Effects of Atorvastatin on Bile Acid Metabolism in High-fat Diet-fed ApoE -/- Mice.

ABSTRACT: Statins are considered as the cornerstone of the prevention and treatment of atherosclerotic cardiovascular disease, where pleiotropic effects are thought to contribute greatly in addition to the lipid-lowering effect. Bile acid metabolism has been gradually reported to be involved in the antihyperlipidemic and antiatherosclerotic effects of statins, but with inconsistent results and few studies carried out on animal models of atherosclerosis. The study aimed to examine the possible role of bile acid metabolism in the lipid-lowering and antiatherosclerotic effects of atorvastatin (ATO) in high-fat diet-fed ApoE -/- mice. The results showed that the levels of liver and faecal TC as well as ileal and faecal TBA were significantly increased in mice of the model group after 20 weeks of high-fat diet feeding compared with the control group, with significantly downregulated mRNA expression of liver LXR-α, CYP7A1, BSEP, and NTCP. ATO treatment further increased the levels of ileal and faecal TBA and faecal TC, but no obvious effect was observed on serum and liver TBA. In addition, ATO significantly reversed the mRNA levels of liver CYP7A1 and NTCP, and no obvious changes were observed in the expression of LXR-α and BSEP. Our study suggested that statins may enhance the synthesis of bile acids and facilitate the reabsorption of bile acids from the ileum via portal into the liver, possibly through the upregulation of the expression of CYP7A1 and NTCP. The results are helpful in enriching the theoretical basis for the clinical use of statins and have good translational value.

Exploring the role of ferroptosis in the doxorubicin-induced chronic cardiotoxicity using a murine model.

Doxorubicin (DOX) is an effective antitumor drug; however, but its clinical application is seriously limited by the cardiotoxicity induced by its use. Recent studies have found that ferroptosis is an important mechanism underlying DOX-induced cardiotoxicity. However, existing studies are based on DOX-induced acute or subacute cardiotoxicity model. Therefore, we established a murine model of DOX-induced chronic cardiotoxicity using the clinically relevant cumulative dose, to evaluate the potential molecular mechanism underlying ferroptosis of cardiomycocytes. Male C57 mice were received intraperitoneal injections of DOX at a dose of 3 mg/kg body weight, once a week for 12 weeks. We dynamically analysed echocardiographic findings, serum myocardial enzyme levels, haematological indexes and cardiac histopathological changes. The results showed that, after receiving a cumulative DOX dose of 15 mg/kg, the mice developed anaemia and the function and structure of the heart changed significantly with an increase in the cumulative DOX dose. Importantly, with a cumulative DOX dose of 36 mg/kg, iron overload occurred in the heart tissue. Moreover, RNA-sequencing analysis and experimental verification revealed that ferropotosis is the underlying mechanism of DOX-induced chronic cardiotoxicity. Our results showed that DOX inhibits Slc7a11 in system-Xc, resulting in the reduction of GSH synthesis to prevent GPX4 from scavenging lipid peroxides. In addition, DOX induced the occurrence of ferroptosis via down-regulating Nrf2 expression to inhibit HO-1 and GPx4 levels. Our study provides a new perspective for evaluating the pathophysiology of DOX-induced chronic cardiotoxicity in the future, and developing new potential therapeutic strategies for the prevention and treatment of DOX-induced cardiotoxicity.

Di'ao Xinxuekang Capsule Improves the Anti-Atherosclerotic Effect of Atorvastatin by Downregulating the SREBP2/PCSK9 Signalling Pathway.

Statins are the first choice for lowering low-density lipoprotein cholesterol (LDL-C) and preventing atherosclerotic cardiovascular disease (ASCVD). However, statins can also upregulate proprotein convertase subtilisin/kexin type 9 (PCSK9), which in turn might limits the cholesterol-lowering effect of statins through the degradation of LDL receptors (LDLR). Di'ao Xinxuekang (DXXK) capsule, as a well-known traditional Chinese herbal medicine for the prevention and treatment of coronary heart disease, can alleviate lipid disorders and ameliorate atherosclerosis in atherosclerosis model mice and downregulate the expression of PCSK9. In this study, we further explored whether DXXK has a synergistic effect with atorvastatin (ATO) and its underlying molecular mechanism. The results showed that both ATO monotherapy (1.3 mg/kg) and ATO combined with DXXK therapy significantly lowered serum lipid levels and reduced the formation of atherosclerotic plaques and the liver lipid accumulation. Moreover, compared with ATO monotherapy, the addition of DXXK (160 mg/kg) to the combination therapy further lowered LDL-C by 15.55% and further reduced the atherosclerotic plaque area by 25.98%. In addition, the expression of SREBP2, PCSK9 and IDOL showed a significant increase in the model group, and the expression of LDLR was significantly reduced; however, there were no significant differences between the ATO (1.3 mg/kg) and the model groups. When ATO was combined with DXXK, the expression of LDLR was significantly increased and was higher than that of the model group and the expression of SREBP2 and PCSK9 in the liver was also significantly inhibited. Moreover, it can be seen that the expression of SREBP2 and PCSK9 in the combination treatment group was significantly lower than that in the ATO monotherapy group (1.3 mg/kg). Besides, the expression of IDOL mRNA in each treatment group was not significantly different from that of the model group. Our study suggests that DXXK might have a synergistic effect on the LDL-C lowering and antiatherosclerosis effects of ATO through the SREBP2/PCSK9 pathway. This indicates that a combination of DXXK and ATO may be a new treatment for atherosclerosis.

