Data/hora: 01/06/2024 14:14:58

Provedor de dados: | 56
País: | Brazil
Título: | Cholesterol-dependent hemolytic activity of Passiflora quadrangularis leaves
Autores: | Yuldasheva,L.N.; Carvalho,E.B.; Catanho,M.-T.J.A.; Krasilnikov,O.V.
Data: | 2005-07-01
Ano: | 2005
Palavras-chave: | Passiflora quadrangularis; Leaf extract; Liposomes; Bilayer permeation; Hemolysin; Membrane cholesterol.
Resumo: | Plants used in traditional medicine are rich sources of hemolysins and cytolysins, which are potential bactericidal and anticancer drugs. The present study demonstrates for the first time the presence of a hemolysin in the leaves of Passiflora quadrangularis L. This hemolysin is heat stable, resistant to trypsin treatment, has the capacity to froth, and acts very rapidly. The hemolysin activity is dose-dependent, with a slope greater than 1 in a double-logarithmic plot. Polyethylene glycols of high molecular weight were able to reduce the rate of hemolysis, while liposomes containing cholesterol completely inhibited it. In contrast, liposomes containing phosphatidylcholine were ineffective. The Passiflora hemolysin markedly increased the conductance of planar lipid bilayers containing cholesterol but was ineffective in cholesterol-free bilayers. Successive extraction of the crude hemolysin with n-hexane, chloroform, ethyl acetate, and n-butanol resulted in a 10-fold purification, with the hemolytic activity being recovered in the n-butanol fraction. The data suggest that membrane cholesterol is the primary target for this hemolysin and that several hemolysin molecules form a large transmembrane water pore. The properties of the Passiflora hemolysin, such as its frothing ability, positive color reaction with vanillin, selective extraction with n-butanol, HPLC profile, cholesterol-dependent membrane susceptibility, formation of a stable complex with cholesterol, and rapid erythrocyte lysis kinetics indicate that it is probably a saponin.
Tipo: | Info:eu-repo/semantics/article
Idioma: | Inglês
Identificador: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2005000700009
Editor: | Associação Brasileira de Divulgação Científica
Relação: | 10.1590/S0100-879X2005000700009
Formato: | text/html
Fonte: | Brazilian Journal of Medical and Biological Research  v.38 n.7 2005
Fonte: | info:eu-repo/semantics/openAccess