scholarly journals The Hydroalcoholic Extract of Uncaria tomentosa (Cat’s Claw) Inhibits the Infection of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) In Vitro

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Andres F. Yepes-Perez ◽  
Oscar Herrera-Calderón ◽  
Cristian A. Oliveros ◽  
Lizdany Flórez-Álvarez ◽  
María I. Zapata-Cardona ◽  
...  
Keyword(s):  
Cytopathic Effect ◽  
Antiviral Effect ◽  
Stem Bark ◽  
Selectivity Index ◽  
Economic Losses ◽  
Uncaria Tomentosa ◽  
Hydroalcoholic Extract ◽  
Plaque Reduction Assay ◽  
Reduction Assay

The coronavirus disease 2019 (COVID-19) has become a serious problem for public health since it was identified in the province of Wuhan (China) and spread around the world producing high mortality rates and economic losses. Nowadays, the WHO recognizes traditional, complementary, and alternative medicine for treating COVID-19 symptoms. Therefore, we investigated the antiviral potential of the hydroalcoholic extract of Uncaria tomentosa stem bark from Peru against SARS-CoV-2 in vitro. The antiviral activity of U. tomentosa against SARS-CoV-2 in vitro was assessed in Vero E6 cells using cytopathic effect (CPE) and plaque reduction assay. After 48 h of treatment, U. tomentosa showed an inhibition of 92.7% of SARS-CoV-2 at 25.0 μg/mL ( p < 0.0001 ) by plaque reduction assay on Vero E6 cells. In addition, U. tomentosa induced a reduction of 98.6% ( p = 0.02 ) and 92.7% ( p = 0.03 ) in the CPE caused by SARS-CoV-2 on Vero E6 cells at 25 μg/mL and 12.5 μg/mL, respectively. The EC50 calculated for the U. tomentosa extract by plaque reduction assay was 6.6 μg/mL (4.89–8.85 μg/mL) for a selectivity index of 4.1. The EC50 calculated for the U. tomentosa extract by TCID50 assay was 2.57 μg/mL (1.05–3.75 μg/mL) for a selectivity index of 10.54. These results showed that U. tomentosa, known as cat's claw, has an antiviral effect against SARS-CoV-2, which was observed as a reduction in the viral titer and CPE after 48 h of treatment on Vero E6 cells. Therefore, we hypothesized that U. tomentosa stem bark could be promising in the development of new therapeutic strategies against SARS-CoV-2.

scholarly journals The hydroalcoholic extract of Uncaria tomentosa (Cat’s claw) inhibits the replication of novel coronavirus (SARS-CoV-2) in vitro

2020 ◽  
Author(s):  
Andres F. Yepes-Perez ◽  
Oscar Herrera-Calderón ◽  
Lizdany Flórez-Álvarez ◽  
María I. Zapata-Cardona ◽  
Lina Yepes ◽  
...  
Keyword(s):  
Antiviral Effect ◽  
Stem Bark ◽  
Selectivity Index ◽  
Economic Losses ◽  
Uncaria Tomentosa ◽  
Hydroalcoholic Extract ◽  
Plaque Reduction Assay ◽  
Reduction Assay ◽  
Novel Coronavirus

AbstractThe coronavirus disease 2019 (COVID-19) has become a serious problem for public health since it was identified in the province of Wuhan (China) and spread around the world producing high mortality rates and economic losses. Nowadays, WHO recognizes traditional, complementary, and alternative medicine for treating COVID-19 symptoms. Therefore, we investigated the antiviral potential of the hydroalcoholic extract of Uncaria tomentosa stem bark from Peru against SARS-CoV-2 in vitro. The antiviral activity of U. tomentosa against SARS-CoV-2 in vitro was assessed in Vero E6 cells using cytopathic effect (CPE) and plaque reduction assay. After 48h of treatment, U. tomentosa showed an inhibition of 92.7 % of SARS-CoV-2 at 25.0 µg/mL (p<0.0001) by plaque reduction assay on Vero E6 cells. In addition, U. tomentosa, induced a reduction of 98.6 % (p=0.02) and 92.7 % (p=0.03) in the CPE caused by SARS-CoV-2 on Vero E6 cells at 25 µg/mL and 12.5 µg/mL, respectively. The EC50 calculated for U. tomentosa extract by plaque reduction assay was 6.6 µg/mL (4.89 – 8.85 µg/mL) for a selectivity index of 4.1. The EC50 calculated for U. tomentosa extract by TCID50 assay was 2.57 µg/mL (1.05 – 3.75 µg/mL) for a selectivity index of 10.54. These results showed that U. tomentosa known as Cat’s claw has antiviral effect against SARS-CoV-2 observed as a reduction in the viral titer and CPE after 48h of treatment on Vero E6 cells. Therefore, we hypothesized that U. tomentosa stem bark, could be promissory to the development of new therapeutic strategies against SARS-CoV-2.

