Cholesterol-dependent hemolytic activity of Passiflora quadrangularis leaves

Abstract

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.

Effect of soaking on the nutritional quality of pequi (Caryocar brasiliense Camb.) peel flour

“…Accordingly, thermal treatments above 100 °C such as cooking and roasting, are sufficient to eliminate this anti-nutritional component, present in the pequi skin flours. On the other hand, hemolysins are important compounds from the biotechnological point of view, given the potential bactericidal and anticancer activities (YULDASHEVA et al, 2005).…”

The influence of nanodiamond on the oxygenation states and micro rheological properties of human red blood cells <italic>in vitro</italic>

“…30 Whole blood samples were first mixed (1∶1; v∕v) with anticoagulant acid citrate dextrose (ACD) solution. In the next step, cNDs of sizes 5 and 100 nm were added to the citrated blood samples (100 μl) in concentrations of 5 μg∕ml and 50 μg∕ml and were incubated for 3 h. Solutions were centrifuged at 160 g (1000 rpm) and 25°C, for 10 min.…”

Comparative effects of the leaves of <i>Gongronema latifolium</i> and <i>Telfaira occidentalis</i> incorporated diets on lipid profiles of rats.

“…There are many bioactive phytochemicals in the leaves of these vegetables and at present, it is not certain, which of them is/ are responsible for the observed effects. Reports have shown that flavonoids, tannins, and saponins may play some roles in hypolipidaemic effect (Ezekwe and Obidoa, 2001;Nwanjo, 2005;Yuldasheva et al, 2005). In this study the hypolipidaemic effects of the two diet preparations were compared and it was observed that Telfairia occidentalis elicited a greater effect than Gongronema latifolium.…”