Toxicological and bioactivity evaluation of blackcurrant press cake, sea buckthorn leaves and bark from Scots pine and Norway spruce extracts under a green integrated approach.

Aqueous extracts from blackcurrant press cake (BC), Norway spruce bark (NS), Scots pine bark (SP), and sea buckthorn leaves (SB) were obtained using maceration and pressurized hot water and tested for their bioactivities. Maceration provided the extraction of higher dry matter contents, including total phenolics (TPC), anthocyanins, and condensed tannins, which also impacted higher antioxidant activity. NS and SB extracts presented the highest mean values of TPC and antioxidant activity. Individually, NS extract presented high contents of proanthocyanidins, resveratrol, and some phenolic acids. In contrast, SB contained a high concentration of ellagitannins, ellagic acid, and quercetin, explaining the antioxidant activity and antibacterial effects. SP and BC extracts had the lowest TPC and antioxidant activity. However, BC had strong antiviral efficacy, whereas SP can be considered a potential ingredient to inhibit α-amylase. Except for BC, the other extracts decreased reactive oxygen species (ROS) generation in HCT8 and A549 cells. Extracts did not inhibit the production of TNF-alpha in lipopolysaccharide-stimulated THP-1 macrophages but inhibited the ROS generation during the THP-1 cell respiratory burst. The recovery of antioxidant compounds from these by-products is incentivized for high value-added applications.

Berberine impairs coxsackievirus B3-induced myocarditis through the inhibition of virus replication and host pro-inflammatory response.

Berberine (BBR), an isoquinoline alkaloid isolated from Rhizoma coptidis, is reported to possess antiviral activity. Our previous study has shown that BBR alleviates coxsackievirus B3 (CVB3) replication in HeLa cells. However, the anti-CVB3 activity of BBR is still unclear in vivo. In this study, we explored the effect of BBR on CVB3-induced viral myocarditis in mice. These results demonstrated the beneficial effect of BBR on alleviating CVB3-induced myocarditis in vivo, which sheds new light on the utility of BBR as a therapeutic strategy against CVB3-induced viral myocarditis.

Antiviral, Cytotoxic and Antioxidant Effects of Tanacetum Vulgare L. Crude Extract In Vitro.

INTRODUCTION: Due to the high prevalence of viral infections having no specific treatment and the constant emergence of resistant viral strains, searching for effective antiviral compounds is crucial. The present study explores in vitro the antiviral activity of ethanolic extract from aerial parts of. AIM: The aim of the current study was to evaluate antiviral activity of ethanolic extract from herbaceous plant. MATERIALS AND METHODS: The crude aqueous ethanolic extract from aerial parts of. RESULTS: The results show that the extract has the lowest toxicity on the MDBK cell line and similar cytotoxicity in Hep-2, whereas in the MDCK cells it has more than twice the highest toxicity. Testing the antiviral activity of. CONCLUSION: The crude extract from aerial parts of the medicinal plant.

Baicalin Inhibits Coxsackievirus B3 Replication by Reducing Cellular Lipid Synthesis.

Baicalin is a flavonoid extracted from Scutellariae Radix and shows a variety of biological activities as reducing lipids, diminishing inflammation, and inhibiting bacterial infection. However, there is no report of baicalin against CVB3 infection. In this study, we found that baicalin can reduce viral titer in a dose-dependent manner in vitro at a dose with no direct virucidal effect. Moreover, we revealed that baicalin can also improve survival rate, reduce heart weight/body weight ratio, prevent virus replication, and relieve myocardial inflammation in the acute viral myocarditis mouse model induced by CVB3. Then, in order to explore the mechanism of baicalin inhibiting CVB3 replication, we respectively examined the expression of autophagosome marker LC3-II by Western blot, tested the concentration of free fatty acid (FFA) and cholesterol (CHO) by commercial kits, detected the mRNA levels of fatty acid synthase (Fasn) and acetyl coenzyme a carboxylase (ACC) by RT-PCR, and observed the lipid content of cells by fluorescence staining. The results showed that CVB3 infection increased autophagosome formation and lipid content in HeLa cells, but these changes were significantly blocked by baicalin. Finally, in order to confirm that baicalin inhibits viral replication and reduces autophagosome formation by reducing cellular lipids, we added exogenous palmitate to cell culture supernatants to promote intracellular lipid synthesis and found that palmitate did not alter LC3-II and CVB3/VP1 expression in HeLa cells with or without CVB3 infection. Interestingly, palmitate can reverse the inhibitory effect of baicalin on autophagosome formation and viral replication. In conclusion, our results indicated that lipids play an important role in CVB3 replication, and the effect of baicalin against CVB3 was associated with its ability to reduce cellular lipid synthesis to limit autophagosome formation.

