Salidroside protects against foam cell formation and apoptosis, possibly via the MAPK and AKT signaling pathways

Salidroside Reduced Ca2+-CaM-CAMKII-Dependent eNOS/NO Activation to Decrease Endothelial Cell Injury Induced by Cold Combined with Hypoxia

To investigate vascular endothelium damage in rats exposed to hypoxic and cold and the effect of salidroside in protecting against this damage. A rat isolated aortic ring hypoxia/cold model was established to simulate exposure to hypoxic and cold. The levels of endothelial cell injury markers were measured by ELISA. TEM was performed to observe the ultrastructure of vascular ring endothelial cells. In vitro assays were performed to verify the effect of salidroside on endothelial cells. CCK-8 and flow cytometry were performed to analyze endothelial cell survival and apoptosis, respectively. Ca2+ concentrations were measured by Flow cytometry, and the expressions of NOS/NO pathway-related proteins were measured by WB. Endothelial cell damage, mitochondrial swelling, autophagy, and apoptosis were increased in the hypoxia group and hypoxia/hypothermia group. All of these effects were inhibited by salidroside. Moreover, exposure to cold combined with hypoxia reduced the NO levels, Ca2+ concentrations and NOS/NO pathway-related protein expression in the hypoxia group and hypoxia/hypothermia group. Salidroside treatment reversed these changes. Salidroside protected against endothelial cell injury induced by cold and hypoxia through reduction of Ca2+-CaM-CAMKII-dependent eNOS/NO activation, thereby preventing mitochondrial damage, reducing ROS levels, and inhibiting apoptosis.

Zhizi-Chuanxiong herb pair alleviates atherosclerosis progression in ApoE-/- mice by promoting the methylation of FGFR3 to inhibit MAPK/ERK-mediated apoptosis

ETHNOPHARMACOLOGICAL RELEVANCE

Gardenia Fructus (Gardenia jasminoides Ellis, Zhizi) and Chuanxiong Rhizoma (Ligusticum chuanxiong Hort., Chuanxiong) are both traditional Chinese medicines with vascular protective effects, which help detoxify and activate blood, and are clinically used to treat atherosclerosis (AS). Previously, Zhizi-Chuanxiong showed good efficacy in attenuating AS progression in rabbits. However, its potential mechanism is yet unclear.

AIM OF THE STUDY

This study aimed to investigate the mechanism of the Zhizi-Chuanxiong herb pair (ZCHP) in attenuating AS progression from the perspective of DNA methylation.

MATERIALS AND METHODS

An AS mouse model was developed with ApoE-/- mice fed a high-fat diet (HFD). The therapeutic effects and mechanisms of ZCHP in treating HFD-induced AS were identified using an automated biochemical analyzer, enzyme-linked immunosorbent assays, histopathology, methyl-capture sequencing (MC-seq), pyrosequencing, quantitative reverse transcription-polymerase chain reaction (RT-qPCR), western blotting, and TUNEL staining.

RESULTS

ZCHP attenuated the development of AS by reducing lipid levels and enhancing the stability of plaques and via anti-inflammation. MC-seq and Kyoto Encyclopedia of Genes and Genomes analysis revealed that ZCHP corrected the expressions of both aberrant hypomethylated and hypermethylated genes, which are involved in the mitogen-activated protein kinase (MAPK) signaling pathway. Protein-protein network interaction analysis and molecular docking showed that fibroblast growth factor 3 (FGFR3) and serine/threonine protein kinase (AKT1) were closely related to the MAPK signaling pathway among differentially methylated genes induced by ZCHP. Furthermore, pyrosequencing showed that ZCHP could induce FGFR3 hypermethylation and AKT1 hypomethylation in the promoter region, which was consistent with the MC-seq results. Molecular docking showed that the ZCHP was more tightly docked to FGFR3. Furthermore, RT-qPCR and western blotting showed that the mRNA and protein expression levels of FGFR3 decreased after treatment with ZCHP. Finally, western blotting showed that ZCHP suppressed the expression of phosphorylated MAPK and phosphorylated extracellular signal-regulated kinase (ERK), and TUNEL staining showed that ZCHP treatment could inhibit apoptosis in AS.