scholarly journals Analysis of In Vitro Cyto- and Genotoxicity of Barbatimão Extract on Human Keratinocytes and Fibroblasts

2018 ◽  
Vol 2018 ◽  
pp. 1-11 ◽  
Author(s):  
Neida L. Pellenz ◽  
Fernanda Barbisan ◽  
Veronica F. Azzolin ◽  
Thiago Duarte ◽  
Aline Bolignon ◽  
...  
Keyword(s):  
Epigallocatechin Gallate ◽  
Human Keratinocytes ◽  
Stem Bark ◽  
Genotoxic Effect ◽  
Bioactive Molecules ◽  
Control Group ◽  
Hydroalcoholic Extract ◽  
Plant Remains ◽  
Calf Thymus

Barbatimão (Stryphnodendron adstringens, Mart.) is a native Brazilian species used in traditional medicine and some commercial preparations owing to its strong wound-healing activity. However, controversy regarding its use due to safety concerns over the potential genotoxic effect of this plant remains. In order to clarify this issue, the effect of hydroalcoholic extract of barbatimão in vitro on cell viability, DNA damage, and induction of apoptosis in two commercial cell lines of keratinocytes (HaCaT) and fibroblasts (HFF-1) was evaluated. Barbatimão stem bark hydroalcoholic extract (70% ethanol) was obtained and lyophilized for subsequent use in all experiments. The main bioactive molecules quantified by HPLC were gallic acid, caffeic acid, quercetin, catechin, and epigallocatechin gallate (EGCG). Barbatimão (0.024 to 1.99 mg/mL) was found to decrease cellular mortality as compared to the control group. GEMO assay, a noncellular DNA protocol that uses H2O2-exposed calf thymus DNA, revealed not only a genotoxic effect of barbatimão, but also a potential genoprotective action against H2O2-triggered DNA fragmentation. These results indicated that barbatimão at concentrations of 0.49 and 0.99 mg/mL, which are near to the levels found in commercial preparations, exerted an in vitro genoprotective effect on cells by decreasing the levels of DNA oxidation quantified by 8-hydroxy-2′-deoxyguanosine (8-OHdG) and reactive oxygen species (ROS) levels. Gene and protein apoptotic markers, quantified by qRT-PCR (BAX/Bcl-2 genes) and immunoassays (Caspases 3 and 8), respectively, also indicated a decrease in apoptotic events in comparison with control cells. Collectively, the results suggest that barbatimão could exert genoprotective and antiapoptotic effects on human keratinocytes and fibroblasts.

In vitro Evaluation of the Anti-Picornavirus Activities of New Synthetic Flavonoids

1995 ◽  
Vol 6 (5) ◽  
pp. 298-306 ◽  
Author(s):  
N. Desideri ◽  
C. Conti ◽  
I. Sestili ◽  
P. Tomao ◽  
M. L. Stein ◽  
...  
Keyword(s):  
Hela Cell ◽  
Cell Cultures ◽  
Methoxy Group ◽  
Synthetic Compounds ◽  
Plaque Reduction Assay ◽  
Poliovirus Type ◽  
Reduction Assay ◽  
New Compounds

