Betaine Intervention as a Novel Approach to Preventing Doxorubicin-Induced Cardiotoxicity

The anthracycline anticancer drug doxorubicin (Dox) is widely prescribed for treating lung, ovary, breast, lymphoma, sarcoma, and pediatric cancer. Mechanistically, Dox intercalates the DNA and inhibits the topoisomerase II enzyme in fast-proliferating cancer. The clinical application of Dox is limited due to its cardiotoxicity, including congestive heart failure, alterations in myocardial structure, arrhythmia, and left ventricular dysfunction. Dox causes cardiotoxicity via various mechanisms, including oxidative stress, mitochondrial dysfunctioning, deranged Ca²⁺ homeostasis, inflammation, fibrosis, downregulating AMPK, etc. Betaine is a zwitterion-based drug known as N, N, N trimethylglycine that regulates the methionine cycle and homocysteine (a risk factor for cardiovascular disease) detoxification through betaine-homocysteine methyltransferases. Betaine is nontoxic and has several beneficial effects in different disease models. Betaine treatment decreases the amyloid β generation, reduces obesity, improves steatosis and fibrosis, and activates AMP-activated protein kinase (AMPK). Further, betaine downregulates 8‑hydroxy-2-deoxyguanosine, malondialdehyde, and upregulates catalases, glutathione peroxidase, and superoxide dismutase activity. Therefore, we hypothesized that betaine might be a rational drug candidate to effectively combat Dox-associated oxidative stress, inflammation, and mitochondrial dysfunction.