Stimulation of neurotrophin synthesis by 4-methylcatechol: a promising approach for neuroprotection

Neurotrophins play a crucial role in the differentiation, maintenance, and survival of various types of peripheral and central neurons. However, the therapeutic use of neurotrophins is limited by their inability to cross the blood-brain barrier and their instability in the bloodstream. One of the promising approaches to utilize neurotrophic actions of these molecules in the therapy of neurodegenerative diseases is the stimulation of neurotrophin synthesis. Here we review the effects of 4-methylcatechol, a nonadrenergic catechol compound, on the synthesis of the neurotrophins nerve growth factor and brain-derived neurotrophic factor in the peripheral and central nervous system. The neuroprotective potential of 4-methylcatechol in animal models of neurodegenerative disorders is discussed, and other agents that enhance neurotrophin synthesis are also mentioned.Biomedical Reviews 1999; 10: 45-54

Ethanol Extract of Chinese Propolis Facilitates Functional Recovery of Locomotor Activity after Spinal Cord Injury

An ethanol extract of Chinese propolis (EECP) was given intraperitoneally to rats suffering from hemitransection of half of their spinal cord (left side) at the level of the 10th thoracic vertebra to examine the effects of the EECP on the functional recovery of locomotor activity and expression of mRNAs of inducible nitric oxide (NO) synthase (iNOS) and neurotrophic factors in the injury site. Daily administration of EECP after the spinal cord injury ameliorated the locomotor function, which effect was accompanied by a reduced lesion size. Furthermore, the EECP suppressed iNOS gene expression, thus reducing NO generation, and also increased the expression level of brain-derived neurotrophic factor and neurotrophin-3 mRNAs in the lesion site, suggesting that the EECP reduced the inflammatory and apoptotic circumstances through attenuation of iNOS mRNA expression and facilitation of mRNA expression of neurotrophins in the injured spinal cord. These results suggest that Chinese propolis may become a promising tool for wide use in the nervous system for reducing the secondary neuronal damage following primary physical injury

Royal Jelly Facilitates Restoration of the Cognitive Ability in Trimethyltin-Intoxicated Mice

Trimethyltin (TMT) is a toxic organotin compound that induces acute neuronal death selectively in the hippocampal dentate gyrus (DG) followed by cognition impairment; however the TMT-injured hippocampal DG itself is reported to regenerate the neuronal cell layer through rapid enhancement of neurogenesis. Neural stem/progenitor cells (NS/NPCs) are present in the adult hippocampal DG, and generate neurons that can function for the cognition ability. Therefore, we investigated whether royal jelly (RJ) stimulates the regenerating processes of the TMT-injured hippocampal DG, and found that orally administered RJ significantly increased the number of DG granule cells and simultaneously improved the cognitive impairment. Furthermore, we have already shown that RJ facilitates neurogenesis of cultured NS/NPCs. These present results, taken together with previous observations, suggest that the orally administered RJ may be a promising avenue for ameliorating neuronal function by regenerating hippocampal granule cells that function in the cognition process