The studies on chemical composition and biological activity of propolis had focused mainly on species Apis mellifera L. (Hymenoptera: Apidae). There are few studies about the uncommon propolis collected by stingless bees of the Meliponini tribe known as geopropolis. The geopropolis from Scaptotrigona postica was collected in the region of Barra do Corda, Maranhão state, Brazil. The chemical analysis of hydromethanolic extract of this geopropolis (HMG) was carried out through HPLC-DAD-ESI-MS/MS and the main constituents found were pyrrolizidine alkaloids and C-glycosyl flavones. The presence of alkaloids in extracts of propolis is detected for the first time in this sample. The antiviral activity of HMG was evaluated through viral DNA quantification experiments and electron microscopy experiments. Quantification of viral DNA from herpes virus showed reduction of about 98% in all conditions and concentration tested of the HMG extract. The results obtained were corroborated by transmission electron microscopy, in which the images did not show particle or viral replication complex. The antiviral activity of C-glycosyl flavones was reported for a variety of viruses, being observed at different points in the viral replication. This work is the first report about the antiviral activity of geopropolis from Scaptotrigona postica, in vitro, against antiherpes simplex virus (HSV).
Since October 2001, the Adolfo Lutz Institute has been receiving vesicular fluids and scab specimens of patients from Paraíba Valley region in the São Paulo and Minas Gerais States and from São Patricio Valley, in the Goiás State. Epidemiological data suggested that the outbreaks were caused by Cowpox virus or Vaccinia virus. Most of the patients are dairy milkers that had vesiculo-pustular lesions on the hands, arms, forearms, and some of them, on the face. Virus particles with orthopoxvirus morphology were detected by direct electron microscopy (DEM) in samples of 49 (66.21%) patients of a total of 74 analyzed. Viruses were isolated in Vero cell culture and on chorioallantoic membrane (CAM) of embryonated chicken eggs. Among 21 samples submitted to PCR using primers for hemagglutinin (HA) gene, 19 were positive. Restriction digestion with TaqI resulted in four characteristic Vaccinia virus fragments. HA nucleotide sequences showed 99.9% similarity with Cantagalo virus, described as a strain of Vaccinia virus. The only difference observed was the substitution of one nucleotide in the position 616 leading to change in one amino acid of the protein in the position 206. The phylogenetic analysis showed that the isolates clustered together with Cantagalo virus, other Vaccinia strains and Rabbitpox virus.
The search for functional foods, which possess bioactive substances, is a new trend for the obtention of alternative and more effective treatments of many diseases with fewer side effects. Geopropolis, elaborated by stingless bees, is a mixture of plant resin sources, wax and soil. In the geopropolis from Scaptotrigona affinis postica (Latreille, 1807), (Hymenoptera, Apidae, Meliponini) was not observed the presence of soil. In a previous study, the extract of geopropolis provided by the beekeeper, from S. postica of Barra do Corda, Maranhão State, exhibited potent antiviral activity against herpes simplex virus. In this study, the propolis extract was prepared experimentally and characterized by RP-HPLC-DAD-ESI-MS/MS. The objective of this study was to evaluate the antiviral activity of an experimentally prepared geopropolis extract from S. postica against Rubella Virus infected Statens Serum Institute Rabbit Cornea (SIRC) cells. Rubella virus infection of susceptible women during the first trimester of pregnancy, often results in a combination of birth defects in newborns. There is not an effective treatment for rubella virus infection. Different protocols were carried out to evaluate, the antiviral effect of geopropolis extract on the viral replication of infectious RV. Cell viability and cell proliferation assays indicated that this geopropolis was not toxic to cultured SIRC cells. In the viral binding assay, antiviral assay, real-time PCR, and transmission electron microscopy, was observed that different concentrations of geopropolis (17, 34 and 68 µg/mL) was able to inhibit the binding of virions to the cell receptor and the production of infectious RV particles in post treated and pre treated infected SIRC cells. The antiviral activity could to be attributed to the high contents of the apigenin derivatives, vicenin-2 and schaftoside. As far as we know, this is the first report about the antiviral activity of geopropolis from Scaptotrigona postica against a Togaviridae virus.
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