scholarly journals Identification of Anti-Severe Acute Respiratory Syndrome-Related Coronavirus 2 (SARS-CoV-2) Oxysterol Derivatives In Vitro

2021 ◽  
Vol 22 (6) ◽  
pp. 3163
Author(s):  
Hirofumi Ohashi ◽  
Feng Wang ◽  
Frank Stappenbeck ◽  
Kana Tsuchimoto ◽  
Chisa Kobayashi ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Viral Replication ◽  
Cultured Cells ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Membrane Vesicles ◽  
Drug Candidates ◽  
Increased Risk ◽  
Derivatives Of

The development of effective antiviral drugs targeting the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) is urgently needed to combat the coronavirus disease 2019 (COVID-19). We have previously studied the use of semi-synthetic derivatives of oxysterols, oxidized derivatives of cholesterol as drug candidates for the inhibition of cancer, fibrosis, and bone regeneration. In this study, we screened a panel of naturally occurring and semi-synthetic oxysterols for anti-SARS-CoV-2 activity using a cell culture infection assay. We show that the natural oxysterols, 7-ketocholesterol, 22(R)-hydroxycholesterol, 24(S)-hydroxycholesterol, and 27-hydroxycholesterol, substantially inhibited SARS-CoV-2 propagation in cultured cells. Among semi-synthetic oxysterols, Oxy210 and Oxy232 displayed more robust anti-SARS-CoV-2 activities, reducing viral replication more than 90% at 10 μM and 99% at 15 μM, respectively. When orally administered in mice, peak plasma concentrations of Oxy210 fell into a therapeutically relevant range (19 μM), based on the dose-dependent curve for antiviral activity in our cell-based assay. Mechanistic studies suggest that Oxy210 reduced replication of SARS-CoV-2 by disrupting the formation of double-membrane vesicles (DMVs); intracellular membrane compartments associated with viral replication. Our study warrants further evaluation of Oxy210 and Oxy232 as a safe and reliable oral medication, which could help protect vulnerable populations with increased risk of developing COVID-19.

scholarly journals Identification of anti-severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) oxysterol derivatives in vitro

2021 ◽  
Author(s):  
Hirofumi Ohashi ◽  
Feng Wang ◽  
Frank Stappenbeck ◽  
Kana Tsuchimoto ◽  
Chisa Kobayashi ◽  
...  
Keyword(s):  
Cell Culture ◽  
Severe Acute Respiratory Syndrome ◽  
Antiviral Activity ◽  
Viral Replication ◽  
Cultured Cells ◽  
Plasma Concentrations ◽  
Hepatitis D ◽  
Infection Assay ◽  
Naturally Occurring ◽  
Increased Risk

AbstractDevelopment of effective antiviral drugs targeting the severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) are urgently needed to combat the coronavirus disease 2019 (COVID-19). Oxysterols, defined as oxidized derivatives of cholesterol, include endogenous (naturally occurring) cholesterol metabolites as well as semi-synthetic oxysterol derivatives. We have previously studied the use of semi-synthetic oxysterol derivatives as drug candidates for inhibition of cancer, fibrosis, and bone regeneration. In this study, we have screened a panel of naturally occurring and semi-synthetic oxysterol derivatives for anti-SARS-CoV-2 activity, using a cell culture infection assay. We show that the natural oxysterols, 7-ketocholesterol, 22(R)-hydroxycholesterol, 24(S)-hydroxycholesterol, and 27-hydroxycholesterol, substantially inhibited SARS-CoV-2 propagation in cultured cells. Among semi-synthetic oxysterols, Oxy186 displayed antiviral activity comparable to natural oxysterols. In addition, related oxysterol analogues Oxy210 and Oxy232 displayed more robust anti-SARS-CoV-2 activities, reducing viral replication more than 90% at 10 μM and 99% at 15 μM, respectively. When orally administered in mice, peak plasma concentrations of Oxy210 fall into a therapeutically relevant range (19 μM), based on the dose-dependent curve for antiviral activity in our cell culture infection assay. Mechanistic studies suggest that Oxy210 reduced replication of SARS-CoV-2 with disrupting the formation of double membrane vesicles (DMVs), intracellular membrane compartments associated with viral replication. Oxy210 also inhibited the replication of hepatitis C virus, another RNA virus whose replication is associated with DMVs, but not the replication of the DMV-independent hepatitis D virus. Our study warrants further evaluation of Oxy210 and Oxy232 as a safe and reliable oral medication, which could help protect vulnerable populations with increased risk developing COVID-19.

