Taurine attenuated methotrexate-induced intestinal injury by regulating NF-κB/iNOS and Keap1/Nrf2/HO-1 signals

A narrative review and new insights into the protective effects of taurine against drug side effects

Taurine, a non-essential amino acid produced from cysteine, is abundant in body tissues and blood plasma. It plays vital roles in growth, osmosis, lipid metabolism, and neurohormonal modulation. Taurine has antioxidant, anti-apoptotic, and anti-inflammatory properties, and its deficiency can lead to various diseases including cardiovascular, diabetic, renal, and liver disorders. This report provides a comprehensive review of the functional properties of taurine in counteracting pharmaceutical-induced side effects. A search across databases such as Scopus, PubMed, MEDLINE, and Web of Science yielded 109 articles, of which 75 were included in the study. These results suggest that the protective effects of taurine involve mechanisms such as influencing pathways of Nrf2/OH-1, PI3-kinase/AKT and ERK2, boosting antioxidants (SOD, GPx and CAT), and suppression of inflammatory cytokines (TNF-α, IL-1β and IL-6). Overall, supplementation with taurine along with medications with significant side effects may mitigate these effects and enhance their efficacy. Further investigation of the interactions between taurine and other nutrients or compounds may provide insights into synergistic effects and novel therapeutic approaches.

Ferulic Acid Inhibits Arsenic-Induced Colon Injury by Improving Intestinal Barrier Function

The prolonged exposure to arsenic results in intestinal barrier dysfunction, which is strongly concerned with detrimental processes such as oxidative stress and the inflammatory response. Ferulic acid (FA), as a phenolic acid, possesses the capability to mitigate arsenic-induced liver damage and cardiotoxic effects dependent on inhibition of oxidative stress and inflammatory responses. FA can mitigate testicular tissue damage and alveolar epithelial dysfunction, the mechanism of which may rely on nuclear factor erythroid 2-related factor 2/heme oxygenase 1 (Nrf2/HO-1) activation and nuclear factor-kappa B (NF-κB) pathway blocking. Based on the antioxidant and anti-inflammatory properties of FA, we speculated that FA might have the potential to inhibit arsenic-induced intestinal damage. To confirm this scientific hypothesis, mice exposed to sodium arsenite were treated with FA to observe colonic histopathology and TJ protein levels, and oxidative stress and TJ protein levels in Caco-2 cells exposed to sodium arsenite were assessed after FA intervention. In addition, molecular levels of NF-κB and Nrf2/HO-1 pathway in colon and Caco-2 cells were also detected. As shown in our data, FA inhibited arsenic-induced colon injury, which was reflected in the improvement of mucosal integrity, the decrease of down-regulated expression of tight junction (TJ) proteins (Claudin-1, Occludin, and ZO-1) and the inhibition of oxidative stress. Similarly, treatment with FA attenuated the inhibitory effect of arsenic on TJ protein expression in Caco-2 cells. In addition to suppressing the activation of NF-κB pathway, FA retrieved the activation of Nrf2/HO-1 pathway in colon and intestinal epithelial cells induced by arsenic. In summary, our findings propose that FA has the potential to mitigate arsenic-induced intestinal damage by preserving the integrity of intestinal epithelial TJs and suppressing oxidative stress. These results lay the groundwork for the potential use of FA in treating colon injuries caused by arsenic.

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.

Role of Nrf2/HO-1, PPAR-γ, and cytoglobin signals in the pathogenesis of methotrexate-induced testicular intoxication in rats and the protective effect of diacerein

Methotrexate (MTX) is an inhibitor of folic acid reductase used in managing a variety of malignancies. Testicular injury by MTX is one of its serious adverse effects. The current investigation aims to assess the protective effects of diacerein (DIA) on testicular injury by MTX and clarify the possible underlying mechanisms. Testicular injury in rats was induced by a single injection of 20 mg/kg body weight of MTX. DIA was given in 25 mg/kg body weight/day and 50 mg/kg body weight/day doses for 10 days. Compared to the MTX group, DIA attenuated testicular intoxication as evidenced by improvement of testicular histopathological abnormalities and increased serum testosterone and luteinizing hormone. DIA attenuated testicular oxidative stress changes by lowering testicular MDA and boosting GSH content and SOD activity. Moreover, administration of DIA attenuated MTX-induced testicular inflammation, as proved by decreased TNF-α and IL-6. At the molecular level, DIA induced significant upregulation in Nrf2, HO-1, PPAR-γ, and cytoglobin protein expression. The present results proved that DIA, in a dose-dependent manner, exhibited notable amelioration of testicular toxicity induced by MTX through augmentation of anti-inflammatory and antioxidant effects combined by upregulating Nrf2/HO-1, PPAR-γ, and cytoglobin signaling.

Untargeted metabolomics analysis reveals spatial metabolic heterogeneity in different intestinal segments of type 1 diabetic mice

Type 1 diabetes (T1D) has been reported to cause systematic metabolic disorders, but metabolic changes in different intestinal segments of T1D remain unclear. In this study, we analyzed metabolic profiles in the jejunum, ileum, cecum and colon of streptozocin-induced T1D and age-matched control (CON) mice by an LC-MS-based metabolomics method. The results show that segment-specific metabolic disorders occurred in the gut of T1D mice. In the jejunum, we found that T1D mainly led to disordered amino acid metabolism and most amino acids were significantly lower relative to CON mice. Moreover, fatty acid metabolism was disrupted mainly in the ileum, cecum and colon of T1D mice, such as arachidonic acid, alpha-linolenic acid and linoleic acid metabolism. Thus, our study reveals spatial metabolic heterogeneity in the gut of T1D mice and provides a metabolic view on diabetes-associated intestinal diseases.

