Cinnamamide derivatives with 4-hydroxypiperidine moiety enhance effect of doxorubicin to cancer cells and protect cardiomyocytes against drug-induced toxicity through CBR1 inhibition mechanism.

Doxorubicin (DOX) is classified by World Health Organization (WHO) as an essential medicine for cancer. However, its clinical application is limited due to resistance development and cardiotoxicity. Many attempts have been made to address these issues with some focused on finding a potential adjuvant therapy. Recently, inhibition of carbonyl reduction of anthracyclines (ANTs), catalyzed by enzymes from carbonyl reductase (CBR) and aldo-keto reductase (AKR) families, emerged as a potential way to simultaneously bypass cancer resistance and alleviate cardiotoxicity of ANTs. In this context, we evaluated the potential application of l synthetic cinnamic acid derivatives (CA) - 1a (2E)-3-(4- chlorophenyl)-1-(4-hydroxypiperidin-1-yl)prop-2-en-1 and 1b (2E)-1-(4-hydroxypiperidin-1-yl)-3-(2-methylphenyl)prop-2-en-1-one. The tested compounds were found to chemosensitize A549 human lung cancer cell line towards DOX-induced viability reduction and apoptosis, while having no effect in non-cancerous lung fibroblasts. Co-treatment with DOX + 1a/1b significantly inhibited the migration of A549 in a Transwell assay. The addition of 1a/1b alleviated menadione-induced viability reduction in H9c2 rat cardiomyoblast cell line. Accordingly, 1a/1b reduced DOX-induced reactive oxygen species (ROS) generation and increased glutathione levels. The compounds were also found to moderate autophagy process and limit inflammatory response in RAW 264.7 macrophage cell line. Inhibitory properties of the compounds towards CBR1 were simulated by molecular modeling and confirmed in vitro in enzyme inhibition assay with recombinant CBR1 protein. In contrast to 1b, 1a has strong CBR1 inhibition, which correlates well with more profound effect elicited by 1a uniformly throughout the other experiments. Finally, no mutagenic, genotoxic or hepatotoxic activity of the compounds were found. The possible products of cytochrome P450 mediated metabolism of 1a and 1b were also established to evaluate the potential impact of first pass effect. Our results suggest that 1a and 1b are promising candidates for DOX adjuvant therapy that may simultaneously chemosensitize cancer cells and alleviate cardiotoxicity. The higher activity of 1a may be linked with CBR1 inhibition.