflammation implicated in the pathogenesis of ulcerative colitis (UC). Due to sophorolipids (SLs) antioxidant and anti-inflammatory properties, they are interestingly becoming more valued for their potential effectiveness in treating a variety of diseases. This study was designed to explore the effect of SLs produced by microbial conversion of Moringa oleifera oil cake using isolated yeast Yarrowia lipolytica against UC induced by acetic acid (AA) in rats.

METHODS

The produced SLs were identified by FTIR, 1H NMR and LC-MS/MS spectra, and administered orally for 7 days (200 mg/kg/day) before AA (2 ml, 4% v/v) to induce UC intrarectally on day eight. Biochemically, the levels of TLR-4, c-Jun N-terminal kinase (JNK), nuclear factor kappa B-p65 (NFκB-p65), interleukin-1beta (IL-1β), malondialdehyd, glutathione, Bax/Bcl2 ratio and the immunohistochemical evaluation of inducible nitric oxide synthase and caspase-3 were assayed.

KEY FINDINGS

SLs significantly reduced OS, inflammatory and apoptotic markers in AA-treated rats, almost like the reference sulfasalazine.

CONCLUSIONS

This study provided a novel impact for SLs produced by microbial conversion of M. oleifera oil cake against AA-induced UC in rats through hampering the TLR-4/p-JNK/NFκB-p65 signalling pathway.

Identification of cuproptosis-associated subtypes and signature genes for diagnosis and risk prediction of Ulcerative colitis based on machine learning

Background

Ulcerative colitis (UC) is a chronic and debilitating inflammatory bowel disease that impairs quality of life. Cuproptosis, a recently discovered form of cell death, has been linked to many inflammatory diseases, including UC. This study aimed to examine the biological and clinical significance of cuproptosis-related genes in UC.

Methods

Three gene expression profiles of UC were obtained from the Gene Expression Omnibus (GEO) database to form the combined dataset. Differential analysis was performed based on the combined dataset to identify differentially expressed genes, which were intersected with cuproptosis-related genes to obtain differentially expressed cuproptosis-related genes (DECRGs). Machine learning was conducted based on DECRGs to identify signature genes. The prediction model of UC was established using signature genes, and the molecular subtypes related to cuproptosis of UC were identified. Functional enrichment analysis and immune infiltration analysis were used to evaluate the biological characteristics and immune infiltration landscape of signature genes and molecular subtypes.

Results

Seven signature genes (ABCB1, AQP1, BACE1, CA3, COX5A, DAPK2, and LDHD) were identified through the machine learning algorithms, and the nomogram built from these genes had excellent predictive performance. The 298 UC samples were divided into two subtypes through consensus cluster analysis. The results of the functional enrichment analysis and immune infiltration analysis revealed significant differences in gene expression patterns, biological functions, and enrichment pathways between the cuproptosis-related molecular subtypes of UC. The immune infiltration analysis also showed that the immune cell infiltration in cluster A was significantly higher than that of cluster B, and six of the characteristic genes (excluding BACE1) had higher expression levels in subtype B than in subtype A.

Conclusions

This study identified several promising signature genes and developed a nomogram with strong predictive capabilities. The identification of distinct subtypes of UC enhances our current understanding of UC's underlying pathogenesis and provides a foundation for personalized diagnosis and treatment in the future.

Morus macroura Miq. Fruit extract protects against acetic acid-induced ulcerative colitis in rats: Novel mechanistic insights on its impact on miRNA-223 and on the TNFα/NFκB/NLRP3 inflammatory axis

Nod-like receptor pyrin domain-1 containing 3 (NLRP3) inflammasome/tumor necrosis factor alpha (TNFα)/nuclear factor kappa B (NFκB) inflammatory pathway is known to be involved in the pathogenesis of ulcerative colitis (UC). Inversely, miRNA-223 can exert counter-regulatory effect on NLRP3 expression. The mulberry tree (Morus macroura) fruit is attaining increased importance for its antioxidant and anti-inflammatory activity in addition to its high safety profile. Accordingly, we attempted to explore the possible protective effect of mulberry fruit extract (MFE) in acetic acid (AA)-induced UC rat model. Phytochemical constituents of MFE were characterized using high performance liquid chromatography coupled to mass spectrometry (HPLC-MS). In the in vivo study, three doses of MFE were orally given for seven days before intra-rectal induction of UC by AA on day eight. Screening study revealed that MFE (300 mg/kg) significantly reduced macroscopic and microscopic UC scores. Biochemically, MFE ameliorated oxidative stress, levels of TNFR1, NLRP3, p-NFκB p65, TNFα, IL-1β, and IL-18, caspase-1 activity, but enhanced miRNA-223 expression. In conclusion, our study provided a novel protective impact for MFE against UC, in which miRNA-223 and TNFα/NFκB/NLRP3 pathway are involved. These results provide a promising step that might encourage further investigations of MFE as a protective agent in UC patients.

