Quercetin prevents small intestinal damage and enhances intestinal recovery during methotrexate-induced intestinal mucositis of rats

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.

Simple preparation and greatly improved oral bioavailability: The supersaturated drug delivery system of quercetin based on PVP K30

Quercetin, as a representative flavonoid, is widely present in daily diet and has been developed as a dietary supplement due to its beneficial physiological activities. However, the application of quercetin is limited due to its poor water solubility and extensive metabolism. So far, the nano-drug delivery systems designed to improve its bioavailability generally have the shortcomings of low drug loading content and difficulty in industrial production. In order to tackle these problems, quercetin supersaturated drug delivery system (QSDDS) was successfully prepared using solvent method, for which PVP K30 was employed as a crystallization and precipitation inhibitor to maintain the supersaturated state of quercetin in aqueous system. The obtained QSDDS, with a relative high drug loading content of 13%, could quickly disperse in water and form colloidal system with the mean particle size of about 200 nm, meanwhile induce the generation of supersaturated quercetin solution more than 12 h. In vivo pharmacokinetic study proved that QSDDS achieved a high absolute bioavailability of 36.05%, 10 times as that of physical quercetin suspension, which was dose-dependent with higher bioavailability at higher dose. Considering the simple preparation method, QSDDS provided a feasible strategy and a simple way to improve oral absorption of insoluble flavonoids.

Anti-inflammatory natural products modulate interleukins and their related signaling markers in inflammatory bowel disease: A systematic review

This review aims to identify in vivo studies investigating the potential of plant substances and their natural molecules in managing inflammatory bowel disease (IBD). Specifically, the objective is to examine the impact of these substances on interleukins and other key inflammatory signaling markers. Relevant articles published up to December 2022 were identified through a search of the PubMed, Scopus, Web of Science, and Embase databases. The search used keywords including "inflammatory bowel disease", "medicinal plants", "natural molecules", "anti-inflammatory", and "ulcerative colitis", and identified 1,878 potentially relevant articles, of which 89 were included in this review after completion of the selection process. This study provides preclinical data on natural products (NPs) that can potentially treat IBD, including ulcerative colitis. The main actions of these NPs relate to their effects on nuclear factor kappa B (NF-κB), the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathway, the regulation of T helper 17/regulatory T cells balance, and oxidative stress. The ability of these NPs to inhibit intestinal inflammation appears to be dependent on lowering levels of the pro-inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β, and IL-17, via the Jun N-terminal kinase (JNK)1, NF-κβ-p65, and STAT3 pathways. In addition, NPs were shown to reduce oxidative stress and the severity of ulcerative colitis, as well as increase the activity of antioxidant enzymes. These actions suggest that NPs represent a promising treatment for IBD, and potentially have greater efficacy and safety than current treatments.

Quercetin Ameliorates Deoxynivalenol-Induced Intestinal Injury and Barrier Dysfunction Associated with Inhibiting Necroptosis Signaling Pathway in Weaned Pigs

Quercetin (Que) is a flavonol compound found in plants, which has a variety of biological activities. Necroptosis, a special form of programmed cell death, plays a vital role in the development of many gastrointestinal diseases. This study aimed to explore whether Que could attenuate the intestinal injury and barrier dysfunction of piglets after deoxynivalenol (DON) exposure through modulating the necroptosis signaling pathway. Firstly, twenty-four weaned piglets were used in a 2 × 2 factorial design and the main factors, including Que (basal diet or diet supplemented with 100 mg/kg Que) and DON exposure (control feed or feed contaminated with 4 mg/kg DON). After feeding for 21 d, piglets were killed for samples. Next, the intestinal porcine epithelial cell line (IPEC-1) was pretreated with or without Que (10 μmol/mL) in the presence or absence of a DON challenge (0.5 μg/mL). Dietary Que increased the body weight, average daily gain, and average daily feed intake (p < 0.05) through the trial. Que supplementation improved the villus height, and enhanced the intestinal barrier function (p < 0.05) indicated by the higher protein expression of occludin and claudin-1 (p < 0.05) in the jejunum of the weaned piglets after DON exposure. Dietary Que also down-regulated the protein abundance of total receptor interacting protein kinase 1 (t-RIP1), phosphorylated RIP1 (p-RIP1), p-RIP3, total mixed lineage kinase domain-like protein (t-MLKL), and p-MLKL (p < 0.05) in piglets after DON exposure. Moreover, Que pretreatment increased the cell viability and decreased the lactate dehydrogenase (LDH) activity (p < 0.05) in the supernatant of IPEC-1 cells after DON challenge. Que treatment also improved the epithelial barrier function indicated by a higher transepithelial electrical resistance (TEER) (p < 0.001), lower fluorescein isothiocyanate-labeled dextran (FD4) flux (p < 0.001), and better distribution of occludin and claudin-1 (p < 0.05) after DON challenge. Additionally, pretreatment with Que also inhibited the protein abundance of t-RIP1, p-RIP1, t-RIP3, p-RIP3, t-MLKL, and p-MLKL (p < 0.05) in IPEC-1 cells after DON challenge. In general, our data suggest that Que can ameliorate DON-induced intestinal injury and barrier dysfunction associated with suppressing the necroptosis signaling pathway.

