Mitochondrial dysfunction and respiratory chain defects in a rodent model of methotrexate-induced enteritis

Sex-specific colonic mitochondrial dysfunction in the indomethacin-induced rat model of inflammatory bowel disease

Introduction: Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract and encompasses Crohn's Disease and Ulcerative Colitis. Women appear to have more severe and recurring symptoms of IBD compared to men, most likely due to hormonal fluctuations. Studies have shown that mitochondrial dysfunction plays a role in the development of inflammation and there is evidence of colon mitochondrial alterations in IBD models and patients. In this study we have identified the presence of sex-specific colon mitochondrial dysfunction in a rat model of IBD. Methods: Eight-week-old male and female rats were treated with indomethacin to induce IBD and mitoTEMPO was administered daily either after or before induction of IBD and until euthanasia. Colons were collected for histology and mitochondrial experiments. Intact mitochondrial respiration, reactive oxygen species (mtROS), the activities of the individual electron transport complexes and the activities of the antioxidant enzymes were measured to assess mitochondrial function. Results: IBD male rats showed a decrease in citrate synthase activity, cardiolipin levels, catalase activity and an increase in mtROS production. IBD females show a decrease in intact colon mitochondrial respiration, colon mitochondria respiratory control ratio (RCR), complex I activity, complex IV activity, and an increase in mtROS. Interestingly, control females showed a significantly higher rate of complex I and II-driven intact mitochondrial respiration, MCFA oxidation, complex II activity, complex III activity, and complex IV activity compared to control males. The use of a mitochondrial-targeted therapy, mitoTEMPO, improved the disease and colon mitochondrial function in female IBD rats. However, in the males there was no observed improvement, likely due to the decrease in catalase activity. Conclusion: Our study provides a better understanding of the role mitochondria in the development of IBD and highlights sex differences in colon mitochondrial function. It also opens an avenue for the development of strategies to re-establish normal mitochondrial function that could provide more options for preventive and therapeutic interventions for IBD.

Molecular signatures of angiogenesis inhibitors: a single-embryo untargeted metabolomics approach in zebrafish

Angiogenesis is a key process in embryonic development, a disruption of this process can lead to severe developmental defects, such as limb malformations. The identification of molecular perturbations representative of antiangiogenesis in zebrafish embryo (ZFE) may guide the assessment of developmental toxicity from an endpoint- to a mechanism-based approach, thereby improving the extrapolation of findings to humans. Thus, the aim of the study was to discover molecular changes characteristic of antiangiogenesis and developmental toxicity. We exposed ZFEs to two antiangiogenic drugs (SU4312, sorafenib) and two developmental toxicants (methotrexate, rotenone) with putative antiangiogenic action. Molecular changes were measured by performing untargeted metabolomics in single embryos. The metabolome response was accompanied by the occurrence of morphological alterations. Two distinct metabolic effect patterns were observed. The first pattern comprised common effects of two specific angiogenesis inhibitors and the known teratogen methotrexate, strongly suggesting a shared mode of action of antiangiogenesis and developmental toxicity. The second pattern involved joint effects of methotrexate and rotenone, likely related to disturbances in energy metabolism. The metabolites of the first pattern, such as phosphatidylserines, pterines, retinol, or coenzyme Q precursors, represented potential links to antiangiogenesis and related developmental toxicity. The metabolic effect pattern can contribute to biomarker identification for a mechanism-based toxicological testing.

Protective effects of empagliflozin on methotrexate induced hepatotoxicity in rats

Methotrexate (MTX), a folic acid antagonist, is commonly prescribed as a cytotoxic drug to treat several conditions such as leukemia and inflammation-related diseases, including rheumatoid arthritis and psoriasis. However, its use in clinical practice has been limited due to its fatal side effects, especially hepatotoxicity. Empagliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor that has recently been reported to exhibit anti-inflammatory and anti-oxidative properties. This study was aimed to evaluate the effect of Empagliflozin on liver injury induced by MTX in rats. The rats were divided into five groups as control, MTX (20 mg/kg; i.p.), Empagliflozin (30 mg/kg/day; i.p.), MTX and Empagliflozin (10 and 30 mg/kg/day; i.p.). Histopathologic alterations were examined for assessment of the liver injury. Furthermore, the levels of tissue malondialdehyde (MDA) and activity of anti-oxidative enzymes, superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase, as well as serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were evaluated. Our results revealed that treatment with Empagliflozin significantly improved histopathologic alterations, and elevated levels of AST and ALT induced by MTX administration. Additionally, altered activities of SOD, GPx, and catalase were significantly improved followed by Empagliflozin treatment. However, the higher dose of Empagliflozin was observed to have several benefits compared to the lower dose. Our data suggest that Empagliflozin might possess a protective role against MTX-induced hepatotoxicity by inhibiting oxidative stress in liver tissue.

Methotrexate Chemotherapy Causes Growth Impairments, Vitamin D Deficiency, Bone Loss, and Altered Intestinal Metabolism-Effects of Calcitriol Supplementation

Vitamin D deficiency or insufficiency is prevalent in childhood cancer patients and survivors after chemotherapy; further studies are needed to investigate the underlying aetiology and effectiveness of vitamin D supplementation in preventing chemotherapy-induced bone loss. This study used a rat model of treatment with antimetabolite methotrexate to investigate whether methotrexate chemotherapy causes vitamin D deficiency and if vitamin D supplementation attenuates the resultant bone loss. Methotrexate treatment (five daily injections) decreased serum vitamin D levels (from 52 to <30 ng/mL), reduced body and bone lengthening and tibial trabecular bone volume, and altered intestinal vitamin D metabolism, which was associated with intestinal mucosal damage known to cause malabsorption of nutrients, including dietary vitamin D and calcium. During the early stage after chemotherapy, mRNA expression increased for vitamin D activation enzyme CYP27B1 and for calcium-binding protein TRPV6 in the intestine. During the intestinal healing stage, expression of vitamin D catabolism enzyme CYP24 increased, and that of TRPV6 was normalised. Furthermore, subcutaneous calcitriol supplementation diminished methotrexate-induced bone loss due to its effect suppressing methotrexate-induced increased bone resorption. Thus, in young rats, methotrexate chemotherapy causes vitamin D deficiency, growth impairments, bone loss, and altered intestinal vitamin D metabolism, which are associated with intestinal damage, and vitamin D supplementation inhibits methotrexate-induced bone loss.

