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Doxorubicin (DOX) is an anthracycline that has excellent anticancer effects during tumor chemotherapy, but it can cause cardiotoxic effects and its clinical use has been limited. Therefore, finding new drugs or methods to prevent or reverse the cardiac damage caused by DOX therapy in cancer patients is essential. Previous studies have identified potential cardioprotective effects of Centella asiatica ( C. asiatica ), and madecassic acid (MA) is a pentacyclic triterpenoid derived from C. asiatica . However, the pharmacological effects of MA on the heart and tumors during tumor chemotherapy are not fully understood. The aim of this study was to investigate the pharmacological function and molecular mechanisms of MA in the heart and tumor during chemotherapy. In a DOX-induced acute heart failure mouse model and a cardiomyocyte injury model, MA reduced cardiomyocyte oxidative stress and the inflammatory response, improved mitochondrial function, and attenuated autophagic flux blockade and apoptosis. Interestingly, MA significantly increased the expression and activity of SIRT1. When SIRT1 was knocked down, the protective effect of MA on cardiomyocytes was significantly inhibited, suggesting that MA may exert cardioprotective effects through the SIRT1 pathway. Interestingly, in contrast to its cardioprotective effect, MA could synergize with DOX and significantly contribute to the anticancer chemotherapeutic effect of DOX by inhibiting proliferation, migration and invasion; promoting apoptosis; and suppressing tumor progression by inhibiting the expression of the DDX5 pathway in tumor cells. Here, we identified the pharmacological functions of the pentacyclic triterpenoid MA in ameliorating DOX-induced cardiotoxicity and enhancing the antitumor efficacy of DOX., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Aim: Resveratrol is a natural plant polyphenol. The present study investigated the effects of resveratrol on the Toll-like receptor 4- (TLR4-) mediated expression and secretion of matrix metalloproteinases (MMPs) in oxidized low-density lipoprotein- (ox-LDL-) treated human umbilical vein endothelial cells (HUVECs)., Methods: Protein expression was analyzed by immunoblotting. The secretion of MMPs was measured by an enzyme-linked immunosorbent assay. The animal experiments were performed with and without resveratrol treatment in high-fat chow-fed mice., Results: Resveratrol inhibited the expression of TLR4, MMP3, and MMP9 in ox-LDL- and lipopolysaccharide- (LPS-) treated HUVECs. Resveratrol reduced the secretion of MMP3 and MMP9 that was induced by ox-LDL and LPS. The TLR4 inhibitor CLI-095 similarly suppressed the expression and secretion of MMP3 and MMP9 in ox-LDL- and LPS-treated HUVECs. Resveratrol attenuated the phosphorylation of the transcription factors nuclear factor- κ B (NF- κ B) and signal transducer and activator of transcription 3 (STAT3) that was induced by ox-LDL and LPS. Resveratrol recovered Sirt1 expression. In the animal experiments, resveratrol decreased TLR4 expression in the aorta, MMP9 levels in plasma, and vascular structural changes in high-fat chow-fed mice, with no significant effect on plasma MMP3 levels., Conclusion: Resveratrol inhibited the TLR4-mediated expression and secretion of MMP3 and MMP9 in ox-LDL-treated HUVECs. The mechanism of action of resveratrol may be associated with the suppression of NF- κ B and STAT3 phosphorylation and restoration of Sirt1 expression. Resveratrol exerts protective effects against vascular structural changes in high-fat chow-fed mice., Competing Interests: The authors declare that they have no competing interests., (Copyright © 2019 Ming Zhang et al.)

Doxorubicin (adriamycin), an anthracycline antibiotic, is commonly used to treat many types of solid and hematological malignancies. Unfortunately, clinical usage of doxorubicin is limited due to the associated acute and chronic cardiotoxicity. Previous studies demonstrated that Astragalus polysaccharide (APS), the extracts of Astragalus membranaceus, had strong anti-tumor activities and anti-inflammatory effects. However, whether APS could mitigate chemotherapy-induced cardiotoxicity is unclear thus far. We used a doxorubicin-induced neonatal rat cardiomyocyte injury model and a mouse heart failure model to explore the function of APS. GFP-LC3 adenovirus-mediated autophagic vesicle assays, GFP and RFP tandemly tagged LC3 (tfLC3) assays and Western blot analyses were performed to analyze the cell function and cell signaling changes following APS treatment in cardiomyocytes. First, doxorubicin treatment led to C57BL/6J mouse heart failure and increased cardiomyocyte apoptosis, with a disturbed cell autophagic flux. Second, APS restored autophagy in doxorubicin-treated primary neonatal rat ventricular myocytes and in the doxorubicin-induced heart failure mouse model. Third, APS attenuated doxorubicin-induced heart injury by regulating the AMPK/mTOR pathway. The mTOR inhibitor rapamycin significantly abrogated the protective effect of APS. These results suggest that doxorubicin could induce heart failure by disturbing cardiomyocyte autophagic flux, which may cause excessive cell apoptosis. APS could restore normal autophagic flux, ameliorating doxorubicin-induced cardiotoxicity by regulating the AMPK/mTOR pathway.

To know whether thioredoxin 1 (Trx1) works for an antioxidant defense mechanism in atherosclerosis, the effect of Trx1 on the release of monocyte chemoattractant protein-1 (MCP-1), a potent chemoattractant for recruitment and accumulation of monocytes/macrophages in the intima of artery vessel, was investigated in human endothelial-like EA.hy 926 cells. It was found that overexpression of Trx1 suppressed, whereas knockdown of endogenous Trx1 enhanced, oxidized low-density lipoprotein (oxLDL)-stimulated MCP-1 release and expression in the cells. It was also observed that overexpression of Trx1 suppressed, whereas depletion of endogenous Trx1 greatly promoted, nuclear translocation of c-Jun and the redox factor-1 (Ref-1). Electrophoretic mobility shift assay showed significantly reduced DNA-binding activity of activator protein-1 (AP-1) in Trx1-overexpressing cells but apparently enhanced DNA binding activity of AP-1 in Trx1-knockdown cells, indicating that nuclear Ref-1 rather than Trx1 itself finally dominates the regulation of AP-1 activity, although Trx1 is considered to upregulate AP-1 activity. It was also observed that Trx1 depressed intracellular generation of reactive oxygen species (ROS). Diphenyleneiodonium (DPI), the inhibitor of NADPH oxidase, suppressed MCP-1 secretion, whereas transient expression of Nox1 enhanced transcription of MCP-1 in endothelial cells. Assays with AP-1 and MCP-1 luciferase reporters further demonstrated that transient expression of Trx1 significantly depressed the transcriptional activity of c-Jun/c-Fos and consequent MCP-1 transcription. This study suggests that Trx1 inherently suppresses MCP-1 expression in vascular endothelium and may prevent atherosclerosis by depressing MCP-1 release. Besides the suppression of intracellular ROS generation, the inhibition of nuclear translocation of AP-1 and Ref-1 are mainly responsible for the downregulation of MCP-1 by Trx1.