Essential role of protein kinase C βI in icariin-mediated protection against atherosclerosis

Epimedium Linn: A Comprehensive Review of Phytochemistry, Pharmacology, Clinical Applications and Quality Control

Epimedium genus is a traditional Chinese medicine, which has functions of tonifying kidney and yang, strengthening tendons and bones, dispelling wind and emoving dampness. It is mainly used for the treatment of impotence and spermatorrhea, osteoporosis, Parkinson's, Alzheimer's, and cardiovascular diseases. The aim of this review is to provide a systematic summary of the phytochemistry, pharmacology, and clinical applications of the Epimedium Linn. In this paper, the relevant literature on Epimedium Linn. was collected from 1987 to the present day, and more than 274 chemical constituents, including flavonoids, phenylpropanoids, lignans, phenanthrenes, and others, were isolated from this genus. Modern pharmacological studies have shown that Epimedium Linn. has osteoprotective, neuroprotective, cardiovascular protective, and immune enhancing pharmacological effects. In addition, Epimedium Linn. has been commonly used to treat osteoporosis, erectile dysfunction, hypertension and cardiovascular disease. In this paper, the distribution of resources, chemical compositions, pharmacological effects, clinical applications and quality control of Epimedium Linn. are progressed to provide a reference for further research and development of the resources of this genus.

Beneficial effects of flavonoids on animal models of atherosclerosis: A systematic review and meta-analysis

Atherosclerosis is the main cause of cardiovascular diseases that seriously endanger human health. The existing treatment drugs are effective, but they have some side effects. Accumulating evidence suggests that flavonoids have attracted wide attention due to their multiple cardioprotective effects and fewer side effects. PubMed, Web of Science database, Embase, and Cochrane Library were searched for studies evaluating the effects of flavonoids against atherosclerosis. 119 studies published from August 1954 to April 2023 were included. Random-effects models were performed for synthesis. Compared with the control group, flavonoids significantly reduced longitudinal and cross-sectional plaque area. The findings indicated that flavonoids significantly reduced the concentrations of serum TC, TG, and LDL-C and increased serum HDL-C concentrations. Besides, flavonoids reduced the levels of circulating pro-inflammatory factors, including TNF-α, IL-1β, and IL-6, and increased the serum IL-10 level. This study provides evidence for the potential cardiovascular benefits of flavonoids.

Virtual screening analysis of natural flavonoids as trimethylamine (TMA)-lyase inhibitors for coronary heart disease

Coronary heart disease (CHD) is defined by atherosclerosis, which can result in stenosis or blockage of the arterial cavity, leading to ischemic cardiac diseases such as angina and myocardial infarction. Accumulating evidence indicates that the gut microbiota plays a vital role in the beginning and progression of CHD. The gut microbial metabolite, trimethylamine-N-oxide (TMAO), is intimately linked to the pathophysiology of CHD. TMAO is formed when trimethylamine (TMA) is converted by flavin-containing monooxygenases in the hepatocytes. Therefore, inhibition of TMA production is essential to reduce TMAO levels. Flavonoids may reduce the risk of death from cardiovascular disease. In this article, we reviewed and evaluated twenty-two flavonoids for the therapy of CHD based on their inhibition of TMA-lyase by molecular docking. Docking results revealed that baicalein, fisetin, acacetin, and myricetin in flavonoid aglycones, and baicalin, naringin, and hesperidin in flavonoid glycosides had a good binding effect with TMA-lyase. This indicates that these chemicals were the most active and could be used as lead compounds for structural modification in the future. PRACTICAL APPLICATIONS: Flavonoids are a large class of polyphenolic compounds found in fruits, vegetables, flowers, tea, and herbal medicines, which are inexorably metabolized and transformed into bioactive metabolites by α-rhamnosidase, β-glucuronidase, β-glucosidase, and nitroreductase produced by the gut microbiota, which plays a beneficial role in the prevention and treatment of cardiovascular diseases. Because flavonoids protect the cardiovascular system and regulate the gut microbiota, and the gut microbiota is directly connected to TMAO, thus, reducing TMAO levels involves blocking the transition of TMA to TMAO, which may be performed by reducing TMA synthesis. Molecular docking results found that baicalein, fisetin, acacetin, and myricetin in flavonoid aglycones, and baicalin, naringin, and hesperidin in flavonoid glycosides had good binding effects on TMA-lyase, which were the most active and could be used as lead compounds for structural modification.

Potential Role of Protein Kinase C in the Pathophysiology of Diabetes-Associated Atherosclerosis

Diabetes mellitus is a metabolic syndrome that affects millions of people worldwide. Recent studies have demonstrated that protein kinase C (PKC) activation plays an important role in hyperglycemia-induced atherosclerosis. PKC activation is involved in several cellular responses such as the expression of various growth factors, activation of signaling pathways, and enhancement of oxidative stress in hyperglycemia. However, the role of PKC activation in pro-atherogenic and anti-atherogenic mechanisms remains controversial, especially under hyperglycemic condition. In this review, we discuss the role of different PKC isoforms in lipid regulation, oxidative stress, inflammatory response, and apoptosis. These intracellular events are linked to the pathogenesis of atherosclerosis in diabetes. PKC deletion or treatment with PKC inhibitors has been studied in the regulation of atherosclerotic plaque formation and evolution. Furthermore, some preclinical and clinical studies have indicated that PKCβ and PKCδ are potential targets for the treatment of diabetic vascular complications. The current review summarizes these multiple signaling pathways and cellular responses regulated by PKC activation and the potential therapeutic targets of PKC in diabetic complications.