Antidiarrheal activity of extracts from Maytenus gonoclada and inhibition of Dengue virus by lupeol

ABSTRACT Diarrhea is an infectious disease caused by bacterial, virus, or protozoan, and dengue is caused by virus, included among the neglected diseases in several underdeveloped and developing countries, with an urgent demand for new drugs. Considering the antidiarrheal potential of species of Maytenus genus, a phytochemical investigation followed by antibacterial activity test with extracts of branches and heartwood and bark of roots from Maytenus gonoclada were conducted. Moreover, due the frequency of isolation of lupeol from Maytenus genus the antiviral activity against Dengue virus and cytotoxicity of lupeol and its complex with β-cyclodextrins were also tested. The results indicated the bioactivity of ethyl acetate extract from branches and ethanol extract from heartwood of roots of M. gonoclada against diarrheagenic bacteria. The lupeol showed potent activity against Dengue virus and low cytotoxicity in LLC-MK2 cells, but its complex with β-cyclodextrin was inactive. Considering the importance of novel and selective antiviral drug candidates the results seem to be promising.

Antiviral activity of a Bacillus sp: P34 peptide against pathogenic viruses of domestic animals

P34 is an antimicrobial peptide produced by a Bacillus sp. strain isolated from the intestinal contents of a fish in the Brazilian Amazon basin with reported antibacterial activity. The aim of this work was to evaluate the peptide P34 for its in vitro antiviral properties against canine adenovirus type 2 (CAV-2), canine coronavirus (CCoV), canine distemper virus (CDV), canine parvovirus type 2 (CPV-2), equine arteritis virus (EAV), equine influenza virus (EIV), feline calicivirus (FCV) and feline herpesvirus type 1 (FHV-1). The results showed that the peptide P34 exhibited antiviral activity against EAV and FHV-1. The peptide P34 inhibited the replication of EAV by 99.9% and FHV-1 by 94.4%. Virucidal activity was detected only against EAV. When P34 and EAV were incubated for 6 h at 37 °C the viral titer reduced from 10(4.5) TCID50 to 10(2.75) TCID50, showing a percent of inhibition of 98.6%. In conclusion, our results demonstrated that P34 inhibited EAV and FHV-1 replication in infected cell cultures and it showed virucidal activity against EAV. Since there is documented resistance to the current drugs used against herpesviruses and there is no treatment for equine viral arteritis, it is advisable to search for new antiviral compounds to overcome these infections.

In vitro inhibition of the bovine viral diarrhoea virus by the essential oil of Ocimum basilicum (basil) and monoterpenes

The bovine viral diarrhoea virus (BVDV) is suggested as a model for antiviral studies of the hepatitis C virus (HCV). The antiviral activity of the essential oil of Ocimum basilicum and the monoterpenes camphor, thymol and 1,8-cineole against BVDV was investigated. The cytotoxicities of the compounds were measured by the MTT (3-(4.5-dimethylthiazol-2-yl)-2.5-diphenyltetrazolium bromide) test, and the antiviral activities were tested by the plaque reduction assay. The oil or compounds were added to the assay in three different time points: a) pre-treatment of the virus (virucidal assay); b) pre-treatment of the cells; or c) post-treatment of the cells (after virus inoculation). The percentage of plaques inhibition for each compound was determined based on the number of plaques in the viral control. The results were expressed by CC50 (50% cytotoxic concentration), IC50 (inhibitory concentration for 50% of plaques) and SI (selectivity index = CC50/IC50). Camphor (CC50 = 4420.12 µgmL-1) and 1,8-cineole (CC50 = 2996.10 µgmL-1) showed the lowest cytotoxicities and the best antiviral activities (camphor SI = 13.88 and 1,8-cineol SI = 9.05) in the virucidal assay. The higher activities achieved by the monoterpenes in the virucidal assay suggest that these compounds act directly on the viral particle.

In vitro antiviral activity of plant extracts on goatpox virus replication.

