RESUMO
Regulatory guidelines for production of plasma-derived products emphasize the need to document methods of viral inactivation and demonstrate the effectiveness of screening methods. Therefore, it is important to evaluate the kinetics of such processes. Togaviridae family virions may be considered as good tools for quality control of haemoderivatives, if they possess large amounts of cholesterol and saturated lipids and high structural lipid/protein ratio in their envelope composition, which give more resistance to classical treatments. The purpose of this study was to evaluate the efficiency of solvent-detergent and heat treatments adopted during the human haemoderivatives processment. Sindbis virus was used as a model for inactivation of enveloped viruses. Semi-processed human factor VIII (FVIII) product experimentally contaminated with Sindbis virus was used to test a solvent-detergent treatment with tri-N-butyl-phosphate (TNBP) and Tween 80. To evaluate thermal inactivation kinetics, lyophilized, and reconstituted samples of Sindbis virus-containing FVIII were incubated up to 30 h at 60 degrees C. The results showed that treatment with TNBP and Tween 80 reduced the infectivity of virus-contaminated FVIII in > or =5.5 log(10) and heat treatment was effective in all samples, although FVIII concentrate had reduced the rate of viral inactivation during a brief period of time.
Assuntos
Tecnologia Biomédica/métodos , Sindbis virus , Tromboplastina/análise , Produtos Biológicos , Temperatura Alta , Humanos , Organofosfatos/farmacocinética , Organofosfatos/farmacologia , Polissorbatos/farmacologia , Controle de Qualidade , Sindbis virus/efeitos dos fármacos , Sindbis virus/isolamento & purificação , Tensoativos/farmacologia , Tromboplastina/efeitos dos fármacos , Inativação de Vírus/efeitos dos fármacosRESUMO
The effect of hesperetin, naringenin and its glycoside form on the Sindbis neurovirulent strain (NSV) replication in vitro was studied. All flavanones tested were not cytotoxic on Baby Hamster cells 21 clone 15 (BHK-21). Antiviral effect was evaluated by a colorimetric assay using MTT (3-(4,5 dimethylthiazol-2-yl)-2,5-dipheyl-tetrazolium bromide) and by plaque reduction assay. Hesperetin and naringenin had inhibitory activity on NSV infection. The 50% inhibitory doses (ID(50%)) of both compounds were 20.5 and 14.9 microg/ml respectively, as established by plaque assay. However their glycosides, hesperidin and naringin did not have inhibitory activity. Implying that the presence of rutinose moiety of flavanones blocks the antiviral effect. Oxygenation on the 3' positions at the B rings on the hesperetin skeleton decrease the anti viral activity at 25 microg/ml.
Assuntos
Antivirais/farmacologia , Flavanonas , Flavonoides/farmacologia , Hesperidina/farmacologia , Sindbis virus/efeitos dos fármacos , Animais , Cricetinae , Sindbis virus/fisiologiaRESUMO
Methanolic extract of leaves and twigs of Guatteria cardoniana R.E. Fries (Annonaceae), a plant from the Venezuelan rain forest, was separated in alkaloid rich fractions and their biological effect on baby hamster kidney (BHK) cell line was studied. The initial plant extract (FA) induced cell proliferation, cytotoxicity as well as antiviral activity, depending on the concentration used. Further separation of this methanolic extract allowed us to separate these biological activities. The fraction with the highest antiviral activity (F7) was chromatographed and three of the nine alkaloid-rich fractions obtained, retained this activity. One of them (F(7)11) exhibited the highest inhibitory effect against a neurotropic Sindbis virus (NSV).
Assuntos
Antivirais/farmacologia , Extratos Vegetais/farmacologia , Animais , Antivirais/isolamento & purificação , Células Cultivadas , Cricetinae , Rim/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Extratos Vegetais/isolamento & purificação , Sindbis virus/efeitos dos fármacos , VenezuelaRESUMO
Partially purified extracts from leaves of Melia azedarach L. (MA) exert a broad range of antiviral effects on DNA and RNA viruses. The effect of MA on different stages of Sindbis virus replicative cycle in BHK cells was investigated. Under one-step growth conditions MA afforded a greater than 90% inhibition in virus yield if added to the cell cultures 2 h before or after infection, and when added 4 h after infection MA still caused a greater than 80% inhibition. Analysis of early events following Sindbis virus infection showed that MA did not affect viral adsorption to or penetration in BHK cell. In contrast, viral RNA and protein synthesis was almost totally inhibited in cells pretreated with MA 2 h before infection, while cellular macromolecular synthesis was similar in MA-treated and untreated cell cultures.