scholarly journals In vitro efficacy of Artemisia extracts against SARS-CoV-2

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Chuanxiong Nie ◽  
Jakob Trimpert ◽  
Sooyeon Moon ◽  
Rainer Haag ◽  
Kerry Gilmore ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Plant Extracts ◽  
Artemisia Annua ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Herbal Extracts ◽  
Traditional Medicines ◽  
Affect Cell Viability ◽  
Feline Coronavirus

Abstract Background Traditional medicines based on herbal extracts have been proposed as affordable treatments for patients suffering from coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Teas and drinks containing extracts of Artemisia annua and Artemisia afra have been widely used in Africa in efforts to prevent SARS-CoV-2 infection and fight COVID-19. Methods The plant extracts and Covid-Organics drink produced in Madagascar were tested for plaque reduction using both feline coronavirus and SARS-CoV-2 in vitro. Their cytotoxicities were also investigated. Results Several extracts as well as Covid-Organics inhibited SARS-CoV-2 and FCoV infection at concentrations that did not affect cell viability. Conclusions Some plant extracts show inhibitory activity against FCoV and SARS-CoV-2. However, it remains unclear whether peak plasma concentrations in humans can reach levels needed to inhibit viral infection following consumption of teas or Covid-Organics. Clinical studies are required to evaluate the utility of these drinks for COVID-19 prevention or treatment of patients.

scholarly journals In vitro efficacy of Artemisia extracts against SARS-CoV-2

2021 ◽  
Author(s):  
Chuanxiong Nie ◽  
Jakob Trimpert ◽  
Sooyeon Moon ◽  
Rainer Haag ◽  
Kerry Gilmore ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Clinical Studies ◽  
Artemisia Annua ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Herbal Extracts ◽  
Traditional Medicines ◽  
Affect Cell Viability ◽  
Feline Coronavirus

AbstractTraditional medicines based on herbal extracts have been proposed as affordable treatments for patients suffering from coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Teas and drinks containing extracts of Artemisia annua and Artemisia afra have been widely used in Africa in efforts to prevent and fight COVID-19 infections. We sought to study the ability of different A. annua and A. afra extracts and the Covid-Organics drink produced in Madagascar to inhibit SARS-CoV-2 and feline coronavirus (FCoV) replication in vitro. Several extracts as well as Covid-Organics inhibit SARS-CoV-2 and FCoV replication at concentrations that did not affect cell viability. It remains unclear whether peak plasma concentrations in humans can reach levels needed to inhibit viral replication following consumption of teas or Covid-Organics. Clinical studies are required to evaluate the utility of these drinks for COVID-19 prevention or treatment in patients.

scholarly journals Caspofungin and LTX-315 inhibit SARS-CoV-2 replication by targeting the nsp12 polymerase

2020 ◽  
Author(s):  
Min Wang ◽  
Fei Ye ◽  
Jiaqi Su ◽  
Jingru Zhao ◽  
Bin Yuan ◽  
...  
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Vero Cells ◽  
Polymerase Activity ◽  
Structural Protein ◽  
Live Virus ◽  
Drug Candidates ◽  
Virtual Screen ◽  
Virus Assay ◽  
Promising Target

Abstract The ongoing severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, previously designated as 2019-nCoV) outbreak has caused global concern1. Currently, there are no clinically approved specific drugs or vaccines available for this virus. The viral polymerase is a promising target for developing broad- spectrum antiviral drugs. Here, based on the highly similar structure of SARS- CoV non-structural protein 12 (nsp12) polymerase subunit2, we applied virtual screen for the available compounds, including both the FDA-approved and under- clinic drugs, to identify potential antiviral molecules against SARS-CoV-2. We found two drugs, the clinically approved anti-fungi drug Caspofungin Acetate (Cancidas) and the oncolytic peptide LTX-315, can bind SARS-CoV-2 nsp12 protein to block the polymerase activity in vitro. Further live virus assay revealed that both Caspofungin Acetate and LTX-315 can effectively inhibit SARS-CoV-2 replication in vero cells. These findings present promising drug candidates for treatment of related diseases and would also stimulate the development of pan- coronavirus antiviral agents.Authors Min Wang, Fei Ye, Jiaqi Su, Jingru Zhao, and Bin Yuan contributed equally to this work.

scholarly journals Vancomycin In Vitro Bactericidal Activity and Its Relationship to Efficacy in Clearance of Methicillin-Resistant Staphylococcus aureus Bacteremia

