Ameliorative impact of sacubitril/valsartan on paraquat-induced acute lung injury: role of Nrf2 and TLR4/NF-κB signaling pathway

Herbicides such as paraquat (PQ) are frequently utilized particularly in developing nations. The present research concentrated on the pulmonary lesions triggered by PQ and the beneficial effect of the angiotensin receptor neprilysin inhibitor (ARNI), sacubitril/valsartan, against such pulmonary damage. Five groups of rats were established: control, ARNI, PQ (10 mg/kg), ARNI 68 + PQ, and ARNI 34 + PQ. Following euthanasia, lungs were isolated and subjected to a histopathological test, and the ELISA technique was used to evaluate oxidative stress biomarkers, toll-like receptor 4 (TLR4), nuclear factor erythroid 2-related factor 2 (Nrf2), phosphatidylinositol-3-kinase (PI3K), phosphorylated protein kinase B (p-AKT), and inflammatory markers: nuclear factor kappa B p65 subunit (NF-κB p65), tumor necrosis factor α (TNFα), and interleukin 1beta (IL-1β). In conjunction with abnormally high levels of malondialdehyde (MDA) and inducible nitric oxide synthase (iNOS), the PQ group also displayed low levels of reduced glutathione (GSH) and total antioxidant capacity (TAC). Additionally, TLR4, PI3K, and p-AKT were significantly elevated together with unusually low level of Nrf2. Moreover, inflammatory biomarkers, NF-κB p65, TNFα, and IL-1β, were abnormally elevated. Meanwhile, ARNI-treated groups reversed all alterations precipitated by PQ in a dose-dependent manner. ARNI could mitigate pulmonary damage triggered by PQ via potential antioxidant anti-inflammatory qualities.

Biochemical and molecular mechanisms of N-acetyl cysteine and silymarin-mediated protection against maneb- and paraquat-induced hepatotoxicity in rats

Oxidative stress is one of the major players in the pathogenesis of maneb (MB) and paraquat (PQ)-induced disorders. N-acetyl cysteine (NAC), a glutathione (GSH) precursor and silymarin (SIL), a naturally occurring antioxidant, encounter oxidative stress-mediated cellular damage. The present study was aimed to investigate the effects of NAC and SIL against MB and/or PQ-induced hepatotoxicity in rats. The levels of hepatotoxicity markers - alanine aminotransaminase (ALT), aspartate aminotransaminase (AST) and total bilirubin, histological changes, oxidative stress indices, phase I and phase II xenobiotic metabolizing enzymes - cytochrome P450 (CYP) and glutathione S-transferase (GST) and pro-inflammatory molecules - inducible nitric oxide synthase (iNOS), tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were measured in animals treated with MB and/or PQ in the presence or absence of NAC and SIL. MB and/or PQ augmented ALT, AST, total bilirubin, lipid peroxidation and nitrite contents and catalytic activities of superoxide dismutase and glutathione peroxidase however, the GSH content was attenuated. NAC and SIL restored the above-mentioned alterations towards basal levels but the restorations were more pronounced in SIL treated groups. Similarly, MB and/or PQ-mediated histopathological symptoms and changes in the catalytic activities/expressions of CYP1A2, CYP2E1, iNOS, TNF-α, and IL-1β were alleviated by NAC and SIL. Conversely, MB and/or PQ-induced GSTA4-4 expression/activity was further increased by NAC/SIL and glutathione reductase activity was also increased. The results obtained thus suggest that NAC and SIL protect MB and/or PQ-induced hepatotoxicity by reducing oxidative stress, inflammation and by modulating xenobitic metabolizing machinery and SIL seems to be more effective.