eNOS-Nitric Oxide System Contributes to a Novel Antiatherogenic Effect of Leonurine via Inflammation Inhibition and Plaque Stabilization

Leonurine: a comprehensive review of pharmacokinetics, pharmacodynamics, and toxicology

Leonurine is an alkaloid unique to the Leonurus genus, which has many biological activities, such as uterine contraction, anti-inflammation, anti-oxidation, regulation of cell apoptosis, anti-tumor, angiogenesis, anti-platelet aggregation, and inhibition of vasoconstriction. This paper summarizes the extraction methods, synthetic pathways, biosynthetic mechanisms, pharmacokinetic properties, pharmacological effects in various diseases, toxicology, and clinical trials of leonurine. To facilitate a successful transition into clinical application, intensified efforts are required in several key areas: structural modifications of leonurine to optimize its properties, comprehensive pharmacokinetic assessments to understand its behavior within the body, thorough mechanistic studies to elucidate how it works at the molecular level, rigorous safety evaluations and toxicological investigations to ensure patient wellbeing, and meticulously conducted clinical trials to validate its efficacy and safety profile.

Leonurine alleviates vancomycin nephrotoxicity via activating PPARγ and inhibiting the TLR4/NF-κB/TNF-α pathway

Vancomycin (VCM) is the first-line antibiotic for severe infections, but nephrotoxicity limits its use. Leonurine (Leo) has shown protective effects against kidney damage. However, the effect and mechanism of Leo on VCM nephrotoxicity remain unclear. In this study, mice and HK-2 cells exposed to VCM were treated with Leo. Biochemical and pathological analysis and fluorescence probe methods were performed to examine the role of Leo in VCM nephrotoxicity. Immunohistochemistry, q-PCR, western blot, FACS, and Autodock software were used to verify the mechanism. The present results indicate that Leo significantly alleviates VCM-induced renal injury, morphological damage, and oxidative stress. Increased intracellular and mitochondrial ROS in HK-2 cells and decreased mitochondrial numbers in mouse renal tubular epithelial cells were reversed in Leo-administrated groups. In addition, molecular docking analysis using Autodock software revealed that Leo binds to the PPARγ protein with high affinity. Mechanistic exploration indicated that Leo inhibited VCM nephrotoxicity via activating PPARγ and inhibiting the TLR4/NF-κB/TNF-α inflammation pathway. Taken together, our results indicate that the PPARγ inhibition and inflammation reactions were implicated in the VCM nephrotoxicity and provide a promising therapeutic strategy for renal injury.

The eNOS-induced leonurine's new role in improving the survival of random skin flap

In reconstructive and plastic surgery, random skin flaps are commonly utilized to treat skin abnormalities produced by a variety of factors. Flap delay procedure is commonly used to reduce flap necrosis. Due to the limitations of various conditions, the traditional surgical improvement can't effectively alleviate the skin flap necrosis. And leonurine (Leo) has antioxidant and anti-inflammatory effects. In this study, we researched the mechanism underlying the influences of varied Leo concentrations on the survival rate of random skin flaps. Our results showed that after Leo treatment, tissue edema and necrosis of the flap were significantly reduced, while angiogenesis and flap perfusion were significantly increased. Through immunohistochemistry and Western blot, we proved that Leo treatment can upregulate the level of angiogenesis, while Leo treatment significantly reduced the expression levels of oxidative stress, apoptosis and inflammation. As a result, it can significantly improve the overall viability of the random skin flaps through the increase of angiogenesis, restriction of inflammation, attenuation of oxidative stress, and reduction of apoptosis. And this protective function was inhibited by LY294002 (a broad-spectrum inhibitor of PI3K) and L-NAME (NG- nitro-L-arginine methyl ester, a non-selective NOS inhibitor). All in all, Leo is an effective drug that can activate the eNOS via the PI3K/Akt pathway. By encouraging angiogenesis, preventing inflammation, minimizing oxidative stress, and lowering apoptosis, Leo can raise the survival rate of random skin flaps. The recommended concentration of Leo in this study was 30 mg/kg.