Virucidal Effect of Guggulsterone Isolated from Commiphora gileadensis.

Commiphora gileadensis, locally known as becham, is a plant used in traditional Arabian medicine for treating headache, constipation, stomach, joint pain, and inflammatory disorders. Several studies have reported its antibacterial properties; however, no study has demonstrated its antiviral activity. This study aimed to evaluate the antiviral activity of C. gileadensis as well as to isolate its active compound and investigate its mode of action. This activity was evaluated using 4 viruses, herpes simplex virus type 2 (HSV-2), respiratory syncytial virus type B (RSV-B), coxsackie virus B type 3, and adenovirus type 5 by performing the plaque reduction assay and the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays for enveloped and nonenveloped viruses, respectively. The methanol extract of C. gileadensis leaves only showed antiviral activity against enveloped viruses with a selectivity index of 11.19 and 10.25 for HSV-2 and RSV-B, respectively. The study of the mechanism underlying antiviral activity demonstrated a virucidal effect by direct contact with these target viruses. The active compound, isolated using bio-guided assays involving TLC, was identified as guggulsterone by HPLC-diode array detection coupled with electrospray ionization mass spectrometry. Guggulsterone is an antagonist of the bile acid receptor and a modulator of cholesterol metabolism; however, its antimicrobial properties have been reported for the first time in this study.

Ginkgo biloba extract may alleviate viral myocarditis by suppression of S100A4 and MMP-3.

Viral myocarditis (VMC) is an inflammatory cardiac disease caused by coxsackievirus B3 (CVB3) that leads to heart failure or sudden death. However, efficient therapeutic strategies for VMC remain lacking. Ginkgo biloba extract was previously demonstrated to have anti-inflammatory activity and had been used in prevention and therapy of some cardiovascular diseases (ie myocardial infarction), indicating Ginkgo biloba extract may be a potential drug for the treatment of VMC. This study was, for the first time, to investigate the intervention effects of Ginkgo biloba extract on VMC model mice and explore its potential mechanisms. As a result, VMC mice model was successfully established by CVB3 infection, exhibiting significantly higher viral titer, serum creatine kinase isoenzyme level, heart weight/body weight ratio, histopathologic scores, collagen volume fraction (CVF), and significantly increased expression of S100A4 and matrix metalloproteinase-3 (MMP-3) at protein and messenger RNA levels compared with the control group. Also, the expression of S100A4 and MMP-3/CVF was positively correlated. Ginkgo biloba extract treatment significantly reversed the trend in all the above parameters. Thus, Ginkgo biloba extract may be a promising therapeutic approach against VMC because it improved myocardial injury and alleviated the degree of myocardial fibrosis through suppression of S100A4 and MMP-3.

Manassantin B shows antiviral activity against coxsackievirus B3 infection by activation of the STING/TBK-1/IRF3 signalling pathway.

Coxsackievirus B3 (CVB3) is an important human pathogen associated with the development of acute pancreatitis, myocarditis, and type 1 diabetes. Currently, no vaccines or antiviral therapeutics are approved for the prevention and treatment of CVB3 infection. We found that Saururus chinensis Baill extract showed critical antiviral activity against CVB3 infection in vitro. Further, manassantin B inhibited replication of CVB3 and suppressed CVB3 VP1 protein expression in vitro. Additionally, oral administration of manassantin B in mice attenuated CVB3 infection-associated symptoms by reducing systemic production of inflammatory cytokines and chemokines including TNF-α, IL-6, IFN-γ, CCL2, and CXCL-1. We found that the antiviral activity of manassantin B is associated with increased levels of mitochondrial ROS (mROS). Inhibition of mROS generation attenuated the antiviral activity of manassantin B in vitro. Interestingly, we found that manassantin B also induced cytosolic release of mitochondrial DNA based on cytochrome C oxidase DNA levels. We further confirmed that STING and IRF-3 expression and STING and TBK-1 phosphorylation were increased by manassantin B treatment in CVB3-infected cells. Collectively, these results suggest that manassantin B exerts antiviral activity against CVB3 through activation of the STING/TKB-1/IRF3 antiviral pathway and increased production of mROS.

