Puerarin Accelerates Re-Endothelialization in a Carotid Arterial Injury Model: Impact on Vasodilator Concentration and Vascular Cell Functions

The beneficial health effects of puerarin in the treatment of cardiovascular diseases: from mechanisms to therapeutics

Cardiovascular diseases (CVDs) are the leading causes of death globally that seriously threaten human health. Although novel western medicines have continued to be discovered over the past few decades to inhibit the progression of CVDs, new drug research and development for treating CVDs with less side effects and adverse reactions are continuously being desired. Puerarin is a natural product found in a variety of medicinal plants belonging to the flavonoid family with potent biological and pharmacological activities. Abundant research findings in the literature have suggested that puerarin possesses a promising prospect in treating CVDs. In recent years, numerous new molecular mechanisms of puerarin have been explored in experimental and clinical studies, providing new evidence for this plant metabolite to protect against CVDs. This article systematically introduces the history of use, bioavailability, and various dosage forms of puerarin and further summarizes recently published data on the major research advances and their underlying therapeutic mechanisms in treating CVDs. It may provide references for researchers in the fields of pharmacology, natural products, and internal medicine.

Effects of Puerarin on the Prevention and Treatment of Cardiovascular Diseases

Puerarin, an isoflavone glycoside derived from Pueraria lobata (Willd.) Ohwi, has been identified as a pharmacologically active component with diverse benefits. A large number of experimental and clinical studies have demonstrated that puerarin is widely used in the treatment of a variety of diseases. Among them, cardiovascular diseases (CVDs) are the leading cause of death in the world, and therefore remain one of the most prominent global public health concerns. In this review, we systematically analyze the preclinical investigations of puerarin in CVDs, such as atherosclerosis, cardiac hypertrophy, heart failure, diabetic cardiovascular complications, myocardial infarction, stroke and hypertension. In addition, the potential molecular targets of puerarin are also discussed. Furthermore, we summarize the clinical trails of puerarin in the treatment of CVDs. Finally, the therapeutic effects of puerarin derivatives and its drug delivery systems are overviewed.

Effects of puerarin on chronic inflammation: Focus on the heart, brain, and arteries

Age-associated increases in physical and mental stress, known as allostatic load, could lead to a chronic low-grade inflammation in the heart, brain, and arteries. This low-grade inflammation potentially contributes to adverse structural and functional remodeling, such as intimal medial thickening, endothelial dysfunction, arterial stiffening, cardiac hypertrophy and ischemia, and cognitive decline. These cellular and tissue remodeling is the fertile soil for the development of age-associated structural and functional disorders in the cardiovascular and cerebrovascular systems in the pathogenesis of obesity, type II diabetes, hypertension, atherosclerosis, heart dysfunction, and cognitive decline. Growing evidence indicates that puerarin, a polyphenol, extracted from Puerara Labota, efficiently alleviates the initiation and progression of obesity, type II diabetes, hypertension, atherosclerosis, cardiac ischemia, cardiac arrythmia, cardiac hypertrophy, ischemic stroke, and cognition decline via suppression of oxidative stress and inflammation. This mini review focuses on recent advances in the effects of puerarin on the oxidative and inflammatory molecular, cellular, tissue events in the heart, brain, and arteries.

Slight up-regulation of Kir2.1 channel promotes endothelial progenitor cells to transdifferentiate into a pericyte phenotype by Akt/mTOR/Snail pathway

It was shown that endothelial progenitor cells (EPCs) have bidirectional differentiation potential and thus perform different biological functions. The purpose of this study was to investigate the effects of slight up‐regulation of the Kir2.1 channel on EPC transdifferentiation and the potential mechanism on cell function and transformed cell type. First, we found that the slight up‐regulation of Kir2.1 expression promoted the expression of the stem cell stemness factors ZFX and NS and inhibited the expression of senescence‐associated β‐galactosidase. Further studies showed the slightly increased expression of Kir2.1 could also improve the expression of pericyte molecular markers NG2, PDGFRβ and Desmin. Moreover, adenovirus‐mediated Kir2.1 overexpression had an enhanced contractile response to norepinephrine of EPCs. These results suggest that the up‐regulated expression of the Kir2.1 channel promotes EPC transdifferentiation into a pericyte phenotype. Furthermore, the mechanism of EPC transdifferentiation to mesenchymal cells (pericytes) was found to be closely related to the channel functional activity of Kir2.1 and revealed that this channel could promote EPC EndoMT by activating the Akt/mTOR/Snail signalling pathway. Overall, this study suggested that in the early stage of inflammatory response, regulating the Kir2.1 channel expression affects the biological function of EPCs, thereby determining the maturation and stability of neovascularization.