Substituted oxazolinylflavons and oxazolinylflavanones were synthesized in order to compare their anti-picornavirus activities with those of related natural and synthetic compounds. The antiviral potencies of the new compounds were evaluated against rhino-virus type 1B and poliovirus type 2 by a plaque reduction assay in HeLa cell cultures. Among the substituted flavanones only 6-chloro-4′-oxazolinylflavanone showed activity against both viruses. A comparison of the effects of 3-substituted flavones indicated that the presence of a 3-methoxy group enhances the activity against rhinovirus, while the presence of a 3-hydroxy group enhances the activity against poliovirus.

scholarly journals Fighting SARS-CoV-2 with green seaweed Ulva sp. extract: extraction protocol predetermines crude ulvan extract anti-SARS-CoV-2 inhibition properties in in vitro Vero-E6 cells assay

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e12398
Author(s):  
Shai Shefer ◽  
Arthur Robin ◽  
Alexander Chemodanov ◽  
Mario Lebendiker ◽  
Robert Bostwick ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Chemical Composition ◽  
Antiviral Activity ◽  
Cytopathic Effect ◽  
Average Molecular Weight ◽  
Ammonium Oxalate ◽  
Extraction Protocol ◽  
Reduction Assay ◽  
Green Seaweed

Due to the global COVID-19 pandemic, there is a need to screen for novel compounds with antiviral activity against SARS-COV-2. Here we compared chemical composition and the in vitro anti- SARS-COV-2 activity of two different Ulva sp. crude ulvan extracts: one obtained by an HCl-based and another one by ammonium oxalate-based (AOx) extraction protocols. The composition of the crude extracts was analyzed and their antiviral activity was assessed in a cytopathic effect reduction assay using Vero E6 cells. We show that the extraction protocols have a significant impact on the chemical composition, anti- SARS-COV-2 activity, and cytotoxicity of these ulvan extracts. The ulvan extract based on the AOx protocol had a higher average molecular weight, higher charge, and 11.3-fold higher antiviral activity than HCl-based extract. Our results strongly suggest that further bioassay-guided investigation into bioactivity of compounds found in Ulva sp. ulvan extracts could lead to the discovery of novel anti-SARS-CoV-2 antivirals.

scholarly journals Plants from Northeast Mexico with Anti-HSV Activity

2013 ◽  
Vol 8 (3) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
David Silva-Mares ◽  
Ernesto Torres-López ◽  
Ana M Rivas-Estilla ◽  
Paula Cordero-Pérez ◽  
Noemí Waksman-Minsky ◽  
...  
Keyword(s):  
Methanolic Extract ◽  
Vero Cells ◽  
Vitro Activity ◽  
Active Principle ◽  
In Vitro Activity ◽  
Plaque Reduction Assay ◽  
Methanolic Extracts ◽  
Reduction Assay ◽  
Hsv 1

Based on chemotaxonomic and ethno-pharmacological criteria, three Mexican plants ( Jatropha dioica, Salvia texana and S. ballotaeflora) were studied for in vitro activity against HSV-1 and HSV-2. Hydro-methanolic extracts were initially evaluated for their toxicity to Vero cells. Both Salvia species displayed cytotoxicity at the lowest dose (125 μg/mL). The J. dioica extract showed only negligible cytotoxicity (CC50 644 μg/mL). Its anti-HSV activity was evaluated using the plaque reduction assay with HSV-1 and HSV-2 (from clinical isolates) infected Vero cells. The hydro-methanolic extract of J. dioica showed IC50s of 280 and 370 μg/mL against HSV-1 and HSV-2, respectively. The n-hexane liquid-liquid partition of J. dioica extract contained the majority of the active principle(s) with IC50 values of 300 and 270 μg/mL for HSV-1 and HSV-2, respectively. Bioassay-guided isolation led to the known diterpene, riolozatrione.

scholarly journals Novel DL-Galactan Hybrids from the Red Seaweed Gymnogongrus Torulosus are Potent Inhibitors of Herpes Simplex Virus and Dengue Virus

2002 ◽  
Vol 13 (2) ◽  
pp. 83-89 ◽  
Author(s):  
CA Pujol ◽  
JM Estevez ◽  
MJ Carlucci ◽  
M Ciancia ◽  
AS Cerezo ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dengue Virus ◽  
Cell Receptor ◽  
Vero Cells ◽  
Red Seaweed ◽  
Plaque Reduction Assay ◽  
Reduction Assay ◽  
Simplex Virus