Aqueous extracts of Syzygium brazzavillense can inhibit the infection with coxsackievirus B4 in vitro.

Traditional practitioners commonly use plant crude extracts to treat various diseases in patients with symptoms that can be seen during enterovirus infections. In this study, the antienteroviral activity of medicinal plants from the Republic of Congo has been evaluated in vitro. Through an ethnopharmacological approach, seven plants grouped into six families were identified. Aqueous and organic extracts of various organs from these plants were prepared. The organic extracts at subcytotoxic concentrations did not inhibit the cytopathic effect (CPE) induced by coxsackievirus (CV)B1-5, CVA6, poliovirus type 1, and enterovirus 71. The aqueous extract of Syzygium brazzavillense, but not those of other plants, inhibited the CPE induced by CVB3 and CVB4 at 30 µg/mL (CC50 ; 2800 µg/mL, IC50 ; 0.8 µg/mL) and by CVB2 and poliovirus type 1 at higher concentrations. When aqueous extract of this plant was mixed with CVB4, the replication of the virus was inhibited. In conclusion, aqueous extracts of Syzygium brazzavillense can inhibit the infection with CVB4 and other enteroviruses in vitro. The present ethnopharmacological investigation helped to identify a plant with potential properties useful to combat enterovirus infections.

Isolation of an antiviral compound from Tunisian olive twig cultivars.

(1) Many studies demonstrated that olive oil and the leaves have several biological activities, but the works on olive twigs remain very limited. In this report, we investigated for anti-coxsackievirus B-3 (CVB-3) and anti-herpes virus type 2 (HSV-2) activities of olive twigs from two Tunisian varieties: Chemlali (CM) and Chétoui (CT). Extraction from the olive twigs was carried out using successively hexane, dichloromethane, ethyl acetate and methanol. The obtained extracts were evaluated for their anti-CVB-3 and anti-HSV-2 activities by MTT and plaque reduction assays, respectively. Only hexane extracts exhibited significant activity with a selectivity index of 6.32±0.67 and 5.24±0.82 for CM and CT, respectively. The active compound was isolated through bio-guided assays using Thin Layer Chromatography (TLC) and identified as 2,4-di-tert-butylphenol (2,4-DTBP) by gas chromatography coupled with mass spectrometry (GC-MS). This work is the first study that demonstrated an antiviral activity of both olive twigs and DTBP.

Cycloartane-type triterpenoid derivatives and a flavonoid glycoside from the burs of Castanea crenata.

Five undescribed cycloartane-type triterpenoids, which were isolated for the first time from the genus, and a flavonoid glycoside together with 11 known compounds were isolated from the burs of Castanea crenata. The structures were elucidated based on the spectroscopic analysis of 1D and 2D NMR and MS data. All isolated compounds were evaluated for antiviral activities against HRV1B-, CVB3-, and PR8-infected cells. Most kaempferol derivatives showed statistically significant antiviral activities against HRV1B-infected cells. Among the tested compounds, kaempferol-3-O-[2″,6″-di-O-Z-p-coumaroyl]-ß-d-glucopyranoside exhibited the most consistent and effective antiviral activities against all infections.

Anti-infective activities of 11 plants species used in traditional medicine in Malaysia.

Treatment of drug resistant protozoa, bacteria, and viruses requires new drugs with alternative chemotypes. Such compounds could be found from Southeast Asian medicinal plants. The present study examines the cytotoxic, antileishmanial, and antiplasmodial effects of 11 ethnopharmacologically important plant species in Malaysia. Chloroform extracts were tested for their toxicity against MRC-5 cells and Leishmania donovani by MTT, and chloroquine-resistant Plasmodium falciparum K1 strain by Histidine-Rich Protein II ELISA assays. None of the extract tested was cytotoxic to MRC-5 cells. Extracts of Uvaria grandiflora, Chilocarpus costatus, Tabernaemontana peduncularis, and Leuconotis eugenifolius had good activities against L. donovani with IC50 < 50 µg/mL. Extracts of U. grandiflora, C. costatus, T. peduncularis, L. eugenifolius, A. subulatum, and C. aeruginosa had good activities against P. falciparum K1 with IC50 < 10 µg/mL. Pinoresinol isolated from C. costatus was inactive against L. donovani and P. falciparum. C. costatus extract and pinoresinol increased the sensitivity of Staphylococcus epidermidis to cefotaxime. Pinoresinol demonstrated moderate activity against influenza virus (IC50 = 30.4 ±â€¯11 µg/mL) and was active against Coxsackie virus B3 (IC50 = 7.1 ±â€¯3.0 µg/mL). ß-Amyrin from L. eugenifolius inhibited L. donovani with IC50 value of 15.4 ±â€¯0.01 µM. Furanodienone from C. aeruginosa inhibited L. donovani and P. falciparum K1 with IC50 value of 39.5 ±â€¯0.2 and 17.0 ±â€¯0.05 µM, respectively. Furanodienone also inhibited the replication of influenza and Coxsackie virus B3 with IC50 value of 4.0 ±â€¯0.5 and 7.2 ±â€¯1.4 µg/mL (Ribavirin: IC50: 15.6 ±â€¯2.0 µg/mL), respectively. Our study provides evidence that medicinal plants in Malaysia have potentials as a source of chemotypes for the development of anti-infective leads.