Identification of diagnostic signatures in ulcerative colitis patients via bioinformatic analysis integrated with machine learning

Ulcerative colitis (UC) is an immune-related disorder with enhanced prevalence globally. Early diagnosis is critical for the effective treatment of UC. However, it still lacks specific diagnostic signatures. The aim of our study was to explore efficient signatures and construct the diagnostic model for UC. Microarray data of GSE87473 and GSE48634, which were obtained from tissue biopsy samples, were downloaded from the Gene Expression Omnibus (GEO), and differently expressed genes (DEGs), GO, and KEGG analyses were performed. We constructed the PPI network via STRING database. The immune infiltration of the samples was evaluated using CIBERSORT methods combined with the LM22 feature matrix. The logistic regression model was constructed, with the expression of selected genes as the predictor variable, and the UC occurrence as the responsive variable. As a result, a total of 126 DEGs between the UC patients and normal counterparts were identified. The GO and KEGG analysis revealed that multiple biological processes, such as antimicrobial humoral immune response mediated by antimicrobial peptide and IL-17 signaling pathway, were enriched. The infiltration of eight immune cell types (B cells naive, Dendritic.cells.activated, Macrophages.M0, Macrophages.M2, Mast.cells.resting, Neutrophils, Plasma.cells, and T.cells.follicular.helper) was significantly different between patients with UC and normal counterparts. The top 50 most significant DEGs were selected for the construction of the PPI network. The average AUC of the logistic regression model in the fivefold cross-validation was 0.8497 in the training set, GSE87473. The AUC of another independent verification set of GSE48634 from the GEO database was 0.7208. In conclusion, we identified potential hub genes, including REG3A, REG1A, DEFA6, REG1B, and DEFA5, which might be significantly associated with UC progression. The logistic regression model based on the five genes could reliably diagnose UC patients.

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.

Regulation of IL-6/STAT-3/Wnt axis by nifuroxazide dampens colon ulcer in acetic acid-induced ulcerative colitis model: Novel mechanistic insight

AIM

Ulcerative colitis (UC) is a common intestinal problem characterized by the diffusion of colon inflammation and immunity dysregulation. Nifuroxazide, a potent STAT-3 inhibitor, exhibits diverse pharmacological properties. The present study aimed to elucidate a novel anti-colitis mechanism of nifuroxazide against the acetic acid-induced UC model.

METHODS

Rats were grouped into control (received vehicle), UC (2 ml of 5% acetic acid by intrarectal infusion), UC plus sulfasalazine (100 mg/kg/day, P.O.), UC plus nifuroxazide (25 mg/kg/day, P.O.), and UC plus nifuroxazide (50 mg/kg/day, P.O.) and lasted for 6 days.

RESULTS

The present study revealed that nifuroxazide significantly reduced UC measures, hematological changes, and histological alteration. In addition, treatment with nifuroxazide significantly down-regulated serum CRP as well as the colonic expressions of MPO, IL-6, TNF-α, TLR-4, NF-κB-p65, JAK1, STAT-3, DKK1 in a dose-dependent manner. Besides, our results showed that the colonic Wnt expression was up-regulated with nifuroxazide treatment. In a dose-dependent manner, nifuroxazide markedly alleviated acetic acid-induced cellular infiltration and improved ulcer healing by increasing intestinal epithelial cell regeneration.

SIGNIFICANCE

Our results collectively indicate that nifuroxazide is an effective anti-colitis agent through regulation of colon inflammation and proliferation via modulation IL-6/STAT-3/Wnt signaling pathway.

Nifuroxazide suppresses UUO-induced renal fibrosis in rats via inhibiting STAT-3/NF-κB signaling, oxidative stress and inflammation

The current work explored the influences of nifuroxazide, an in vivo inhibitor of signal transducer and activator of transcription-3 (STAT-3) activation, on tubulointerstitial fibrosis in rats with obstructive nephropathy using unilateral ureteral obstruction (UUO) model. Thirty-two male Sprague Dawley rats were assigned into 4 groups (n = 8/group) at random. Sham and UUO groups were orally administered 0.5% carboxymethyl cellulose (CMC) (2.5 mL/kg/day), while Sham-NIF and UUO-NIF groups were treated with 20 mg/kg/day of NIF (suspended in 0.5% CMC, orally). NIF or vehicle treatments were started 2 weeks after surgery and continued for further 2 weeks. NIF treatment ameliorated kidney function in UUO rats, where it restored serum creatinine, blood urea, serum uric acid and urinary protein and albumin to near-normal levels. NIF also markedly reduced histopathological changes in tubules and glomeruli and attenuated interstitial fibrosis in UUO-ligated kidneys. Mechanistically, NIF markedly attenuated renal immunoexpression of E-cadherin and α-smooth muscle actin (α-SMA), diminished renal oxidative stress (↓ malondialdehyde (MDA) levels and ↑ superoxide dismutase (SOD) activity), lessened renal protein expression of phosphorylated-STAT3 (p-STAT-3), phosphorylated-Src (p-Src) kinase, the Abelson tyrosine kinase (c-Abl) and phosphorylated nuclear factor-kappaB p65 (pNF-κB p65), decreased renal cytokine levels of transforming growth factor-β1 (TGF-β1), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and monocyte chemoattractant protein-1 (MCP-1) and reduced number of cluster of differentiation 68 (CD68) immunolabeled macrophages in UUO renal tissues, compared to levels in untreated UUO kidneys. Taken together, NIF treatment suppressed interstitial fibrosis in UUO renal tissues, probably via inhibiting STAT-3/NF-κB signaling and attenuating renal oxidative stress and inflammation.