The significance of quercetin-loaded advanced nanoformulations for the management of diabetic wounds

Quercetin is a well-known plant flavanol that exhibits multiple biological activities, including antioxidant, anti-inflammatory and anticancer activities. The role of quercetin in wound healing has been widely explored by a range of researchers in different models. However, the physicochemical properties, such as solubility and permeability, of this compound are low, which ultimately limits its bioavailability on the target site. To overcome these limitations for successful therapy, scientists have developed a range of nanoformulations that provide effective therapeutic potential. In this review, the broad mechanism of quercetin for acute and chronic wounds is covered. A compilation of recent advances on the horizon of wound healing via quercetin is incorporated with several advanced nanoformulations.

Quantification of the Quercetin Nanoemulsion Technique Using Various Parameters

Natural antioxidant polyphenolic compounds obtained from different plants are considered antioxidants for curing various chronic pathological diseases such as cardiovascular disorders and cancer. Quercetin (a polyphenolic flavonol) has attracted much attention from dietitians and medicinal chemists due to its wide variety of pharmacological activities, including anti-diabetic, anti-hypertensive, anti-carcinogenic, anti-asthmatic, anti-viral, and antioxidant activities. Furthermore, structurally, it is well suited to stabilize emulsions. The present review depicts the important role of the quercetin nanoemulsion technique, used to enhance the solubility of target materials both in vivo and in vitro as well as to decrease the risk of degradation and metabolism of drugs. Researchers have used cryo-TEM to study the morphology of quercetin nanoemulsions. The effects of various parameters such as pH, salts, and solvent concentration on quercetin nanoemulsion have been investigated for quercetin nanoemulsion. Many studies have used UV–Vis spectroscopy and HPLC for the characterization of these particles such as solubility, stability, and encapsulating efficiency.

Therapeutic effects and mechanisms of plant-derived natural compounds against intestinal mucositis

Intestinal mucositis is a clinically related adverse reaction of antitumor treatment. Majority of patients receiving high-dose chemical therapy, radiotherapy, and bone-marrow transplant suffer from intestinal mucositis. Clinical manifestations of intestinal mucositis mainly include pain, body-weight reduction, inflammatory symptom, diarrhea, hemoproctia, and infection, which all affect regular nutritional input and enteric function. Intestinal mucositis often influences adherence to antitumor treatment because it frequently restricts the sufferer’s capacity to tolerate treatment, thus resulting in schedule delay, interruption, or premature suspension. In certain circumstances, partial and general secondary infections are found, increasing the expenditures on medical care and hospitalization. Current methods of treating intestinal mucositis are provided, which do not always counteract this disorder. Against this background, novel therapeutical measures are extremely required to prevent and treat intestinal mucositis. Plant-derived natural compounds have lately become potential candidates against enteric injury ascribed to the capacity to facilitate mucosal healing and anti-inflammatory effects. These roles are associated with the improvement of intestinal mucosal barrier, suppression of inflammatory response and oxidant stress, and modulation of gut microflora and immune system. The present article aims at systematically discussing the recent progress of plant-derived natural compounds as promising treatments for intestinal mucositis.

Targeting inflammation and redox aberrations by perindopril attenuates methotrexate-induced intestinal injury in rats: Role of TLR4/NF-κB and c-Fos/c-Jun pro-inflammatory pathways and PPAR-γ/SIRT1 cytoprotective signals

AIMS

The use of methotrexate (MTX), a classical immunosuppressant and anti-cancer agent, is associated with multiple organ toxicities, including the intestinal injury. Components of the renin-angiotensin system are expressed in the intestinal epithelium and mucosal immune cells where they provoke pro-inflammatory and pro-oxidant action. The present study was conducted to investigate the potential ability of perindopril (PER), an angiotensin-converting enzyme inhibitor (ACEI), to attenuate MTX-induced intestinal injury with emphasis on the role of the pro-inflammatory TLR4/NF-κB and c-Fos/c-Jun pathways alongside PPAR-γ and SIRT1 cytoprotective signals.

