Cancer continues to be a predominant cause of mortality globally, with chemotherapy serving as a pivotal component in its management (Alhowail, 2025; Alsaud et al., 2023). Among chemotherapeutic agents, cisplatin (CIS) is extensively utilized due to its efficacy against solid tumors, including those in testicular, ovarian, and lung cancers. Nevertheless, its clinical application is considerably limited by severe dose-dependent toxicities, primarily affecting the liver, kidneys, and heart (Aldubayan, 2025b; Alotayk et al., 2023). CIS induces toxic effects across various tissues, manifesting as ototoxicity (75%–100%), nephrotoxicity (72%) (Bunel et al., 2017), hepatotoxicity (36%) (Al-Malki and Sayed, 2014), and cardiotoxicity (6%) (Hu et al., 2018). Hepatotoxicity associated with CIS administration remains a critical clinical issue, as hepatic dysfunction can impair drug metabolism, intensify systemic toxicity, and necessitate dose reduction or cessation of therapy. The mechanisms underlying cisplatin-induced hepatotoxicity are multifaceted, involving oxidative imbalance, inflammatory cascades, mitochondrial dysfunction, and apoptotic cell death within hepatocytes (Hassan et al., 2020; Wu et al., 2025).

Oxidative stress constitutes a fundamental and early event in cisplatin-induced hepatotoxicity, resulting from the excessive generation of reactive oxygen species (ROS) and the impairment of endogenous antioxidant defense mechanisms (Fathy et al., 2022). Cisplatin disrupts mitochondrial respiratory function and promotes electron leakage, leading to excessive ROS production and lipid peroxidation within hepatocyte membranes. This oxidative imbalance compromises cellular integrity, perturbs calcium homeostasis, and activates redox-sensitive signaling pathways, including inflammatory mediators and apoptotic cascades (Raouf et al., 2025). In hepatic tissue, sustained oxidative stress further exacerbates mitochondrial dysfunction and sensitizes hepatocytes to programmed cell death, thereby amplifying liver injury. Collectively, these processes underscore oxidative stress as a pivotal upstream mechanism that links cisplatin exposure to inflammation, apoptosis, and subsequent fibrotic remodeling in the liver (Man et al., 2020; Oliveira et al., 2024).

Apoptosis is a critical factor in the hepatocellular damage caused by CIS. The initiation of pro-apoptotic mediators, particularly caspase-3, marks a significant terminal stage in the apoptotic process, leading to DNA fragmentation and disruption of membrane integrity (Lu and Cederbaum, 2006; Taghizadeh et al., 2021; Wu et al., 2025). Studies have shown that caspase-3 expression is elevated in liver tissues following CIS exposure, which is associated with extensive hepatocellular necrosis and impaired liver function (Bekhit et al., 2023; Lu and Cederbaum, 2006; Wu et al., 2025). Consequently, modulating apoptotic pathways, particularly by regulating caspase-3 activity, could be a viable strategy to reduce cisplatin-induced liver injury.

Beyond its involvement in apoptosis, nuclear receptor signaling plays a crucial role in maintaining hepatic homeostasis and mediating responses to xenobiotic injury. The Retinoid X Receptor-Alpha (RXR-α), a member of the nuclear receptor superfamily, functions as a transcriptional regulator by forming heterodimers with other nuclear receptors, including peroxisome proliferator-activated receptors and retinoic acid receptors. RXR-α is integral to various physiological functions, including lipid metabolism, inflammation, and cell survival (Gyamfi et al., 2008). Research has demonstrated that changes in RXR-α expression or activity are linked to hepatic inflammation and apoptosis. Restoring RXR-α signaling has been shown to confer hepatoprotective benefits in various toxic and inflammatory scenarios (Abdel-Bakky et al., 2021; Xu et al., 2024). Despite these findings, its specific contribution to cisplatin-induced liver injury remains poorly characterized.

The biochemical analysis of serum liver function markers is crucial for understanding the extent of hepatocellular damage and the liver’s metabolic capabilities. Elevated levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) are indicative of hepatocellular and biliary injury. In contrast, increased total bilirubin (TBIL) and lactate dehydrogenase (LDH) levels suggest compromised hepatic clearance and membrane integrity. On the other hand, decreased levels of total protein (TP) and albumin (ALB) point to a reduced synthetic capacity and overall hepatic dysfunction (Aubrecht et al., 2013; Thakur et al., 2024). These biomarkers collectively provide sensitive measures for evaluating cisplatin-induced hepatotoxicity and the effectiveness of potential hepatoprotective treatments (Bademci et al., 2021).