Mito-TEMPO mitigates 5-fluorouracil-induced intestinal injury via attenuating mitochondrial oxidative stress, inflammation, and apoptosis: an in vivo study

BACKGROUND

Recent evidences highlight role of mitochondria in the development of 5-fluorouracil (5-FU)-induced intestinal toxicity. Mitochondria-targeted antioxidants are well-known for their protective effects in mitochondrial oxidative stress- mediated diseases. In the present study, we investigated protective effect of Mito-TEMPO in 5-FU-induced intestinal toxicity.

METHODS

Mito-TEMPO (0.1 mg/kg b.w.) was administered intraperitoneally to male BALB/c mice for 7 days, followed by co-administration of 5-FU for next 4 days (intraperitoneal 12 mg/kg b.w.). Protective effect of Mito-TEMPO on intestinal toxicity was assessed in terms of histopathological alterations, modulation in inflammatory markers, apoptotic cell death, expression of 8-OhDG, mitochondrial functional status and oxidative stress.

RESULTS

5-FU administered animals showed altered intestinal histoarchitecture wherein a shortening and atrophy of the villi was observed. The crypts were disorganized and inflammatory cell infiltration was noted. Mito-TEMPO pre-protected animals demonstrated improved histoarchitecture with normalization of villus height, better organized crypts and reduced inflammatory cell infiltration. The inflammatory markers and myeloperoxidase activity were normalized in mito-TEMPO protected group. A significant reduction in intestinal apoptotic cell death and expression of 8-OhDG was also observed in mito-TEMPO group as compared to 5-FU group. Further, mtROS, mtLPO and mitochondrial antioxidant defense status were improved by mito-TEMPO.

CONCLUSION

Mito-TEMPO exerted significant protective effect against 5-FU-induced intestinal toxicity. Therefore, it may be used as an adjuvant in 5-FU chemotherapy.

Sex-specific colonic mitochondrial dysfunction in the indomethacin-induced inflammatory bowel disease model in rats

Introduction

Inflammatory bowel disease (IBD) is characterized by chronic inflammation of the gastrointestinal tract and encompasses Crohn's disease and ulcerative colitis. Women appear to have more severe and recurring symptoms of IBD compared to men, most likely due to hormonal fluctuations. Studies have shown that mitochondrial dysfunction plays a role in the development of inflammation and there is evidence of colon mitochondrial alterations in IBD models and patients. In this study we have identified the presence of sex-specific colon mitochondrial dysfunction in a rat model of IBD.

Methods

Eight-week-old male and female rats were treated with indomethacin to induce IBD and mitoTEMPO was administered daily either after or before induction of IBD and until euthanasia. Colons were collected for histology and mitochondrial experiments. Intact mitochondrial respiration, reactive oxygen species (mtROS), the activities of the individual electron transport complexes and the activities of the antioxidant enzymes were measured to assess mitochondrial function.

Results

IBD male rats showed a decrease in citrate synthase activity, cardiolipin levels, catalase activity and an increase in mtROS production. IBD females show a decrease in intact colon mitochondrial respiration, colon mitochondria respiratory control ratio (RCR), complex I activity, complex IV activity, and an increase in mtROS. Interestingly, control females showed a significantly higher rate of complex I and II-driven intact mitochondrial respiration, MCFA oxidation, complex II activity, complex III activity, and complex IV activity compared to control males. The use of a mitochondrial-targeted therapy, mitoTEMPO, improved the disease and colon mitochondrial function in female IBD rats. However, in the males there was no observed improvement, likely due to the decrease in catalase activity.

Conclusions

Our study provides a better understanding of the role mitochondria in the development of IBD and highlights sex differences in colon mitochondrial function. It also opens an avenue for the development of strategies to re-establish normal mitochondrial function that could provide more options for preventive and therapeutic interventions for IBD.

Restored intestinal integrity, nutrients transporters, energy metabolism, antioxidative capacity and decreased harmful microbiota were associated with IUGR piglet's catch-up growth before weanling

BACKGROUND

Intrauterine growth restriction (IUGR) is a major inducer of higher morbidity and mortality in the pig industry and catch-up growth (CUG) before weanling could significantly restore this negative influence. But there was limited knowledge about the underlying mechanism of CUG occurrence.

METHODS

Eighty litters of newborn piglets were divided into normal birth weight (NBW) and IUGR groups according to birth weight. At 26 d, those piglets with IUGR but over average body weight of eighty litters of weaned piglets were considered as CUG, and the piglets with IUGR still below average body weight were considered as NCUG. This study was conducted to systemically compare the intestinal difference among NBW, CUG and NCUG weaned piglets considering the crucial role of the intestine for piglet growth.

