Combination of benzo[a]phenothiazines with acyclovir against herpes simplex virus

Carnosic Acid Inhibits Herpes Simplex Virus Replication by Suppressing Cellular ATP Synthesis

Acquiring resistance against antiviral drugs is a significant problem in antimicrobial therapy. In order to identify novel antiviral compounds, the antiviral activity of eight plants indigenous to the southern region of Hungary against herpes simplex virus-2 (HSV-2) was investigated. The plant extracts and the plant compound carnosic acid were tested for their effectiveness on both the extracellular and intracellular forms of HSV-2 on Vero and HeLa cells. HSV-2 replication was measured by a direct quantitative PCR (qPCR). Among the tested plant extracts, Salvia rosmarinus (S. rosmarinus) exhibited a 90.46% reduction in HSV-2 replication at the 0.47 μg/mL concentration. Carnosic acid, a major antimicrobial compound found in rosemary, also demonstrated a significant dose-dependent inhibition of both extracellular and intracellular forms of HSV-2. The 90% inhibitory concentration (IC90) of carnosic acid was between 25 and 6.25 μg/mL. Proteomics and high-resolution respirometry showed that carnosic acid suppressed key ATP synthesis pathways such as glycolysis, citrate cycle, and oxidative phosphorylation. Inhibition of oxidative phosphorylation also suppressed HSV-2 replication up to 39.94-fold. These results indicate that the antiviral action of carnosic acid includes the inhibition of ATP generation by suppressing key energy production pathways. Carnosic acid holds promise as a potential novel antiviral agent against HSV-2.

Triterpenes and Phenolic Compounds from Euphorbia deightonii with Antiviral Activity against Herpes Simplex Virus Type-2

Two undescribed compounds, 3β,7β-dihydroxy-24-methylenelanosta-8-ene-11-one (1) and neolignane deightonin (4) were isolated from the aerial parts of Euphorbia deightonii Croizat together with six known compounds, namely, kansenone (2), euphorbol-7-one (3), dehydrodiconiferyl diacetate (5), marylaurencinol D (6), scoparon (7), and 3,4,3′-tri-O-methylellagic acid (8). The structures of the isolated compounds were determined by HRESIMS, 1D (1H, 13C JMOD) and 2D NMR (HSQC, HMBC, 1H–1H COSY, NOESY) spectroscopic analysis, and by comparison of the assignments with literature data. The anti-herpes simplex virus type-2 activity of the isolated compounds were investigated by qRT-PCR assay on Vero cells after determining cytotoxic concentration 50% (CC50). Compounds 1, 3, 4, and 7 exhibited inhibitory effects with respective IC50 values of 7.05, 2.42, 11.73, and 0.032 µM. Scoparon (7) showed the strongest anti-HSV activity with a selectivity index of 10.93.

Comparison of Solution Chemical Properties and Biological Activity of Ruthenium Complexes of Selected β-Diketone, 8-Hydroxyquinoline and Pyrithione Ligands

In this work, the various biological activities of eight organoruthenium(II) complexes were evaluated to reveal correlations with their stability and reactivity in aqueous media. Complexes with general formula [Ru(η6-p-cymene)(X,Y)(Z)] were prepared, where (X,Y) represents either an O,O-ligand (β-diketone), N,O-ligand (8-hydroxyquinoline) or O,S-pyrithione-type ligands (pyrithione = 1-hydroxypyridine-2(1H)-thione) with Cl- or 1,3,5-triaza-7-phosphaadamantane (PTA) as a co-ligand (Z). The tested complexes inhibit the chlamydial growth on HeLa cells, and one of the complexes inhibits the growth of the human herpes simplex virus-2. The chlorido complexes with N,O- and O,S-ligands displayed strong antibacterial activity on Gram-positive strains including the resistant S. aureus (MRSA) and were cytotoxic in adenocarcinoma cell lines. Effect of the structural variation on the biological properties and solution stability was clearly revealed. The decreased bioactivity of the β-diketone complexes can be related to their lower stability in solution. In contrast, the O,S-pyrithione-type complexes are highly stable in solution and the complexation prevents the oxidation of the O,S-ligands. Comparing the binding of PTA and the chlorido co-ligands, it can be concluded that PTA is generally more strongly coordinated to ruthenium, which at the same time decreased the reactivity of complexes with human serum albumin or 1-methylimidazole as well as diminished their bioactivity.

