Ethanolamine as a cardioprotective agent in doxorubicin-induced cardiotoxicity

Introduction: Doxorubicin is an anthracycline chemotherapeutic drug prescribed to approximately 50% of paediatric cancer patients as it effectively treats a wide range of tumours. However, like most anticancer drugs, it is associated with debilitating side effects, including cardiotoxicity. Ethanolamine has previously been shown to protect the isolated heart against ischaemia-reperfusion injury, however, its use as a cardioprotective agent against doxorubicin-induced cardiotoxicity has not been assessed. Therefore, in this study, we investigate the effects of ethanolamine on doxorubicin-induced cardiotoxicity. Methods: This study aimed to evaluate the effect of ethanolamine in different in vitro and in vivo models of doxorubicin-induced cardiotoxicity. The dose-dependent effects of ethanolamine (3 μM-300 mM) on doxorubicin (5 μM or 10 μM)-induced cytotoxicity were determined in H9c2 cardiomyoblasts, isolated murine cardiomyocytes and H9c2/3T3 coculture. Metabolic activity and cell viability were determined using MTT and LDH assays for H9c2, fibroblasts and coculture experiments, and trypan blue exclusion and LDH assays in murine cardiomyocytes. Apoptotic activity was measured in cardiomyocytes and coculture studies. Coculture experiments tested whether ethanolamine protected cardiac cells by causing release of factors from fibroblasts, using H9c2 cocultured with H9c2s as a negative control. Doses of 1.6, 16, and 160 mg/kg ethanolamine were used to treat male and female C57/Bl6 mice exposed to acute (one dose of 20 mg/kg doxorubicin) or chronic (3 doses of 6mg/kg doxorubicin administered once per week for 3 weeks) treatment. After 1 week (acute) or 6 weeks (chronic) of treatment, cardiac biomarkers, and cardiac histology were assessed in all animals. Statistical significance was determined using one-way ANOVA followed by Dunnett’s post hoc test. Where two factors had to be considered, a two-way ANOVA followed by Dunnett’s post hoc was used. Differences in non-parametric data were analysed using the Kruskal-Wallis test followed by Dunn’s multiple comparisons test. A p-value of < 0.05 was seen to be statistically significant. Results: Ethanolamine did not mitigate the effects of doxorubicin on H9c2 cells in monoculture or primary cardiomyocytes. In co-culture, 3 µM ethanolamine increased metabolic activity (782.15±432.08%) compared to doxorubicin alone (69.72±10.99%; 10p=0.0206). However, there were no differences in metabolic activity between control and doxorubicin-only groups. Doxorubicin alone did not cause significant changes in weight, heart rate, BNP and troponin levels, ventricular width, or immune cell score in our in vivo models of acute and chronic doxorubicin-induced cardiotoxicity. Ethanolamine also did not affect weight, heart rate, troponin levels or ventricular width in either model of DCT, and BNP levels or immune cell score in the acute model. However, pretreatment with 16 mg/kg ethanolamine increased serum levels of BNP (161.2±31.52 pg/mL) compared to doxorubicin alone (86.42±13.02 pg/mL; p=0.0099). When separated by sex, this increase was only seen in female animals. Additionally, pretreatment with 160 mg/kg ethanolamine decreased the immune cell score (0.17±0.05) compared to 6 mg/kg doxorubicin alone (0.30±0.06; p=0.0439). Conclusion: High doses of ethanolamine increased biomarkers of cardiac damage in the chronic model of doxorubicin-induced cardiotoxicity and reduced the presence of inflammatory cells. This suggests complex interactions between ethanolamine treatment, cardiac metabolism, and immune responses during cardiac distress. The lack of an effect of doxorubicin in acute and chronic models highlights the need to include more precise measurements of cardiac function and histological analysis to fully characterise cardiac damage. Our findings suggest ethanolamine is unlikely to be an effective therapy for doxorubicin-induced cardiotoxicity and may increase cardiac damage. This study highlights the necessity for further research to determine whether ethanolamine in the diet poses a risk to doxorubicin-treated patients.

Grantor dc:publisher

University College Cork

Year dc:date.issued

2025

Author dc:creator

• Victory, Réalta

Advisors dc:contributor.advisor

• Kelly, Roisin
• Barry, Orla P.

• Cardiotoxicity
• Doxorubicin
• Ethanolamine
• Cancer
• Cardioprotection

Statement dc:rights

• © 2025, Réalta Victory.

Licence dc:rights.uri

• https://creativecommons.org/licenses/by/4.0/

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10468/18469

OAI identifier oai:identifier

oai:cora.ucc.ie:10468/18469