Modulation of platelet functions by European toad (Bufo Bufo) skin secretions components

Abstract

Background: A growing number of reports indicate that amphibian skin secretions may have a remarkable medical importance; however, the effects of the components of some dermal secretions on blood platelets and hemostasis are inadequately recognized. Since our previous studies demonstrated that the general Bufo bufo skin secretions induced platelet aggregation in platelet-rich plasma, this work was designed to study the effects of the components of some fractions on platelet functions to comprehend its possible mechanism of action as platelet modulators. Methods: Chromatographic separation of B. bufo general skin secretions was carried out using size exclusion chromatography. Rabbit platelets were purified by column chromatography on Sepharose 4B. Various aspects of platelet function such as activation, aggregation, and adhesion were evaluated. Results: One fraction, out of 7, dose-dependently induced aggregation of isolated platelets and was used in further experiments. The studied fraction was shown to induce platelet adhesion onto fibrinogen-coated surface. Furthermore, the results demonstrated the effects of the fraction on some processes that involved in platelets activation: The fraction components facilitated (Ca2+) i mobilization and attenuated platelets Akt phosphorylation, but had no effect on platelet serotonin secretion. Membrane integrity was determined using lactate dehydrogenase (LDH) assay. No increased LDH release was recorded that means no platelet damage, which could lead to misinterpretation of the data, occurred. Conclusion: The results suggest that components of the B. bufo skin secretions may be a promising source of natural compounds which can modulate platelet functions.

Keywords

• amphibian skin secretions
• platelet activation
• platelet adhesion
• platelet aggregation
• platelets