RESULTS

The results indicated that the mRNA expression of nutrients (amino acids, glucose, and fatty acids) transporters, and mitochondrial electron transport chain (ETC) I were upregulated in CUG piglets' gut with improved morphology compared with those NCUG, as well as the ratio of P-AMPK/AMPK protein expression which is the indicator of energy metabolism. Meanwhile, CUG piglet's gut showed higher antioxidative capacity with increased SOD and GSH-Px activity, decreased MDA levels, as well as higher mRNA expressions of Nrf2, Keap1, SOD, and GSH-Px. Furthermore, inflammatory parameters including TNF-α, IL-1β, IL-6, and IL-12 factors, and the activation of MAPK and NF-κB signaling pathways were significantly elevated in the NCUG intestine, while the protein expression of ZO-1, Occludin and Claudin-1 was reduced. The alpha diversity of fecal microbiota was higher in CUG piglets in contrast with NCUG piglets, and the increased beneficial bacteria and decreased pathogenic bacteria was also observed in CUG piglets.

CONCLUSIONS

CUG piglet's intestine showed comprehensive restoration including higher nutrients transport, energy metabolism, antioxidant capacity, and intestinal physical barrier, while lower oxidative stress, inflammatory response, and pathogenic microbiota.

Albiflorin ameliorates inflammation and oxidative stress by regulating the NF-κB/NLRP3 pathway in Methotrexate-induced enteritis

Methotrexate (MTX) treats various diseases but also damages intestinal barrier and leads to enteritis. Albiflorin (ALB) has a variety of pharmacological effects, including antioxidant, anti-inflammation and anti-apoptosis. In the present study, we evaluated the therapeutic effect of ALB on MTX-induced enteritis and investigated the possible mechanisms involved. Male SD rats were intraperitoneally injected with 7 mg/kg MTX for three consecutive days to establish the enteritis model. ALB (20 or 40 mg/kg/day) was intragastrically administrated since two days prior MTX treatment and lasted for six days. We found that ALB treatment increased body weight and intestinal weight of rats with MTX injection. The disease activity index (DAI) score was also decreased after ALB administration. In histological examination, ALB treatment attenuated inflammatory cells infiltration and promoted survival of goblet cells. In detection of inflammatory-associated factors, ALB treatment decreased CD68⁺ cells infiltration, inhibited myeloperoxidase activity, and suppressed intercellular cell adhesion molecule-1 and cyclooxygenase-2 expression. Additionally, ALB reduced malondialdehyde, glutathione levels, inhibited superoxide dismutase activity and suppressed reactive oxygen species production. Moreover, ALB treatment effectively inhibited NLRP3, as well as caspase 1 p20 and interleukin (IL)-1β and 18 expression. Finally, nuclear factor-κB (NF-κB) p65 phosphorylation and nuclear translocation were also demonstrated to be blocked upon ALB treatment. In conclusion, our findings indicated that ALB alleviated MTX-induced enteritis via inhibiting the NF-κB/NLRP3 pathway.

The Intestinal Redox System and Its Significance in Chemotherapy-Induced Intestinal Mucositis

Chemotherapy-induced intestinal mucositis (CIM) is a significant dose-limiting adverse reaction brought on by the cancer treatment. Multiple studies reported that reactive oxygen species (ROS) is rapidly produced during the initial stages of chemotherapy, when the drugs elicit direct damage to intestinal mucosal cells, which, in turn, results in necrosis, mitochondrial dysfunction, and ROS production. However, the mechanism behind the intestinal redox system-based induction of intestinal mucosal injury and necrosis of CIM is still undetermined. In this article, we summarized relevant information regarding the intestinal redox system, including the composition and regulation of redox enzymes, ROS generation, and its regulation in the intestine. We innovatively proposed the intestinal redox “Tai Chi” theory and revealed its significance in the pathogenesis of CIM. We also conducted an extensive review of the English language-based literatures involving oxidative stress (OS) and its involvement in the pathological mechanisms of CIM. From the date of inception till July 31, 2021, 51 related articles were selected. Based on our analysis of these articles, only five chemotherapeutic drugs, namely, MTX, 5-FU, cisplatin, CPT-11, and oxaliplatin were shown to trigger the ROS-based pathological mechanisms of CIM. We also discussed the redox system-mediated modulation of CIM pathogenesis via elaboration of the relationship between chemotherapeutic drugs and the redox system. It is our belief that this overview of the intestinal redox system and its role in CIM pathogenesis will greatly enhance research direction and improve CIM management in the future.

Galangin mitigates oxidative stress, inflammation, and apoptosis in a rat model of methotrexate hepatotoxicity

Methotrexate (MTX) is an efficient chemotherapeutic agent for treating various malignancies and autoimmune diseases. However, the long-term use of MTX can result in hepatotoxicity and this limits its use. Galangin (Gal) is a potent flavonoid with various biological activities; however, its protective effect against MTX hepatotoxicity has not been previously investigated. This study evaluated the hepatoprotective of Gal against MTX-induced liver injury. Rats received Gal for 10 days and a single dose of MTX (20 mg/kg) at day 7. The administration of MTX induced liver damage reflected by increased serum biomarkers of liver function and histopathological manifestations. MTX increased hepatic reactive oxygen species (ROS), nitric oxide (NO), malondialdehyde (MDA), and pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), and diminished GSH and antioxidant enzymes. Gal relieved liver injury, ameliorated liver function, oxidative stress, and inflammation markers, and increased antioxidants in MTX-treated rats. In addition, Gal decreased the expression of inflammation and apoptosis markers in MTX-treated rats. In conclusion, Gal possesses a hepatoprotective effect mediated by attenuating oxidative damage, inflammation, and apoptosis in rats.