2007 ◽  
Vol 51 (7) ◽  
pp. 2582-2586 ◽  
Author(s):  
Pamela A. Moise ◽  
George Sakoulas ◽  
Alan Forrest ◽  
Jerome J. Schentag
Keyword(s):  
Staphylococcus Aureus ◽  
Median Time ◽  
Bactericidal Activity ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Accessory Gene ◽  
Vancomycin Therapy ◽  
Methicillin Resistant ◽  
Vancomycin Mics

ABSTRACT We examined the relationship between the time to clearance of methicillin-resistant Staphylococcus aureus (MRSA) bacteremia while patients were receiving vancomycin therapy and the in vitro bactericidal activity of vancomycin. Vancomycin killing assays were performed with 34 MRSA bloodstream isolates (17 accessory gene regulator group II [agr-II] and 17 non-agr-II isolates) from 34 different patients with MRSA bacteremia for whom clinical and microbiological outcomes data were available. Vancomycin doses were prospectively adjusted to achieve peak plasma concentrations of 28 to 32 μg/ml and trough concentrations of 8 to 12 μg/ml. Bactericidal assays were performed over 24 h with ∼107 to 108 CFU/ml in broth containing 16 μg/ml vancomycin. The median time to clearance of bacteremia was 6.5 days for patients with MRSA isolates demonstrating ≥2.5 reductions in log10 CFU/ml at 24 h and >10.5 days for patients with MRSA isolates demonstrating <2.5 log10 CFU/ml by 24 h (P = 0.025). The median time to clearance was significantly longer with MRSA isolates with vancomycin MICs of 2.0 μg/ml compared to that with MRSA isolates with MICs of ≤1.0 μg/ml (P = 0.019). The bacteremia caused by MRSA isolates with absent or severely reduced delta-hemolysin expression was of a longer duration of bacteremia (10 days and 6.5 days, respectively; P = 0.27) and had a decreased probability of eradication (44% and 78%, respectively; P = 0.086). We conclude that strain-specific microbiological features of MRSA, such as increased vancomycin MICs and decreased killing by vancomycin, appear to be predictive of prolonged MRSA bacteremia while patients are receiving vancomycin therapy. Prolonged bacteremia and decreased delta-hemolysin expression may also be related. Evaluation of these properties may be useful in the consideration of antimicrobial therapies that can be used as alternatives to vancomycin for the treatment of MRSA bacteremia.

scholarly journals Cytotoxic Activity of Camptothecin and Paclitaxel in Newly Established Continuous Human Medullary Thyroid Carcinoma Cell Lines

2004 ◽  
Vol 89 (5) ◽  
pp. 2397-2401 ◽  
Author(s):  
K. Kaczirek ◽  
M. Schindl ◽  
A. Weinhäusel ◽  
C. Scheuba ◽  
C. Passler ◽  
...  
Keyword(s):  
Thyroid Carcinoma ◽  
Medullary Thyroid Carcinoma ◽  
Cell Lines ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Medullary Thyroid ◽  
Cell Counts ◽  
In Vitro Investigation ◽  
Ic50 Values

At the time of diagnosis, more than one quarter of patients with medullary thyroid carcinoma (MTC) has distant metastases. Only few of these patients can be cured by surgery. Standard chemotherapy is characterized by low response rates and short response time. The establishment of eight human MTC cell lines provides a new basis for in vitro investigation of cytotoxic drugs. Camptothecin (CPT) and paclitaxel, which never have been investigated in the treatment of MTC, were tested for their cytotoxic profile in comparison with the clinically ineffective dacarbazine. Eight MTC cell lines were established from seven patients with MTC. IC50 values were calculated from dose-response relationships using cell counts and a formazan dye assay (WST-1). IC50 values were 3.5 ± 1.2 nmol/liter for CPT and 8.2 ± 1.9 nmol/liter for paclitaxel. Dacarbazine showed no reduction of cell proliferation at concentrations 10-fold higher than clinically achievable. Given peak plasma concentrations of 65 ± 20 nmol/liter for CPT and 1 μmol/liter for paclitaxel, these promising in vitro results provide a basis for the performance of clinical trials in patients with advanced MTC.

scholarly journals Pharmacological Advances of Chloroquine and Hydroxychloroquine: From Antimalarials to Investigative Therapies in COVID-19