Four plants having known medicinal properties were screened for inhibition of goatpox virus (GTPV) replication in vitro. Of the 4 plants, extract of Acacia arabica (Babul) and Eugenia jambolana (Jamun) leaves had inhibition (%) 99.70 and 99.92 at their maximum non toxic concentrations, 99.93 +/- 0.38 and 1999.73 +/- 0.50 microg/ml, respectively in all cytopathic effect (CPE) inhibition assays. Inhibition of GTPV virus replication was further confirmed by PCR and SYBR Green based quantitative real-time QPCR assays specific for GTPV. Results indicated that the extract of Acacia arabica and Eugenia jambolana leaves inhibited GTPV replication in vitro.

Virucidal activity presence in Trichilia glabra leaves / Presencia de actividad antiviral en hojas de Trichilia glabra

Different immunomodulatory activities present in Trichilia glabra (TG) leaf extracts have already been described. Particularly, chloroform-methanol extracts were responsible for an in-vivo anti-inflammatory effect. The effect of such extracts on the infectivity of enveloped and naked viruses were investigated. Methanolic fraction extracts were active against herpes simplex virus type 1 (HSV-1) and vesicular stomatitis virus (VSV), while no activity against poliovirus type 3 was observed. VSV was slightly more affected than HSV-1: 2.8 log10 reduction in VSV titer against 2.4 log10reduction in HSV-1 titer when 0.25 mg/ml F2 fraction was tested and a reduction of 2.7 log10in VSV virus titer and of 1.5 log10in HSV-1 virus titer was observed when 0.25 mg/ml F3 fraction was tested. Results obtained in this work suggest a potential pharmaceutical use of TG extract components.

Previamente se han descripto distintas actividades inmunomoduladoras, presentes en extractos de hojas de Trichilia glabra (TG). En particular, se ha demostrado una actividad antiinflamatoria presente en extractos metanólicos. En este trabajo se investigó la actividad virucida de dichos extractos sobre virus envueltos y desnudos. Distintos extractos metanólicos han inactivado en forma moderada los virus herpes simplex tipo 1 (HSV-1) y el virus de la estomatitis vesicular (VSV), mientras no evidenciaron actividad sobre poliovirus tipo 3. VSV resultó algo mas afectado que HSV-1: se observó una reducción en el título viral de 2,8 log10para VSV y de 2,4 log10para HSV-1 cuando se uso una concentración de 0,25 mg/ml de la fracción F2 y una reducción de 2,7 log10para VSV y de 1,5 log 10para HSV-1 cuando se usó una concentración de 0,25 mg/ml de la fracción F3. Los resultados obtenidos en este trabajo, sugieren un potencial uso farmacéutico de los componentes presentes en los extractos de TG.

Purification and properties of antiviral proteins from the leaves of Bougainvillea xbuttiana.

A non-phytotoxic, resistance inducing, proteinaceous antiviral principle was purified by ammonium sulphate fractionation, ion exchange chromatography and gel filtration from the leaves of Bougainvillea xbuttiana. It imparted resistance against tobacco mosaic virus (TMV) and sunnhemp rosette virus (SRV) in their respective test hosts viz. Nicotiana glutinosa, N. tabacum var. Samsun NN, and Cyamopsis tetragonoloba, respectively. The purified principle eluted as a single peak upon gel filtration, but exhibited two polypeptides on SDS-PAGE with Mr 28,000 and 24,000. The two polypeptides were found to be highly basic, rich in lysine with pI around 10.0 and 10.5, respectively. Since this principle effected local lesion inhibition in both treated and untreated top leaves of test host, it might be acting in the initial stages of virus infection as a systemic inducer.

Study on cephalopod's ink for anti-retroviral activity.

Aqueous extracts of ink from four cephalopods, adult and young Sepiella inermis and Loligo duvaucelli were tested against Moloney murine leukaemia virus reverse transcriptase (MMLV RT). Ink from young cephalopods, S. intermis and L. duvaucelli showed strong inhibition of MMLV RT.