In vitro antiviral activity of twenty-seven medicinal plant extracts from Southwest Nigeria against three serotypes of echoviruses.

BACKGROUND: Echoviruses, a serotype of enteroviruses, infect millions of people globally and there is no specific drug treatment or vaccine available for its management. The screening of medicinal plants used locally for the treatment of infectious diseases, can provide a reliable option in the discovery of potent therapeutic compounds. This study was carried out to investigate the antiviral activities of 27 medicinal plant extracts, belonging to 26 different plant species, selected from Nigerian ethnobotany, against echovirus 7, 13 and 19 serotypes (E7, E13 and E19, respectively). METHODS: The plants were macerated in methanol and the cytotoxicities of the crude extracts were evaluated on the rhabdomyosarcoma cell line using the MTT assay. The antiviral activity of the plant extracts and fractions against echoviruses (E7, E13, and E19) was determined using the neutralisation assay, an assay that measures the inhibition of cytopathic effect on cell culture. RESULTS: The crude extract of Macaranga barteri leaves had the highest cytotoxicity with CC50 value of 0.27 µg/mL. This was followed by Crinum jagus (9.88 µg/mL) and Terminalia ivorensis (12.14 µg/mL). The antiviral screening showed that ten out of the 27 crude plant extracts tested were active on E7 and E19, inhibiting the cytopathic effect of the virus in tissue culture. None of the extracts inhibited the cytopathic effect caused by E13 serotype. Amongst the active plant extracts, the methanol extract of M. barteri leaves had the highest antiviral activity on both E7 and E9 with IC50 values of 0.028 and 0.0017 ng/mL, respectively, followed by the Ageratum conyzoides extract (0.208 µg/mL, E7; 0.006 µg/mL, E19) and Mondia whitei extract (0.038 µg/mL, E7; 0.005 µg/mL, E19). Amongst the fractions of M. barteri, the DCM fraction was most the active and selective on E7 (IC50 = 0.0075 ng/mL; SI = 19,896.54) and E19 (IC50 = 0.0175 ng/mL; SI = 8581.24). CONCLUSION: Our research has demonstrated that Macaranga barteri extracts has potent antiviral activity against echoviruses E7 and E19, and our findings suggest that this extract may have potential as a therapeutic agent in the treatment of enteroviral infections.

Discovery of Bioactive Natural Products for the Treatment of Acute Respiratory Infections - An Integrated Approach.

In this work, an integrated approach for the identification of new antiviral agents from natural sources for the treatment of acute respiratory infections is presented. The approach comprises (i) the selection of starting material based on traditional knowledge, (ii) phenotypic screening of extracts for antiviral activity, and (iii) the implementation of in silico predictions to identify antiviral compounds and derive the molecular mechanism underlying their biological activity. A variety of starting materials from plants and fungi was selected for the production of 162 extracts. These extracts were tested in cytopathic effect inhibition assays against influenza virus A/Hong Kong/68 (HK/68), rhinovirus A2 (RV-A2), and coxsackie virus B3 (CV-B3). All extracts were also evaluated regarding their cytotoxicity. At an IC50 threshold of 50 µg/mL, 20, 11, and 14% of all tested extracts showed antiviral activity against HK/68, CV-B3, and RV-A2, respectively. Among all active extracts (n = 47), 68% showed antiviral activity against one of the investigated viruses, whereas 31% inhibited at least two viruses. Herein, we present a comprehensive dataset of probed extracts along with their antiviral activities and cytotoxicity. Application examples presented in this work illustrate the phytochemical workflow for the identification of antiviral natural compounds. We also discuss the challenges, pitfalls, and advantages of the integrated approach.