A novel series of DL-galactan hybrids extracted from the red seaweed Gymnogongrus torulosus, was evaluated for its in vitro antiviral properties against herpes simplex virus type 2 (HSV-2) and dengue virus 2 (DEN-2). These compounds were very active against both viruses with inhibitory concentration 50% (IC50) values in the range 0.6–16 μg/ml for HSV-2 and 0.19–1.7 μg/ml for DEN-2, respectively, as determined in a virus plaque reduction assay in Vero cells. The DL-galactans lacked of cytotoxic effects, on stationary as well as on actively dividing cells, and anticoagulant properties. Some of the compounds showed a variable level of direct inactivating effect on both virions, with virucidal concentration 50% values exceeding the IC50s obtained by plaque reduction assay. Full inhibitory activity was achieved when the galactans were present during virus adsorption period, suggesting that the mode of action of these compounds is an interference in the binding of the surface envelope glycoprotein with the cell receptor.

scholarly journals Mangifera foetida L. (Macang) Source of Potent Antiviral Activity of Against Dengue Virus Serotype 2 (Anti DENV2)

2021 ◽  
Vol 2049 (1) ◽  
pp. 012018
Author(s):  
Fitmawati ◽  
Maya Safitri ◽  
S.N. Kholifah ◽  
Emrizal ◽  
Rodesia Mustika Roza
Keyword(s):  
Dengue Virus ◽  
Vero Cells ◽  
Stem Bark ◽  
Selectivity Index ◽  
Assay Method ◽  
Bark Extract ◽  
Standard Curve ◽  
Virus Serotype ◽  
Stem Bark Extract

Abstract The new discovery about the potential of Mangifera foetida L. as an antiviral will help conservation efforts in nature while maintaining and increasing its biodiversity value. This study aims to characterize the in vitro potential of three varieties of M. foetida L. against the dengue virus. Dengue virus is infected in Vero cells, viral replication was measured using the Viral ToxGlo Assay method. The selectivity ability of Mangifera foetida L. stem bark extract to inhibit the dengue virus was seen from the Selectivity Index (SI) value. The standard curve between the concentration of the compound (μg/mL) and % cell viability was analyzed by linear regression using Microsoft Excel 2010 software. The results showed that the selectivity index (SI) value of M. foetida L stem bark extract of Limus, Manis and Batu varieties were 7.58, 6.82 and 16.43, respectively. It was concluded that the extract of Macang stem bark of the Limus, Manis and Batu varieties had the potential to be used as an antiviral for dengue.

scholarly journals Evaluation of 19 antiviral drugs against SARS-CoV-2 Infection

2020 ◽  
Author(s):  
Shufeng Liu ◽  
Christopher Z. Lien ◽  
Prabhuanand Selvaraj ◽  
Tony T. Wang
Keyword(s):  
Clinical Trials ◽  
Severe Acute Respiratory Syndrome ◽  
Cytopathic Effect ◽  
Therapeutic Index ◽  
Antiviral Effect ◽  
Antiviral Drugs ◽  
Global Pandemic

AbstractThe global pandemic of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 or 2019-nCoV) has prompted multiple clinical trials to jumpstart search for anti-SARS-CoV-2 therapies from existing drugs, including those with reported in vitro efficacies as well as those ones that are not known to inhibit SARS-CoV-2, such as ritonavir/lopinavir and favilavir. Here we report that after screening 19 antiviral drugs that are either in clinical trials or with proposed activity against SARS-CoV-2, remdesivir was the most effective. Chloroquine only effectively protected virus-induced cytopathic effect at around 30 µM with a therapeutic index of 1.5. Our findings also suggest that velpatasvir, ledipasvir, ritonavir, litonavir, lopinavir, favilavir, sofosbuvir, danoprevir, and pocapavir do not have direct antiviral effect.

scholarly journals Enhanced Inhibition of Orthopoxvirus Replication In Vitro by Alkoxyalkyl Esters of Cidofovir and Cyclic Cidofovir