Sacubitril/valsartan (VS) represents a novel class of angiotensin receptor–neprilysin inhibitors, approved for the treatment of heart failure with reduced ejection fraction. While its cardiovascular benefits are well-established, emerging research highlights VS’s potential cytoprotective, antioxidative, anti-inflammatory, and anti-apoptotic effects across multiple organ systems (Pascual-Figal et al., 2021). Recent evidence suggests that VS confers protective effects by mitigating oxidative stress and restoring redox equilibrium, in addition to its anti-apoptotic properties. Experimental investigations have shown that VS diminishes oxidative damage and enhances antioxidant capacity in models of chemotherapy and ischemia-induced organ injury. This indicates that the modulation of oxidative stress may play a role in its cytoprotective effects (Mahmoud Refaie et al., 2023; Mohany et al., 2022).

Importantly, VS has been shown to alleviate CIS-induced cardiotoxicity by lowering caspase-3 expression and promoting redox balance in cardiac tissues (Mahmoud Refaie et al., 2023). Previous research has demonstrated that VS downregulates caspase-3 expression and restores the Bcl-2/Bax balance in diabetic kidney disease, thereby confirming its anti-apoptotic potential via the caspase-3/Bax/Bcl-2 axis (Mohany et al., 2022). These findings underscore VS’s ability to protect against chemotherapy-induced tissue injury by modulating apoptotic and inflammatory pathways. However, despite promising results in renal and cardiac models, the protective potential of VS against cisplatin-induced hepatic injury remains to be elucidated. Consequently, this study aims to examine the hepatoprotective effects of VS against CIS-induced hepatotoxicity in rats by assessing caspase-3-mediated apoptosis and RXR-α signaling pathways.

In conclusion, CIS-induced multi-organ toxicity poses a substantial challenge in oncological treatment, necessitating the development of effective protective strategies. VS, with its dual mechanisms of action, shows promise as a novel therapeutic intervention. This study aims to provide a comprehensive understanding of the protective effects of VS, offering new hope for patients undergoing chemotherapy based on CIS. This research could pave the way for its clinical application as an adjunct therapy to mitigate CIS-induced toxicity.

In this study, we evaluated the efficacy of VS treatment in alleviating CIS-induced hepatotoxicity in rats through comprehensive in vivo experiments that included assessment of hematologic and liver function biomarkers. Furthermore, we investigated the mechanisms underlying VS-mediated mitigation of CIS-induced hepatotoxicity, with a particular focus on modulation of anti-apoptotic pathways and regulation of RXR-α protein expression in rat liver tissues. Rats subjected to CIS treatment exhibited a 30% survival mortality rate by day 10. In contrast, the CIS co-administration with VS reduced mortality to 10%, compared to 0% in the VS-treated alone and control groups. There was a reduction in final body weight compared to the control group. This observation is consistent with previous research, which indicates that although rats resumed weight gain after cessation of CIS treatment, their overall growth rate remained lower than that of control rats (Mokhtar et al., 2021). Cisplatin administration is commonly associated with weight loss, primarily due to its emetogenic effects, which lead to reduced appetite, gastrointestinal toxicity, and diarrhea (He et al., 2023). The administration of VS increased body weight, potentially attributable to its anti-apoptotic properties.

The present study demonstrated that the administration of CIS in rats resulted in significant hepatic injury, as evidenced by both histopathological alterations and elevated biochemical markers indicative of liver dysfunction. Notably, VS treatment substantially ameliorated these deleterious effects, suggesting a hepatoprotective effect mediated through anti-oxidative and anti-apoptotic mechanisms. Histological analysis with H&E staining revealed that CIS induced significant hepatic damage, predominantly affecting the pericentral and midzonal regions. This damage was characterized by sinusoidal congestion, vacuolar degeneration, disruption of hepatic cords, and hepatocellular necrosis. The current findings are consistent with previous studies showing that cisplatin preferentially damages centrilobular hepatocytes, which contain high levels of cytochrome P450, making them more vulnerable to oxidative stress (Abdel-Daim et al., 2019; Palipoch et al., 2014).