MATERIALS AND METHODS

The intestinal injury was induced by a single-dose injection of 20 mg/kg of MTX i.p at the end of the 5th day. PER was administrated once daily in a dose of 1 mg/kg, i.p, for five days before MTX and five days later.

RESULTS

Herein, perindopril attenuated the intestinal injury as seen by lowering the histopathological aberrations and preserving the goblet cells in villi/crypts. These beneficial actions were associated with downregulating the expression of the pro-inflammatory angiotensin II, TNF-α, IL-1β, and IL-6 cytokines, alongside upregulating the anti-inflammatory angiotensin (1-7) and IL-10. At the molecular level, perindopril downregulated the TLR4/NF-κB and c-Fos/c-Jun pathways in inflamed intestine of rats. Moreover, it attenuated the pro-oxidant events by lowering intestinal MDA and boosting GSH, SOD, and GST antioxidants together with PPAR-γ and SIRT1 cytoprotective signals. The aforementioned findings were also highlighted using molecular docking and network pharmacology analysis.

CONCLUSIONS

Perindopril demonstrated notable mitigation of MTX-induced intestinal injury through suppression of TLR4/NF-κB and c-Fos/c-Jun pathways alongside the augmentation of PPAR-γ/SIRT1 cytoprotective signals.

The protective effects of quercetin nano-emulsion on intestinal mucositis induced by 5-fluorouracil in mice

BACKGROUND

Intestinal mucositis is one of chemotherapeutics' most common adverse effects, such as 5-fluorouracil (5-FU). Quercetin (QRC), a naturally occurring flavonoid, has approved antioxidant and anti-inflammatory properties. Thus, in this article, the preventive and curative effects of emulsion and nano-emulsion formulations of QRC were investigated in a model of 5-FU-induced intestinal mucositis using biochemical, histopathological, and molecular approaches.

METHOD

Thirty-six mice were divided into six different groups: Control (normal saline), 5-FU (a single dose of 5-FU 300 mg/kg), pre-treatment groups (pre-QRC, and pre-QRC-nano, receiving QRC 5 mg/kg emulsion and nano-emulsion before the induction of mucositis, respectively), and post-treatment groups (post-QRC, and post-QRC-nano, receiving QRC 5 mg/kg emulsion and nano-emulsion after the induction of mucositis, respectively).

FINDING

The administration of quercetin emulsion and nano-emulsion could significantly alleviate the oxidant-antioxidant balance of mice serum samples and reverse the destructive histopathologic changes induced by 5-FU in the intestine tissue. Nevertheless, although the expression of both pro-inflammatory genes, NF-κB and HIF-1α, was decreased when quercetin was administered to mice, this reduction was not statistically significant.

CONCLUSION

The administration of quercetin emulsion and nano-emulsion formulations could ameliorate the oxidative damage induced by chemotherapeutics, such as the 5-FU. Therefore, if confirmed in further studies, it could be used in clinical settings as a preventive and curative agent to decrease such catastrophic adverse events in chemotherapy patients.

Quercetin Dietary Supplementation Advances Growth Performance, Gut Microbiota, and Intestinal mRNA Expression Genes in Broiler Chickens

Simple Summary

The biological activity of quercetin is diverse, particularly antioxidant, antimicrobial, and antibacterial. The impacts of quercetin nutritional supplementations on growth performance, humoral immunity, gut microbiota and mRNA in broiler chickens were recorded.

Abstract

Quercetin was fed to groups of broiler chickens at concentrations of 200, 400, and 800 ppm, and a control group was supplemented with a basal diet. Results revealed that quercetin dietary supplementation numerically improved the growth performance traits and significantly increased (p < 0.05) the European production efficiency factor (EPEF) in the 200 ppm group. The total coliforms and Clostridium perfringens were decreased (p < 0.05) in quercetin-supplemented groups. Conversely, Lactobacillus counts were increased (p < 0.05), due to improvement of the gut microbiota environment in quercetin-supplemented groups. Moreover, the mRNA expression of intestinal Cu/Zn-superoxide dismutase (SOD1), glutathione peroxidase (GSH-Px) and nutritional transporters, including glucose transporter 2 (GLUT2), peptide transporter 1 (PEPT1), and fatty acid synthase (FAS) genes, were significantly upregulated in quercetin-supplemented groups. Quercetin enhanced intestinal morphometry. We can suggest quercetin supplementation in broiler chickens by levels between 200 and 400 ppm to enhance their development and gut environment.