Protective effect of Di'ao Xinxuekang capsule against doxorubicin-induced chronic cardiotoxicity.

ETHNOPHARMACOLOGICAL RELEVANCE: Di'ao Xinxuekang capsule (DXXK) extracted from Dioscorea nipponica Makino is a well-known traditional Chinese herbal medicinal product widely used in the treatment of cardiovascular disease, such as myocardial ischemia and arrhythmia. The active ingredients of DXXK were also traditionally utilized for treating cardiovascular disease in the former Soviet Union after the 1960s. As a specific type of cardiovascular disease, doxorubicin (DOX)-induced cardiotoxicity is characterized by arrhythmia, myocardial ischemia, and heart failure. AIM OF THE STUDY: This study aimed to investigate the potential protective effect of DXXK against chronic cardiotoxicity induced by DOX. MATERIALS AND METHODS: A mouse model of chronic cardiotoxicity induced by DOX and an in vitro model of DOX-induced myocardial damage were created to assess the protective effect of DXXK. Cardiac functional parameters, serum levels of CK-MB and LDH and cardiac histopathological indicators were determined in the mouse model. Moreover, cell viability was measured by the MTT method, and the effect of DXXK on the anticancer activity of DOX was also investigated by utilizing 4T1, HepG2, and H460 cell lines. Furthermore, the levels of markers of oxidative stress indexes (SOD, GSH, MDA) and inflammation (TNF-α, IL-1α) were measured using biochemical and Elisa kits, respectively. The level of ROS in H9c2 cardiomyocyte was determined by flow cytometry. The protein expression levels of HIF-1α and NF-κB p65 were measured by western blotting. Finally, molecular docking was performed to visualize the patterns of interactions between the effective molecule and targeted protein. RESULTS: DXXK alleviated DOX-induced chronic cardiotoxicity as shown by the reversal of changes in levels of myocardial enzymes and left ventricular function and structure. DXXK exhibits antioxidant and anti-inflammatory activities. We also observed that DXXK might increase the protein expression level of HIF-1α and decrease the protein expression level of NF-κB p65. Further results of in vitro experiments showed that DXXK could protect cardiomyocyte against DOX-induced production of ROS, but DXXK had no effect on the anticancer activity of DOX. The results of molecular docking showed that dioscin and pseudoprotodioscin were the top two compounds of DXXK, which had high affinity with HIF-1α and NF-κB p65. CONCLUSIONS: Our results indicated that DXXK could protect against cardiotoxicity induced by DOX and alleviate oxidative stress and inflammation in vivo and in vitro via the regulation of HIF-1α and down NF-κB p65.

Dioscin and diosgenin: Insights into their potential protective effects in cardiac diseases.

BACKGROUND AND ETHNOPHARMACOLOGICAL RELEVANCE: Dioscin and diosgenin derived from plants of the genus Dioscoreaceae such as D. nipponica and D. panthaica Prain et Burk. Were utilized as the main active ingredients of traditional herbal medicinal products for coronary heart disease in the former Soviet Union and China since 1960s. A growing number of research showed that dioscin and diosgenin have a wide range of pharmacological activities in heart diseases. AIM OF THE STUDY: To summarize the evidence of the effectiveness of dioscin and diosgenin in cardiac diseases, and to provide a basis and reference for future research into their clinical applications and drug development in the field of cardiac disease. METHODS: Literatures in this review were searched in PubMed, ScienceDirect, Google Scholar, China National Knowledge Infrastructure (CNKI) and Web of Science. All eligible studies are analyzed and summarized in this review. RESULTS: The pharmacological activities and therapeutic potentials of dioscin and diosgenin in cardiac diseases are similar, can effectively improve hypertrophic cardiomyopathy, arrhythmia, myocardial I/R injury and cardiotoxicity caused by doxorubicin. But the bioavailability of dioscin and diosgenin may be too low as a result of poor absorption and slow metabolism, which hinders their development and utilization. CONCLUSION: Dioscin and diosgenin need further in-depth experimental research, clinical transformation and structural modification or research of new preparations before they can be expected to be developed into new therapeutic drugs in the field of cardiac disease.