Cytoprotective effects of spirulina extract against doxorubicin‐induced cardiotoxicity: Biochemical evidences and translational perspectives in cardio-oncology.
e15042 Background: Spirulina, a blue-green algae used in the daily diet of natives of Africa and America, has antioxidant, anticancer, antiviral, hepatoprotective, immune enhancing and lipid-lowering effects. Considering that doxorubicin-induced cardiotoxicity involves myocardial inflammation, ferroptosis and overexpression of several cytokines involved in cell dead and apoptosis, the use of spirulina during exposure to doxorubicin could be an intriguing method to reduces myocardial injuries in cancer patients undergoing treatment with anthracyclines. Methods: Human fetal cardiomyocytes (HFC cell line) were exposed to doxorubicin (from 10 to 500 nM), alone or in combination with spirulina extract (from 10 to 100 µg/ml) for 24 and 48h. After the incubation period, we performed the following tests: determination of cell viability, through analysis of mitochondrial dehydrogenase activity, study of lipid peroxidation (quantifying cellular Malondialdehyde and 4-hydroxynonenal), intracellular Ca2+ homeostasis. Moreover, pro-inflammatory studied were also performed (activation of NLRP3 inflammasome; expression of TLR4/MyD88; mTORC1 Fox01/3a; transcriptional activation of p65/NF-κB and secretion of cytokines involved in cardiotoxicity (Interleukins 1β, 8, 6). Results: Spirulina extract, co-incubated with doxorubicin exerts cardioprotective effects, enhancing cell viability of 20-36.7 % compared to untreated cells (p<0,01 for all); spirulina extract reduced significantly the cardiotoxicity through MyD88/NF-KB/cytokines axis and mTORC1 Fox01/3α mediated mechanisms and reduces oxidative damages of doxorubicin resulting in lower intracellular calcium content. Conclusions: For the first time, it was demonstrated that spirulina extract exert anti-inflammatory and cytoprotective properties in myocardial cells exposed to growing concentration of doxorubicin leading to preclinical studies in mice analyzing any effects on cardiac strain and left ventricular ejection function.