Xinxuekang Regulates Reverse Cholesterol Transport by Improving High-density Lipoprotein Synthesis, Maturation, and Catabolism

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.

Atheroprotective Effects and Mechanisms of Postmarketing Chinese Patent Formulas in Atherosclerosis Models: A Systematic Review

BACKGROUND

Some postmarketing Chinese patent formulas have been widely used to treat atherosclerosis (AS) and play critical roles in Chinese healthcare. However, the usage of these herbs is yet controversial due to unclear effects and lack of understanding of the mechanism of action. With the modernization of traditional Chinese formulas, we are to elucidate the atheroprotective properties of these remedies from successful postmarketing experiments in vivo.

METHODS

In this systematic review, we critically searched the databases, applied stringent criteria, assessed the methodological quality, and examined the current evidence in vivo.

RESULTS

Consequently, 60 studies were included in the present qualitative synthesis. Data on models, high-fat diet, intervention time, outcome measures, efficacy, and mechanisms were collected. Finally, 23 formulas that could alleviate AS were correlated to the amelioration of plaques, improvement of plaque stability, modification of lipid level and lipid metabolism, and the effects of anti-inflammation and antioxidant stress with multiple components and targets. However, the methodological quality was low and incomplete among the included literature.

CONCLUSIONS

Thus, taken together, the studies on postmarketing Chinese patent formulas would provide a novel approach to improve the treatment of AS, and rigorously designed studies would provide high-quality evidence.

Di'ao Xinxuekang: Therapeutic Potential in Cardiovascular Diseases

Background：Cardiovascular disease is the leading cause of death in both developed and developing countries. Di'ao Xinxuekang (DAXXK) is a pure Chinese medicine herbal preparation refined from dioscin extracted from the roots of Dioscorea panthaica Prain et Burk and Diosorea nipponica Makino. Objective: To evaluate the application of DAXXK in Cardiovascular disease. Methods: We searched and summarized all the studies on DAXXK and Cardiovascular disease in pumend, Google, and CNKI. Results：Modern pharmacological studies have shown that DAXXK has pharmacological effects such as dilating blood vessels, lowering blood pressure and cardiac load, improving hemodynamics, lowering blood lipids and anti-platelet aggregation, and is widely used for the therapy of various kinds of cardiovascular diseases, including hypertension, atherosclerosis, coronary heart disease (CHD), angina pectoris (AP) and myocardial infarction. We provide an overview of the clinical efficacy, molecular mechanisms, safety and therapeutic potential of DAXXK in the treatment of cardiovascular disease, aiming to provide clues and evidence for clinical decision-making. Conclusion：DAXXK exerts cardiovascular protection by regulating a variety of cardiovascular disease-related signaling pathways.

Polydatin attenuates atherosclerosis in apolipoprotein E-deficient mice: Role of reverse cholesterol transport

BACKGROUND

Polydatin has been recently shown to possess extensive cardiovascular pharmacological activities. However, its protective effect against atherosclerosis in vivo remains poorly understood. The aim of the present study was to evaluate the potential effects of polydatin on high fat diet (HFD)-induced atherosclerosis using ApoE^-/- mice, and explore the underlying mechanisms involved, especially focusing on reverse cholesterol transport (RCT) regulation.

METHODS

after 12 weeks treatment, serum samples, mouse aorta, liver, peritoneal macrophages were collected to determine lipid profiles, atherosclerotic lesions, hepatic steatosis, foam cell formation and expression of related molecules. RAW264.7 macrophages were used to study cholesterol efflux.

RESULTS

Polydatin improved serum lipid profiles, attenuated atherosclerosis and hepatic steatosis. Furthermore, polydatin may facilitate RCT by stimulating cholesterol efflux through ATP-binding cassette transporters (ABC) A1, ABCG1 and scavenger receptor class B type I (SR-BI) in macrophages, increasing serum levels of high density lipoprotein and apolipoprotein A-I, promoting of SR-BI-mediated cholesterol uptake of liver, increasing secretion of cholesterol into bile by ABCG5/ABCG8 and improving cholesterol metabolism by CYP7A1 pathway. Polydatin also regulated the protein expressions of hepatic fatty acid synthase and peroxisome proliferator-activated receptor-α. Additionally, polydatin reduced hepatic and aortic reactive oxygen species generation, normalized activities of antioxidant enzymes and increased protein expressions of NADPH-oxidase (NOX) 2 and NOX4 in liver. Polydatin also prevented hepatic and aortic inflammation as evidenced by the reduced macrophage infiltration and mRNA expressions of tumor necrosis factor-α and interleukin-6 in both aorta and liver.