2020 ◽  
Vol 15 (9) ◽  
pp. 1934578X2095364
Author(s):  
Yang Song ◽  
Elise Fields
Keyword(s):  
Severe Acute Respiratory Syndrome ◽  
Adverse Effects ◽  
Viral Infection ◽  
Therapeutic Potential ◽  
Pharmacological Activities ◽  
Pharmaceutical Applications ◽  
Natural Alkaloid ◽  
Derivatives Of ◽  
Existing Chemicals

During the coronavirus disease 2019 (COVID-19) pandemic, numerous existing chemicals have been screened for antiviral potential against the emerging coronavirus severe acute respiratory syndrome coronavirus 2. Chloroquine and hydroxychloroquine, after exhibiting potent in vitro efficacy, have gained tremendous attention. Both therapeutics are derivatives of natural alkaloid quinine and were first synthesized to treat malaria. Thereafter, the pharmaceutical applications of the agents have expanded to many new areas. In this article, the medicinal history and pharmacological activities of chloroquine and hydroxychloroquine are summarized. Antimalarial, anti-inflammatory, antitumor, antiviral properties, and therapeutic potential in the emerging viral infection COVID-19 are discussed. Pharmacokinetics, adverse effects, and toxicities are reviewed.

scholarly journals Endothelial microparticle formation in moderate concentrations of homocysteine and methionine in vitro

2011 ◽  
Vol 16 (1) ◽  
Author(s):  
Małgorzata Sekuła ◽  
Greta Janawa ◽  
Elżbieta Stankiewicz ◽  
Ewa Stępień
Keyword(s):  
Dietary Habits ◽  
Umbilical Vein ◽  
Plasma Concentrations ◽  
Annexin V ◽  
Membrane Vesicles ◽  
Cell Culture Supernatant ◽  
Mthfr Polymorphism ◽  
Blood Disorder ◽  
Umbilical Vein Endothelial Cells

AbstractMicroparticles (MPs) are small membrane vesicles released by stimulated or apoptotic cells, including the endothelium. Hyperhomocysteinemia (HHcy) is a blood disorder characterized by an increase in the plasma concentrations of total homocysteine (Hcy). The plasma Hcy level is determined by environmental factors (dietary habits, i.e. the intake of folic acid, FA) and genetic factors (N 5,N 10-methylenetetrahydro-folate reductase, MTHFR, polymorphism 677C>T). To evaluate whether moderate Hcy concentrations induce endothelial MP formation, the role of FA supplementation and the influence of MTHFR polymorphism were analysed. Human umbilical vein endothelial cells (HUVEC) were treated in vitro with 50 μM of Hcy and methionine (Met). The MP number and apoptotic phenotype were analyzed using flow cytometry. Increasing doses of FA (5, 15 and 50 μM) were used to reduce the HHcy effect. The MTHFR 677C>T polymorphism was determined. HUVEC stimulated by Hcy produced significantly more MPs than HUVEC under the control conditions: 3,551 ± 620 vs 2,270 ± 657 kMP (p = 0.02). Supplementation with FA at concentrations of 5, 15 and 50 μM reduced the MP count in the cell culture supernatant to 345 ± 332, 873 ± 329, and 688 ± 453 kMP, respectively (p = 0.03). MTHFR 677C>T heterozygosity was associated with a significant increase in MP formation after stimulation with Hcy compared to the control conditions: 3,617 ± 152 vs 1,518 ± 343 kMP (p = 0.02). Furthermore, the MTHFR genotype altered MP formation after Met loading. On average, 24% of the entire MP population was apoptotic (annexin V-positive). Endothelial function impairment due to HHcy is related to MP shedding, which may involve platelets and other blood and vascular cells. MP shedding is a physiological response to moderate HHcy.

Inhibitory Effect of Piracetam on Platelet-rich Thrombus Formation in an Animal Model

1998 ◽  
Vol 79 (01) ◽  
pp. 222-227 ◽  
Author(s):  
F. Stockmans ◽  
W. Deberdt ◽  
Å. Nyström ◽  
E. Nyström ◽  
J. M. Stassen ◽  
...  
Keyword(s):  
Platelet Aggregation ◽  
Ex Vivo ◽  
Peak Plasma ◽  
Thrombus Formation ◽  
Plasma Concentrations ◽  
Inhibitory Effect ◽  
Human Platelets ◽  
Cell Deformability