Kakonein restores diabetes-induced endothelial junction dysfunction via promoting autophagy-mediated NLRP3 inflammasome degradation

In diabetes‐induced complications, inflammatory‐mediated endothelial dysfunction is the core of disease progression. Evidence shows that kakonein, an isoflavone common in Pueraria, can effectively treat diabetes and its complications. Therefore, we explored whether kakonein protects cardiovascular endothelial function by inhibiting inflammatory responses. In this study, C57BL/6J mice were injected with streptozocin to establish a diabetes model and treated with kakonein or metformin for 7 days. The protective effect of kakonein on cardiovascular endothelial junctions and NLRP3 inflammasome activation was verified through immunofluorescence and ELISA assay. In addition, the regulation of autophagy on the NLRP3 inflammasome was investigated through Western blot, immunofluorescence and RT‐qPCR. Results showed that kakonein restored the function of endothelial junctions and inhibited the assembly and activation of the NLRP3 inflammasome. Interestingly, kakonein decreased the expression of NLRP3 inflammasome protein by not reducing the transcriptional levels of NLRP3 and caspase‐1. Kakonein activated autophagy in an AMPK‐dependent manner, which reduced the activation of the NLRP3 inflammasome. In addition, kakonein inhibited both hyperglycaemia‐induced cardiovascular endothelial junction dysfunction and NLRP3 inflammasome activation, similar to autophagy agonist. Our findings indicated that kakonein exerts a protective effect on hyperglycaemia‐induced chronic vascular disease by regulating the NLRP3 inflammasome through autophagy.

Salviae miltiorrhizae radix and puerariae lobatae radix herbal formula improves circulation, vascularization and gait function in a peripheral arterial disease rat model

ETHNOPHARMACOLOGICAL RELEVANCE

DG is a herbal formula, containing the root of Salvia miltiorrhiza Bunge (Danshen) and the root of Pueraria lobate (Willd.) Ohwi (Gegen), has a history of usage in China for cardiovascular protection and anti-atherosclerosis.

AIM OF THE STUDY

The present study aims to determine the beneficial effect of DG on the hind-limb ischemia rat model which mimics peripheral arterial disease (PAD) and its vasodilative effect on isolated femoral artery.

MATERIALS AND METHODS

The vasodilatory effects were assessed by contractile responses to DG in the isolated femoral artery and its underlying mechanisms were evaluated by the involvement of endothelium, potassium channel and calcium channel. For hind-limb ischemia study, treatment outcomes were assessed by evaluating hind-limb blood flow, functional limb recovery, muscle histology and angiogenesis.

RESULTS

Our results demonstrated positive dose-dependent vasodilatory response to DG via an endothelium-independent mechanism that involved inwardly rectifying K⁺ channels and Ca²⁺ channels. We also demonstrated significant improvement in blood perfusion and micro-vessel density in the ischemic limb and positive effects in functional limb recovery.

CONCLUSION

In conclusion, our study supported the potential use of DG as a novel treatment for symptomatic PAD.

Oscillating shear stress mediates mesenchymal transdifferentiation of EPCs by the Kir2.1 channel

Although endothelial progenitor cells (EPCs) are considered to be an essential source of vascular endothelial repair, their bidirectional differentiation determines that they play a double-edged role in the restoration of endothelial injury. In this research, we investigated the effect of Kir2.1 ion channel on the transdifferentiation of endothelial progenitor cells (EPCs) under the oscillating shear stress (OSS) and the molecular mechanisms underlying the pathological vascular remodeling. EPCs were treated with OSS (± 3.5 dynes/cm², 1 Hz) simulated with the parallel flow chamber system. The results have shown that OSS promoted the expression of α-SMA and SM22, markers of mesenchymal cells on EPCs. Moreover, OSS also increased expression of Kir2.1 in EPCs. The down-regulation of Kir2.1 reduced OSS-induced EPC mesenchymal transdifferentiation. The overexpression of Kir2.1 suppressed the angiogenic abilities of EPCs in vitro. In parallel, the overexpression of Kir2.1 on EPCs thickened the carotid tunica intima in rat carotid artery balloon injured model in vivo. Taken together, those data indicated that the OSS could facilitate the transdifferentiation of EPCs by increasing Kir2.1 expression. This study provides a novel insight into the pathogenesis of cardiovascular diseases and gives evidence for Kir2.1 as a potential therapeutic target.

Oscillatory shear stress induces the transition of EPCs into mesenchymal cells through ROS/PKCζ/p53 pathway

AIMS

Studies indicate that the pattern of shear stress determines the direction of endothelial progenitor cells (EPCs) differentiation. However, the mechanism remains largely unknown. Herein, we try to identify the role of oscillatory shear stress (OSS) in the transdifferentiation of EPCs into mesenchymal cells and the mechanism involved.

MATERIALS AND METHODS

OSS was applied to EPCs using the flow chamber system in vitro. Matrigel, Boyden chamber, and healing assay were used to observe the changes in EPCs function. Further, 2',7'-dichlorofluorescein diacetate (DCFH-DA) probe and/or western blot were performed to detect the expression of reactive oxygen species (ROS), p53 and PKCζ in EPCs. EPCs transduced with Lentivirus carrying Tp53 were implanted into the arterial vessel in the balloon injured rat model, and neointimal thickening was verified by HE staining.

