Atividade antiviral e virucida de extratos hidroalcoólicos de própolis marrom, verde e de abelhas Jataí (Tetragonisca angustula) frente ao herpersvírus bovino tipo 1 (BoHV-1) e ao vírus da diarreia viral bovina (BVDV) / Antiviral and virucidal activity of hydroalcoholic extracts of propolis brown, green and jataí bees (Tetragonisca angustula) against Bovine Herpesvirus Type-1 (BoHV-1) and Bovine Viral Diarrhea Virus (BVDV)

Dentre as propriedades biológicas da própolis, a atividade antimicrobiana tem merecido destacada atenção. No presente trabalho, descreve-se a ação antiviral e virucida de três extratos hidroalcoólicos de própolis (marrom, verde e de abelhas jataí (Tetragonisca angustula), frente ao Herpesvírus Bovino tipo (BoHV-1) e ao Vírus da Diarreia Viral Bovina (BVDV). Os três extratos hidroalcoólicos foram obtidos de extração etanólica e são oriundos do sul do Brasil. A composição química dos extratos de própolis foi determinada pela cromatografia líquida de alta eficiência acoplada a espectrômetro de massas (UFLC-PDA-ESI-TOF/MS) que identificou e quantificou compostos como: ácido cafeico e ácido p-cumárico, ácido clorogênico, ácido ferúlico, além de flavonoides como a rutina. A toxicidade celular bem como a atividade antiviral dos extratos de própolis em monocamadas de células MDBK (Madin-Darby Bovine Kidney) foi avaliada através de observação microscópica e quantificada pelo teste de MTT (3-(4,5 dimetiltiazol-2yl)-2-5-difenil-2H tetrazolato de bromo). O extrato de própolis de abelhas jataí demonstrou ser menos citotóxico (1,57µg/mL), quando comparado aos extratos verde (0,78µg/mL) e marrom (0,39µg/mL). Quanto a atividade antiviral, a própolis verde demostrou maior eficácia em ambos os tratamentos celulares (pós e pré-exposição) frente ao BoHV-1 em relação aos outros extratos, ou seja, houve maior viabilidade celular quando comparada aos controles de células e vírus. Já a de jataí apresentou atividade frente aos dois vírus (BoHV-1 e BVDV) no método pré-infecção, enquanto a própolis marrom demonstrou ação apenas frente ao BoHV-1 também no método pré-infecção. Para determinação da atividade virucida foram utilizadas diferentes diluições dos vírus, bem como temperaturas e tempos distintos de incubação. A própolis verde a 37°C propiciou a maior redução no título viral (4,33log) em relação a marrom (log = 3,5log) e de jataí (log = 3,24log). No entanto, frente ao BVDV a própolis jataí apresentou os melhores resultados em ambas as temperaturas (22oC e 37oC). Portanto, os extratos avaliados apresentaram atividade antiviral e virucida frente ao BoHV-1 e BVDV, o que os torna alvo para o desenvolvimento de novos biofármacos como alternativa ao uso de antivirais comerciais em Medicina Veterinária.(AU)

Among the biological properties of propolis, the antimicrobial activity has received prominent attention. In this paper, we describe the antiviral and virucidal effect of three hydroalcoholic extracts of propolis (brown, green and jataí bees (Tetragonisca angustula), against bovine herpesvirus type-1 (BoHV-1) and bovine viral diarrhea Virus (BVDV). All hydroalcoholic extracts were obtained from ethanol extraction. The chemical composition of propolis extracts was determined by high-performance liquid chromatography coupled to mass spectrometer (UFLC-PDA-ESI-TOF/MS) to identify and quantify compounds such as caffeic acid and p-coumaric acid, chlorogenic acid, ferulic, and flavonoids such as rutin. Cell toxicity and antiviral activity of propolis extracts in monolayers of MDBK cells (Madin-Darby Bovine Kidney) were assessed by microscopic observation and quantified by the MTT assay (3- (4.5 dimethylthiazol-2yl) -2- 5-diphenyl-2H-tetrazolato bromine). Propolis extract from Jataí bees proved to be less cytotoxic (1.57mg / ml) when compared to green extracts (0.78mg / ml) and brown (0.39mg/mL). Regarding antiviral activity, propolis has shown greater efficacy in both cellular treatments (post and pre-exposure) against BoHV-1 when compared to other extracts, ie, there was increased cell viability compared to cell and virus controls. Extracts from Jataí showed activity against both viruses (BoHV-1 and BVDV) infection in the pre-test, whereas brown propolis demonstrated action only against the BoHV-1 in the pre-infection method. To determine the virucidal activity, it were used different dilutions of virus, as well as different temperatures and incubation times. The green propolis at 37°C led to a greater reduction in viral titer (4.33log) compared to brown (3.5log) and jataí (3.24log). Jataí propolis showed the best results in both temperatures (22oC and 37oC) when tested against BVDV. In summary, the evaluated extracts showed antiviral and virucidal activity against BoHV-1 and BVDV, and may be important targets for the development of new compounds as an alternative to commercial antivirals.(AU)