Vinpocetine mitigates methotrexate-induced duodenal intoxication by modulating NF-κB, JAK1/STAT-3, and RIPK1/RIPK3/MLKL signals

OBJECTIVES

Methotrexate (MTX) is an antimetabolite agent widely used to manage a variety of tumors and autoimmune diseases. Nonetheless, MTX-induced intestinal intoxication is a serious adverse effect limiting its clinical utility. Inflammation and oxidative stress are possible mechanisms for MTX-induced intestinal toxicity. Vinpocetine (VNP) is a derivative of the alkaloid vincamine with potent anti-inflammatory and antioxidant effects. The current study investigated the protective intestinal impact of VNP in attenuating MTX-induced intestinal intoxication in rats.

MATERIALS AND METHODS

VNP was administered orally in a dose of 20 mg/kg, while MTX was injected intraperitoneal in a dose of 20 mg/kg.

RESULTS

VNP administration attenuated drastic histological changes induced by MTX and preserved both normal villus and crypt histology. VNP significantly attenuated oxidative injury by upregulating intestinal Nrf2 and HO-1 expression. VNP attenuated inflammation by reducing MPO, NO2-, TNF-α, and IL-1β levels mediated by downregulating NF-κB, NDAPH-oxidase, IRF3, p-JAK-1, and p-STAT-3 expressions. Moreover, VNP potently counteracted intestinal necroptosis by effectively downregulating RIPK1, RIPK3, MLKL, and caspase-8 proteins.

CONCLUSION

Therefore, VNP may represent a promising approach that can attenuate intestinal toxicity in patients receiving MTX.

Amelioration of neurobehavioral, biochemical, and morphological alterations associated with silver nanoparticles exposure by taurine in rats

The adverse effect of silver nanoparticles (AgNPs) on the nervous system is an emerging concern of public interest globally. Taurine, an essential amino acid required for neurogenesis in the nervous system, is well-documented to possess antioxidant, anti-inflammatory, and antiapoptotic activities. Yet, there is no report in the literature on the effect of taurine on neurotoxicity related to AgNPs exposure. Here, we investigated the neurobehavioral and biochemical responses associated with coexposure to AgNPs (200 µg/kg body weight) and taurine (50 and 100 mg/kg body weight) in rats. Locomotor incompetence, motor deficits, and anxiogenic-like behavior induced by AgNPs were significantly alleviated by both doses of taurine. Taurine administration enhanced exploratory behavior typified by increased track plot densities with diminished heat maps intensity in AgNPs-treated rats. Biochemical data indicated that the reduction in cerebral and cerebellar acetylcholinesterase activity, antioxidant enzyme activities, and glutathione level by AgNPs treatment were markedly upturned by both doses of taurine. The significant abatement in cerebral and cerebellar oxidative stress indices namely reactive oxygen and nitrogen species, hydrogen peroxide, and lipid peroxidation was evident in rats cotreated with AgNPs and taurine. Further, taurine administration abated nitric oxide and tumor necrosis factor-alpha levels cum myeloperoxidase and caspase-3 activities in AgNPs-treated rats. Amelioration of AgNPs-induced neurotoxicity by taurine was confirmed by histochemical staining and histomorphometry. In conclusion, taurine via attenuation of oxido-inflammatory stress and caspase-3 activation protected against neurotoxicity induced by AgNPs in rats.

Oxycodone alleviates mifepristone-stimulated human endometrial stromal cell injury by activating the Keap1/Nrf2/HO-1 signaling pathway

BACKGROUND

Endometrial injury is a common disease in women caused by intrauterine inflammation, infections, and endocrine disorders. Human endometrial stromal cells (hEndoSCs) can maintain endometrial homeostasis and play an important role in repairing endometrial injury. Mifepristone, a steroidal anti-progesterone drug, is widely used in the field of reproductive medicine worldwide. Mifepristone-induced hEndoSC injury has been used to study endometrial injury in vitro. At present, the pathogenesis and potential regulatory mechanisms of oxycodone in endometrial injury remain unknown.

AIMS

We aimed to evaluate the functions of oxycodone in mifepristone-stimulated hEndoSC injury and analyze its potential molecular mechanism.

MATERIALS & METHODS

hEndoSC viability, cytotoxicity, and apoptosis were analyzed using the methyl thiazolyl tetrazolium assay, the lactate dehydrogenase assay, and flow cytometry, respectively. Furthermore, the levels of cleaved-Caspase3, Keap1, Nrf2, HO-1, and NQO1 were assessed using reverse transcription quantitative polymerase chain reaction and western blot analysis, and the release of inflammatory cytokines was determined using the enzyme-linked immunosorbent assay.

RESULTS

We observed that oxycodone had no adverse effects on hEndoSCs; rather, it protected hEndoSCs against mifepristone-induced endometrial damage, as confirmed by the enhanced cell viability, reduced number of apoptotic cells, decreased Caspase3 activity and inflammatory cytokine secretion, and increased Keap1/Nrf2/HO-1 pathway-related protein expression. In addition, we found that the protective effects of oxycodone on mifepristone-induced hEndoSC injury were inhibited by ML385 (a Keap1/Nrf2/HO-1 inhibitor).

CONCLUSION

In summary, we confirmed that oxycodone alleviates mifepristone-induced hEndoSC injury by activating the Keap1/Nrf2/HO-1 signaling pathway.