Hyperoside Nanomicelles Alleviate Atherosclerosis by Modulating the Lipid Profile and Intestinal Flora Structure in High-Fat-Diet-Fed Apolipoprotein-E-Deficient Mice

Atherosclerosis (AS) is a serious threat to human health and the main pathological basis of cardiovascular disease. Hyperoside (Hyp), a flavonoid found mainly in traditional Chinese herbs, can exert antitumor, anti-inflammatory, antioxidant, and cardiovascular-protective effects. Herein, we prepared hybrid nanomicelles (HFT) comprising Hyp loaded into pluronic F-127 and polyethylene glycol 1000 vitamin E succinate and assessed their effects on AS. To establish an AS model, apolipoprotein-E-deficient (ApoE^-/-) mice were fed a high-fat diet. We then analyzed the effects of HFT on AS-induced changes in aortic tissues and metabolic markers, simultaneously assessing changes in gut flora community structure. In mice with AS, HFT significantly reduced the aortic plaque area; decreased levels of total cholesterol, triglyceride, low-density lipoprotein cholesterol, inflammatory factors, and inducible nitric oxide synthase (NOS); increased high-density lipoprotein cholesterol, endothelial NOS, superoxide dismutase, catalase, and glutathione levels; and promoted the proliferation of beneficial gut bacteria. HFT could regulate intestinal flora structure and lipid metabolism and inhibit inflammatory responses. These beneficial effects may be mediated by inhibiting nuclear factor kappa B signal activation, reducing inflammatory factor expression and improving gut microflora structure and dyslipidemia. The present study provides an empirical basis for the development and clinical application of new dosage forms of Hyp.

Differential expression profile of miRNAs between stable and vulnerable plaques of carotid artery stenosis patients

Plaque vulnerability is associated with the degree of carotid artery stenosis (CS) and the risk of stroke. MicroRNAs (miRNAs) exert critical functions in disease progression, although only a few miRNAs have been well identified in CS. Therefore, this study aimed to investigate the differential expression profile of miRNAs and their potential functions in plaques of CS patients. Three CS patients with stable plaques and three patients with vulnerable plaques who underwent carotid endarterectomy were enrolled in this study. Differentially expressed miRNAs (DEmiRNAs) between patients with stable and vulnerable plaques were determined using small RNA sequencing. Target genes of DEmiRNAs were predicted and submitted to functional analyses. Validation of dysregulated DEmiRNAs was determined using quantitative real-time polymerase chain reaction (qRT-PCR). After sequencing, 76 DEmiRNAs were identified in vulnerable plaques, including 53 upregulated miRNAs and 23 downregulated miRNAs. Next, 23,495 target genes of the identified DEmiRNAs were predicted and functionally analyzed. This indicated that the target genes of the identified DEmiRNAs were mainly enriched in protein phosphorylation, transcription, nitrogen compound metabolism, endocytosis and autophagy, and related to signaling pathways of Hippo, MAPK, insulin, TGF-β, FoxO, AMPK and p53. Furthermore, qRT-PCR results for six miRNAs showed that five (83%) of them (hsa-miR-511-5p, hsa-miR-150-5p, hsa-miR-378a-5p, hsa-miR-365b-5p and hsa-miR-6511b-5p) were consistent with the sequencing results. Differential expression profiles and potential function of miRNAs associated with plaque stability in CS patients are identified for the first time, which should help to understand the regulatory mechanism of plaque stability in CS.

Exogenous Hydrogen Sulfide Activates PI3K/Akt/eNOS Pathway to Improve Replicative Senescence in Human Umbilical Vein Endothelial Cells

Background

Endothelial cell senescence is one of the key mechanistic factors in the pathogenesis of atherosclerosis. In terms of molecules, the phosphatidylinositol 3-kinase/protein kinase B/endothelial nitric oxide synthase (PI3K/Akt/eNOS) signaling plays an important role in the prevention and control of endothelial cell senescence, while hydrogen sulfide (H2S) improves the induced precocious senescence of endothelial cells through the PI3K/Akt/eNOS pathway. Comparatively, replicative senescence in endothelial cells is more in line with the actual physiological changes of human aging. This study aims to investigate the mechanism by which H2S improves endothelial cell replicative senescence and the involvement of the PI3K/Akt/eNOS pathway.