CONCLUSION

Our findings suggest that ZCHP can effectively attenuate AS progression by inhibiting MAPK/ERK signaling-mediated apoptosis via FGFR3 hypermethylation in the promoter region.

Mechanism of salidroside against coronary artery disease by network pharmacology analysis

BACKGROUND

Rosenroot (Rhodiola rosea) is a traditional Chinese herbal medicine. It has been used to treat patients with coronary artery disease (CAD). Salidroside is the main active constituent of rosenroot. This study was designed to explore the mechanism of salidroside in treating CAD and its role in angiogenesis in CAD systematically.

METHODS

In this study, potential targets related to salidroside and CAD were obtained from public databases. Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), Disease Ontology (DO) and CellMarker enrichment analyses were performed. The binding of salidroside to angiogenesis-related targets was assessed by PyMOL and Ligplot. Furthermore, the effects of salidroside on collateral circulation were evaluated by correlation analysis of these angiogenesis-related targets with the coronary flow index (CFI), and the influence of salidroside on human umbilical vein endothelial cell (HUVEC) proliferation and migration was assessed.

RESULTS

Eighty-three targets intersected between targets of salidroside and CAD. GO and KEGG analyses indicated that salidroside mainly treated CAD through angiogenesis and anti-inflammatory action. There were 12 angiogenesis-related targets of salidroside in coronary heart disease, among which FGF1 (r = 0.237, P = 2.597E-3), KDR (r = 0.172, P = 3.007E-2) and HIF1A (r = -0.211, P = 7.437E-3) were correlated with the coronary flow index (CFI), and salidroside docked well with them. Finally, cell experiments confirmed that salidroside promoted the proliferation and migration of HUVECs.

CONCLUSIONS

This study revealed the potential molecular mechanism of salidroside on angiogenesis in CAD and provided new ideas for the clinical application of salidroside in the treatment of CAD.

Cyclophilin A accelerates SiO2-induced macrophage foaming

Silicosis is a common occupational disease characterized by lung inflammation, fibrosis and pulmonary dysfunction caused by long-term inhalation of free SiO₂. Cell foaming and the change of CyPA have been observed in SiO₂-induced macrophages, but the specific mechanism of CyPA in SiO₂-induced foam cells remains poorly understood. The purpose of this study is to explore the mechanism of CyPA in SiO₂-induced macrophage foaming and its effect on silicosis. We found that overexpression of CyPA promoted the macrophage foaming and the expression of COL I and α-SMA, while silencing CyPA inhibites the macrophage foaming and the expression of COL I and α-SMA. After blocking the expression of CD36 on the basis of overexpression CyPA, we found it inhibites the macrophage foaming. In conclusion, CyPA can affect the foaming of macrophages and may participate in silicosis fibrosis.

The Promoting Effect of Traumatic Brain Injury on the Incidence and Progression of Glioma: A Review of Clinical and Experimental Research

The role of traumatic brain injury in the development of glioma is highly controversial since first presented. This is not unexpected because traumatic brain injuries are overwhelmingly more common than glioma. However, the causes of post-traumatic glioma have been long discussed and still warrant further research. In this review, we have presented an overview of previous cohort studies and case–control studies. We have summarized the roles of microglial cells, macrophages, astrocytes, and stem cells in post-traumatic glioma formation and development, and reviewed various carcinogenic factors involved during traumatic brain injury, especially those reported in experimental studies indicating a relationship with glioma progression. Besides, traumatic brain injury and glioma share several common pathways, including inflammation and oxidative stress; however, the exact mechanism underlying this co-occurrence is yet to be discovered. In this review, we have summarized current epidemiological studies, clinical reports, pathophysiological research, as well as investigations evaluating the probable causes of co-occurrence and treatment possibilities. More efforts should be directed toward elucidating the relationship between traumatic brain injury and glioma, which could likely lead to promising pharmacological interventions towards designing therapeutic strategies.