SummaryIntravenous administration of piracetam to hamsters reduced the formation of a platelet-rich venous thrombus induced by a standardised crush injury, in a dose-dependent fashion with an IC50 of 68 ± 8 mg/kg. 200 mg/kg piracetam also significantly reduced in vivo thrombus formation in rats. However, in vitro aggregation of rat platelets was only inhibited with piracetam-concentrations at least 10-fold higher than plasma concentrations (6.2 ± 1.1 mM) obtained in the treated animals. No effects were seen on clotting tests.In vitro human platelet aggregation, induced by a variety of agonists, was inhibited by piracetam, with IC50’s of 25-60 mM. The broad inhibition spectrum could be explained by the capacity of piracetam to prevent fibrinogen binding to activated human platelets. Ex vivo aggregations and bleeding times were only minimally affected after administration of 400 mg/kg piracetam i.v. to healthy male volunteers, resulting in peak plasma levels of 5.8 ± 0.3 mM.A possible antiplatelet effect of piracetam could be due to the documented beneficial effect on red blood cell deformability leading to a putative reduction of ADP release by damaged erythrocytes. However similarly high concentrations were needed to prevent stirring-induced “spontaneous” platelet aggregation in human whole blood.It is concluded that the observed antithrombotic action of piracetam cannot satisfactorily be explained by an isolated direct effect on platelets. An additional influence of piracetam on the rheology of the circulating blood and/or on the vessel wall itself must therefore be taken into consideration.

Performance of Murine Soluble Thrombomodulin (rmsTM) in a Murine Model of Endotoxin-Induced Sepsis.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3933-3933
Author(s):  
David E. Joyce ◽  
Haifeng Xu ◽  
Sumeet Mathur ◽  
Francis J. Castellino
Keyword(s):  
Protein C ◽  
Time Course ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Initial Time ◽  
Survival Study ◽  
Sepsis Model ◽  
Survival Difference

Abstract The endothelial surface protein thrombomodulin (TM) generates activated protein C (aPC) that protects from sepsis-related DIC, vascular inflammation, and apoptosis. The purpose of this study is to evaluate a novel recombinant mouse soluble TM (Eli Lilly, Indianapolis, IN) in a murine lethal endotoxin (LPS) sepsis model to determine both kinetic and survival endpoints. A dose effective in rodent reperfusion studies was employed in this sepsis model (D. Berg, Eli Lilly). C57BL6 mice were injected concomitantly with rmsTM 5 mg/kg (s.c.) and LPS 14 ug/g (i.p.) at time zero. Plasma concentrations were determined from citrated plasma at 3, 12, 24, and 48 hr, and plasma rmsTM concentrations were determined by ELISA. In vitro determinations of mouse aPC amidolytic activity and rmsTM dependent fibrinogen clotting time assays utilized rmsTM, murine thrombin, fibrinogen, and Protein C (Enzyme Research Labs). The in-vivo time-dependent mouse plasma kinetic studies confirmed plasma concentrations comparable to that achieved in human sTM antithrombotic studies. Thus, an rmsTM dose of 5 mg/kg was chosen for the 7-day LPS survival study (20% survival model). Twenty age-and weight-matched male C57BL6 mice, age 8–14 weeks, were treated with LPS 14 ug/g or LPS and rmsTM, 5 mg/kg, s.c. Survival curves were analyzed by Wilcoxon rank sum test (power 80%, alpha 2.5, p&lt;0.05). An initial time course after rmsTM s.c. injection yielded a peak plasma rmsTM level at 3 hr (5,000 ng/mL) which persisted up to 48 hr (2,000 ng/mL). In vitro activation of aPC was saturating (2,000 ng/mL aPC with &lt;20 ng/mL rmsTM). Prolongation of the thrombin clot time occurred at approximately 10 ug/ml of rmsTM. The LPS survival study in C57BL6 administered LPS (14 ug/g, i.p.) or LPS and rmsTM 5mg/kg s.c. demonstrated no survival difference (P=0.63). In vitro evaluation of aPC generation by rmsTM yielded ample amounts of aPC. Similarly, reduction of thrombin activity by rmsTM occurred at higher rmsTM concentrations. Thus, the lack of survival difference seen between endotoxemic mice treated with saline or adjunctive rmsTM in this model may be from the lack of thrombin inhibition, the lack of persistent (rmsTM:Thrombin) PC activation, or by more efficient clearance of aPC. Species specificity of TM is less likely a contributing factor. Further elucidation of the murine thrombin/thrombomodulin regulatory mechanism in vivo may be necessary to help explain our unexpected sTM survival results.

Sign in / Sign up

Export Citation Format

Share Document