Mason trichrome staining revealed further evidence of increased collagen deposition around the central vein and sinusoidal spaces, indicative of early fibrotic remodeling driven by HSC activation (Bataller and Brenner, 2005; Hassan et al., 2020). In contrast, the co-administration of VS with CIS significantly enhanced hepatic architecture, reduced congestion, and minimized necrosis. Additionally, collagen accumulation was substantially diminished in the VS + CIS group, indicating a suppression of extracellular matrix deposition and inhibition of HSC activation. These findings suggest that VS mitigates CIS-induced liver fibrosis, potentially through the modulation of the angiotensin II and TGF-β/Smad pathways, both of which are recognized mediators of stellate cell-driven fibrogenesis (An et al., 2024; Suzuki et al., 2023; Zhang et al., 2021). Angiotensin II (Ang II) plays a crucial role in the development of cisplatin-induced hepatotoxicity and fibrogenesis. While traditionally recognized for its vasoactive properties, Ang II also acts as a significant pro-oxidant, pro-inflammatory, and pro-fibrotic agent in liver tissue (Bataller et al., 2000). Cisplatin exposure has been shown to activate the hepatic renin–angiotensin system, thereby increasing Ang II signaling. This activation results in the generation of reactive oxygen species via NADPH oxidase, activation of NF-κB, and the release of pro-inflammatory cytokines, thereby worsening liver cell damage (Bataller et al., 2000; Macêdo et al., 2014; Ozkok and Edelstein, 2014). Additionally, Ang II directly triggers hepatocyte apoptosis through mitochondrial dysfunction and caspase-3 activation. It also promotes the activation of hepatic stellate cells and the deposition of extracellular matrix via the TGF-β/Smad signaling pathway, thereby accelerating fibrotic changes (Bataller and Brenner, 2005; Dewidar et al., 2019). Sacubitril/valsartan mitigates these pathological mechanisms through complementary pharmacological actions. Valsartan inhibits the binding of Ang II to the AT₁ receptor, thereby reducing Ang II-mediated oxidative stress, inflammatory signaling, apoptosis, and stellate cell activation. Simultaneously, sacubitril inhibits neprilysin, leading to increased circulating and local natriuretic peptide levels, which exert anti-inflammatory, anti-apoptotic, and anti-fibrotic effects in hepatic tissue (Suzuki et al., 2023). The combined suppression of Ang II–driven injury pathways and enhancement of protective natriuretic peptide signaling provides a mechanistic basis for the observed reduction in caspase-3 activation, attenuation of collagen deposition, and preservation of hepatic architecture in the VS + CIS group.

Oxidative stress represents a pivotal early mechanism in cisplatin-induced hepatotoxicity and serves as a critical trigger for subsequent apoptotic and fibrotic responses (Aboraya et al., 2022). In the present study, CIS administration markedly increased hepatic ROS generation and MDA levels, indicating excessive oxidative burden and enhanced lipid peroxidation. These findings are consistent with previous reports demonstrating that cisplatin disrupts hepatic redox homeostasis by promoting ROS overproduction and membrane lipid damage, thereby exacerbating hepatocellular injury (Abdel-Daim et al., 2019; Aboraya et al., 2022). Importantly, co-treatment with the VS significantly attenuated the CIS-induced elevation of ROS and MDA, indicating partial restoration of hepatic redox balance. This antioxidative effect of VS likely contributes to the observed preservation of hepatic architecture, suppression of caspase-3–mediated apoptosis, and attenuation of extracellular matrix deposition. Collectively, these results suggest that modulation of oxidative stress constitutes a potential mechanism underlying the hepatoprotective effects of VS against cisplatin-induced liver injury.

Beyond the oxidative stress effect, immunofluorescence analysis demonstrated pronounced expression of c-caspase-3 in pericentral hepatocytes and HSCs of rats administered CIS, indicating activation of apoptotic mechanisms. This observation is consistent with previous research, which has shown that CIS induces apoptosis in hepatocytes by disrupting the mitochondrial Bax/Bcl-2 equilibrium and activating caspase-3 (Hassan et al., 2020). In contrast, the combined treatment with VS and CIS significantly reduced c-caspase-3 expression, suggesting that VS inhibits caspase-dependent apoptosis. This anti-apoptotic effect of VS has been previously documented in cardiac and renal models of cisplatin toxicity, in which VS downregulated caspase-3 by suppressing NF-κB (Mahmoud Refaie et al., 2023; Mohany et al., 2022; Yadav, 2015). Therefore, the hepatoprotective effect observed in this study likely involves similar molecular signaling mechanisms.

In addition to its anti-apoptotic effects, VS may also help preserve RXR-α expression in hepatocytes and hepatic stellate cells. RXR-α is a critical nuclear receptor that forms heterodimers with PPARs, LXRs, and FXRs to regulate lipid metabolism, detoxification, and hepatocyte survival (Xu et al., 2024). Previous study reported that depletion of RAR-α and RXR-α was accompanied by enhanced caspase-3–dependent apoptosis in N-acetyl-p-aminophenol-induced liver injury, demonstrating a direct association between retinoid receptor loss and apoptotic signaling (Abdel-Bakky et al., 2021). In line with these findings, the partial restoration of RXR-α expression observed in the VS + CIS group suggests that VS may help maintain retinoid receptor integrity, thereby limiting caspase-3–mediated apoptosis and contributing to overall hepatocellular protection.