2002 ◽  
Vol 46 (4) ◽  
pp. 991-995 ◽  
Author(s):  
Earl R. Kern ◽  
Caroll Hartline ◽  
Emma Harden ◽  
Kathy Keith ◽  
Natalie Rodriguez ◽  
...  
Keyword(s):  
Animal Models ◽  
Oral Absorption ◽  
Cowpox Virus ◽  
Plaque Reduction Assay ◽  
Antiviral Compounds ◽  
Cytotoxicity Studies ◽  
Reduction Assay ◽  
Oral Activity ◽  
Long Chain

ABSTRACT The nucleotide phosphonates cidofovir (CDV) and cyclic cidofovir (cCDV) are potent antiviral compounds when administered parenterally but are not well absorbed orally. These compounds have been reported to have activity against orthopoxvirus replication in vitro and in animal models when administered parenterally or by aerosol. To obtain better oral activity, we synthesized a novel series of analogs of CDV and cCDV by esterification with two long-chain alkoxyalkanols, 3-hexadecyloxy-1-propanol (HDP-CDV; HDP-cCDV) or 3-octadecyloxy-1-ethanol (ODE-CDV; ODE-cCDV). Their activities were evaluated and compared with those of CDV and cCDV in human foreskin fibroblast (HFF) cells infected with vaccinia virus (VV) or cowpox virus (CV) using a plaque reduction assay. The 50% effective concentrations (EC50s) against VV in HFF cells for CDV and cCDV were 46.2 and 50.6 μM compared with 0.84 and 3.8 μM for HDP-CDV and HDP-cCDV, respectively. The EC50s for ODE-CDV and ODE-cCDV were 0.20 and 1.1 μM, respectively. The HDP analogs were 57- and 13-fold more active than the parent nucleotides, whereas the ODE analogs were 231- and 46-fold more active than the unmodified CDV and cCDV. Similar results were obtained using CV. Cytotoxicity studies indicated that although the analogs were more toxic than the parent nucleotides, the selective index was increased by 4- to 13-fold. These results indicate that the alkoxyalkyl esters of CDV and cCDV have enhanced activity in vitro and need to be evaluated for their oral absorption and efficacy in animal models.

scholarly journals In vitro efficacy of Artemisinin-based treatments against SARS-CoV-2

2020 ◽  
Author(s):  
Kerry Gilmore ◽  
Yuyong Zhou ◽  
Santseharay Ramirez ◽  
Long V. Pham ◽  
Ulrik Fahnøe ◽  
...  
Keyword(s):  
Artemisia Annua ◽  
Peak Plasma ◽  
Plasma Concentrations ◽  
Active Pharmaceutical Ingredients ◽  
Proof Of Concept ◽  
Plaque Reduction Assay ◽  
Prophylactic Efficacy ◽  
Pharmaceutical Ingredients ◽  
Reduction Assay

AbstractEffective and affordable treatments for patients suffering from coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), are needed. We report in vitro efficacy of Artemisia annua extracts as well as artemisinin, artesunate, and artemether against SARS-CoV-2. The latter two are approved active pharmaceutical ingredients of anti-malarial drugs.Proof-of-concept for prophylactic efficacy of the extracts was obtained using a plaque-reduction assay in VeroE6 cells. Subsequent concentration-response studies using a high-throughput antiviral assay, based on immunostaining of SARS-CoV-2 spike glycoprotein, revealed that pretreatment and treatment with extracts, artemisinin, and artesunate inhibited SARS-CoV-2 infection of VeroE6 cells. In treatment assays, artesunate (50% effective concentration (EC50): 7 μg/mL) was more potent than the tested plant extracts (128-260 μg/mL) or artemisinin (151 μg/mL) and artemether (>179 μg/mL), while generally EC50 in pretreatment assays were slightly higher. The selectivity index (SI), calculated based on treatment and cell viability assays, was highest for artemisinin (54), and roughly equal for the extracts (5-10), artesunate (6) and artemether (<7). Similar results were obtained in human hepatoma Huh7.5 cells. Peak plasma concentrations of artesunate exceeding EC50 values can be achieved. Clinical studies are required to further evaluate the utility of these compounds as COVID-19 treatment.

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