CONCLUSION

These findings indicated that polydatin can inhibit atherosclerosis through enhancement of overall RCT. In addition, anti-oxidative and anti-inflammatory effect of polydatin may also contribute to its inhibitory effects on atherosclerosis.

Di'ao Xinxuekang Capsule, a Chinese Medicinal Product, Decreases Serum Lipids Levels in High-Fat Diet-Fed ApoE-/- Mice by Downregulating PCSK9

Numerous risk factors are responsible for the development of atherosclerosis, for which an increased serum level of low-density lipoprotein cholesterol (LDL-C) is a driving force. By binding to the low-density lipoprotein cholesterol receptor (LDLR) and inducing LDLR degradation, proprotein convertase subtilisin/kexin type 9 (PCSK9) plays a key role in cholesterol homeostasis regulation. The inducement of PCSK9 expression is also an important reason for statin intolerance. The Di'ao Xinxuekang (DXXK) capsule extracted from Dioscorea nipponica Makino is a well-known traditional Chinese herbal medicinal product used in atherosclerotic cardiovascular disease. Although DXXK has been widely used in atherosclerotic cardiovascular treatment for nearly 30 years, studies on the potential mechanisms of the lipid-lowering effect are very limited. The purpose of the present study was to demonstrate the possible involvement of the PCSK9/LDLR signaling pathway in the lipid-lowering and antiatherosclerotic effect of DXXK in high-fat diet-fed ApoE^-/- mice. The results showed that DXXK treatment alleviated hyperlipidemia, fat accumulation, and atherosclerosis formation in ApoE^-/- mice. Furthermore, changes in the expression of PCSK9 mRNA in liver tissue and the circulating PCSK9 level in ApoE^-/- mice were both reversed after DXXK treatment, and upregulation of LDLR in the liver was also detected in the protein level in DXXK-treated mice. Our study is the first to show that DXXK could alleviate lipid disorder and ameliorate atherosclerosis with downregulation of the PCSK9 in high-fat diet-fed ApoE^-/- mice, suggesting that DXXK may be a potential novel therapeutic treatment and may support statin action in the treatment of atherosclerosis.

The Signaling Pathways Involved in the Antiatherosclerotic Effects Produced by Chinese Herbal Medicines

Cardiovascular diseases (CVDs) are considered to be the predominant cause of death in the world. Chinese herb medicines (CHMs) have been widely used for the treatment of CVDs in Asian countries for thousands of years. One reason of high efficacy of CHMs in treating CVDs is attributed to their inhibition in atherosclerosis (AS) development, a critical contributor to CVDs occurrence. Cumulative studies have demonstrated that CHMs alleviate atherogenesis via mediating pathophysiologic events involved in AS. However, there is deficiency in the summaries regarding antiatherogenic signal pathways regulated by CHMs. In this review, we focus on the signal cascades by which herb medicines and relevant extractives, derivatives, and patents improve proatherogenic processes including endothelium dysfunction, lipid accumulation, and inflammation. We mainly elaborate the CHMs-mediated signaling pathways in endothelial cells, macrophages, and vascular smooth muscle cells of each pathogenic event. Moreover, we briefly describe the other AS-related factors such as thrombosis, autophagy, immune response, and noncoding RNAs and effects of CHMs on them in the way of cascade regulation, which is helpful to further illustrate the molecular mechanisms of AS initiation and progression and discover newly effective agents for AS management.

The role of adiponectin and adipolin as anti-inflammatory adipokines in the formation of macrophage foam cells and their association with cardiovascular diseases

Obesity is one of the major public health concerns that is closely associated with obesity-related disorders such as type 2 diabetes mellitus (T2DM), hypertension, and atherosclerosis. Atherosclerosis is a chronic disease characterized by excess cholesterol deposition in the arterial intima and the formation of foam cells. Adipocytokines or adipokines are secreted by the adipose tissue as endocrine glands; adiponectin and adipolin are among these adipokines that are associated with obese and insulin-resistant phenotypes. Adipolin and adiponectin are cytokines that exert substantial impact on obesity, progression of atherosclerosis, insulin resistance, and glucose metabolism. In this paper, we review the formation of macrophage foam cells, which are associated with atherosclerosis, and the macrophage mechanism, which includes uptake, esterification, and release. We also summarize current information on adipose tissue-derived hormone and energy homeostasis in obesity. Finally, the role of adipokines, e.g., adipoline and adiponectin, in regulating metabolic, cardiovascular diseases is discussed.