Efficacy of Nutrients in Reducing the Symptoms of Radiation Induced Oral Mucositis in a Hamster Model

Radiation-induced oral mucositis (RIOM) is a painful, dose-limiting toxicity in cancer therapy. RIOM was induced by radiation on the left buccal pouch mucosa of Golden Syrian hamsters (n = 8/group). Animals were treated topically with polyphenols (Curcumin or Quercetin) or amino acids/metabolite mixtures (Alanyl-Glutamine or Arginine + Glutamine + β-Hydroxy β-methylbutyric acid (Arg/Gln/HMB)) for over 20 day. Progression of RIOM was assessed using a standard visual scoring six-point scale, for differences in severity of mucositis (score ≥3) (Chi-square analysis) and in the daily group scores (Mann-Whitney rank sum test). Compared to the controls, there was a significant reduction in number of days with severe RIOM (score ≥3) in the treatment groups: Curcumin (50 μg/ml) = 17%; Control = 38.5%, p < 0.001; Quercetin (50 μg/ml) = 27.6% and Quercetin (100 μg/ml) = 25%; Control = 41.3%, p = 0.007 and p = 0.001, respectively; Arg/Gln/HMB (50 mg/ml) = 31.9%; Control = 50.0%, p = 0.040. In addition, Curcumin (50 μg/ml), Quercetin (100 μg/ml) and Arg/Gln/HMB (100 mg/ml) groups had lower mucositis scores (≥3) on at least two consecutive time points over the course of the study than their respective controls. There were no significant group differences in deaths or body weight. This study demonstrates the potential benefits of topical application of either plant polyphenols or amino acid/metabolite mixtures in addressing severity and progression of RIOM.

Protective Effect of Quercetin Nanoemulsion on 5-Fluorouracil-Induced Oral Mucositis in Mice

The target of this study was to evaluate the efficacy, histopathological, oxidative stress, and molecular effects of quercetin (QRC) in mice with oral mucositis induced by 5-fluorouracil (5-FU). Thirty-six albino male mice with oral mucositis induced by 5-FU as a chemotherapeutic agent were used in this study. The animals were randomly divided into 6 groups: control group, mucositis (MUC) group, pretreatment group, posttreatment group, and two last groups including nanoemulsion form of QRC with a dose of 5 mg/kg in both pretreatment and posttreatment. In the present evaluation, fewer oral lesions were observed in the QRC posttreatment groups compared to the pretreatment and nanoemulsion receiving groups. In the SOD assay, the most significant difference was observed in the posttreatment nanogroup (41.073 ± 1.24) and pretreatment nanogroup (43.453 ± 2.60) in comparison to the 5-FU group (30.897 ± 1.93). The results of CAT assay also showed a significant difference in nano-posttreatment (124.60 ± 10.85), posttreatment (135.4 ± 9.82), and nano-pretreatment groups (128.80 ± 7.20) compared to the 5-FU group (55.07 ± 8.91). The expression of inflammatory genes such as Hif-1α and NfκB in this group was lower than in the other groups, although this difference was not significant. It seems that the use of QRC can improve the treatment process of oral mucositis induced by 5-FU.

Protective effects of a novel Lactobacillus rhamnosus strain with probiotic characteristics against lipopolysaccharide-induced intestinal inflammation in vitro and in vivo

Lipopolysaccharides (LPS), a main component of the Gram-negative bacterial cell wall, can damage the epithelial wall barrier and induce chronic intestinal inflammation. The purpose of this study is to evaluate whether the novel L. rhamnosus could alleviate intestinal inflammation and damage induced by LPS and explore the possible underlying molecular mechanism. L. rhamnosus JL-1 was selected from five L. rhamnosus strains due to its strong adherence capacity to Caco-2 cells (92.89%) and it could survive in simulated gastrointestinal juices. Whole genome sequencing analysis showed that there were no translocation and inversion regions in the genome of L. rhamnosus JL-1 compared with L. rhamnosus GG. Comparative genomic analysis showed that there were encoding genes related to adhesion, acid resistance and bile salt resistance in the genome of L. rhamnosus JL-1. Both in vitro and in vivo experiments indicated that LPS challenge inhibited the mRNA and protein expression of pro-inflammatory cytokines (TNF-α, IL-1β and IL-6). However, the mRNA and protein expressions of pro-inflammatory cytokines were inhibited by pre-treatment with L. rhamnosus JL-1 in a dose-dependent manner. The result of histopathology analysis of ileum showed that oral administration of L. rhamnosus JL-1 reduced pathological damage induced by LPS. Furthermore, it was revealed that L. rhamnosus JL-1 could inhibit the mRNA and protein expressions of TLR4 and NF-κB. These results strongly suggested that L. rhamnosus JL-1 relieved LPS-induced intestinal inflammation by inhibiting the TLR4/NF-κB signaling pathway. To sum up, L. rhamnosus JL-1 has a potential probiotic function and plays an important role in preventing LPS-induced intestinal inflammation and damage.

