Natural regulatory peptides are
biologically active compounds that are produced by various cells and provide a
link among the main
regulatory systems of the body. The field of research into the biologic
activity of endogenous regulatory peptides is extremely vast. These peptides affect the cardiovascular,
immune, reproductive, endocrine, digestive, and other systems, alter energy
metabolism, and are especially effective in the regulation of the central
nervous system. Despite of the wide range of preventive and therapeutic effects of natural
regulatory peptides and proteins, their application in clinical practice is
difficult. This is primarily because of their extreme instability, as they are
rapidly degraded by proteases of the gastrointestinal tract, blood, cerebrospinal
fluid, and other biologic media. Compounds with higher stability (i.e., a considerably
longer half-life compared with that of natural molecules) and the ability to
provide a directional
effect on the various body
systems were obtained from modifications of endogenous regulatory peptides. Synthetic analogs of regulatory peptides,
as a rule, contain only natural amino acids in their composition, and their
biodegradation does not
lead to the formation of toxic products; thus, they have fewer side effects. This review focuses on the consideration
of two synthetic regulatory peptides, Semax and Selank, which were the bases
for the creation of new drugs that are used effectively in the treatment of
various diseases of the nervous system. The synthetic analog of an
adrenocorticotropic hormone 4-10 fragment (ACTH4-10)
Semax is a powerful neuroprotective agent that is particularly effective as a
therapy for stroke. Selank was synthesized on the basis of the natural
immunomodulator tuftsin. Selank is a powerful anxiolytic that is used as a
therapy for generalized anxiety disorder and neurasthenia without sedative and
muscle-relaxant effects. This review presents the results of research aimed at
studying the influence of these peptides on the transcriptome of brain cells.
The problems of drugs developed based on the clinical activities of Semax and
Selank are discussed separately.