The Large Action of Chlorpromazine: Translational and Transdisciplinary Considerations in the Face of COVID-19

Coronavirus disease 2019 (COVID-19) is a severe acute respiratory syndrome (SARS) in humans that is caused by SARS-associated coronavirus type 2 (SARS-CoV-2). In the context of COVID-19, several aspects of the relations between psychiatry and the pandemic due to the coronavirus have been described. Some drugs used as antiviral medication have neuropsychiatric side effects, and conversely some psychotropic drugs have antiviral properties. Chlorpromazine (CPZ, Largactil®) is a well-established antipsychotic medication that has recently been proposed to have antiviral activity against SARS-CoV-2. This review aims to 1) inform health care professionals and scientists about the history of CPZ use in psychiatry and its potential anti- SARS-CoV-2 activities 2) inform psychiatrists about its potential anti-SARS-CoV-2 activities, and 3) propose a research protocol for investigating the use of CPZ in the treatment of COVID-19 during the potential second wave. The history of CPZ's discovery and development is described in addition to the review of literature from published studies within the discipline of virology related to CPZ. The early stages of infection with coronavirus are critical events in the course of the viral cycle. In particular, viral entry is the first step in the interaction between the virus and the cell that can initiate, maintain, and spread the infection. The possible mechanism of action of CPZ is related to virus cell entry via clathrin-mediated endocytosis. Therefore, CPZ could be useful to treat COVID-19 patients provided that its efficacy is evaluated in adequate and well-conducted clinical trials. Interestingly, clinical trials of very good quality are in progress. However, more information is still needed about the appropriate dosage regimen. In short, CPZ repositioning is defined as a new use beyond the field of psychiatry.

Correlation between detergent activity and anti-herpes simplex virus-2 activity of commercially available vaginal gels

OBJECTIVE

Herpes simplex virus-2 (HSV-2) infections are almost exclusively sexually transmitted. The presence of vaginal gels during sexual activity may have a significant positive or negative impact on viral transmission. Therefore we investigated three off-the-shelf vaginal lubricants and one pH restoring gel to evaluate their impact on HSV-2 replication.

RESULTS

HeLa cells were infected with untreated virions and virions incubated with the particular gels. The accumulation of viral genomes was monitored by quantitative PCR (qPCR) method at 24 h post infection. Two of the tested gels had no significant effect on HSV-2 replication at the maximum applied concentration, while two had a strong inhibitory effect (~ 98% reduction of replication). The replication inhibitory effect was observed at various multiplicity of infection (MOI 0.4-6.4) and the two inhibitory gels were also capable of inhibiting the HSV-2 induced cytopathic effect on HeLa cells. The surface tension decreasing activity-an indication of detergent activity-was strongly correlated with the anti-HSV-2 activity of the gels (R²: 0.88). Our results indicate that off-the-shelf vaginal gels have a markedly different anti-HSV-2 activity that may influence HSV-2 transmission.

Effect of novel phenothiazine derivatives on brain dopamine in Wistar rats

Background

Neurotransmitters are involved in several functions in the brain and the body of living things. Changes in the level of neurotransmitters in the brain are associated with several illnesses. Some of the drugs are controlling the neurotransmitter by adjusting the level in the brain and are exclusively used in the treatment of psychological disorders. The purpose of the study was to find out the effect of novel synthesised phenothiazine derivatives (GC1, GC2 and GC8) either alone (7.5 mg/kg or 15 mg/kg, oral) or in combination with amphetamine on the experimental animals.

Results

Dopamine level in rat brain was estimated by a spectroscopic method using the UV-visible double beam spectrophotometer at 735 nm. The results revealed that these derivatives blocked the brain dopamine level significantly. The compound GC8 (15 mg/kg) significantly reduced the level of dopamine (0.151 ± 0.04, 0.284 ± 0.03) as similar to that of a standard drug. Furthermore, compounds GC2 (15 mg/kg) and GC1 (15 mg/kg) exhibited a varying level of dopamine inhibition level and have been found at 0.203 ± 0.06 μg/ml, 0.302 ± 0.04 μg/ml, 0.234 ± 0.02 μg/ml and 0.318 ± 0.07 μg/ml, respectively, after the administration of these derivatives either alone or in combination with amphetamine.

Conclusions

The study revealed that the compound 2-amino-6-(3-hydroxy-4-methyl phenyl) pyrimidine-4-yl) (7-chloro-10-(3- (N, N-dimethylamino) propyl)-10H-phenothiazine-3-yl) methanone (GC8, 15 mg/kg) extensively reduced the dopamine level. The order of dopamine-inhibiting effect of the selected compound was found to be GC8 > GC2 > GC1. The increased body weight and relative brain-body weight were also observed in the tested animals due to more intake of food and fluid retention.

Graphical abstract

Phenanthrenes from Juncus Compressus Jacq. with Promising Antiproliferative and Anti-HSV-2 Activities

Juncaceae species are rich sources of phenanthrenes. The present study has focused on the isolation and structure determination of biologically active components from Juncus compressus. Eleven compounds (nine phenanthrenes and two flavonoids) have been isolated from the plant by the combination of different chromatographic methods. Two compounds (compressins A (Compound 1) and B (Compound 2)) are novel natural products, while seven phenanthrenes (effusol (Compound 3), effususol (Compound 4), juncusol (Compound 5), 2-hydroxy-1-methyl-4-oxymethylene-5-vinyl-9,10-dihydrophenanthrene (Compound 6), 7-hydroxy-1-methyl-2-methoxy-5-vinyl-9,10-dihydrophenanthrene (Compound 7), effususin A (Compound 8), and dehydroeffusol (Compound 9)), and two flavonoids (apigenin (Compound 10) and luteolin (Compound 11) were isolated for the first time from the plant. Compressin B (Compound 2) is a dimeric phenanthrene, in which two juncusol monomers (Compound 5) are connecting through their C-3 atoms. The structure elucidation of the isolated compounds was carried out using 1D, 2D NMR spectroscopic methods and HR-MS measurements. In vitro investigation of the antiproliferative effect of the phenanthrenes on two cervical (HeLa and SiHa) and an ovarian human tumor cell line (A2780) revealed that compounds have remarkable antiproliferative activity, mainly on the HeLa cell line. Moreover, juncusol (Compound 5) proved to possess significant antiviral activity against the herpes simplex 2 virus (HSV-2).