Labdane-type diterpenoids from Vitex limonifolia and their antivirus activities.

Phytochemical investigation of the methanol extract of Vitex limonifolia leaves led to the isolation of three new labdane-type diterpenoids, vitexlimolides A-C (1-3) and eight known compounds, 5,4'-dihydroxy-3,7-dimethoxyflavone (4), vitecetin (5), 5,4'-dihydroxy-7,3'-dimethoxyflavone (6), verrucosin (7), 2α, 3α-dihydroxy-urs-12-en-28-oic acid (8), euscaphlic acid (9), 18,19-seco, 2α, 3α-dihydroxy-19-oxo-urs-11,13(18)-dien-28-oic acid (10), and maslinic acid (11). Their chemical structures were elucidated by physical and chemical methods. All compounds were evaluated for antiviral activities against CVB3, HRV1B, and EV71 viruses. As a result, compounds 4 and 6 showed potent antiviral activity against CVB3 infection with IC50 values of 0.12 ± 0.06 and 1.86 ± 0.18 (µM), respectively.

Antiviral effect of compounds derived from Angelica archangelica L. on Herpes simplex virus-1 and Coxsackievirus B3 infections.

The dichloromethane extract from fruits of Angelica archangelica L. was separated by the modern high-performance countercurrent chromatography (HPCCC). The extract and five pure compounds: xanthotoxin, bergapten, imperatorin, phellopterin and isoimperatorin, and the mixture of imperatorin and phellopterin, have been studied as the potential antiviral agents against Herpes simplex virus type l and Coxsackievirus B3. The cytotoxicity was measured using the MTT method. Compounds were tested for the in vitro antiviral activity using the cytopathic effect (CPE) inhibitory assay and by the virus titre reduction assay. Real-time PCR was used to quantify the relative inhibition of the HSV-1 replication. The results indicate that the highest activity was demonstrated by the extract, imperatorin, phellopterin and the mixture of imperatorin and phellopterin, reducing the HSV-1 replication by 5.61 log, 4.7 log, 3.01 log and 3.73 log, respectively. The influence of isolated compounds on the CVB3 replication was not significant. Only the extract caused the decrease in the titre of virus in relation to the virus control. Our results show that coumarins of A. archangelica L. might be a potential candidate for the development of the alternative natural anti- HSV-1 compound. Moreover, the presence of isopentenyloxy moiety at C-8 position significantly improves their activity.

Berberine Restricts Coxsackievirus B Type 3 Replication via Inhibition of c-Jun N-Terminal Kinase (JNK) and p38 MAPK Activation In Vitro.

BACKGROUND At present, the treatment of coxsackievirus-induced myocarditis remains difficult. Berberine (BBR), an isoquinoline alkaloid isolated from traditional medicine herbs, exhibits significant anti-viral efficacy against various viruses. However, the underlying mechanism by which BBR controls CVB3 infection has not yet been reported. The purpose of this study was to investigate the anti-viral efficacy of BBR against CVB3 infection and its mechanism. MATERIAL AND METHODS In our experiments, the protein levels of VP1 and MAPKs signal pathway were measured by Western blot. The mRNA level of VP1 was measured by RT-PCR. The virus titers were determined by TCID50 assay. RESULTS We found that BBR treatment significantly decreased CVB3 replication in HeLa cells. In addition, the BBR treatment reduced the phosphorylation levels of JNK and p38 MAPK upon CVB3 infection in both HeLa cells and primary rat myocardial cells. CONCLUSIONS Taken together, these results suggest that BBR inhibits CVB3 replication through the suppression of JNK and p38 MAPK activation, shedding new light on the investigation of therapeutic strategies against CVB3-induced viral myocarditis.

Fructus Amomi Cardamomi Extract Inhibit Coxsackievirus-B3 Induced Myocarditis in Murine Myocarditis Model.

