RESUMEN
An ethanolic extract of leaves from the tree Casearia sylvestris, known as guaçatonga in Brazil, was tested for in vitro activity against oral pathogenic bacteria and fungi. The results showed susceptibility of all the microorganisms tested. This study suggests a potential use of ethanolic extract of C. sylvestris as a novel treatment of oral infectious conditions, such as denture stomatitis, periodontitis and dental caries.
Asunto(s)
Antibacterianos , Casearia , Extractos Vegetales/uso terapéutico , BocaRESUMEN
The local absorption rate, clearance and tissue distribution of Crotalus durissus terrificus venom, (Cdt) were examined using a two-antibody sandwich ELISA assay. We compared the biodistribution of both free or encapsulated Cdt in mice. Following subcutaneous injection of 10 microg/mouse of free Cdt (0.8 LD50), venom was detected in serum after 15 min, showed its highest level at 30 min (45+/-5 ng/ml) and was cleared from the circulation after 6 h. After 2 h of inoculation, venom was detected in the kidney (57+/-9 ng/g of tissue), spleen (18+/-4 ng/g of tissue) and brain (14+/-6 ng/g of tissue). For both subcutaneous or intravenous injection of free Cdt, venom was firstly detected in the kidney. No Cdt appeared either in the kidney, spleen, brain, or other tissues after subcutaneous inoculation of encapsulated venom even though a higher dose was used, 25 microg/mouse (2 LD50). Venom remained at the site of injection for a period of 1 week. Following intravenous injection of encapsulated venom (5 microg/mouse, 2 LD50), venom was detected in liver and spleen tissues. The biodistribution of encapsulated venom is discussed in relation to the effects of reduction of toxicity and increase of adjuvanticity.
Asunto(s)
Venenos de Crotálidos/farmacocinética , Animales , Encéfalo/metabolismo , Venenos de Crotálidos/administración & dosificación , Venenos de Crotálidos/metabolismo , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/metabolismo , Portadores de Fármacos/farmacocinética , Ensayo de Inmunoadsorción Enzimática , Inyecciones Intravenosas , Inyecciones Subcutáneas , Riñón/metabolismo , Liposomas , Tasa de Depuración Metabólica , Ratones , Sensibilidad y Especificidad , Bazo/metabolismo , Distribución TisularRESUMEN
Crotoxin isolated from the venom of Crotalus durissus terrificus (South American rattlesnake) was incorporated into liposomes by the dehydration-rehydration vesicle method using different membrane compositions and the co-encapsulation of immunostimulants. Crotoxin was also encapsulated into liposomes formed from a non-phospholipid amphiphile, a mixture of polyoxyethylene 2-cetyl ether, dicetyl phosphate and cholesterol. The preparations were characterized in relation to stability, toxicity and the protection of mice against whole venom after immunization. All liposome preparations were quite stable, retaining more than 75% of the originally encapsulated crotoxin after 1 week of incubation at physiological temperature. Co-encapsulation with lipopolysaccharide increased the leakage of crotoxin. In contrast, co-encapsulation of the lipid moiety of lipopolysaccharide did not influence the stability of liposomes. Toxicity of liposomes was dependent on membrane composition. Liposomes made with phospholipids that were resistant to phospholipase A(2) activity were less toxic. Mice immunized with three doses of the 1 x LD50 of crotoxin encapsulated into liposomes, and with associated immunostimulants, were protected against challenge with 8 x subcutaneous LD50 of C. durissus terrificus venom. Using the same immunization schedule, liposomes made from a non-phospholipid mixture and without immunostimulants achieved 100% protection.
Asunto(s)
Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/química , Crotoxina/administración & dosificación , Crotoxina/inmunología , Membranas Artificiales , Adyuvantes Inmunológicos/toxicidad , Animales , Crotoxina/toxicidad , Femenino , Inyecciones Subcutáneas , Dosificación Letal Mediana , Liposomas , Ratones , Ratones Endogámicos BALB CRESUMEN
The venom of Bothrops jararaca (BjV) snake was encapsulated into liposomes. The toxicity and ability of the resultant liposomes to protect mice were evaluated. No acute toxicity was found in mice, when liposomes were subcutaneously injected whereas the same dose of venom emulsified in Freund's adjuvant caused the mice to die. Immunization with the venom containing liposomes and associated immunostimulants, protected 50% of mice after challenge with BjV (4 x LD50). The hemorrhagic activity induced by BjV was reduced after immunization with liposomes associated with immunostimulants, similarly to immunization with BjV emulsified in Freund's adjuvant. However, mice immunized with BjV:Freund's were better protected against the lethal effects of the venom.