The Therapeutic Effects and Mechanisms of Salidroside on Cardiovascular and Metabolic Diseases: An Updated Review

The increasing incidence of metabolic and cardiovascular diseases has severely affected global human health and life safety. In recent years, some effective drugs with remarkable curative effects and few side effects found in natural compounds have attracted attention. Salidroside (SAL), a phenylpropane glycoside, is the main active ingredient of the plateau plant Rhodiola. So far, many animal experiments proved that SAL has good biological activity against some metabolic and cardiovascular diseases. However, most of these reports are scattered. This review systematically summarizes the pharmacological progress of SAL in the treatment of several metabolic (e. g., diabetes and non-alcoholic fatty liver disease) and cardiovascular (e. g., atherosclerosis) diseases in a timely manner to promote the clinical application and basic research of SAL. Accumulating evidence proves that SAL has beneficial effects on these diseases. It can improve glucose tolerance, insulin sensitivity, and β-cell and liver functions, and inhibit adipogenesis, inflammation and oxidative stress. Overall, SAL may be a valuable and potential drug candidate for the treatment of metabolic and cardiovascular diseases. However, more studies especially clinical trials are needed to further confirm its therapeutic effects and molecular mechanisms.

Chinese Herbal Medicines and Active Metabolites: Potential Antioxidant Treatments for Atherosclerosis

Atherosclerosis is a complex chronic disease that occurs in the arterial wall. Oxidative stress plays a crucial role in the occurrence and progression of atherosclerotic plaques. The dominance of oxidative stress over antioxidative capacity generates excess reactive oxygen species, leading to dysfunctions of the endothelium and accelerating atherosclerotic plaque progression. Studies showed that Chinese herbal medicines and traditional Chinese medicine (TCM) might regulate oxidative stress; they have already been used to treat diseases related to atherosclerosis, including stroke and myocardial infarction. This review will summarize the mechanisms of oxidative stress in atherosclerosis and discuss studies of Chinese herbal medicines and TCM preparations treating atherosclerosis, aiming to increase understanding of TCM and stimulate research for new drugs to treat diseases associated with oxidative stress.

Salidroside downregulates microRNA‑133a and inhibits endothelial cell apoptosis induced by oxidized low‑density lipoprotein

Vascular endothelial cell apoptosis is regulated by microRNA-133a (miR-133a), which participates in the formation of atherosclerotic (AS) plaques, leading to the development of several cardiovascular diseases. Salidroside (SAL), the main component of Rhodiola, is considered to exert anti-AS effect; however, its mode of action remains unclear. Thus, the present study aimed to determine whether SAL inhibits endothelial cell apoptosis through the miR-133a pathway. Cultured human coronary artery endothelial cells (HCAECs) were exposed to oxidized low-density lipoprotein (ox-LDL). Cell viability and cytotoxicity were monitored by MTT assay. In parallel, the mRNA expression levels of miR-133a and Bcl-xL, and the protein levels of anti-apoptotic Bcl-xL and activated caspase-3 were measured. The apoptotic levels were examined by flow cytometry. Furthermore, the effects of silencing and overexpressing miR-133a on the parameters mentioned above were evaluated. Exposure to ox-LDL induced an increase in the expression of miR-133a, with a concomitant decrease in the level of Bcl-xL in the HCAECs; these effects were reversed by treatment with SAL. Importantly, the effects of SAL were impaired upon the silencing of miR-133a, whereas the overexpression of miR-133a partly restored the effects of SAL. On the whole, the findings of the present study demonstrate that SAL inhibits the ox-LDL-induced upregulation of miR-133a expression, while promoting the expression of Bcl-xL, thereby preventing endothelial cell apoptosis.

