[The interaction of Cupressus sempervirens L. proanthocyanidolic oligomers with elastase and elastins]

Cupressus sempervirens L. proanthocyanidolic (O.P.C.) oligomers inhibited the esterolytic activity of pancreatic elastase with a Cl50 of 0.0075 mg/ml when a sap substrate suc(Al)3NA was used in a Tris-HCl 0.05 M buffer with a pH of 7.5. Inhibition was slightly lower when the ionic strength of the buffer was increased. Elastolytic activity was inhibited using an elastinorcein substrate with a Cl50 of 0.05 mg/ml, whatever the pH or the ionic strength of the buffer. The oligomers bound with the elastase to form a precipitant complex where a 2 mg/ml concentration of oligomers precipitated the elastase at 1 mg/ml. Insoluble elastin fixed few 150 micrograms oligomers for 1 mg of elastin but the latter was partly protected by the subsequent action of the elastase. Soluble elastin fixed a greater number of oligomers but it was the peptids of elastin enzyme hydrolysis which fixed the largest amount: around 1500 micrograms per mg. The oligomers-elastin complex seems to be more stable than that of oligomers-elastase which regains part of its esterase activity. The elastic fibers seem to be protected by the O.P.C.