A comparative study on the influence of an ivy preparation and an ivy/thyme combination on the β-adrenergic signal transduction.

The β-adrenergic receptor (βAR) is relevant for surfactant formation in alveolar type 2 cells and reduction of intracellular calcium concentration in bronchial muscle cells and thus for secretolytic and bronchospasmolytic effects. Herbal medicinal products that affect the βAR system are used to treat common cold and bronchitis accompanied with mucus covered and narrowed airways. The present work compares the influence of an ivy preparation and an ivy/thyme combination on the β-adrenergic signal transduction.

α-Hederin inhibits G protein-coupled receptor kinase 2-mediated phosphorylation of β2-adrenergic receptors.

Background: Recently is has been shown that α- and β-hederin increase the β2-adrenergic responsiveness of alveolar type II cells (A549) and human airway smooth muscle cells (HASM), respectively, by inhibiting the internalization of β2-adrenergic receptors (β2AR) under stimulating conditions. Internalization of β2AR is initiated by phosphorylations of certain serines and threonines by cAMP dependent protein kinase A (PKA) and G protein-coupled receptor kinases (GRK).

Purpose: To evaluate the effect of α-hederin on PKA and GRK2 mediated phosphorylation of GFP-tagged β2AR.