Diallyl Disulfide Attenuates Methotrexate-Induced Hepatic Oxidative Injury, Inflammation and Apoptosis and Enhances its Anti-Tumor Activity

BACKGROUND

Methotrexate (MTX) is used potently for a wide range of diseases. However, hepatic intoxication by MTX hinders its clinical use.

OBJECTIVES

The present study was conducted to investigate the diallyl disulfide (DADS) ability to ameliorate MTX-induced hepatotoxicity.

METHODS

Thirty-two rats were randomly divided into four groups: normal control, DADS (50 mg/kg/day, orally), MTX (single i.p. injection of 20 mg/kg) and DADS+MTX. Liver function biomarkers, histopathological examinations, oxidative stress, inflammation, and apoptosis biomarkers were investigated. Besides, an in vitro cytotoxic activity study was conducted to explore the modulatory effects of DADS on MTX cytotoxic activity using Caco-2, MCF-7, and HepG2 cells.

RESULTS

DADS significantly reduced the increased serum activities of ALT, AST, ALP, and LDH. These results were confirmed by the alleviation of liver histopathological changes. It restored the decreased GSH content and SOD activity, while significantly decreased MTX-induced elevations in both MDA and NO2 - contents. The hepatoprotective effects were mechanistically mediated through the up-regulation of hepatic Nrf-2 and the down-regulation of Keap-1, P38MAPK, and NF- κB expression levels. In addition, an increase in Bcl-2 level with a decrease in the expression of both Bax and caspase-3 was observed. The in vitro study showed that DADS increased MTX antitumor efficacy.

CONCLUSION

DADS potently alleviated MTX-induced hepatotoxicity through the modulation of Keap-1/Nrf-2, P38MAPK/NF-κB and apoptosis signaling pathways and effectively enhanced the MTX cytotoxic effects, which could be promising for further clinical trials.

Sinapic acid mitigates methotrexate-induced hepatic injuries in rats through modulation of Nrf-2/HO-1 signaling

The present research has been investigated to study the protective outcomes of sinapic acid (SA) against methotrexate (MTX) encouraged liver damage in rats by modulating the Nrf2/HO-1 and NF-κB signaling pathways. The animals were arbitrarily allocated into four groups: group I rats administered a 0.5% carboxymethyl cellulose (CMC) vehicle orally for 15 consecutive days with a single intravenous standard saline injection (0.9% NaCl) on day seven. Groups II, III, and IV were injected intraperitoneally with 20 mg MTX/kg on 7th day. Animals in group III and IV were treated orally for 14 days with 20 mg of SA/kg dissolved daily in 0.5% CMC respectively. In all experimental groups, liver function, biochemical, histopathological and molecular changes were evaluated. MTX-induced changes in liver function indices like ALT, AST, and ALP are substantially restored with SA pretreatment. Moreover, antioxidant defense mechanisms (GSH, SOD, and CAT) and oxidative/nitrostative stress (MDA and NO) and inflammatory cytokine (TNF-α, IL-β and MPO) were also substantially restored. Furthermore, the conclusions indicate that SA prevents the hepatic damage caused by MTX through apoptosis inhibition and stimulation of Nrf2/HO-1-medial antioxidant enzymes by NF-κB inhibition. Histological findings have shown that SA therapy has greatly protected liver damage caused by MTX.

Mitochondria as Key Players in the Pathogenesis and Treatment of Rheumatoid Arthritis

Mitochondria are major energy-producing organelles that have central roles in cellular metabolism. They also act as important signalling hubs, and their dynamic regulation in response to stress signals helps to dictate the stress response of the cell. Rheumatoid arthritis is an inflammatory and autoimmune disease with high prevalence and complex aetiology. Mitochondrial activity affects differentiation, activation and survival of immune and non-immune cells that contribute to the pathogenesis of this disease. This review outlines what is known about the role of mitochondria in rheumatoid arthritis pathogenesis, and how current and future therapeutic strategies can function through modulation of mitochondrial activity. We also highlight areas of this topic that warrant further study. As producers of energy and of metabolites such as succinate and citrate, mitochondria help to shape the inflammatory phenotype of leukocytes during disease. Mitochondrial components can directly stimulate immune receptors by acting as damage-associated molecular patterns, which could represent an initiating factor for the development of sterile inflammation. Mitochondria are also an important source of intracellular reactive oxygen species, and facilitate the activation of the NLRP3 inflammasome, which produces cytokines linked to disease symptoms in rheumatoid arthritis. The fact that mitochondria contain their own genetic material renders them susceptible to mutation, which can propagate their dysfunction and immunostimulatory potential. Several drugs currently used for the treatment of rheumatoid arthritis regulate mitochondrial function either directly or indirectly. These actions contribute to their immunomodulatory functions, but can also lead to adverse effects. Metabolic and mitochondrial pathways are attractive targets for future anti-rheumatic drugs, however many questions still remain about the precise role of mitochondrial activity in different cell types in rheumatoid arthritis.

