Cardioprotective effects of sodium thiosulfate against doxorubicin-induced cardiotoxicity in male rats

Thiosulphate sulfurtransferase: Biological roles and therapeutic potential

Mitochondria are central to eukaryotic cell function, driving energy production, intermediary metabolism, and cellular homeostasis. Dysregulation of mitochondrial function often results in oxidative stress, a hallmark of numerous diseases, underscoring the critical need for maintaining mitochondrial integrity. Among mitochondrial enzymes, thiosulfate sulfurtransferase (TST) has emerged as a key regulator of sulfur metabolism, redox balance, and Fe-S protein maintenance. Beyond its well-known role in cyanide detoxification, TST facilitates hydrogen sulfide (H2S) metabolism by catalyzing the transfer of sulfur from persulfides (R-SSH) to thiosulfate (S2O32-), promoting H2S oxidation and preventing its toxic accumulation. Additionally, TST contributes to the thiol-dependent antioxidant system by regulating reactive sulfur species and sustaining mitochondrial functionality through its role in sulfide-driven bioenergetics. This review highlights the biochemical and therapeutic significance of TST in mitochondrial and cellular health, emphasizing its protective roles in diseases associated with oxidative stress and mitochondrial dysfunction. Dysregulation of TST has been implicated in diverse pathologies, including specific metabolic disorders, neurological diseases, cardiovascular conditions, kidney dysfunction, inflammatory bowel disease, and cancer. These associations underline TST's potential as a biomarker and therapeutic target. Therapeutic strategies to activate the TST pathway are explored, with a focus on sodium thiosulfate (STS), novel small molecule (Hit 2), and recombinant hTST protein. STS, an FDA-approved compound, has demonstrated antioxidant and anti-inflammatory effects across multiple preclinical models, mitigating oxidative damage and improving mitochondrial integrity. A slow-release oral formulation of STS is under development, offering promise for expanding its clinical applications. Small molecule activators like Hit 2 and hTST protein have shown efficacy in enhancing mitochondrial respiration and reducing oxidative stress, though both reagents need further in vitro and in vivo investigations. Despite promising advancements, TST-based therapies remain underexplored. Future research should focus on leveraging TST's interplay with pathways like NRF2 signaling, investigating its broader protective roles in cellular health, and developing targeted interventions. Enhancing TST activity represents an innovative therapeutic approach for addressing mitochondrial dysfunction, oxidative stress, and their associated pathologies, offering new hope for the treatment of diseases associated with mitochondrial dysfunction.

Cardioprotective effect of chelidonic acid against doxorubicin-induced cardiac toxicity in rats

INTRODUCTION AND OBJECTIVES

The current study evaluates the effect of chelidonic acid on doxorubicin-induced cardiac toxicity. Chelidonic acid (CA) is a natural pyran-skeleton heterocyclic compound found in rhizomes of the perennial plant, celandine (Chelidonium majus).

METHODS

Wistar rats were given an intraperitoneal injection of doxorubicin (1.25 mg/kg, cumulative dose of 20 mg/kg) four times per week for a duration of four weeks to induce cardiotoxicity. CA treatment (10, 20, and 40 mg/kg orally for four weeks) was started together with doxorubicin.

RESULTS

CA treatment reduced myocardial damage and improved cardiac dysfunction in doxorubicin-treated rats. It improved blood pressure, restored ST wave height and normalized the QTc interval compared to the rats treated only with doxorubicin. Administration of CA for four weeks reduced left ventricular end-diastolic pressure. Moreover, CA treatment decreased the level of cardiac markers such as creatine kinase-myocardial band (CK-MB), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and cardiac troponin-T. Masson's trichrome, hematoxylin, and eosin staining of heart tissue revealed that CA attenuated the deleterious effects of doxorubicin and prevented further damage and fibrosis in rats.

CONCLUSION

The study findings confirm that CA treatment can protect the myocardium against doxorubicin-induced cardiotoxicity.

Doxorubicin and cyclophosphamide mode of chemotherapy-related cardiomyopathy: Review of preclinical model

Over the past 70 years, there has been extensive research focused on preventing chemotherapy-related cardiovascular complications. However, the current state of cardio-oncology research has raised more questions than answers. Experimental studies often present data that are difficult to compare and, at times, contradictory. One notable limitation in translating experimental findings to clinical practice is the reliance on models that administer only one chemotherapeutic drug to experimental animals, despite the common use of multidrug cancer treatments in real clinical settings. This article aims to discuss our own experience in modeling an experimental rat model of cardiomyopathy induced by the administration of two chemotherapeutic drugs, doxorubicin (adriamycin) and cyclophosphamide (AC mode of chemotherapy) - Avagimyan A., et al model, along with a subsequent review of morphological changes based on our personal archive.

