In ovo inhibition of fowlpoxvirus replication by a gall extract from Guiera senegalensis.

Several field isolates of fowlpoxvirus (FPV) from Burkina Faso, West Africa, were isolated and partly evaluated by molecular analysis. In addition, the in ovo antiviral activity against FPV of a gall extract from Guiera senegalensis was determined. Three viral isolates were obtained from suspected fowlpox cases after passage in embryonating chicken eggs and their poxviral identity confirmed by electron microscopy. All isolates were found to be pathogenic for chicks and all grew well in cell culture. Polymerase chain reaction and sequencing of amplicons revealed sequences identical with those of other FPV strains. The most studied isolate was then employed for use in an antiviral assay. An aqueous acetone extract from the galls of G. senegalensis was found to inhibit both virus-induced pock formation and to reduce viral titre in embryonating chicken eggs. The suggested mechanism of action is the activation of the alternative complement pathway and the inhibition of FPV-induced cholesterogenesis in ovo by constituents of the gall extract.

The phytochemical composition and in vitro antiviral activity of decoctions from galls of Guiera senegalensis J.F. Gmel. (Combretaceae) and their relative non-toxicity for chickens.

Aqueous decoctions obtained from the galls of Guiera senegalensis were screened to determine their phytochemical composition and in vitro antiviral activity against fowlpox virus. In addition, we wanted to investigate the toxic effects, if any, of crude extracts in chickens. Steroids as well as cardiac glycosides not previously reported, an alkaloid, polyphenols and saponins were detected in the various fractions of organic solvents used for extracting the decoctions. Antiviral activity was determined by cytopathic effect inhibition assay in primary chicken embryo skin cells. The 50% inhibitory concentration (EC50) was shown to be 15.6 microg/ml. Toxicity for cells was established by determining the 50% cytotoxic concentration (CCy50). A value of 90 microg/ml and a selectivity index (CCy50/EC50) of 5.8 were obtained. In vivo studies of toxicity were performed in chickens that were dosed orally with decoctions of several concentrations for 2 weeks and then monitored for 3 months. No significant changes in several blood chemical parameters were obtained, except for a significant decline in SGOT levels in birds dosed with 100 mg/kg. These levels were nevertheless within the accepted normal range. The findings suggest that aqueous decoctions of galls from G. senegalensis are non-toxic for chickens when administered orally, even at a daily dose of 100 mg/kg for 14 days.

Inhibition of fowlpox virus by an aqueous acetone extract from galls of Guiera senegalensis J. F. Gmel (Combretaceae).

An aqueous acetone extract from the galls of Guiera senegalensis was screened for in vitro antiviral activity against fowlpox virus (FPV). Cytopathic effect (CPE) inhibition and plaque inhibition assays were used to show presence of antiviral effects against FPV, whilst cytotoxicity assays established the relative safety of the extract for cells in vitro. Phytochemical analyses revealed the presence of phenolic compounds including flavonoids, tannins and anthocyanins as well as steroids and alkaloids. Thin-layer chromatographical (TLC) analysis also revealed the presence of quercitrin, quercetin, kaempferol, apigenin, rutin, gallic acid as well as unknown flavonoids and unknown phenolic acids. The antiviral effect of the extract was partially attributed to phenolic components including flavonoids.

Isolation of surface tubules of fowlpox virus.

Surface tubules of fowlpox virus were isolated using chemical and physical methods. Suspensions of lipid cytoplasmic inclusion bodies were obtained by treating infected chorioallantoic membranes with 1% trypsin. Inclusions were treated with ultrasonic sound, detergents, and enzymes and were examined by electron microscopy. Although lipase treatment altered the morphology of lipid inclusions, no viral surface tubules were recovered. Treatment with the detergent Nonidet-P40 followed by 2-mercaptoethanol disrupted virions without allowing surface tubules to be recovered. Disruption of lipid inclusions by ultrasonic sound or manual grinding of chorioallantoic membranes produced free virions but only small numbers of tubules. These results indicate that surface tubules can be recovered, but that the lipid nature of cytoplasmic inclusions interferes with procedures commonly used in tubule purification.

[Effect of iosan and bradofen on the viruses of Newcastle disease, laryngotracheitis and fowl pox]. / Deistvie na iozan i bradofen vurkhu virusite na psevdochumata, laringotrakheits i sharkodifteriiata po ptitsite

Tested was the effect of the iodoform preparation iosan and the quaternary ammonium preparation bradofen against the viruses of the Newcastle disease (strain La Sota), laryngotracheitis (strain TsNIIP) and fowl pox (strain FK) in birds. The following results were obtained: 1. To a concentration of 3% (262 ppm of active iodine) and exposure of 45 min. to iosan the virus of laryngotracheitis was sensitive; that of Newcastle disease perished at a conc. of 5% (525 ppm of active iodine for 15 min); and that of fowl pox was not inactivated at a 30 min. exposure to a conc. of 7% (875 ppm of active iodine.) 2. Bradofen inactivated the Newcastle disease virus in a conc. of 0.5 per cent for 30 min., while the pox virus withstood a conc. of 1.5% up to the 30 th min. The virus of laryngotracheitis was inactivated by a conc. of 2 per cent for 45 min. The disinfection effect of the tested preparations was assessed as satisfactory.