L-carnitine reverses methotrexate-induced nephrotoxicity in experimental rat model: Insight on SIRT1/PGC-1α/Nrf2/HO-1 axis

Sitagliptin exhibits protective effects against methotrexate-induced testicular toxicity: The involvement of oxidative stress-related factors

Methotrexate (MTX) is widely prescribed to treat different malignancies as well as autoimmune diseases. However, it causes a range of side effects in different organs such as testis. This study aims to clarify the role of dipeptidyl peptidase 4 (DPP4) in MTX-induced testicular damage via pathways involved in oxidative stress and evaluates the protective effects of sitagliptin as a DPP4 inhibitor. Twenty-four animals randomly allocated into four groups including: (I) control, (II) MTX (20 mg/kg, i.p.), (III) sitagliptin (20 mg/kg, i.p., for four consecutive days), and MTX + sitagliptin in which received chemicals resembling group II and III. Histopathological examinations conducted to assess the structural changes in testes of different experimental groups. Also, ELISA method employed to investigate the levels of DPP4, AKT, p-AKT, nuclear factor erythroid 2-related factor 2 (Nrf2), and heme oxygenase-1 (HO-1). In addition, the total malondialdehyde (MDA) content and the activity of superoxide dismutase (SOD) were assessed. The results indicated that MTX administration was accompanied with testicular damage, which reversed by sitagliptin treatment. The biochemical observations demonstrated that MTX markedly increased the levels of DPP4, decreased p-AKT/AKT ratio followed by a marked decrement in Nrf2 and HO-1 levels. Also, it was observed that MTX decreased the activity of SOD and increased total MDA content in testicular specimen. However, sitagliptin treatment diminished mentioned alterations effectively. Altogether, our findings supported the possible role of DPP4 in MTX-induced testicular toxicity along with the potential protective features of sitagliptin via suppressing of the histopathological and biochemical alterations induced by MTX.

Redox signaling and skeletal muscle adaptation during aerobic exercise

Redox regulation is a fundamental physiological phenomenon related to oxygen-dependent metabolism, and skeletal muscle is mainly regarded as a primary site for oxidative phosphorylation. Several studies have revealed the importance of reactive oxygen and nitrogen species (RONS) in the signaling process relating to muscle adaptation during exercise. To date, improving knowledge of redox signaling in modulating exercise adaptation has been the subject of comprehensive work and scientific inquiry. The primary aim of this review is to elucidate the molecular and biochemical pathways aligned to RONS as activators of skeletal muscle adaptation and to further identify the interconnecting mechanisms controlling redox balance. We also discuss the RONS-mediated pathways during the muscle adaptive process, including mitochondrial biogenesis, muscle remodeling, vascular angiogenesis, neuron regeneration, and the role of exogenous antioxidants.

Targeting oxidative stress with natural products: A novel strategy for esophageal cancer therapy

Esophageal cancer (ESC) is a malignant tumor that originates from the mucosal epithelium of the esophagus and is part of the digestive tract. Although the exact pathogenesis of ESC has not been fully elucidated, excessive oxidative stress is an important characteristic that leads to the development of many cancers. Abnormal expression of several proteins and transcription factors contributes to oxidative stress in ESCs, which alters the growth and proliferation of ESCs and promotes their metastasis. Natural compounds, including alkaloids, terpenes, polyphenols, and xanthine compounds, can inhibit reactive oxygen species production in ESCs. These compounds reduce oxidative stress levels and subsequently inhibit the occurrence and progression of ESC through the regulation of targets and pathways such as the cytokine interleukins 6 and 10, superoxide dismutase, the NF-+ACY-kappa+ADs-B/MAPK pathway, and the mammalian Nrf2/ARE target pathway. Thus, targeting tumor oxidative stress has become a key focus in anti-ESC therapy. This review discusses the potential of Natural products (NPs) for treating ESCs and summarizes the application prospects of oxidative stress as a new target for ESC treatment. The findings of this review provide a reference for drug development targeting ESCs. Nonetheless, further high-quality studies will be necessary to determine the clinical efficacy of these various NPs.

The Impact of the High-Fructose Corn Syrup on Cardiac Damage via SIRT1/PGC1-α Pathway: Potential Ameliorative Effect of Selenium

High-fructose corn syrup (HFCS) has been a subject of intense debate due to its association with cardiovascular risks. This study investigates the potential protective effects of selenium (Se) supplementation against cardiac damage induced by HFCS. Thirty-two male Wistar albino rats were divided into four equal groups: control, CS (20%-HFCS), CS with Se (20%-HFCS, 0.3 mg/kg-Se), and Se (0.3 mg/kg-Se) only. After a 6-week period, heart and aorta tissues were collected for histopathological, immunohistochemical, biochemical, and genetic analyses. HFCS consumption led to severe cardiac pathologies, increased oxidative stress, and altered gene expressions associated with inflammation, apoptosis, and antioxidant defenses. In the CS group, pronounced oxidative stress within the cardiac tissue was concomitant with elevated Bcl-2-associated X protein (Bax) expression and diminished expressions of B-cell-lymphoma-2 (Bcl-2), nuclear factor erythroid 2-related factor 2 (Nrf2), peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1-α), and silenced information regulator 1 (SIRT1). Se supplementation mitigated these effects, showing protective properties. Immunohistochemical analysis supported these findings, demonstrating decreased expressions of caspase-3, tumor necrosis factor-alpha (TNF-α), IL-1β, and vascular endothelial growth factor (VEGF) in the CS + Se group compared to the CS group. The study suggests that Se supplementation exerts anti-inflammatory, antioxidant, and antiapoptotic effects, potentially attenuating HFCS-induced cardiovascular toxicity. These findings highlight the importance of dietary considerations and selenium supplementation in mitigating cardiovascular risks associated with HFCS consumption.

