Neuroprotective effects of cerebrolysin, a combination of different active fragments of neurotrophic factors and peptides on the whole body hyperthermia-induced neurotoxicity: modulatory roles of co-morbidity factors and nanoparticle intoxication.

Military personals are often exposed to adverse environmental circumstances, for example, heat stress during peacekeeping or combat operations in summer months or in desert areas leading to disturbed mental functions. The suitable therapeutic strategies to treat heat-induced mental anomalies are still not worked out. Thus, exploration of suitable therapeutic strategies to minimize heat-induced abnormal brain function is needed in suitable animal models. Previous works from our laboratory show that rats exposed to whole body hyperthermia (WBH) for 4 h at 38 °C exhibited profound neuronal, glial, and axonal damages in the cerebral cortex, hippocampus, cerebellum, thalamus, and hypothalamus in a specific manner at light microscopy. Electron microscopy further revealed endothelial cell membrane damage, that is, breakdown of the blood-brain barrier (BBB) after WBH in the brain areas showing cellular damages. These observations indicate that breakdown of the BBB is instrumental in hyperthermia-induced brain injury. Pretreatment with cerebrolysin (2.5 ml or 5 ml/kg, i.v. 30 min before WBH), a mixture of various neurotropic factors and active peptide fragments significantly attenuated BBB disruption and brain damage following heat exposure in a dose-dependent manner. Furthermore, repeated administration of cerebrolysin (5 ml/kg, i.v.) starting from 30 min to 1h after but not after 1.5 or 2 h WBH markedly reduced the BBB disruption and neurotoxicity. Taken together our observations suggest that cerebrolysin if administered within 1 h after WBH in suitable doses induce marked reduction in neurotoxicity. This indicated that cerebrolysin has potential therapeutic value to treat heat stress victims to prevent mental dysfunction in future clinical settings.