Phytochemicals in Chemoprevention: A Cost-Effective Complementary Approach

Cancer is one of the leading causes of death across the world. Although conventional cancer treatments such as chemotherapy and radiotherapy have effectively decreased cancer progression, they come with many dose-limiting side-effects. Phytochemicals that naturally occur in spices, fruits, vegetables, grains, legumes, and other common foods are surprisingly effective complements to conventional cancer treatments. These biologically active compounds demonstrate anticancer effects via cell signaling pathway interference in cancerous cells. In addition, phytochemicals protect non-cancerous cells from chemotherapy-induced side-effects. This paper addresses the not only the potential of phytochemicals quercetin, isoflavones, curcumin, catechins, and hesperidin in terms of cancer treatment and protection against side-effects of chemotherapy, but also methods for increasing phytochemical bioavailability.

Phytochemical add-on therapy to DMARDs therapy in rheumatoid arthritis: In vitro and in vivo bases, clinical evidence and future trends

The use of biologically active compounds derived from plants i.e. phytochemicals, have been known for ages for their pharmacological activities in the treatment of autoimmune disorders like rheumatoid arthritis (RA). Besides enormous scientific evidence, the therapeutic potential of phytochemicals is often undervalued. The treatment in RA involves the use of synthetic and biological disease modifying anti-rheumatic drugs (DMARDs). However, the long-term treatment in RA is associated with the risk of gastrointestinal, liver, pulmonary and renal toxicities and serious infections including latent tuberculosis, pneumococcus influenza, herpes zoster and hepatitis. These adverse effects sometimes lead to discontinuation of the therapy. A relatively new vision based on the combination of DMARDs with phytochemicals exhibiting anti-inflammatory, anti-arthritic, anti-oxidant, hepatoprotective and nephroprotective properties for the treatment of RA has achieved substantial importance in the last decade. From this perspective, the present review focuses on the combination of DMARDs (primarily MTX) with phytochemicals that have shown synergistic therapeutic effects while decreasing the toxic repercussions of current RA therapy. The review covers recent evidences of such combination studies that have shown promising results both in experimental arthritic models and clinical arthritis. Few of the combinations including resveratrol, sinomenine, coenzyme Q10 exhibited considerable interest because of their efficacy as an adjuvant to the MTX/standard DMARDs therapy in clinical trials. Besides giving an overview of such combination studies the review also critically discusses the limitations with the use of phytochemicals (e.g. solubility, permeability and bioavailability) compromising their clinical application. Additionally, it stresses upon the need of novel delivery systems and pharmaceutical technologies to increase the therapeutic efficacy of the combination therapy. Overall, the review unveils the potential of phytochemicals in combination with DMARDs with increased tolerability and superior efficacy in further refining the future of the RA therapy.

Pueraria tuberosa: A Review on Traditional Uses, Pharmacology, and Phytochemistry

Pueraria tuberosa (Roxb. ex Willd.) DC. (Fabaceae), also known as Indian Kudzu (vidari kand), is a perennial herb distributed throughout India and other Asian countries. Traditionally, tuber and leaves of this plant have extensively been reported for nutritional and medicinal properties in Ayurveda as well as in Chinese traditional practices. The objective of the present review is to compile and update the published data on traditional uses, pharmacological potential, and phytochemistry of compounds isolated from the plant Pueraria tuberosa. P. tuberosa extracts and its purified compounds possess multiple activities such as anticancer, anticonvulsant, antidiabetic, antifertility, anti-inflammatory, antioxidant, anti-stress, antiulcerogenic, cardioprotective, hypolipidemic, hepatoprotective, immunomodulatory, nephroprotective, nootropic, neuroprotective, and wound healing. Tuber and leaf extracts of P. tuberosa contain several bioactive constituents such as puerarin, daidzein, genistein, quercetin, irisolidone, biochanin A, biochanin B, isoorientin, and mangiferin, which possess an extensive range of pharmacological activities. The extensive range of pharmacological properties of P. tuberosa provides opportunities for further investigation and presents a new approach for the treatment of ailments. Many phytochemicals have been identified and characterized from P. tuberosa; however, some of them are still unexplored, and there is no supporting data for their activities and exact mechanisms of action. Therefore, further investigations are warranted to unravel the mechanisms of action of individual constituents of this plant.

