Cerebrolysin
Cerebrolysin is a parenterally administered, peptide-based nootropic derived from purified porcine brain proteins. It is a complex mixture of low-molecular-weight peptides and amino acids designed to provide neuroprotective and neurotrophic effects.
Composition
Low-molecular-weight fraction (<10 kDa) of purified porcine brain proteins.
Contains biologically active peptides, neuropeptides, and amino acids.
Not a single, defined peptide sequence; a mixture mimicking endogenous neurotrophic factors.
Mechanism of Action
- Neurotrophic Activity: Promotes neuronal growth, sprouting, and survival, similar to naturally occurring neurotrophic factors (e.g., NGF, BDNF).
- Neuroprotection: Reduces apoptosis by modulating anti- and pro-apoptotic proteins, stabilizes calcium homeostasis, and protects neurons from ischemic and excitotoxic damage.
- Synaptic Plasticity: Enhances synaptic formation and transmission, supporting learning and memory.
- Metabolic Enhancement: Improves cerebral glucose utilization and protein synthesis.
Indications
(in use in multiple countries; not in Canada or the U.S. ):
Ischemic Stroke (acute and recovery phases)
Vascular Dementia
Alzheimer’s Disease
Traumatic Brain Injury (TBI)
PE-22-28
PE-22-28 is a synthetic 7–amino acid fragment derived from the C-terminus of pituitary adenylate cyclase-activating polypeptide (PACAP), designed to retain neuroprotective effects while reducing activation of the primary PACAP receptor.
Structure
7–amino acid sequence: Leu-Ser-Ala-Leu-Leu-Ser-Leu
Derived from the C-terminal region of PACAP, engineered to selectively modulate receptor activity and minimize side effects.
Mechanism of Action
- Receptor Modulation: Acts as a partial agonist at the PAC1 receptor, triggering neuroprotective signaling pathways (e.g., MAPK/ERK) without producing the full cAMP response of full-length PACAP.
- Neuroprotection: Promotes neuronal survival, reduces brain inflammation, and protects against oxidative stress and excitotoxicity.
- Reduced Side Effects: By avoiding strong G-protein (cAMP) activation, it may limit hypotension, tachycardia, and other PACAP-related side effects.
Indications
(Preclinical and investigational uses):
Neurodegenerative Diseases (e.g., Alzheimer’s, Parkinson’s)
Ischemic Stroke
Traumatic Brain and Spinal Cord Injury
Selank
Selank is a synthetic heptapeptide analog of the endogenous immunomodulatory peptide tuftsin, known for its anxiolytic and nootropic effects without the sedative or muscle-relaxant properties of traditional benzodiazepines.
Structure
7–amino acid sequence: Thr-Lys-Pro-Arg-Pro-Gly-Pro
Synthetic analog of tuftsin, designed to retain immunomodulatory and neuromodulatory activity.
Mechanism of Action
- GABA System Modulation: Modulates GABA expression and degradation, producing a calming, anxiolytic effect.
- Serotonin and Dopamine Regulation: Adjusts monoamine neurotransmitter levels, contributing to mood stabilization and anti-anxiety effects.
- Enkephalinase Inhibition: Protects endogenous enkephalins from degradation, prolonging their positive neuromodulatory effects.
- Immune Modulation: Influences immune system activity, linking immunomodulation to effects on anxiety and stress-related behaviors.
Indications
(Approved in Russia; not FDA-approved in the U.S.):
Anxiety Disorders and Generalized Anxiety
Depression (adjunct therapy)
Neurotic and Stress-Related Conditions
Cognitive Enhancement under Stress
Semax
Semax is a synthetic heptapeptide analog of the ACTH(4-10) fragment, designed as a potent nootropic and neuroprotective agent without corticotropic (hormone-releasing) activity.
Structure
7–amino acid sequence: Met-Glu-His-Phe-Pro-Gly-Pro
Features a C-terminal Pro-Gly-Pro tripeptide extension to enhance stability and potency.
Synthetic analog of ACTH(4-10), retaining neuroprotective and cognitive-enhancing properties.
Mechanism of Action
- BDNF Upregulation: Increases expression of Brain-Derived Neurotrophic Factor (BDNF), supporting neuronal survival, plasticity, and cognitive function.
- Neurotrophic Effects: Enhances neurotrophin activity (e.g., NGF, BDNF) and receptor functionality.
- Neurotransmitter Modulation: Influences dopaminergic, serotonergic, and GABAergic pathways, improving attention, learning, and memory.
- Cerebrovascular Improvement: Increases cerebral blood flow and provides antioxidant protection against ischemia and oxidative stress.
Indications
(Used in Russia):
Ischemic Stroke and Transient Ischemic Attack (TIA)
Cognitive and Memory Disorders
Optic Nerve Atrophy and Glaucoma
Off-label: Cognitive enhancement and focus