Anti-hypercholesterolemic Effects and a Good Safety Profile of SCM-198 in Animals: From ApoE Knockout Mice to Rhesus Monkeys

Although several lipid-lowering agents have been introduced for the treatment of atherosclerosis (AS), currently marketed medications have not solved the problem completely. This study aims to investigate the effects of leonurine (SCM-198) on dyslipidemia in mammals with ApoE knockout (ApoE-/-) mice, New Zealand white rabbits and senile Rhesus monkeys fed with high fat diet were dosed daily with leonurine or atorvastatin. The serum total cholesterol (TC), triglyceride (TG), low density lipoprotein (LDL), and high-density lipoprotein (HDL) were determined. Moreover, in Rhesus monkeys, bodyweight, arterial ultrasound of right common carotid artery, Apolipoprotein A1 (ApoA1) and ApoB levels, hematologic and toxicological examinations were detected. Serum TC and TG in both mice and rabbits were significantly reduced by SCM-198 and atorvastatin. In the 10 mg/kg SCM-198 group of monkeys, maximum TC reduction of 24.05% was achieved at day 150, while 13.16% LDL reduction achieved at day 60, without arterial morphologic changes or adverse events. Atorvastatin (1.2 mg/kg) showed similar effects as SCM-198 in improving lipid profiles in monkeys, yet its long-term use could induce tolerance. Furthermore, leonurine suppressed genes expression of fatty acid synthesis, such as fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD-1), sterol regulatory element-binding protein (SREBF) in liver in high fat diet feeding ApoE-/- mice. SCM-198, with a reliable safety profile, is of high value in improving lipid profiles in mammals, providing an alternative to a substantial population who are statin-intolerant

Hydrogen Sulfide Protects HUVECs against Hydrogen Peroxide Induced Mitochondrial Dysfunction and Oxidative Stress

10.1371/journal.pone.0053147PLoS ONE82

The Two-Way Switch Role of ACE2 in the Treatment of Novel Coronavirus Pneumonia and Underlying Comorbidities

December 2019 saw the emergence of the coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which has spread across the globe. The high infectivity and ongoing mortality of SARS-CoV-2 emphasize the demand of drug discovery. Angiotensin-converting enzyme II (ACE2) is the functional receptor for SARS-CoV-2 entry into host cells. ACE2 exists as a membrane-bound protein on major viral target pulmonary epithelial cells, and its peptidase domain (PD) interacts SARS-CoV-2 spike protein with higher affinity. Therefore, targeting ACE2 is an important pharmacological intervention for a SARS-CoV-2 infection. In this review, we described the two-way switch role of ACE2 in the treatment of novel coronavirus pneumonia and underlying comorbidities, and discussed the potential effect of the ACE inhibitor and angiotensin receptor blocker on a hypertension patient with the SARS-CoV-2 infection. In addition, we analyzed the S-protein-binding site on ACE2 and suggested that blocking hot spot-31 and hot spot-353 on ACE2 could be a therapeutic strategy for preventing the spread of SARS-CoV-2. Besides, the recombinant ACE2 protein could be another potential treatment option for SARS-CoV-2 induced acute severe lung failure. This review could provide beneficial information for the development of anti-SARS-CoV-2 agents via targeting ACE2 and the clinical usage of renin-angiotensin system (RAS) drugs for novel coronavirus pneumonia treatment

Novel protective effects of pulsed electromagnetic field ischemia/reperfusion injury rats

Synopsis Extracorporeal pulsed electromagnetic field (PEMF) has shown the ability to regenerate tissue by promoting cell proliferation. In the present study, we investigated for the first time whether PEMF treatment could improve the myocardial ischaemia/reperfusion (I/R) injury and uncovered its underlying mechanisms. In our study, we demonstrated for the first time that extracorporeal PEMF has a novel effect on myocardial I/R injury. The number and function of circulating endothelial progenitor cells (EPCs) were increased in PEMF treating rats. The in vivo results showed that per-treatment of PEMF could significantly improve the cardiac function in I/R injury group. In addition, PEMF treatment also reduced the apoptosis of myocardial cells by up-regulating the expression of anti-apoptosis protein B-cell lymphoma 2 (Bcl-2) and down-regulating the expression of pro-apoptosis protein (Bax). In vitro, the results showed that PEMF treatment could significantly reduce the apoptosis and reactive oxygen species (ROS) levels in primary neonatal rat cardiac ventricular myocytes (NRCMs) induced by hypoxia/reoxygenation (H/R). In particular, PEMF increased the phosphorylation of protein kinase B (Akt) and endothelial nitric oxide synthase (eNOS), which might be closely related to attenuated cell apoptosis by increasing the releasing of nitric oxide (NO). Therefore, our data indicated that PEMF could be a potential candidate for I/R injury

Antioxidant enzyme activities in each study groups.

<p>The data shown are mean ± SEM (n = 6). ** <i>p</i><0.01 vs control. # <i>p</i><0.05, ## <i>p</i><0.01 vs vehicle + H₂O₂ group.</p

Cell viability and death assay of HUVECs subjected to different concentrations of NaHS with or without H₂O₂.