Role of Rutin in 5-Fluorouracil-Induced Intestinal Mucositis: Prevention of Histological Damage and Reduction of Inflammation and Oxidative Stress

Intestinal mucositis, characterized by inflammatory and/or ulcerative processes in the gastrointestinal tract, occurs due to cellular and tissue damage following treatment with 5-fluorouracil (5-FU). Rutin (RUT), a natural flavonoid extracted from Dimorphandra gardneriana, exhibits antioxidant, anti-inflammatory, cytoprotective, and gastroprotective properties. However, the effect of RUT on inflammatory processes in the intestine, especially on mucositis promoted by antineoplastic agents, has not yet been reported. In this study, we investigated the role of RUT on 5-FU-induced experimental intestinal mucositis. Swiss mice were randomly divided into seven groups: Saline, 5-FU, RUT-50, RUT-100, RUT-200, Celecoxib (CLX), and CLX + RUT-200 groups. The mice were weighed daily. After treatment, the animals were euthanized and segments of the small intestine were collected to evaluate histopathological alterations (morphometric analysis); malondialdehyde (MDA), myeloperoxidase (MPO), and glutathione (GSH) concentrations; mast and goblet cell counts; and cyclooxygenase-2 (COX-2) activity, as well as to perform immunohistochemical analyses. RUT treatment (200 mg/kg) prevented 5-FU-induced histopathological changes and reduced oxidative stress by decreasing MDA concentrations and increasing GSH concentrations. RUT attenuated the inflammatory response by decreasing MPO activity, intestinal mastocytosis, and COX-2 expression. These results suggest that the COX-2 pathway is one of the underlying protective mechanisms of RUT against 5-FU-induced intestinal mucositis.

Animal models of mucositis: critical tools for advancing pathobiological understanding and identifying therapeutic targets

PURPOSE OF REVIEW

Mucositis remains a prevalent, yet poorly managed side effect of anticancer therapies. Mucositis affecting both the oral cavity and gastrointestinal tract predispose to infection and require extensive supportive management, contributing to the growing economic burden associated with cancer care. Animal models remain a critical aspect of mucositis research, providing novel insights into its pathogenesis and revealing therapeutic targets. The current review aims to provide a comprehensive overview of the current animal models used in mucositis research.

RECENT FINDINGS

A wide variety of animal models of mucositis exist highlighting the highly heterogenous landscape of supportive oncology and the unique cytotoxic mechanisms of different anticancer agents. Golden Syrian hamsters remain the gold-standard species for investigation of oral mucositis induced by single dose and fractionated radiation as well as chemoradiation. There is no universally accepted gold-standard model for the study of gastrointestinal mucositis, with rats, mice, pigs and dogs all offering unique perspectives on its pathobiology.

SUMMARY

Animal models are a critical aspect of mucositis research, providing unprecedent insight into the pathobiology of mucositis. Introduction of tumour-bearing models, cyclic dosing scheduled, concomitant agents and genetically modified animals have been integral in refining our understanding of mucositis.

Quercetin Protects Against Lipopolysaccharide-Induced Intestinal Oxidative Stress in Broiler Chickens through Activation of Nrf2 Pathway

We investigated the potential ability of quercetin to protect against lipopolysaccharide (LPS)-induced intestinal oxidative stress in broiler chickens and the potential role of the Nrf2 (nuclear factor erythroid 2-related factor 2) signaling pathway. One-day-old broiler chickens (n = 240) were randomized into four groups: saline-challenged broiler chickens fed a basal diet (Con), LPS-challenged broiler chickens on a basal diet (LPS), and LPS-treated broiler chickens on a basal diet containing either 200 or 500 mg/kg of quercetin (Que200+LPS or Que500+LPS). Quercetin (200 mg/kg) significantly alleviated LPS-induced decreased duodenal, jejunal, and illeal villus height and increased the crypt depth in these regions. Quercetin significantly inhibited LPS-induced jejunal oxidative stress, including downregulated reactive oxygen species (ROS), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) levels, and it upregulated superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels. Quercetin relieved LPS-induced jejunal mitochondria damage and upregulated mitochondrial DNA copy number-related gene expression, including cytochrome c oxidase subunit 1 (COX1), ATP synthase F0 subunit 6 (ATP6), and NADH dehydrogenase subunit 1 (ND1). Quercetin attenuated the LPS-induced inhibition of Nrf2 activation, translocation, and downstream gene expression, including heme oxygenase-1 (HO-1), NAD (P) H dehydrogenase quinone 1 (NQO1), and manganese superoxide dismutase (SOD2). Additionally, quercetin attenuated the LPS-inhibition of c-Jun N-terminal kinase (JNK), Extracellular Regulated protein Kinases (ERK), and p38MAPK (p38) phosphorylation in the MAPK pathway. Thus, quercetin attenuated LPS-induced oxidative stress in the intestines of broiler chickens via the MAPK/Nrf2 signaling pathway.