Coxsackievirus B3 (CVB3) is the main cause of acute myocarditis and dilated cardiomyopathy. Plant extracts are considered as useful materials to develop new antiviral drugs. We had previously selected candidate plant extracts, which showed anti-inflammatory effects. We examined the antiviral effects by using a HeLa cell survival assay. Among these extracts, we chose the Amomi Cardamomi (Amomi) extract, which showed strong antiviral effect and preserved cell survival in CVB3 infection. We investigated the mechanisms underlying the ability of Amomi extract to inhibit CVB3 infection and replication. HeLa cells were infected by CVB3 with or without Amomi extract. Erk and Akt activities, and their correlation with virus replication were observed. Live virus titers in cell supernatants and viral positive- and negative-strand RNA amplification were measured. Amomi extract significantly increased HeLa cell survival in different concentrations (100-10 µg/ml). CVB3 capsid protein VP1 expression (76%) and viral protease 2A-induced eIF4G1 cleavage (70%) were significantly decreased in Amomi extract (100 µg/ml) treated cells. The levels of positive- (20%) and negative-strand (80%) RNA were dramatically decreased compared with the control, as revealed by reverse transcription-PCR. In addition, Amomi extract improved mice survival (51% vs 26%) and dramatically reduced heart inflammation in a CVB3-induced myocarditis mouse model. These results suggested that Amomi extract significantly inhibited Enterovirus replication and myocarditis damage. Amomi may be developed as a therapeutic drug for Enterovirus.

Essential Oil Composition, Antioxidant, Cytotoxic and Antiviral Activities of Teucrium pseudochamaepitys Growing Spontaneously in Tunisia.

The chemical composition, antioxidant, cytotoxic and antiviral activities of the essential oil obtained by hydrodistillation from the aerial parts of Teucrium pseudochamaepitys (Lamiaceae) collected from Zaghouan province of Tunisia are reported. The essential oil was analyzed by gas chromatography equipped with a flame ionization detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC/MS). Thirty-one compounds were identified representing 88.6% of the total essential oil. Hexadecanoic acid was found to be the most abundant component (26.1%) followed by caryophyllene oxide (6.3%), myristicin (4.9%) and α-cubebene (3.9%). The antioxidant capacity of the oil was measured on the basis of the scavenging activity to the stable 2,2-diphenyl-1-picrylhydrazyl (DPPH). The IC50 value of the oil was evaluated as 0.77 mg·mL(-1). In addition, the essential oil was found to possess moderate cytotoxic effects on the HEp-2 cell line (50% cytotoxic concentration (CC50)=653.6 µg·mL(-1)). The potential antiviral effect was tested against Coxsackievirus B (CV-B), a significant human and mouse pathogen that causes pediatric central nervous system disease, commonly with acute syndromes. The reduction of viral infectivity by the essential oil was measured using a cytopathic (CPE) reduction assay.

Panax Notoginseng Saponins Ameliorates Coxsackievirus B3-Induced Myocarditis by Activating the Cystathionine-γ-Lyase/Hydrogen Sulfide Pathway.

This study is to determine the therapeutic effects of Panax notoginseng saponins (PNSs) on coxsackievirus B3 (CVB3)-induced myocarditis, and whether cystathionine-γ-lyase (CSE)/hydrogen sulfide (H2S) pathway is involved. Mouse model of myocarditis was induced by CVB3 infection, and the mice were subjected to vehicle (saline) or drug treatments (sodium bisulfide (NaHS), propargylglycine (PAG), or PNSs). The results showed that there were inflammatory cell infiltrations, interstitial edemas, and elevated inflammatory cytokines, in CVB3-induced myocarditis. PAG administration increased, whereas NaHS treatment decreased the severity of the myocarditis. PNS treatment dramatically alleviated these myocardial injuries and decreased the viral messenger RNA (mRNA) expression by the enhanced expression of CSE/H2S pathway. Moreover, the therapeutic effects of PNSs on myocarditis were stronger than those of NaHS. Finally, the effect of PNSs on CSE/H2S pathway and cardiac cell protection were verified in cultured cardiac cells. PNSs may be a promising medication for viral myocarditis therapy.

Structure-activity relationship of N-benzenesulfonyl matrinic acid derivatives as a novel class of coxsackievirus B3 inhibitors.

A novel series of N-benzenesulfonyl matrinic amine/amide and matrinic methyl ether analogues were designed, synthesized and evaluated for their in vitro anti-coxsackievirus B3 (CVB3) activities. The structure-activity relationship (SAR) studies revealed that introduction of a suitable amide substituent on position 4' could greatly enhance the antivirus potency. Compared to the lead compounds, the newly synthesized matrinic amide derivatives 21c-d and 21j exhibited stronger anti-CVB3 activities with lower micromolar IC50 from 2.5 µM to 2.7 µM, and better therapeutic properties with improved selectivity index (SI) from 63 to 67. The SAR results provided powerful information for further strategic optimization, and these top compounds were selected for the next evaluation as novel enterovirus inhibitors.