Impact of natural products on the cholesterol transporter ABCA1

ETHNOPHARMACOLOGICAL RELEVANCE

In different countries and areas of the world, traditional medicine has been and is still used for the treatment of various disorders, including chest pain or liver complaints, of which we now know that they can be linked with altered lipid and cholesterol homeostasis. As ATP-binding cassette transporter A1 (ABCA1) plays an essential role in cholesterol metabolism, its modulation may be one of the molecular mechanisms responsible for the experienced benefit of traditional recipes. Intense research activity has been dedicated to the identification of natural products from traditional medicine that regulate ABCA1 expression.

AIMS OF THE REVIEW

This review surveys natural products, originating from ethnopharmacologically used plants, fungi or marine sources, which influence ABCA1 expression, providing a reference for future study.

MATERIALS AND METHODS

Information on regulation of ABCA1 expression by natural compounds from traditional medicine was extracted from ancient and modern books, materia medica, and electronic databases (PubMed, Google Scholar, Science Direct, and ResearchGate).

RESULTS

More than 60 natural compounds from traditional medicine, especially traditional Chinese medicine (TCM), are reported to regulate ABCA1 expression in different in vitro and in vivo models (such as cholesterol efflux and atherosclerotic animal models). These active compounds belong to the classes of polyketides, terpenoids, phenylpropanoids, tannins, alkaloids, steroids, amino acids and others. Several compounds appear very promising in vivo, which need to be further investigated in animal models of diseases related to ABCA1 or in clinical studies.

CONCLUSION

Natural products from traditional medicine constitute a large promising pool for compounds that regulate ABCA1 expression, and thus may prevent/treat diseases related to cholesterol metabolism, like atherosclerosis or Alzheimer's disease. In many cases, the molecular mechanisms of these natural products remain to be investigated.

Ameliorative Effects and Cellular Aspects of Phytoconstituents in Atherosclerosis

Atherosclerosis is a cardiovascular disease that involves vessels through the development of fatty streaks and plaques. Plant-based compounds can help treat or prevent atherosclerosis by affecting various factors that are involved in the disease. The present review discusses our current knowledge of the major cellular and molecular mechanisms of phytotherapeutics for the treatment of atherosclerosis. Numerous studies have evaluated the antiatherosclerotic activity of phytoconstituents to provide preliminary evidence of efficacy, but only a few studies have delineated the underlying molecular mechanisms. Plant-derived phytotherapeutics primarily targets abnormal levels of lipoproteins, endothelial dysfunction, smooth muscle cell migration, foam cell development, and atheromatous plaque formation. Nonetheless, the principal mechanisms that are responsible for their therapeutic actions remain unclear. Further pharmacological studies are needed to elucidate the underlying molecular mechanisms of the antiatherosclerotic response to these phytoconstituents.

The interrelationship between cerebral ischemic stroke and glioma: a comprehensive study of recent reports

Glioma and cerebral ischemic stroke are two major events that lead to patient death worldwide. Although these conditions have different physiological incidences, ~10% of ischemic stroke patients develop cerebral cancer, especially glioma, in the postischemic stages. Additionally, the high proliferation, venous thrombosis and hypercoagulability of the glioma mass increase the significant risk of thromboembolism, including ischemic stroke. Surprisingly, these events share several common pathways, viz. hypoxia, cerebral inflammation, angiogenesis, etc., but the proper mechanism behind this co-occurrence has yet to be discovered. The hypercoagulability and presence of the D-dimer level in stroke are different in cancer patients than in the noncancerous population. Other factors such as atherosclerosis and coagulopathy involved in the pathogenesis of stroke are partially responsible for cancer, and the reverse is also partially true. Based on clinical and neurosurgical experience, the neuronal structures and functions in the brain and spine are observed to change after a progressive attack of ischemia that leads to hypoxia and atrophy. The major population of cancer cells cannot survive in an adverse ischemic environment that excludes cancer stem cells (CSCs). Cancer cells in stroke patients have already metastasized, but early-stage cancer patients also suffer stroke for multiple reasons. Therefore, stroke is an early manifestation of cancer. Stroke and cancer share many factors that result in an increased risk of stroke in cancer patients, and vice-versa. The intricate mechanisms for stroke with and without cancer are different. This review summarizes the current clinical reports, pathophysiology, probable causes of co-occurrence, prognoses, and treatment possibilities.

