Comparative study of antioxidant properties of immunoregulatory peptides.

We studied antioxidant properties of immunofan, bursin, cyclobursin, thymopoietin II fragment, glycine, and Siberian ginseng. Experiments were performed in 2 model systems: Fe(2+)-induced oxidation of multilamellar phospholipid liposomes in a heterogeneous water-lipid system and oxidation of luminol induced by alpha,alpha'-azo-bis(isobutyramidine dihydrochloride) in a homogenous aqueous system. By the ability to entrap lipid peroxyl radicals, antioxidant activity of substances decreased in the following order: Siberian ginseng extract>bursin>cyclobursin>thymopoietin II fragment>immunofan, glycine.