The biochemical modifications identified in this study provide additional support for the histopathological and molecular observations. The administration of CIS resulted in pronounced elevations in AST, ALT, ALP, TBIL, and LDH, along with significant reductions in total TP and ALB. These biochemical parameters serve as indicators of hepatocellular injury, cholestasis, and impaired hepatic synthetic function (Abd Rashid et al., 2021; Palipoch and Punsawad, 2013). It is crucial to recognize that serum albumin and total protein have relatively long half-lives, approximately 19–21 days. As a result, the reductions observed during this short-term experimental period may not exclusively reflect a compromised hepatic synthetic capacity (Levitt and Levitt, 2016). Additionally, cisplatin-induced nephrotoxicity has been shown to increase urinary protein loss, which may contribute to the observed decrease in circulating protein levels (Alharbi and Aldubayan, 2025; Levitt and Levitt, 2016; Ozkok and Edelstein, 2014). Therefore, the reductions in total protein and albumin in this study should be interpreted as systemic effects of cisplatin-induced toxicity rather than isolated signs of hepatic synthetic dysfunction. These modifications are consistent with prior research indicating that it reduces TP and ALB levels following cisplatin administration, indicative of membrane leakage and hepatocyte necrosis (Palipoch and Punsawad, 2013; Yadav, 2015). Notably, the co-administration of VS successfully restored these biochemical parameters to normal levels, indicating a potential protective role in maintaining hepatocellular integrity and metabolic function. This positive outcome is consistent with the observed preservation of hepatic architecture and the decreased caspase-3 expression in the VS + CIS group. Additionally, the simultaneous restoration of RXR-α expression in hepatocytes suggests that VS may enhance nuclear receptor–mediated regulatory pathways, which are crucial for liver function and cell survival, thereby augmenting its hepatoprotective potential.

A key strength of this study is its novel demonstration of the hepatoprotective effects of VS in mitigating CIS-induced hepatotoxicity. The study offers novel mechanistic insights into the anti-apoptotic effects of VS, as evidenced by histopathological, biochemical, and immunofluorescence analyses that show reduced caspase-3 activation and partial restoration of RXR-α expression. This comprehensive evaluation reinforces the causal relationship between VS treatment and protection against apoptosis-mediated hepatic injury. However, several limitations of this study warrant acknowledgment. The investigation primarily concentrated on apoptotic markers, omitting the assessment of oxidative stress and inflammatory mediators, which are also critical contributors to CIS-induced liver injury. Furthermore, the absence of a valsartan-only treatment group precludes distinguishing the specific effects of valsartan from the combined actions of VS. Future research should incorporate these parameters, alongside molecular signaling analyses, to comprehensively elucidate the mechanistic basis and clinical potential of VS for hepatic protection. In addition, although the current findings indicate a strong association between VS treatment and reduced caspase-3 activation, the causal role of caspase-3 inhibition was not confirmed using selective caspase-3 inhibitors or activators. Furthermore, other significant molecular contributors to cisplatin-induced liver injury, such as NF-κB-mediated inflammatory signaling and the TGF-β/Smad pathway, were not directly assessed. These pathways are well recognized for their roles in regulating cytokine production, hepatic stellate cell activation, and extracellular matrix deposition during cisplatin-induced hepatotoxicity (Gazwi et al., 2024). Although the 10-day experimental duration is adequate to induce acute cisplatin-related liver injury (Eisa et al., 2021; Gholampour et al., 2022) and to demonstrate the hepatoprotective effects of VS, as short-term VS administration has been shown to attenuate apoptosis, inflammation, and fibrotic responses in experimental models of drug combination in an organ-toxicity model (Elemam et al., 2025; Mahmoud Refaie et al., 2023), longer-term studies are necessary to evaluate chronic hepatic outcomes and the sustained hepatoprotective effects of VS, thus warranting further investigation in future studies.

In conclusion, the administration of CIS led to notable structural and biochemical changes in the liver, characterized by significant hepatocellular damage, increased liver enzyme activities, enhanced caspase-3-mediated apoptosis, and decreased RXR-α expression. Co-treatment with VS significantly alleviated these detrimental effects, improving liver architecture, normalizing biochemical parameters, and partially restoring RXR-α expression. Collectively, these findings indicate that VS exerts hepatoprotective effects primarily through its anti-apoptotic action and modulation of RXR-α–associated survival signaling, suggesting its potential as an adjunctive agent against CIS-induced hepatotoxicity.