The Gastrointestinal Exertional Heat Stroke Paradigm: Pathophysiology, Assessment, Severity, Aetiology and Nutritional Countermeasures

Exertional heat stroke (EHS) is a life-threatening medical condition involving thermoregulatory failure and is the most severe condition along a continuum of heat-related illnesses. Current EHS policy guidance principally advocates a thermoregulatory management approach, despite growing recognition that gastrointestinal (GI) microbial translocation contributes to disease pathophysiology. Contemporary research has focused to understand the relevance of GI barrier integrity and strategies to maintain it during periods of exertional-heat stress. GI barrier integrity can be assessed non-invasively using a variety of in vivo techniques, including active inert mixed-weight molecular probe recovery tests and passive biomarkers indicative of GI structural integrity loss or microbial translocation. Strenuous exercise is strongly characterised to disrupt GI barrier integrity, and aspects of this response correlate with the corresponding magnitude of thermal strain. The aetiology of GI barrier integrity loss following exertional-heat stress is poorly understood, though may directly relate to localised hyperthermia, splanchnic hypoperfusion-mediated ischemic injury, and neuroendocrine-immune alterations. Nutritional countermeasures to maintain GI barrier integrity following exertional-heat stress provide a promising approach to mitigate EHS. The focus of this review is to evaluate: (1) the GI paradigm of exertional heat stroke; (2) techniques to assess GI barrier integrity; (3) typical GI barrier integrity responses to exertional-heat stress; (4) the aetiology of GI barrier integrity loss following exertional-heat stress; and (5) nutritional countermeasures to maintain GI barrier integrity in response to exertional-heat stress.

Fractionated Antioxidant and Anti-inflammatory Kernel Oil from Torreya fargesii

Polymethylene-interrupted polyunsaturated fatty acids (PMI-PUFAs) are emerging functional lipids with proven antioxidant and anti-inflammatory effects. In this study, a typical PMI-PUFA, sciadonic acid (C20:3, 5c 11c 14c), was enriched in the kernel oil of Torreya fargesii (T. fargesii) by fractionation. Fractionated kernel oil of T. fargesii (containing 25% sciadonic acid) showed equal stability and similar radical scavenging ability compared with the non-fractionated oil. In anti-inflammatory tests, fractionated kernel oil was shown to inhibit the activity of phosphodiesterase (PDE-5, efficiency 80% at 133.7 μg/mL) and lipoxygenase-5 (LOX-5, efficiency 65% at 66.7 μg/mL) more effectively than the non-fractionated oil. This shows that increasing the amount of sciadonic acid can enhance the anti-inflammatory effect of the kernel oil. This research also indicates that fractionation is a feasible way to obtain sciadonic acid-rich functional oil with potential pharmacological effects.

The Effect of Dietary Quercetin on the Glutathione Redox System and Small Intestinal Functionality of Weaned Piglets

Quercetin has been shown to alleviate mucosal damage and modulate the glutathione (GSH) redox system in the colon of rodents. In the current study, we assessed whether quercetin was able to mitigate small intestinal dysfunction in weaned pigs. Here, 224 weaned piglets were fed a diet containing quercetin at either 0, 100, 300, or 900 mg/kg diet until d14 post-weaning, followed by a common basal diet until d42. Eight animals per treatment were sampled at d5 and d14 post-weaning. In these animals, the small intestinal histomorphology, barrier function, and protein abundance of occludin, caspase-3, and proliferating cell nuclear antigen were assessed. None of these parameters were affected, and neither did quercetin improve performance up to d42 post-weaning. The GSH redox system was evaluated in blood, small intestinal mucosa, and liver. Quercetin did not affect the glutathione peroxidase, glutathione reductase, and glutamate–cysteine ligase activity in these tissues. In contrast, the hepatic glutathione transferase (GST) activity was significantly increased by quercetin supplementation at d5 post-weaning of 100, 300, and 900 mg/kg. Importantly, d5 was characterized by a more oxidized GSH redox status. To conclude, dietary quercetin had little effect on the small intestine, but did upregulate hepatic GST in the occurrence of redox disturbance.

Chemical features of the oligochitosan-glycated caseinate digest and its enhanced protection on barrier function of the acrylamide-injured IEC-6 cells

Whether caseinate oligochitosan-glycation of the transglutaminase-type followed by trypsin digestion could lead to better protection against the acrylamide-induced cell barrier damage was investigated. Compared with caseinate digest, glycated caseinate digest had similar amount of Lys and Arg but lower -NH₂ (0.557 versus 0.508 mol/kg protein) and total amide (1.12 versus 1.05 mol/kg protein) contents, and contained glucosamine at 5.74 g/kg protein. Acrylamide damaged barrier function of IEC-6 cells efficiently, leading to increased paracellular permeability and lactate dehydrogenase release, decreased trans-epithelial electrical resistance, and destroyed tight junction. The two digests alleviated these barrier dysfunctions via reversing index values. Three cellular proteins (ZO-1, occludin, and claudin-1) crucial to tight junction were up-regulated by the two digests. Furthermore, glycated caseinate digest was always more effective than caseinate digest to improve cell barrier function. This oligochitosan glycation is thus desired, as it ensures glycated protein digest with higher potential to protect intestinal barrier function.

