Prospects for the use of intranasally administered insulin and insulin-like growth factor-1 in cerebral ischemia

Currently, the approaches used to treat stroke have significant limitations, and neuroprotective therapy is ineffective. In this regard, the search for effective neuroprotectors and the development of new neuroprotective strategies in cerebral ischemia are still relevant. Insulin and insulin-like growth factor-1 (IGF-1) play a key role in the functioning of the brain, are involved in the regulation of growth, differentiation and survival of neurons, neuronal plasticity, food intake, control peripheral metabolism and endocrine functions. They have a complex effect on the brain, including neuroprotective effects in cerebral ischemia and stroke. Experiments on animals and cell cultures have shown that insulin and IGF-1 under hypoxic conditions improve energy metabolism in neurons and glial cells, have a positive effect on blood microcirculation in the brain, restore nerve cell functions and neurotransmission processes, and have anti-inflammatory and antiapoptotic effects on brain cells. Of greatest interest to the clinic is the intranasal route of administration of insulin and IGF-1, since it allows dosed delivery of these hormones directly to the brain, bypassing the blood-brain barrier. Intranasally administered insulin demonstrates a pronounced positive effect in the correction of cognitive impairment in elderly people with neurodegenerative and metabolic disorders. Insulin and IGF-1 administered intranasally improve increase the survival of animals with ischemic stroke. The review discusses literature data and the results of our own studies on the mechanisms of the neuroprotective action of intranasally administered insulin and IGF-1 in cerebral ischemia and the prospects for their use to normalize CNS functions and reduce neurodegenerative changes in this pathology.