Acción virucida directa sobre el virus influenza de un extracto de Punica granatum L (granada) / Direct virucidal action against influenza virus of an extract of Punica granatum L (granada)

INTRODUCCIÓN: la especie vegetal Punica granatum L. se conoce en Cuba como granada. A esta planta se le atribuye acción anticatarral en la medicina tradicional, entre otras propiedades. En estudios previos realizados al extracto hidroalcohólico liofilizado preparado con el fruto de esta planta, se informaron la presencia de numerosos componentes químicos, la mayoría flavonoides. Estos compuestos, unidos a la variedad de metabolitos secundarios detectados, le confieren a este liofilizado la posibilidad de poseer acción antiinfluenza, tal como ha sido demostrado en estudios previos del mismo. OBJETIVO: evaluar la acción virucida directa del extracto hidroalcohólico liofilizado de P. granatum frente a la cepa Influenza A/Mississippi/1/85 (H3N2), con diferentes variantes de tratamiento. MÉTODOS: las variantes de tratamiento directo se realizaron en 27 combinaciones de las variables; tiempo de contacto de: 60, 30 y 15 minutos; concentración del extracto de: 1000, 200 y 125 µg/mL y temperatura de incubación de la mezcla extracto-virus: 4, 25 y 37 0C. La presencia o no de la hemaglutinina del virus influenza en cada una de las muestras tratadas, se midió por la titulación de la Inhibición de la Hemaglutinación (IHA) y el título infectivo viral (DIE50). RESULTADOS: la concentración mínima efectiva para ejercer el extracto liofilizado, la acción virucida directa, in vitro, fue 125 µg/mL, a los 15 minutos. La acción virucida directa de éste extracto estuvo siempre presente en las diferentes temperaturas y tiempos de exposición ensayados. CONCLUSIONES: la variante de ensayo que utilizó 125 µg/mL, con independencia del tiempo y la temperatura de tratamiento, resultó suficiente efectiva para reducir la presencia de hemaglutinina del virus influenza.

INTRODUCTION: Punica granatum L. is known in Cuba as grenade. In traditional medicine, among other properties, antiflu action is attributed to this plant. In previous studies with the hydroalcoholic lyophilized extract, prepared with the fruit of this specie, several chemical compounds were reported, specially the presence of flavonoids. The variety of secondary metabolites detected for this lyophilized extract, added to a flavonoid fraction confers a high possibility of anti-influenza activity, as has been demonstrated in previous studies. OBJECTIVE: to evaluate the virucidal activity of the hydroalcoholic lyophilized extract of P. granatum against Influenza A/Mississippi/1/85 (H3N2), with different schemes of treatments. METHODS: the different schemes of treatments included 27 variants of the variables such as contact time of 60, 30 and 15 minutes; extract concentration of 1000, 200 and 125 µg/mL; an incubation temperature of the mix extract-virus of 4, 25 and 37 0C; and the corresponding replicas. The presence or not of hemaglutinin of influenza virus in each one of the treated samples, was measured by titration of Hemaglutination Inhibition (HAI) and the Embryo Infection Doses (EID50). RESULTS: the minimal effective concentration to show in the hydroalcoholic lyophilized extract the direct virucidal action in vitro was 125 µg/mL, in 15 minutes of contact. This virucidal action was always present in the different assessed temperature and time exposures. CONCLUSIONS: the treatment of 125 µg/mL, regardless of time and temperature of treatment, was effective enough to reduce the presence of hemaglutinin of the influenza virus.

Virucidal activity of Colombian Lippia essential oils on dengue virus replication in vitro

The inhibitory effect of Lippia alba and Lippia citriodora essential oils on dengue virus serotypes replication in vitro was investigated. The cytotoxicity (CC50) was evaluated by the MTT assay and the mode of viral inhibitory effect was investigated with a plaque reduction assay. The virus was treated with the essential oil for 2 h at 37ºC before cell adsorption and experiments were conducted to evaluate inhibition of untreated-virus replication in the presence of oil. Antiviral activity was defined as the concentration of essential oil that caused 50 percent reduction of the virus plaque number (IC50). L. alba oil resulted in less cytotoxicity than L. citriodora oil (CC50: 139.5 vs. 57.6 μg/mL). Virus plaque reduction for all four dengue serotypes was observed by treatment of the virus before adsorption on cell. The IC50 values for L. alba oil were between 0.4-32.6 μg/mL and between 1.9-33.7 μg/mL for L. citriodora oil. No viral inhibitory effect was observed by addition of the essential oil after virus adsorption. The inhibitory effect of the essential oil seems to cause direct virus inactivation before adsorption on host cell.

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.