Folinate Supplementation Ameliorates Methotrexate Induced Mitochondrial Formate Depletion In Vitro and In Vivo

(1) Background: Antifolate methotrexate (MTX) is the most common disease-modifying antirheumatic drug (DMARD) for treating human rheumatoid arthritis (RA). The mitochondrial-produced formate is essential for folate-mediated one carbon (1C) metabolism. The impacts of MTX on formate homeostasis in unknown, and rigorously controlled kinetic studies can greatly help in this regard. (2) Methods: Combining animal model (8-week old female C57BL/6JNarl mice, n = 18), cell models, stable isotopic tracer studies with gas chromatography/mass spectrometry (GC/MS) platforms, we systematically investigated how MTX interferes with the partitioning of mitochondrial and cytosolic formate metabolism. (3) Results: MTX significantly reduced de novo deoxythymidylate (dTMP) and methionine biosyntheses from mitochondrial-derived formate in cells, mouse liver, and bone marrow, supporting our postulation that MTX depletes mitochondrial 1C supply. Furthermore, MTX inhibited formate generation from mitochondria glycine cleavage system (GCS) both in vitro and in vivo. Folinate selectively rescued 1C metabolic pathways in a tissue-, cellular compartment-, and pathway-specific manner: folinate effectively reversed the inhibition of mitochondrial formate-dependent 1C metabolism in mouse bone marrow (dTMP, methionine, and GCS) and cells (dTMP and GCS) but not methionine synthesis in liver/liver-derived cells. Folinate failed to fully recover hepatic mitochondrial-formate utilization for methionine synthesis, suggesting that the efficacy of clinical folinate rescue in MTX therapy on hepatic methionine metabolism is poor. (4) Conclusion: Conducting studies in mouse and cell models, we demonstrate novel findings that MTX specifically depletes mitochondrial 1C supply that can be ameliorated by folinate supplementation except for hepatic transmethylation. These results imply that clinical use of low-dose MTX may particularly impede 1C metabolism via depletion of mitochondrial formate. The MTX induced systematic and tissue-specific formate depletion needs to be addressed more carefully, and the efficacy of folinate with respect to protecting against such depletion deserves to be evaluated in medical practice.

Protective Effect of Polydatin on Jejunal Mucosal Integrity, Redox Status, Inflammatory Response, and Mitochondrial Function in Intrauterine Growth-Retarded Weanling Piglets

Intrauterine growth retardation (IUGR) delays the gut development of neonates, but effective treatment strategies are still limited. This study used newborn piglets as a model to evaluate the protective effect of polydatin (PD) against IUGR-induced intestinal injury. In total, 36 IUGR piglets and an equal number of normal birth weight (NBW) littermates were fed either a basal diet or a PD-supplemented diet from 21 to 35 days of age. Compared with NBW, IUGR induced jejunal damage and barrier dysfunction of piglets, as indicated by observable bacterial translocation, enhanced apoptosis, oxidative and immunological damage, and mitochondrial dysfunction. PD treatment decreased bacterial translocation and inhibited the IUGR-induced increases in circulating diamine oxidase activity (P = 0.039) and D-lactate content (P = 0.004). The apoptotic rate (P = 0.024) was reduced by 35.2% in the PD-treated piglets, along with increases in villus height (P = 0.033) and in ratio of villus height to crypt depth (P = 0.049). PD treatment promoted superoxide dismutase (P = 0.026) and glutathione S-transferase activities (P = 0.006) and reduced malondialdehyde (P = 0.015) and 8-hydroxy-2′-deoxyguanosine accumulation (P = 0.034) in the jejunum. The PD-treated IUGR piglets showed decreased jejunal myeloperoxidase activity (P = 0.029) and tumor necrosis factor alpha content (P = 0.035) than those received a basal diet. PD stimulated nuclear sirtuin 1 (P = 0.028) and mitochondrial citrate synthase activities (P = 0.020) and facilitated adenosine triphosphate production (P = 0.009) in the jejunum of piglets. Furthermore, PD reversed the IUGR-induced declines in mitochondrial DNA content (P = 0.048), the phosphorylation of adenosine monophosphate-activated protein kinase alpha (P = 0.027), and proliferation-activated receptor gamma coactivator 1 alpha expression (P = 0.033). Altogether, the results indicate that PD may improve jejunal integrity, mitigate mucosal oxidative and immunological damage, and facilitate mitochondrial function in IUGR piglets.

Chicoric acid prevents methotrexate hepatotoxicity via attenuation of oxidative stress and inflammation and up-regulation of PPARγ and Nrf2/HO-1 signaling

Chicoric acid (CA) is a natural antioxidant with promising hepatoprotective activity. We investigated the potential of CA to prevent methotrexate (MTX) hepatotoxicity, pointing to the role of Nrf2/HO-1 signaling and PPARγ. Rats received CA for 15 days and were then injected with MTX at day 16. Blood and tissue samples were collected for analysis at day 19. CA ameliorated liver function markers and mitigated histological alterations in MTX-induced rats. Pre-treatment with CA suppressed reactive oxygen species and lipid peroxidation and enhanced antioxidants in MTX-induced rats. Moreover, CA upregulated hepatic Nrf2, HO-1, NQO-1, and PPARγ, and attenuated inflammation. Consequently, CA inhibited apoptosis by increasing Bcl-2 expression and suppressing Bax, cytochrome c, and caspase-3 in MTX-administered rats. In conclusion, CA prevented oxidative stress, inflammation, and liver injury induced by MTX by activating Nrf2 /HO-1 signaling and PPARγ.

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.

Ferulic acid prevents oxidative stress, inflammation, and liver injury via upregulation of Nrf2/HO-1 signaling in methotrexate-induced rats

Liver injury is one of the adverse effects of methotrexate (MTX). Ferulic acid (FA) is an antioxidant phytochemical that confers hepatoprotective efficacy; however, its effect against MTX hepatotoxicity remains unexplored. This study investigated the role of FA in modulating oxidative stress, inflammation, Nrf2/HO-1 signaling, and PPARγ in MTX-administered rats. Following oral FA supplementation for 15 days, rats received a single dose of MTX at day 16 and samples were collected at day 19. MTX provoked multiple histological manifestations, including degenerative changes, steatosis, inflammatory cells infiltration and hemorrhage, and altered serum transaminases, bilirubin, and albumin. Reactive oxygen species, lipid peroxidation, and nitric oxide were increased in the liver of rats that received MTX. FA prevented all histological alterations, ameliorated liver function markers, suppressed oxidative stress, and boosted antioxidants in MTX-induced rats. FA reduced serum TNF-α and IL-1β, and hepatic NF-κB p65, Bax, and caspase-3, whereas increased Bcl-2, Nrf2, NQO1, HO-1, and PPARγ. In conclusion, FA prevented MTX hepatotoxicity by activating Nrf2/HO-1 signaling and PPARγ, and attenuating oxidative stress, inflammation, and cell death.