The role of traditional Chinese medicine in the treatment of atherosclerosis through the regulation of macrophage activity

Atherosclerosis (AS) is the main cause of ischemic cardiovascular, cerebrovascular and peripheral vascular diseases. Macrophage activity has been proven to play a critical role during the AS pathological process, which involves the adhesion, aggregation of mononuclear-macrophages, cell differentiation of M1/M2 macrophages as part of complex mechanisms occurring during lipid metabolism, apoptosis, autophagy, inflammation and immune reaction. Therefore, the development of effective AS treatments is likely to target macrophage activity. Certain herbal extracts (such as Salvia miltiorrhiza) have exhibited enormous potential for AS treatment in the past. Here, we aim to provide a summary on the current understanding of the type of action and the underlying target/pathway in macrophage regulation of certain herbal extracts used in Traditional Chinese Medicine for treatment of AS.

Protective Effects of Salidroside against Carbon Tetrachloride (CCl4)-Induced Liver Injury by Initiating Mitochondria to Resist Oxidative Stress in Mice

The antioxidant effect of salidroside has been proven, but its role in liver injury is poorly understood. In this study, we aimed to evaluate the protective effects and mechanism of salidroside on liver injury induced by carbon tetrachloride (CCl4) in vivo. Mice were pretreated with salidroside (60 mg/kg, intraperitoneally injected, i.p.) once per day for 14 consecutive days and then administered with CCl4 (15.95 g/kg, i.p.) for 24 h to produce a liver injury model. Salidroside attenuated hepatic transaminase elevation in serum and ameliorated liver steatosis and necrosis, thereby suggesting its protective effect on the liver. Salidroside antagonized CCl4-induced toxicity by equilibrating antioxidation system, thereby inhibiting reactive oxygen species accumulation, and restoring mitochondrial structure and function. Salidroside exerts antioxidant and liver-protective effects by selectively inhibiting the activation of genes, including growth arrest and DNA -damage-inducible 45 α (Gadd45a), mitogen-activated protein kinase 7 (Mapk7), and related RAS viral oncogene homolog 2 (Rras2), which induce oxidative stress in the mitogen-activated protein kinase pathway. These results revealed that salidroside can protect the liver from CCl4-induced injury by resisting oxidative stress and protecting mitochondrial function.

Salidroside protects against ox-LDL-induced endothelial injury by enhancing autophagy mediated by SIRT1-FoxO1 pathway

Background

Atherosclerosis is a condition with the vascular accumulation of lipid plaques, and its main major contributing factor is endothelial injury induced by oxidized low-density lipoprotein (ox-LDL). Salidroside (SAL) is the primary active ingredient of Rhodiola rosea, and exhibits antioxidant properties on endothelial cells and alleviates atherosclerosis. However, the effect of SAL on autophagy in ox-LDL-induced vascular endothelial injury remains unclear. Here, we investigated the effect and underlying mechanisms of SAL on autophagy in human umbilical vein endothelial cells (HUVECs).

Methods

HUVECs were incubated with ox-LDL to induce in vitro atherosclerosis model. The cell viability and injury were evaluated by cell counting kit-8 (CCK-8) assay and lactate dehydrogenase (LDH) release assay. The oxidative stress was evaluated by NADPH oxidase, malondialdehyde (MDA) and superoxide dismutase (SOD) activities. Immunofluorescence was performed to detect autophagy using LC3β antibody. Quantitative real-time PCR (qRT-PCR) and western blot were performed to measure the mRNA expressions of SIRT1 and Forkhead box O1 (FOXO1). Nicotinamide (NAM) and AS1842856 were used to inhibit activities of SIRT1 and FOXO1, respectively.