Methods

we established a model of replicative senescence in human umbilical vein endothelial cells (HUVECs) and explored the effect of 200 μmol/L sodium hydrosulfide (NaHS; a donor of H2S) on senescence, which was determined by cell morphology, the expression level of plasminogen activator inhibitor 1 (PAI-1), and the positive rate of senescence-associated β-galactosidase (SA-β-Gal) staining. Cell viability was detected by MTT assay to evaluate the effect of NaHS and the PI3K inhibitor, LY294002. Meanwhile, the protein expression of PI3K, Akt, p-Akt, and eNOS in endothelial cells of each group was detected by Western blot.

Results

the replicative senescence model was established in HUVECs at the passage of 16 cumulative cell population doubling values (CPDL). Treatment with NaHS not only significantly reduced the expression of PAI-1 and the positive rate of SA-β-Gal in HUVEC's replicative senescence model but also notably increased the expression of PI3K, p-Akt, p-eNOS, and the content of nitric oxide(NO). However, the effects of NaHS on the expression of the pathway and the content of NO in HUVECs were abolished when LY294002 specifically inhibited PI3K.

Conclusion

NaHS improves the replicative senescence of HUVECs with the contribution of the PI3K/Akt/eNOS pathway.

Mechanism of homocysteine-mediated endothelial injury and its consequences for atherosclerosis

Homocysteine (Hcy) is an intermediate amino acid formed during the conversion from methionine to cysteine. When the fasting plasma Hcy level is higher than 15 μmol/L, it is considered as hyperhomocysteinemia (HHcy). The vascular endothelium is an important barrier to vascular homeostasis, and its impairment is the initiation of atherosclerosis (AS). HHcy is an important risk factor for AS, which can promote the development of AS and the occurrence of cardiovascular events, and Hcy damage to the endothelium is considered to play a very important role. However, the mechanism by which Hcy damages the endothelium is still not fully understood. This review summarizes the mechanism of Hcy-induced endothelial injury and the treatment methods to alleviate the Hcy induced endothelial dysfunction, in order to provide new thoughts for the diagnosis and treatment of Hcy-induced endothelial injury and subsequent AS-related diseases.

Magnesium Supplementation Affects the Expression of Sirtuin1, Tumor Protein P53 and Endothelial Nitric Oxide Synthase Genes in Patients with Atherosclerosis: A Double-Blind, Randomized, Placebo-Controlled Trial

Magnesium seems to play a role in improving cardiovascular function, but its exact mechanism is unknown. In this study, we hypothesized that magnesium could modulate the expression of genes involved in atherosclerosis. The aim of the present investigation was to evaluate the effect of magnesium sulfate on the expression of sirtuin1 (SIRT1), tumor protein p53 (TP53), and endothelial nitric oxide synthase (eNOS) genes in patients with atherosclerosis. This study was a placebo-controlled double-blind randomized clinical trial on 56 patients with angiographically proven atherosclerosis. Participants were randomly divided into two groups receiving 300 mg/day magnesium sulfate (n = 29) and placebo (n = 27) for three months (following up every month). Fasting blood samples were taken before and after the intervention and total RNA was extracted and used to evaluate the expression level of SIRT1, TP53, and eNOS genes by Real-Time PCR. The expression of eNOS gene was significantly increased (P < 0.0001) and the expression of TP53 gene was decreased (P = 0.02) in the magnesium sulfate group compared to the placebo group. But SIRT1 gene expression was not significantly different between the two groups. Our findings demonstrate that magnesium sulfate supplementation may have a protective role against the progression of atherosclerosis through upregulation of eNOS and downregulation of TP53 gene. Trial registration: This present clinical trial has been registered in the Iranian Registry of Clinical Trials (IRCT) with the registration code of "IRCT20151028024756N3", https://www.irct.ir/trial/29097?revision=114102. Registered on 16 December 2019.