Influence of the Maillard-type caseinate glycation with lactose on the intestinal barrier activity of the caseinate digest in IEC-6 cells

The glycated caseinate digest of the Maillard-type shows lower capability than the caseinate digest to enhance the intestinal barrier function of IEC-6 cells.

Ameliorating Iron Overload in Intestinal Tissue of Adult Male Rats: Quercetin vs Deferoxamine

OBJECTIVE

The aim of our study is to compare the role of the new natural alternative (Quercetin) with the current iron-chelation therapy (Deferoxamine (DFO)) in the effect of iron overload on small intestinal tissues and to investigate the possible underlying molecular mechanisms of such toxicity.

METHODS

Forty-two adult male albino rats were divided into six groups: control groups, DFO, Quercetin, iron overload, iron overload+DFO, and iron overload+Quercetin groups. Animals received daily intraperitoneal injection of Deferoxamine (125 mg /kg), Quercetin (10 mg/kg), and ferric dextran (200 mg/kg) for 2 weeks.

RESULTS

Iron overloaded group showed significant increase in serum iron, total iron binding capacity (TIBC), transferrin saturation percentage (TS %) hepcidin (HEPC), serum ferritin, nontransferrin bound iron (NTBI), and small intestinal tissues iron levels. Iron overload significantly increased the serum oxidative stress indicator (MDA) and reduced serum total antioxidant capacity (TAC). On the other hand, iron overload increased IL6 and reduced IL10 in small intestinal tissues reflecting inflammatory condition and increased caspase 3 reactivity indicating apoptosis and increased iNOs expressing cell indicting oxidative stress especially in ileum. In addition, it induced small intestinal tissues pathological alterations. The treatment with Quercetin showed nonsignificant differences as compared to treatment with DFO that chelated the serum and tissue iron and improved the oxidative stress and reduced tissue IL6 and increased IL10 and decreased caspase 3 and iNOs expressing cells in small intestinal tissues. Moreover, it ameliorated the iron overload induced pathological alterations.

CONCLUSION

Our study showed the potential role of Quercetin as iron chelator like DFO in case of iron overload induced small intestinal toxicity in adult rats because of its serum and tissue iron chelation, improvement of serum, and small intestinal oxidative stress, ameliorating iron induced intestinal inflammation, apoptosis, and histopathological alterations.

Effects of Maillard-type caseinate glycation on the preventive action of caseinate digests in acrylamide-induced intestinal barrier dysfunction in IEC-6 cells

Dietary acrylamide has attracted widespread concern due to its toxic effects; however, its adverse impact on the intestines is less assessed. Protein glycation of the Maillard-type is widely used for property modification, but its potential effect on preventive efficacy of protein digest against the acrylamide-induced intestinal barrier dysfunction is quite unknown. Caseinate was thus glycated with lactose. Two tryptic digests from the glycated caseinate and untreated caseinate (namely GCN digest and CN digest) were then assessed for their protective effects against acrylamide-induced intestinal barrier dysfunction in the IEC-6 cell model. The results showed that acrylamide at 1.25–10 mmol L⁻¹ dose-dependently had cytotoxic effects on IEC-6 cells, leading to decreased cell viability and increased lactate dehydrogenase release. Acrylamide also brought about barrier dysfunction, including decreased trans-epithelial electrical resistance (TEER) value and increased epithelial permeability. However, the two digests at 12.5–100 μg mL⁻¹ could alleviate this dysfunction via enhancing cell viability by 70.2–83.9%, partly restoring TEER values, and decreasing epithelial permeability from 100% to 76.6–94.1%. The two digests at 25 μg mL⁻¹ strengthened the tight junctions via increasing tight junction proteins ZO-1, occludin, and claudin-1 expression by 11.5–68.6%. However, the results also suggested that the GCN digest always showed lower protective efficacy than the CN digest in the cells. It is concluded that Maillard-type caseinate glycation with lactose endows the resultant tryptic digest with impaired preventive effect against acrylamide-induced intestinal barrier dysfunction, highlighting another adverse effect of the Maillard reaction on food proteins.

Glycated caseinate digest of the Maillard-type has lower protective action than caseinate digest against acrylamide-induced barrier dysfunction in IEC-6 cells.