Sahar S. Alotaibi

Renal ischemia/reperfusion injury (RI/RI) is one of the major causes of acute kidney injury (AKI). Low molecular weight-dextran sulphate (LMW-DS) is a bioactive polysaccharide with anti-inflammatory and cytoprotective properties. This study investigated the nephroprotective potential of LMW-DS against the RI/RI. RI/RI rat model underwent surgery that involved a complete bilateral clamping of renal hila for 30 min, followed by unclamping for 30 min. LMW-DS (5 mg/kg, s.c.) was injected 5 min before unclamping. After 24 h, kidneys were collected for biochemical, histopathological, and immunohistochemical examinations. RI/RI dramatically induced renal deterioration, as reflected by marked elevation in the levels of renal oxidative stress, tumor necrosis factor-α, interleukin-6, and toll-like receptor-4, indicating lipid peroxidation and inflammatory response. Furthermore, RI/RI caused upregulation of kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin. Additionally, morphological alterations and collagen deposition were also detected in kidney tissues. The immunohistochemical analysis revealed a strong positive immunoreaction for p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, and caspase-3. Treatment with LMW-DS produced a pronounced amelioration in the altered parameters induced by RI/RI. In conclusion, LMW-DS exerts nephroprotective effects against RI/RI by restoring redox balance, suppressing inflammatory signaling, JNK/p38 MAPK, and caspase-3, highlighting its potential as a therapeutic strategy for renal I/R-induced AKI.

Background and Purpose: Methotrexate (MTX) is a widely used therapeutic agent for inflammatory and malignant diseases; however, its prolonged use is associated with hepatotoxicity through mechanisms that remain inadequately understood. This study aims to elucidate these mechanisms and assess the hepatoprotective potential of indole-3-acetic acid (IAA). Methods: Rats were allocated into five groups: control (group 1), IAA-treated (group 2), MTX-treated (group 3), quercetin (QUR) + MTX (group 4), and IAA + MTX (group 5). Hepatic function was assessed through the evaluation of serum liver enzymes, oxidative stress, and inflammatory and apoptotic markers using biochemical, molecular, histopathological, and immunohistochemical analyses. Results: The MTX-treated group demonstrated a significant increase in hepatic oxidative stress, inflammation, and apoptotic markers. Co-administration of IAA or QUR with MTX markedly reduced malondialdehyde (MDA) levels, while enhancing glutathione (GSH) levels and superoxide dismutase (SOD) activity. Moreover, hepatic inflammatory markers, including TNF-α, IL-6, and IL-1β, were significantly decreased in the IAA- and QUR-treated groups. Immunohistochemical analysis further revealed a reduced expression of NF-κB, TLR4, and caspase-3 in hepatic tissues following QUR-MTX or IAA-MTX treatments. Conclusions: IAA exhibited hepatoprotective effects against MTX-induced liver injury, comparable to QUR, by modulating the TLR4/NF-κB/caspase-3 pathway. These findings highlight its potential clinical application in reducing MTX-associated hepatic complications.