Leonurine Attenuates Obesity-Related Vascular Dysfunction and Inflammation

Oxidative stress in adipose tissue is a crucial pathogenic mechanism of obesity-associated cardiovascular diseases. Chronic low-grade inflammation caused by obesity increases ROS production and dysregulation of adipocytokines. Leonurine (LEO) is an active alkaloid extracted from Herba Leonuri and plays a protective role in the cardiovascular system. The present study tested whether LEO alleviates inflammation and oxidative stress, and improves vascular function in an obese mouse model. Here, we found that obesity leads to inflammation and oxidative stress in epididymal white adipose tissue (EWAT), as well as vascular dysfunction. LEO significantly improved inflammation and oxidative stress both in vivo and in vitro. Obesity-induced vascular dysfunction was also improved by LEO as evidenced by the ameliorated vascular tone and decreased mesenteric artery fibrosis. Using mass spectrometry, we identified YTHDF1 as the direct target of LEO. Taken together, we demonstrated that LEO improves oxidative stress and vascular remodeling induced by obesity and targets YTHDF1, raising the possibility of LEO treating other obesity-related metabolic syndromes.

Leonurine: A compound with the potential to prevent acute lung injury

Sepsis is an intense immune response to infection that contributes to the pathophysiological process of acute lung injury (ALI). Inflammation and oxidative stress serve an important role in the development of ALI. Leonurine (LEO) is a natural phenolic alkaloid extracted from Leonurus cardiaca, which possesses anti-inflammatory and antioxidative properties. Therefore, the aim of the present study was to explore the effect of LEO on sepsis-induced ALI and to investigate its underlying mechanism. MTT and Cell Counting Kit-8 assays were performed to measure cell viability. The levels of reactive oxygen species, lactate dehydrogenase and malondialdehyde, as well as the activity of superoxidase dismutase, were quantified using commercial assay kits. The expression levels of specific inflammatory cytokines were measured by using ELISA. In addition, western blotting was employed to assess the expression levels of cytokines, including TNF-α, IL-6, nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1. The findings demonstrated that LEO increased the viability of lipopolysaccharide (LPS)-stimulated BEAS-2B human lung epithelial cells in a dose-dependent manner. Additionally, LEO suppressed LPS-induced oxidative stress and inflammatory cytokine release in BEAS-2B cells. Treatment with Nrf2 inhibitor reversed the effects of LEO treatment on LPS-induced oxidative stress and inflammatory response in BEAS-2B cells. Taken together, the data of the present study indicated that LEO attenuated LPS-induced ALI through the inhibition of oxidative stress and inflammation regulated by the Nrf2 signaling pathway. Therefore, LEO may be a novel and effective agent for the prevention of sepsis-induced ALI.

The tandem stenosis mouse model: Towards understanding, imaging, and preventing atherosclerotic plaque instability and rupture

The rupture of unstable atherosclerotic plaques is the major cause of cardiovascular mortality and morbidity. Despite significant limitations in our understanding and ability to identify unstable plaque pathology and prevent plaque rupture, most atherosclerosis research utilises preclinical animal models exhibiting stable atherosclerosis. Here, we introduce the tandem stenosis (TS) mouse model that reflects plaque instability and rupture, as seen in patients. The TS model involves dual ligation of the right carotid artery, leading to locally predefined unstable atherosclerosis in hypercholesterolaemic mice. It exhibits key characteristics of human unstable plaques, including plaque rupture, luminal thrombosis, intraplaque haemorrhage, large necrotic cores, thin or ruptured fibrous caps and extensive immune cell accumulation. Altogether, the TS model represents an ideal preclinical tool for improving our understanding of human plaque instability and rupture, for the development of imaging technologies to identify unstable plaques, and for the development and testing of plaque-stabilising treatments for the prevention of atherosclerotic plaque rupture.