A direct quantitative PCR-based measurement of herpes simplex virus susceptibility to antiviral drugs and neutralizing antibodies

Herpes simplex viruses (HSV) are common human pathogens that can cause painful but benign manifestations and recurrent complaints, but can also cause significant morbidity and mortality on infection of the eye or brain and with disseminated infection of an immunosuppressed patient or a neonate. HSV growth inhibition measurement by plaque or yield reduction is a key task in the development of novel antiviral compounds but the manual methods are very labour intensive. The sensitive and specific PCR technology could be an effective method for quantitation of HSV DNA related to virus replication; however the currently described PCR approaches have a major limitation, namely the requirement of purification of DNA from the infected cells. This limitation makes this approach unfeasible for high-throughput screenings. The monitoring of HSV specific antibody titre is essential in vaccination trials and in the improvement of HSV-based oncolytic virotherapy. Usually, conventional cytopathic effect-based and plaque reduction neutralization tests are applied to measure the neutralization titre, but these methods are also time-consuming. To overcome this, we developed a quantitative PCR (qPCR) method for the detection of HSV-2 DNA directly from the infected cells (direct qPCR) and the method was further adapted to measure the titre of HSV specific neutralizing antibody in human sera. The conditions of direct qPCR assay were optimized to measure the antiviral activity of known and novel antiviral substances. Using HSV-2 seronegative and seropositive patients' sera, the validity of the direct qPCR neutralization test was compared to traditional cytopathic effect-based assay. The direct qPCR method was able to detect the HSV-2 DNA quantitatively between multiplicity of infection 1/64 and 1/4194304, indicating that the dynamic range of the detection was approximately 65,500 fold with high correlation between the biological and technical replicates. As a proof of the adaptability of the method, we applied the direct qPCR for antiviral inhibitory concentration 50 (IC₅₀) measurements of known and novel antiviral compounds. The measured IC₅₀ of acyclovir was ∼0.28μg/ml, similar to the previously published IC₅₀ value. The IC₅₀ of novel antiviral candidates was between 1.6-3.1μg/ml. The direct qPCR-based neutralization titres of HSV positive sera were 1:32-1:64, identical to the neutralization titres determined using a traditional neutralization assay. The negative sera did not inhibit the HSV-2 replication in either of the tests. Our direct qPCR method for the HSV-2 growth determination of antiviral IC₅₀ and neutralization titre is less time-consuming, less subjective and a more accurate alternative to the traditional plaque titration and growth reduction assays.

Recent progress in biological activities of synthesized phenothiazines

This review summarizes recent medicinal chemistry investigations in vitro and in vivo in search for new phenothiazines of promising biological activities. New phenothiazine derivatives (over 50 main structures) contain dialkylaminoalkyl, cycloaminoalkyl and aminoalkyl substituents and their acyl and sulfonyl derivatives, and other substituents with varied the monocyclic (pyrazole, thiazole, oxadiazole, thiadiazole, tetrazole) and bicyclic (quinolizine, pyrazolopyrimidine, thiazolopyridine, azabicyclononane and spiro[chromanpyrimidine] heterocycles linked directly or via the alkyl chain with the thiazine nitrogen atom or with the benzene ring. The modifications of the tricyclic ring system with the bicyclic homoaromatic ring (naphthalene) and monocyclic and bicyclic azine rings (pyridine, pyrimidine, pyrazine and quinoline) led to compounds of significant biological activities. Recently obtained phenothiazines exhibit promising antibacterial, antifungal, anticancer, antiviral, anti-inflammatory, antimalarial, antifilarial, trypanocidal, anticonvulsant, analgesic, immunosuppressive and multidrug resistance reversal properties. These activities were the results of the actions of phenothiazines on biological systems via the interaction of the pharmacophoric substituent (in some cases of strict length), via the interaction of the multicyclic ring system (π-π interaction, intercalation in DNA) and via the lipophilic character allowing the penetration through the biological membranes. The activities were examined by using various biological systems such as cell lines, bacteria, viruses, parasites, laboratory mice, rats and rabbits, and monolayer and bilayer membranes. Some mechanisms of the actions are discussed. This review shows current tendency in the phenothiazine synthesis (without synthetic routes) and reveals the phenothiazine core to be very potent pharmacophoric moiety which can be a rich source of new compounds having desirable biological activities.