Atividade antiviral de extratos de plantas medicinais disponíveis comercialmente frente aos herpesvírus suíno e bovino / Antiviral activity of commercially available medicinal plants on suid and bovine herpesviruses

O presente trabalho teve como objetivo pesquisar a atividade antiviral in vitro de plantas medicinais disponíveis comercialmente sobre herpesvírus suíno (SuHV-1) e bovino (BoHV-1). As espécies adquiridas foram Mikania glomerata, Cymbopogon citratus, Equisetum arvense, Peumus boldus, Solanum paniculatum, Malva sylvestris, Piper umbellatun e Solidago microglossa. A citotoxicidade dos extratos foi avaliada na linhagem celular MDBK pelas alterações morfológicas das células e obtenção da concentração máxima não citotóxica (CMNC) de cada planta. A atividade antiviral foi realizada com os extratos em suas respectivas CMNC e avaliada com base na redução do título viral e expressos em porcentagem de inibição. Os extratos aquosos de Peumus boldus e Solanum paniculatum apresentaram atividade antiviral sobre o SuHV-1 com 98% de inibição viral enquanto o de Peumus boldus inibiu apenas o BoHV-1 em 99%.

This paper aims to find commercially available medicinal plants showing antiviral activity in vitro on suid and bovine herpesviruses. The following species were tested: Mikania glomerata, Cymbopogon citratus, Equisetum arvense, Peumus boldus, Solanum paniculatum, Malva sylvestris, Piper umbellatun and Solidago microglossa. The cytotoxicity was evaluated by morphological changes in cells determining the maximum not cytotoxic concentration (MNCC). The antiviral activity was evaluated by viral title reduction. The extracts from Peumus boldus and Solanum paniculatum showed antiviral activity against SuHV-1 with 98% of inhibition. The extract of Peumus boldus also showed activity against BoHV-1 with 99% of inhibition.

Antiviral activity of crude extracts of Guarea guidona.

Crude extracts of leaves and fruits of Guarea guidona were tested for antiviral activity against pseudorabies virus and foot-and-mouth disease virus in the IB-RS-2 pig cell line and against bovine herpesvirus-1 (BHV-1) in the GBK bovine cell line. The highest nontoxic doses of extracts from fruits and leaves were 125 micrograms/ml and 500 micrograms/ml. respectively. Crude extracts presented antiviral activity against pseudorabies virus with a decrease in virus titer of 3.0 log units at 500 micrograms/ml. Virucidal activity was not observed at 62.5 micrograms/ml. Preformed cell monolayers showed no cytotoxic effect after 48 h in the presence of 500 micrograms/ml in pig cells. G. guidona leaves did not induce an antiviral state but exhibited antiviral effects during the early stage of viral infection.

Antiviral activity of crude extracts of Guarea guidona

Crude extracts of leaves and fruits of Guarea guidona were tested antiviral activity against pseudorabies virus and foot-and-mouth disease virus in the IB-RS-2 pig cell line and against bovine herpesvirus-1 (BHV-1) in the GBK bovine Cell line. The highest nontoxic doses of extracts from fruits and leaves were 125 mug/ml and 500 mug/ml, respectively. Crude extracts presented antiviral activity against pseudorabies virus with a decrease in virus titer of 3.0 log units at 500 mug/ml. Virucidal activity was not observed at 62.5 mug/ml. Preformed cell monolayers showed no cytotoxic effect after 48 h in the presence of 500 mug/ml in pig cells. G. guidona leaves did not induce an antiviral state but exhibited antiviral effects during the early stage of viral infection.

Investigation of hycanthone binding to DNA in chromatin with different supra-organization, composition, and function.

Hycanthone is a drug used for the clinical treatment of schistosomiasis, although inducing chromosomes breaks and mutagenesis when it enters the DNA double helix. Based on visual observation of characteristics of basophilia and anisotropy after toluidine blue staining, a preferential binding of hycanthone to heterochromatin could be demonstrated for the nuclei of the Malpighian tubules of Triatoma infestans. In other cellular systems like cattle kidney cells in culture, plant cells, and mouse lymphocytes, the drug could be demonstrated to bind heterochromatin and euchromatin, irrespective of the packing state of the latter. When penetrating the various heterochromatin types (with the exception of T. infestans), the drug induced a chromatin loosening that could favor incidence of chromatin breaks. The variation of hycanthone binding to DNA in different cell types is possibly related to differences in composition, stereo-arrangement and stability of the DNA-protein complexes involved.