Isoliquiritigenin inhibits apoptosis and ameliorates oxidative stress in rheumatoid arthritis chondrocytes through the Nrf2/HO-1-mediated pathway

Rheumatoid arthritis (RA) is a chronic inflammatory condition known for its irreversible destructive impact on the joints. Chondrocytes play a pivotal role in the production and maintenance of the cartilage matrix. However, the presence of inflammatory cytokines can hinder chondrocyte proliferation and promote apoptosis. Isoliquiritigenin (ISL), a flavonoid, potentially exerts protective effects against various inflammatory diseases. However, its specific role in regulating the nuclear factor E2-associated factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway in chondrocytes in RA remains unclear. To investigate this, this study used human chondrocytes and Sprague-Dawley rats to construct in vitro and in vivo RA models, respectively. The study findings reveal that cytokines markedly induced oxidative stress, the activation of matrix metalloproteinases, and apoptosis both in vitro and in vivo. Notably, ISL treatment significantly mitigated these effects. Moreover, Nrf2 or HO-1 inhibitors reversed the protective effects of ISL, attenuated the expression of Nrf2/HO-1 and peroxisome proliferator-activated receptor gamma-coactivator-1α, and promoted chondrocyte apoptosis. This finding indicates that ISL primarily targets the Nrf2/HO-1 pathway in RA chondrocytes. Moreover, ISL treatment led to improved behavior scores, reduced paw thickness, and mitigated joint damage as well as ameliorated oxidative stress in skeletal muscles in an RA rat model. In conclusion, this study highlights the pivotal role of the Nrf2/HO-1 pathway in the protective effects of ISL and demonstrates the potential of ISL as a treatment option for RA.

Infliximab Ameliorates Methotrexate-Induced Nephrotoxicity in Experimental Rat Model: Impact on Oxidative Stress, Mitochondrial Biogenesis, Apoptotic and Autophagic Machineries

Accumulating data confirms that Methotrexate (MTX), a well-known immunosuppressive and anticancer drug, causes nephrotoxicity. Infliximab (INF), the inhibitor of tumor necrosis factor-alpha (TNF-α), was proven to have anti-inflammatory properties. Thus, it may have potential in preventing MTX-induced nephrotoxicity. Therefore, this study aimed to inspect the prospective nephroprotective effect of INF on MTX-induced rat nephrotoxicity through investigating the possible molecular mechanisms, including its interference with different death routes, oxidative stress as well as mitochondrial biogenesis. Rats received an INF intraperitoneal single dose of 7 mg/kg 72 h prior to a single 20 mg/kg MTX injection. MTX nephrotoxicity was demonstrated by significantly increased serum levels of the renal indicators urea and creatinine as well as renal inflammatory markers TNF-α and Interleukin-6 (IL-6) and the renal oxidative stress marker malondialdehyde (MDA), while renal antioxidant enzyme superoxide dismutase (SOD) was significantly decreased compared to control. INF injection prior to MTX markedly reversed these MTX-induced effects. Besides, MTX impaired mitochondrial biogenesis, while INF attenuated this impairment, as indicated by increased expression of peroxisome proliferator-activated receptor-γ coactivator-1α (PGC-1α). Finally, MTX triggered apoptotic and autophagic cascades in renal tissues as evidenced by reduced anti-apoptotic Bcl-2 protein expression as well as elevated expression of the pro-apoptotic protein Bax and both key regulators of autophagy; beclin-1 and LC-3, whereas INF pretreatment counteracted these apoptotic and autophagic effects of MTX. Summarily, these results suggest that INF provides protection against MTX-induced nephrotoxicity which could be elucidated by its antioxidant, anti-inflammatory, anti-apoptotic and anti-autophagic effects as well as upregulating mitochondrial biogenesis.

Redox Regulation of Nrf2 in Cisplatin-Induced Kidney Injury

Cisplatin, a potent chemotherapeutic agent, is marred by severe nephrotoxicity that is governed by mechanisms involving oxidative stress, inflammation, and apoptosis pathways. The transcription factor Nrf2, pivotal in cellular defense against oxidative stress and inflammation, is the master regulator of the antioxidant response, upregulating antioxidants and cytoprotective genes under oxidative stress. This review discusses the mechanisms underlying chemotherapy-induced kidney injury, focusing on the role of Nrf2 in cancer therapy and its redox regulation in cisplatin-induced kidney injury. We also explore Nrf2's signaling pathways, post-translational modifications, and its involvement in autophagy, as well as examine redox-based strategies for modulating Nrf2 in cisplatin-induced kidney injury while considering the limitations and potential off-target effects of Nrf2 modulation. Understanding the redox regulation of Nrf2 in cisplatin-induced kidney injury holds significant promise for developing novel therapeutic interventions. This knowledge could provide valuable insights into potential strategies for mitigating the nephrotoxicity associated with cisplatin, ultimately enhancing the safety and efficacy of cancer treatment.