Protective effects of hesperidin against MTX-induced hepatotoxicity in male albino rats

Hesperidin (HD), a bioflavonoid, has been shown to exert hepatoprotective effects. Our aim is to investigate the possible protective effects of HD against methotrexate (MTX) hepatotoxicity in adult male Sprague-Dawley (SD) rats that were divided into four groups (10 rats/each) and were exposed to MTX with or without HD co-administration for consecutive 28 days. The results showed that HD significantly ameliorated MTX-induced increase in liver enzymes and histopathological changes. Hepatic oxidative stress was suppressed by HD, as evidenced by the decrease in malondialdehyde (MDA), with a concomitant increase in total antioxidant activity (TAC), catalase (CAT), and glutathione (GSH) levels. Moreover, co-administration of HD with MTX remarkably upregulated the expression of Nrf2 and HO-1 compared with the MTX group. By the decrease in nuclear factor-kB (NF-κB) pathway and tumor necrosis factor α (TNF-α), HD obviously attenuated inflammatory response in MTX-lesioned livers. Likewise, the downregulation of P53 by HD could explain its antiapoptotic effects as indicated by increase BCl2 and the significant decrease of caspase-9 mRNA expression as compared with the MTX group. Thus, these findings revealed the hepatoprotective nature of HD against MTX hepatotoxicity by attenuating the pro-inflammatory and apoptotic mediators and improving antioxidant aptitude.

Histopathological and biomedical parameters determination in the protective effect of crocin on hepatotoxicity induced by methotrexate in rats

Introduction: Methotrexate (Met) as a chemotherapy drug has many side effects, such as infiltration of neutrophils and development of oxidative stress. Crocin (Cro), a carotenoid isolated from saffron, has numerous therapeutic characteristics including anticancer and antioxidant activities. This study was designed to evaluate the effects of Cro against hepatic damage in rats induced by Met. Methods: In this study, 48 male Wistar rats were randomly assigned into 8 groups, control normal (saline), Met control-treated group (20 mg/kg), Cro groups (12.5, 25, 50 mg/kg) and Met + Cro treated groups (12.5, 25, 50 mg/kg). Treatments were administered by intraperitoneal injection daily for 28 days. Griess technique was hired for the determination of serum nitrite oxide (NO) level. Concentrations of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were determined in order to assess liver function disturbances. In addition, Thiobarbituric acid reactive species, antioxidant capacity, diameter of hepatocytes and central hepatic vein (CHV) were investigated. Results: Met administration significantly increased the liver malondialdehyde (MDA) and NO level, the mean diameter of CHV, hepatocytes and hepatic enzymes. Met also decreased the tissue FRAP level compared to the normal control group (P < 0.01). The Cro and Cro + Met treatments in all doses significantly reduced the mean diameter of hepatocytes and CHV, hepatic enzymes, hepatic MDA and NO levels and increased the tissue FRAP level compared to the Met control group (P < 0.01). Conclusion: It seems that Cro administration improves liver injury induced by Met in rats.

Modulation of methotrexate-induced intestinal mucosal injury by dietary factors

Methotrexate (MTX)-induced intestinal mucosal injury in animals has been studied to understand how MTX can cause gastrointestinal disorders, but the pathogenesis of gastrointestinal disorders is still uncertain. We have attempted to reveal how dietary factors influence intestinal toxicity due to MTX. Mice were fed normal chow (NC) or a high-fat high-sucrose diet (HFHSD) before oral administration of MTX. While MTX significantly decreased the survival rates of mice fed HFHSD, the intestinal epithelial injury was detected. MTX excretion in the feces of mice fed HFHSD was reduced. Change of diets between NC and HFHSD influences the survival. The survival rates of the mice fed a high-sucrose diet or control diet were higher than those fed HFHSD. Higher survival rates were observed in mice fed a high-fat high-sucrose diet modified (HFHSD-M) in which casein was replaced by soybean-derived proteins. The survival rates of mice treated with vancomycin were lower than those administered neomycin. Microbiome and metabolome analyses on feces suggest a similarity of the intestinal environments of mice fed NC and HFHSD-M. HFHSD may modify MTX-induced toxicity in intestinal epithelia on account of an altered MTX distribution as a result of change in the intestinal environment.

The footprints of mitochondrial impairment and cellular energy crisis in the pathogenesis of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and Fanconi's syndrome: A comprehensive review

Fanconi's Syndrome (FS) is a disorder characterized by impaired renal proximal tubule function. FS is associated with a vast defect in the renal reabsorption of several chemicals. Inherited and/or acquired conditions seem to be connected with FS. Several xenobiotics including many pharmaceuticals are capable of inducing FS and nephrotoxicity. Although the pathological state of FS is well described, the exact underlying etiology and cellular mechanism(s) of xenobiotics-induced nephrotoxicity, serum electrolytes imbalance, and FS are not elucidated. Constant and high dependence of the renal reabsorption process to energy (ATP) makes mitochondrial dysfunction as a pivotal mechanism which could be involved in the pathogenesis of FS. The current review focuses on the footprints of mitochondrial impairment in the etiology of xenobiotics-induced FS. Moreover, the importance of mitochondria protecting agents and their preventive/therapeutic capability against FS is highlighted. The information collected in this review may provide significant clues to new therapeutic interventions aimed at minimizing xenobiotics-induced renal injury, serum electrolytes imbalance, and FS.