Results

Exposure of HUVECs to ox-LDL (100 μg/mL) reduced cell viability, increased cellular MDA, and reduced SOD in a concentration-dependent manner. The pretreatment with SAL (20, 50 and 100 μM) significantly enhanced the cell viability and decreased LDH release in HUVECs exposed to ox-LDL (100 μg/mL). ox-LDL induced autophagy in HUVECs, which was further enhanced by pretreatment with SAL. However, SAL attenuated increase in oxidative stress in HUVECs induced by ox-LDL. ox-LDL reduced mRNA and protein expressions of SIRT1 and FOXO1, which could be reversed by SAL. The protective, anti-oxidative and pro-autophagic effects of SAL could be obviously abolished by cotreatment with SIRT1 inhibitor or FOXO1 inhibitor.

Conclusion

Salidroside shows protective effect on endothelial cell induced by ox-LDL, and the mechanisms might be related to autophagy induction via increasing SIRT1 and FoxO1 expressions.

Salidroside attenuates oxidized low‑density lipoprotein‑induced endothelial cell injury via promotion of the AMPK/SIRT1 pathway

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial damage contributes to the initiation and pathogenesis of atherosclerosis. Salidroside can alleviate atherosclerosis and attenuate endothelial cell injury induced by ox-LDL. However, the mechanisms involved in this process are not fully understood. Therefore, the purpose of the present study was to investigate the role of the adenosine monophosphate-activated protein kinase (AMPK)/sirtuin (SIRT)1 pathway in the protection of salidroside against ox-LDL-induced human umbilical vein endothelial cells (HUVECs) injuries. The results revealed that salidroside reverses ox-LDL-induced HUVECs injury as demonstrated by the upregulation of cell viability and downregulation of LDH release. In addition, salidroside increased the expression of the SIRT1 protein in ox-LDL-treated HUVECs. Next, it was demonstrated that SIRT1 knockdown induced by transfection with small interfering (si)RNA targeting SIRT1 (siSRT1) abolished the protection of salidroside against ox-LDL-induced HUVECs injuries. This was illustrated by a decrease in cell viability and an increase in LDH release, caspase-3 activity and apoptosis rate. Furthermore, salidroside mitigated ox-LDL-induced reactive oxygen species production, upregulated malondialdehyde content and NADPH oxidase 2 expression and decreased superoxide dismutase and glutathione peroxidase activities, while these effects were also reversed by siSIRT1 transfection. In addition, it was demonstrated that salidroside suppressed ox-LDL-induced mitochondrial dysfunction as demonstrated by the increase in mitochondrial membrane potential and decreases in cytochrome c expression, and Bax/Bcl-2 reductions. However, these effects were eliminated by SIRT1 knockdown. Finally, it was demonstrated that salidroside significantly upregulated the phosphorylated-AMPK expression in ox-LDL-treated HUVECs and AMPK knockdown induced by transfection with AMPK siRNA (siAMPK) leads to elimination of the salidroside-induced increase in cell viability and the decrease in LDH release. Notably, siAMPK transfection further decreased the expression of SIRT1. In conclusion, these results suggested that salidroside protects HUVECs against ox-LDL injury through inhibiting oxidative stress and improving mitochondrial dysfunction, which were dependent on activating the AMPK/SIRT1 pathway.

The Role of Natural Products in Targeting Cardiovascular Diseases via Nrf2 Pathway: Novel Molecular Mechanisms and Therapeutic Approaches

Cardiovascular diseases (CVDs) are closely linked to cellular oxidative stress and inflammation. This may be resulted from the imbalance generation of reactive oxygen species and its role in promoting inflammation, thereby contributing to endothelial dysfunction and cardiovascular complications. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that plays a significant role in regulating expression of antioxidant and cytoprotective enzymes in response to oxidative stress. Natural products have emerged as a potential source of bioactive compounds which have shown to protect against atherogenesis development by activating Nrf2 signaling. This review aims to provide a comprehensive summary of the published data on the function, regulation and activation of Nrf2 as well as the molecular mechanisms of natural products in regulating Nrf2 signaling. The beneficial effects of using natural bioactive compounds as a promising therapeutic approach for the prevention and treatment of CVDs are reviewed.