Increased ROS levels, antioxidant defense disturbances and bioenergetic disruption induced by thiosulfate administration in the brain of neonatal rats

Sulfite oxidase deficiencies, either caused by deficiency of the apoenzyme or the molybdenum cofactor, and ethylmalonic encephalopathy are inherited disorders that impact sulfur metabolism. These patients present with severe neurodeterioration accompanied by cerebral cortex and cerebellum abnormalities, and high thiosulfate levels in plasma and tissues, including the brain. We aimed to clarify the mechanisms of such abnormalities, so we assessed the ex vivo effects of thiosulfate administration on energetic status and oxidative stress markers in cortical and cerebellar tissues of newborn rats. Thiosulfate (0.5 µmol/g) or PBS (vehicle) was injected into the fourth ventricle of rat pups. Thirty minutes after the injection, animals were euthanized and the brain structures were utilized for the experiments. Our data showed that thiosulfate decreased the reduced glutathione (GSH) concentrations, and superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST) activities in the cortical structure. Thiosulfate also increased DCFH oxidation, hydrogen peroxide generation and glutathione reductase activity. In the cerebellum, thiosulfate reduced SOD and glutathione peroxidase activities but increased GST and CAT activities as well as DCFH oxidation. Regarding energy metabolism, thiosulfate specifically decreased complex IV activity in the cortex, whereas it increased cerebellar complex I and creatine kinase activities, indicating bioenergetic disturbances. The results suggest that the accumulation of thiosulfate causing redox disruption and bioenergetic alterations has a prominent role in the pathogenesis of sulfur metabolism deficiencies.

Anethole alleviates Doxorubicin-induced cardiac and renal toxicities: Insights from network pharmacology and animal studies

Doxorubicin (Dox) is widely used as a chemotherapy drug, while anethole (AN) is primarily known as the main aromatic component in various plant species. This research focused on the impact of AN on the cardiac and renal toxicity induced by Dox and to understand the underlying mechanisms. For cardiac toxicity, Wistar rats were categorized into four groups: a Control group; a Dox group, where rats received 2.5 mg/kg of Dox intraperitoneally every other day; and two Dox + AN groups, where animals were administered Dox (2.5 mg/kg/every other day, IP) along with 125 mg/kg or 250 mg/kg of AN, respectively. The renal toxicity study included similar groups, with the Dox group receiving a single dose of 20 mg/kg of Dox intraperitoneally on the tenth day, and the Dox + AN groups receiving 125 mg/kg and 250 mg/kg of AN for two weeks, alongside the same dose of Dox (20 mg/kg, IP, once on the 10th day). Parameters assessed included ECG, cardiac injury markers (CK, CK-MB, and LDH), and kidney function tests (Cr, BUN, uric acid, LDL, Kim-1, NGAL, and CysC). Antioxidant activity, lipid peroxidation, inflammation, and apoptotic markers were also monitored in heart and renal tissues. Gene expression levels of the TLR4/MyD88/NFκB pathway, along with Bax and Bcl-2, were evaluated. Dox significantly altered ECG, elevated cardiac injury markers, and renal function markers. It also augmented gene expressions of TLR4/MyD88/NFκB, amplified oxidative stress, inflammatory cytokines and apoptotic markers. Conversely, AN reduced cardiac injury markers and kidney function tests, improved ECG, diminished TLR4/MyD88/NFκB gene expression, and alleviated oxidative stress by increasing antioxidant enzyme activities and reducing inflammatory cytokines. AN also enhanced Bcl-2 levels and inhibited Bax and the cleavage of caspase-3 and 9. AN countered the lipid peroxidation, oxidative stress, inflammation, and apoptosis induced by Dox, marking it as a potential preventive strategy against Dox-induced nephrotoxic and cardiotoxic injuries.

Rifampicin efficacy against doxorubicin-induced cardiotoxicity in mice

BACKGROUND

The toxic effect of doxorubicin on the heart limits its clinical usage in cancer therapy. This work intended to investigate, for the first time, the efficacy of rifampicin administration against doxorubicin-induction of cardiotoxicity in mice. Forty adult male albino mice were distributed into four sets: Control, Doxorubicin, Doxorubicin + Rifampicin 0.107, and Doxorubicin + Rifampicin 0.214, with n = 10 for each. Heart histopathology and biochemical assays for heart function tests [creatine kinase (CK), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), cardiac troponin I (cTnI), atrial natriuretic peptide (ANP), and vascular endothelial growth factor (VEGF)], oxidative stress [malondialdehyde (MDA) and superoxide dismutase (SOD)], and minerals [phosphorus, sodium, potassium, and calcium] were done.

RESULTS

Doxorubicin-induced cardiotoxicity using a total dose of 15 mg/kg was confirmed histologically. Cardiomyocytes showed congestion, necrosis, edema, and inflammatory cell infiltration. Biochemically, elevations in LDH, CK, and AST activities, p < 0.001, as well as increases in cTnI and ANP levels, p < 0.001, increased oxidative stress (MDA, p < 0.001), high minerals (Na, K, p < 0.001, P, p < 0.01, and Ca, p < 0.05), with reduced VEGF concentration, p < 0.001, and low antioxidant (SOD, p < 0.001) were observed in the Doxorubicin group compared to control. Co-treatment with rifampicin significantly (p < 0.001) reduced the increased oxidative stress, high Na and K, increased LDH, CK, AST, cTnI, and ANP, and elevated the low SOD toward the normal ranges. Our histological data supported our biochemical data; rifampicin dose 0.214 mg/kg showed better improvements than dose 0107.

CONCLUSIONS

Our results demonstrated that rifampicin could help protect the body against doxorubicin-induced cardiotoxicity through its antioxidative effect.