Methotrexate hepatotoxicity is associated with oxidative stress, and down-regulation of PPARγ and Nrf2: Protective effect of 18β-Glycyrrhetinic acid

18β-glycyrrhetinic acid (18β-GA) is a bioactive component of licorice with promising hepatoprotective activity. However, its protective mechanism on methotrexate (MTX) hepatotoxicity in not well defined. We investigated the hepatoprotective effect of 18β-GA, pointing to the role of peroxisome proliferator activated receptor gamma (PPARγ) and the redox-sensitive nuclear factor erythroid 2-related factor 2 (Nrf2). Wistar rats were orally administered 18β-GA (50 and 100 mg/kg) 7 days either before or after MTX injection. MTX induced significant increase in circulating liver function marker enzymes and bilirubin with concomitant declined albumin levels. Serum pro-inflammatory cytokines, and liver malondialdehyde and nitric oxide were significantly increased in MTX-induced rats. Treatment with 18β-GA significantly reduced serum enzymes of liver function, bilirubin and pro-inflammatory cytokines. 18β-GA attenuated MTX-induced oxidative stress and restored the antioxidant defenses. In addition, 18β-GA improved liver histological structure and decreased the expression of Bax whereas increased Bcl-2 expression. MTX-induced rats showed significant down-regulation of Nrf2, hemoxygenase-1 and PPARγ, an effect that was markedly reversed by 18β-GA supplemented either before or after MTX. In conclusion, 18β-GA protected against MTX-induced liver injury, possibly by activating Nrf2 and PPARγ, and subsequent attenuation of inflammation, oxidative stress and apoptosis. Therefore, 18β-GA can provide protection against MTX-induced hepatotoxicity.

Rutin attenuates intestinal toxicity induced by Methotrexate linked with anti-oxidative and anti-inflammatory effects

BACKGROUND

Methotrexate (MTX) is recognized as an anti-metabolite in cancer chemotherapy and is associated with various toxicities assigned to inflammation and oxidative stress. Rutin has been reported to have significant anti-inflammatory, antioxidant along with antiulcer properties. The present study was undertaken to corroborate the effect of rutin against MTX induced intestinal toxicity in experimental animals.

METHOD

Six groups of rats (n = 6) were dosed with normal saline (3 ml/kg,i.p.); MTX (2.5 mg/kg,i.p.); rutin (50 and 100 mg/kg,i.p.); rutin + MTX (50 mg/kg + 2.5 mg/kg,i.p.); rutin + MTX (100 mg/kg + 2.5 mg/kg,i.p.) for seven consecutive days and sacrificed on eighth day. The intestinal contents were scrutinized physiologically (pH, total acidity, free acidity, CMDI), biochemically (TBARS, protein carbonyl, SOD, catalase and GSH) and for immunoregulatory cytokines (IL-2, IL-4 and IL-10).

RESULTS AND DISCUSSION

The administration of rutin demonstrated significant protection against intestinal lesions damaged by MTX. The treatment with rutin elicited noticeable inhibition of free acidity (26.20%), total acidity (22.05%) and CMDI (1.16%) in the experimental animals similar to control. In MTX treated toxic group, the levels of oxidative markers and immunoregulatory cytokines significantly increased in comparison to control, which was subsequently restored after rutin treatment. Rutin also demonstrated 75.63, 81.00 and 80.43% inhibition of cyclooxygenase-1 and 2, and 15-lipoxygenase respectively.

CONCLUSION

The positive modulation of MTX toxicity could be attributed to the free radical scavenging and anti-inflammatory (dual inhibition of arachidonic acid pathways) potential of rutin.

Severe apoptotic enteropathy caused by methotrexate treatment for rheumatoid arthritis

The folic acid antagonist methotrexate is a cornerstone treatment of rheumatoid arthritis. Its use is limited chiefly by gastrointestinal toxicity, which is among the main reasons for methotrexate discontinuation. Here, we report the case of a 40-year-old man on chronic methotrexate therapy in whom life-threatening apoptotic enteropathy with watery diarrhea and hypovolemic shock developed after he was switched from the oral to the intramuscular route, with no change in dosage. Colonic biopsies suggested drug-induced colitis, showing a nonspecific, mildly inflammatory infiltrate of lymphocytes and plasma cells, dilated damaged crypts, and a marked increase in basal crypt apoptosis (>20 apoptotic bodies/100 crypts). Clinicians should be aware that methotrexate can cause life-threatening apoptotic enteropathy. Increased basal crypt apoptosis in colonic biopsies with more than 5 apoptotic bodies/100 crypts should routinely suggest drug-induced enteropathy.

Pre-administration of turmeric prevents methotrexate-induced liver toxicity and oxidative stress

BACKGROUND

Methotrexate (MTX) is an antimetabolite broadly used in treatment of cancer and autoimmune diseases. MTX-induced hepatotoxicity limits its application. We investigated hepatoprotective effects of turmeric in MTX-induced liver toxicity.

METHODS

All experiments were performed on male Wistar albino rats that were randomly divided into six groups. Group one received saline orally for 30 days (control group), groups two and three received turmeric extract (100, 200 mg/kg respectively) orally for 30 days, group four received single dose, of MTX IP at day 30, groups five and six received turmeric extract 100 and 200 mg/kg orally respectively for 30 days and single dose of methoterxate IP (20 mg/kg) at day 30. Four days after MTX injection animals were sacrificed and evaluated. Blood ALT and AST (indicators of hepatocyte injury), ALP and bilirubin (markers of biliary function), albumin (reflect liver synthetic function) as well as the plasma TAS concentration (antioxidant defenses) were determined. The cellular antioxidant defense activities were examined in liver tissue samples using SOD, CAT, and GSH-Px for the oxidative stress, and MDA for lipid peroxidation. In addition, liver damage was evaluated histopathologically.