KEY FINDINGS

OSS enhanced the expression of mesenchymal cell markers alpha-smooth muscle actin (α-SMA) and smooth muscle 22 alpha (SM22α) on EPCs. In the meantime, OSS time-dependently decreased p53 expression in EPCs, which was partially abolished by treatment with ROS scavenger N-acetylcysteine (NAC) or protein kinase C zeta (PKCζ) inhibitor Go6983. Moreover, the p53 agonist tenovin-1 attenuated the changes of OSS-mediated the mesenchymal cell markers and EPCs function. Besides, we also found that transplanting EPCs transfected with LV-Tp53 significantly inhibited neointimal thickening and promoted reendothelialization in vivo.

SIGNIFICANCE

This study demonstrates OSS-induced EPC transdifferentiation into mesenchymal cells and ROS/PKCζ/p53 pathway play an essential role in it. It may serve as a promising therapeutic target for cardiovascular disease in the future.

Comparative pharmacokinetics of major bioactive components from Puerariae Radix-Gastrodiae Rhizome extracts and their intestinal absorption in rats

Puerariae Radix (PR) and Gastrodiae Rhizome (GR) is frequently used in traditional herbal formulas to treat cardio-cerebral vascular diseases due to their synergistic effects. In this study, to elucidate the action mechanism of PR-GR in vivo, a simple and reliable ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method for simultaneous determination of nine bioactive ingredients from PR-GR in plasma was developed and applied to a comparative pharmacokinetic study following oral administration of PR, GR, and PR-GR aqueous extracts in rats. The effect of GR on the absorption of components of PR was also investigated by single-pass intestinal perfusion study. Results showed that comparing to the single herbs, PR-GR extract significantly increased the systemic exposure of puerarin, 3'-hydroxypuerarin, 3'-methoxypuerarin, 6″-O-xylosylpuerarin, daidzin, genistein, and gastrodin. Moreover, the intestinal absorption of puerarin and daidzin could be improved by GR extract and inhibitors of P-glycoprotein and multidrug resistanceassociated protein 2, respectively. These results indicate that the combination of PR and GR increases the levels of their bioactive ingredients exposed in the blood, and GR increases the absorption of ingredients of PR may by inhibition of the efflux mediated by P-glycoprotein and multidrug resistanceassociated protein 2. This is the first report for the pharmacokinetics and intestinal absorption of PR-GR, which may explain their synergetic effects in the treatment of circulatory systematic diseases and provide a meaningful insight for their clinical applications.

Shear stress-mediated changes in the expression of complement regulatory protein CD59 on human endothelial progenitor cells by ECM-integrinαVβ3-F-actin pathway in vitro

Membrane regulatory proteins, such as CD46, CD55, and CD59, prevent excess complement activation and to protect cells from damage. Previous investigations confirmed that shear stress in the physiological range was more favorable for endothelial progenitor cells (EPCs) to repair injured vascular endothelial cells and operates mainly in atheroprotective actions. However, detailed events that contribute to shear stress-induced protection in EPCs, particularly the mechanisms of signal transduction, remain poorly understood. In this study, we observed shear stress-mediated changes in the expression of complement regulatory proteins CD46, CD55, and CD59 on human EPCs and focused on the mechanical transmission mechanism in transformed cells in response to the ECM-F-actin pathway in vitro. Shear stress was observed to promote the expression of complement regulatory protein CD59, but not CD46 or CD55, on EPCs. In addition, the shear stress-induced CD59 expression was confirmed to be associated with the ECM components and was alleviated in EPCs pretreated with GRGDSP, which inhibits ECM components-integrin interaction. Furthermore, shear stress also promotes the rearrangement and polymerization of F-actin. However, shear stress-induced CD59 expression was reduced when the F-actin stress fiber formation process was delayed by Gly-Arg-Gly-Asp-Ser-Pro (GRGDSP) or destroyed by cytochalasin D (Cyto D), while Jasplakinolide (JAS) reversed the expression of CD59 through promotion of F-actin polymerization and its stabilizing capacities. Our results indicates that shear stress is an important mediator in EPC expression of CD59 regulated by the ECM-F-actin pathway, which is a key factor in preventing membrane attack complex (MAC) -mediated cell autolysis.

Puerarin blocks the signaling transmission mediated by P2X3 in SG and DRG to relieve myocardial ischemic damage

P2X₃ receptors in stellate ganglia (SG) and cervical dorsal root ganglia (DRG) neurons are involved in sympathoexcitatory reflex induced by myocardial ischemic damage. Puerarin, a major active ingredient extracted from the traditional Chinese plant medicine Ge-gen, has been widely used in treatment of myocardial and cerebral ischemia. The present study is aimed to observe the effects of puerarin on the signaling transmission mediated by P2X₃ receptor in SG and DRG after myocardial ischemic damage. Our results showed that systolic blood pressure and heart rate increased, and the expression levels of P2X₃ mRNA and protein in SG and DRG were up-regulated after myocardial ischemic damage. Puerarin reduced systolic blood pressure and heart rate, relieved pain and decreased up-regulated expression of P2X₃ mRNA and protein in SG and DRG after myocardial ischemia. Puerarin inhibited the up-regulated ATP-activated currents in DRG neurons after myocardial ischemia. Thus, puerarin can relieve myocardial ischemic damage through blocking the P2X₃ signaling transmission and then depressed the aggravated sympathoexcitatory reflex.