<p>(<b>A</b>)–(<b>C</b>) MTT assay. (<b>A</b>) HUVECs were treated with 10–500 μM NaHS for 6 hours. (<b>B</b>) HUVECs were treated with 0.2–1.5 mM H₂O₂ for 4 hours. (<b>C</b>) HUVECs were pretreated with vehicle or 30–500 μM NaHS for 6 hours, followed by exposure to 600 μM H₂O₂ for another 4 hours. (<b>D</b>) LDH Release. HUVECs were pretreated with vehicle or 300 μM NaHS and 10 mM PAG for 6 hours, followed by exposure to 600 μM H₂O₂ for another 4 hours. Cell viability in each treatment group is expressed as a percentage of control. (<b>E</b>)–(<b>H</b>) Hoechst staining. HUVECs were pretreated with vehicle, 300 μM NaHS or 10 mM PAG for 6 hours, followed by exposure to 600 μM H₂O₂ for another 4 hours. Cells were observed under ×200 microscopy. Scale bar is shown at 100 μm. (<b>I</b>)–(<b>M</b>) Annexin V/PI staining detected by flow cytometry. HUVECs were pretreated with vehicle or 300 μM NaHS and 10 mM PAG for 6 hours, followed by exposure to 600 μM H₂O₂ for another 4 hours. The data shown are mean ± SEM (n = 9). ** <i>p</i><0.01 vs control. ## <i>p</i><0.01 vs vehicle + H₂O₂.</p

Effects of NaHS on protein expressions of antioxidant enzymes.

<p>(<b>A</b>) Western-blot analysis showing the intensities of Catalase, SOD-1, SOD-2, GST and GPx in each group, (<b>B</b>)–(<b>F</b>) bar charts indicating the different intensities of antioxidant proteins between groups. Values were normalized against the control values. The data shown are mean ± SEM (n = 6). * <i>p</i><0.05, ** <i>p</i><0.01 vs control. # <i>p</i><0.05, ## <i>p</i><0.01 vs vehicle + H₂O₂ group.</p

Effects of NaHS on H₂S levels and H₂S synthesizing enzyme activities.

<p>(<b>A</b>) The changes of H₂S levels in medium for each treatment group (expressed in μM). (<b>B</b>) CSE activities in HUVECs lysate of each group, presented as μmol/h/g. (<b>C</b>) CSE protein expressions levels as determined using western blot analysis. (<b>D</b>) CSE mRNA expression levels as determined by real-time PCR. (<b>E</b>) CBS protein expressions levels and (<b>F</b>) The CBS mRNA expression tested by real-time PCR. The values in (C)–(F) were normalized against the control values. The data shown are mean ± SEM (n = 6). * <i>p</i><0.05, ** <i>p</i><0.01 vs control. # <i>p</i><0.05 vs vehicle + H₂O₂ group.</p

Ultrastructural changes in HUVECs induced by H₂O₂ using transmission electron microscopy.

<p>(<b>A</b>)–(<b>D</b>) showed HUVECs with legible nucleus. Scale bar is shown at 1 μm. (<b>E</b>)–(<b>H</b>) showed mitochondria. Scale bar is shown at 0.2 μm. (<b>A</b>) and (<b>E</b>) cell and mitochondria in the control group; (<b>B</b>) and (<b>F</b>) cell and mitochondria in vehicle + H₂O₂ group; (<b>C</b>) and (<b>G</b>) cell and mitochondria in NaHS + H₂O₂ group; (<b>D</b>) and (<b>H</b>) cell and mitochondria in PAG + H₂O₂ group.</p

Effects of NaHS on mitochondrial function.

<p>(<b>A</b>) ATP synthesis. After pretreatment with vehicle, 300 μM NaHS or 10 mM PAG for 6 hours and followed by exposure to 600 μM H₂O₂ for another 4 hours, HUVECs were harvested to collect mitochondria. The rate of ATP synthesis was expressed by µmol ATP/min/g of mitochondrial protein. (<b>B</b>) Release of cytochrome c from mitochondria. After treatments as previous description, HUVECs were harvested to collect mitochondria and cytosol. The protein expression was tested by western blot. The bar chart showed the ratio of cytochrome c in cytosol to that in mitochondria, indicating the intensity of release of cytochrome c. (<b>C</b>) MDA changes in HUVECs mediated by H₂O₂. The data are expressed at nmol/mg. (<b>D</b>) Fluorescent intensity of DPPP in HUVECs mediated by H₂O₂. (<b>E</b>) ROS production was stained by 10 μM H₂DCFDA for 20 min, whose oxidation product (DCF) fluorescence indicated ROS formation. (<b>F</b>) ROS production was stained by 5 μM DHE for 30 min, which fluorescence indicated ROS formation. The absorbance values in (D)–(F) of HUVECs were normalized against the values for normal controls and expressed as a percentage of control. (<b>G</b>)–(<b>L</b>) JC-1 staining. Red fluorescence represents the mitochondrial aggregate form of JC-1, indicating intact mitochondrial membrane potential. Green fluorescence represents the monomeric form of JC-1, indicating dissipation of Δ<i>Ψ</i>_m. (G)–(J) HUVECs were stained with JC-1. (K) CCCP was the positive control. Cells were observed under ×200 microscopy. Scale bar is shown at 100 μm. (L) Ratio of red to green fluorescence, indicating ratio of JC-1 polymer/monomer. The data shown are mean ± SEM (n = 6). * <i>p</i><0.05, ** <i>p</i><0.01vs control. # <i>p</i><0.05, ## <i>p</i><0.01 vs vehicle + H₂O₂ group.</p