RESULTS

MTX significantly induced liver damage (P<0.05) and decreased its antioxidant capacity, while turmeric was hepatoprotective. Liver tissue microscopic evaluation showed that MTX treatment induced severe centrilobular and periportal degeneration, hyperemia of portal vein, increased artery inflammatory cells infiltration and necrosis, while all of histopathological changes were attenuated by turmeric (200 mg/kg).

CONCLUSION

Turmeric extract can successfully attenuate MTX-hepatotoxicity. The effect is partly mediated through extract's antinflammatory activity.

Methotrexate Promotes Platelet Apoptosis via JNK-Mediated Mitochondrial Damage: Alleviation by N-Acetylcysteine and N-Acetylcysteine Amide

Thrombocytopenia in methotrexate (MTX)-treated cancer and rheumatoid arthritis (RA) patients connotes the interference of MTX with platelets. Hence, it seemed appealing to appraise the effect of MTX on platelets. Thereby, the mechanism of action of MTX on platelets was dissected. MTX (10 μM) induced activation of pro-apoptotic proteins Bid, Bax and Bad through JNK phosphorylation leading to ΔΨm dissipation, cytochrome c release and caspase activation, culminating in apoptosis. The use of specific inhibitor for JNK abrogates the MTX-induced activation of pro-apoptotic proteins and downstream events confirming JNK phosphorylation by MTX as a key event. We also demonstrate that platelet mitochondria as prime sources of ROS which plays a central role in MTX-induced apoptosis. Further, MTX induces oxidative stress by altering the levels of ROS and glutathione cycle. In parallel, the clinically approved thiol antioxidant N-acetylcysteine (NAC) and its derivative N-acetylcysteine amide (NACA) proficiently alleviate MTX-induced platelet apoptosis and oxidative damage. These findings underpin the dearth of research on interference of therapeutic drugs with platelets, despite their importance in human health and disease. Therefore, the use of antioxidants as supplementary therapy seems to be a safe bet in pathologies associated with altered platelet functions.

Strategies, models and biomarkers in experimental non-alcoholic fatty liver disease research

Non-alcoholic fatty liver disease encompasses a spectrum of liver diseases, including simple steatosis, steatohepatitis, liver fibrosis and cirrhosis and hepatocellular carcinoma. Non-alcoholic fatty liver disease is currently the most dominant chronic liver disease in Western countries due to the fact that hepatic steatosis is associated with insulin resistance, type 2 diabetes mellitus, obesity, metabolic syndrome and drug-induced injury. A variety of chemicals, mainly drugs, and diets is known to cause hepatic steatosis in humans and rodents. Experimental non-alcoholic fatty liver disease models rely on the application of a diet or the administration of drugs to laboratory animals or the exposure of hepatic cell lines to these drugs. More recently, genetically modified rodents or zebrafish have been introduced as non-alcoholic fatty liver disease models. Considerable interest now lies in the discovery and development of novel non-invasive biomarkers of non-alcoholic fatty liver disease, with specific focus on hepatic steatosis. Experimental diagnostic biomarkers of non-alcoholic fatty liver disease, such as (epi)genetic parameters and '-omics'-based read-outs are still in their infancy, but show great promise. In this paper, the array of tools and models for the study of liver steatosis is discussed. Furthermore, the current state-of-art regarding experimental biomarkers such as epigenetic, genetic, transcriptomic, proteomic and metabonomic biomarkers will be reviewed.

Gastrointestinal dysfunction in autism spectrum disorder: the role of the mitochondria and the enteric microbiome

Autism spectrum disorder (ASD) affects a significant number of individuals worldwide with the prevalence continuing to grow. It is becoming clear that a large subgroup of individuals with ASD demonstrate abnormalities in mitochondrial function as well as gastrointestinal (GI) symptoms. Interestingly, GI disturbances are common in individuals with mitochondrial disorders and have been reported to be highly prevalent in individuals with co-occurring ASD and mitochondrial disease. The majority of individuals with ASD and mitochondrial disorders do not manifest a primary genetic mutation, raising the possibility that their mitochondrial disorder is acquired or, at least, results from a combination of genetic susceptibility interacting with a wide range of environmental triggers. Mitochondria are very sensitive to both endogenous and exogenous environmental stressors such as toxicants, iatrogenic medications, immune activation, and metabolic disturbances. Many of these same environmental stressors have been associated with ASD, suggesting that the mitochondria could be the biological link between environmental stressors and neurometabolic abnormalities associated with ASD. This paper reviews the possible links between GI abnormalities, mitochondria, and ASD. First, we review the link between GI symptoms and abnormalities in mitochondrial function. Second, we review the evidence supporting the notion that environmental stressors linked to ASD can also adversely affect both mitochondria and GI function. Third, we review the evidence that enteric bacteria that are overrepresented in children with ASD, particularly Clostridia spp., produce short-chain fatty acid metabolites that are potentially toxic to the mitochondria. We provide an example of this gut–brain connection by highlighting the propionic acid rodent model of ASD and the clinical evidence that supports this animal model. Lastly, we discuss the potential therapeutic approaches that could be helpful for GI symptoms in ASD and mitochondrial disorders. To this end, this review aims to help better understand the underlying pathophysiology associated with ASD that may be related to concurrent mitochondrial and GI dysfunction.