Role of IL-6/STAT3 pathway in mediating the protective effect of agomelatine against methotrexate-induced lung/intestinal tissues damage in 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.

Cadmium-induced lung injury is associated with oxidative stress, apoptosis, and altered SIRT1 and Nrf2/HO-1 signaling; protective role of the melatonin agonist agomelatine

Cadmium (Cd) is a hazardous heavy metal extensively employed in manufacturing polyvinyl chloride, batteries, and other industries. Acute lung injury has been directly connected to Cd exposure. Agomelatine (AGM), a melatonin analog, is a drug licensed for treating severe depression. This study evaluated the effect of AGM against Cd-induced lung injury in rats. AGM was administered in a dose of 25 mg/kg/day orally, while cadmium chloride (CdCl2) was injected intraperitoneally in a dose of 1.2 mg/kg to induce lung injury. Pre-treatment with AGM remarkably ameliorated Cd-induced lung histopathological abrasions. AGM decreased reactive oxygen species (ROS) production, lipid peroxidation, suppressed NDAPH oxidase, and boosted the antioxidants. AGM increased Nrf2, GCLC, HO-1, and TNXRD1 mRNA, as well as HO-1 activity and downregulated Keap1. AGM downregulated Bax and caspase-3 and upregulated Bcl-2, SIRT1, and FOXO3 expression levels in the lung. In conclusion, AGM has a protective effect against Cd-induced lung injury via its antioxidant and anti-apoptotic effects mediated via regulating Nrf2/HO-1 and SIRT1/FOXO3 signaling.

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.

Protective effect of rivastigmine against lung injury in acute pancreatitis model in rats via Hsp 70/IL6/ NF-κB signaling cascade

Acute lung injury (ALI) that develops as a result of AP can progress to acute respiratory distress syndrome. Some hypotheses are proposed to explain the pathophysiology of AP and its related pulmonary hazards. This experiment aimed to evaluate the mitigating action of rivastigmine (Riva) in lung injury that occurs on the top of acute pancreatitis (AP) induced in rats. Thirty-two male Wister rats were randomized to one of four groups: control, Riva-treated, acute pancreatitis (AP), and acute pancreatitis treated by Riva. Serum amylase and lipase levels were assessed. Pulmonary oxidative stress and inflammatory indicators were estimated. A pancreatic and pulmonary histopathological examination, as well as an immunohistochemical study of HSP70, was carried out. Riva significantly attenuated the L-arginine-related lung injury that was characterized by increased pulmonary inflammatory biomarkers (interleukin-6 [IL-6]), nuclear factor kappa B (NF-κB), tumor necrosis factor-α (TNF-α), increased pulmonary oxidative markers (total nitrite/nitrate [NOx]), MDA, decreased total antioxidant capacity (TAC), and reduced glutathione level (GSH)) with increased caspase-3 expression. Therefore, Riva retains potent ameliorative effects against lung injury that occur on the top of AP by relieving oxidative stress, inflammation, and apoptosis via HSP70/IL6/NF-κB signaling.