Icariin isolated from Epimedium brevicornum Maxim attenuates learning and memory deficits induced by d-galactose in rats.
The effects of icariin (ICA), a major constituent of flavonoids from the Chinese medical herb Epimedium brevicornum Maxim, on spatial memory performances and expressions of hippocampus brain-derived neurotrophic factor (BDNF) and tyrosine kinase TrkB (tropomyosin receptor kinase B) were investigated in d-galactose (d-gal)-treated rats. Subcutaneous injection of d-gal (500mg/kg/d) for four months caused memory loss as detected by the Morris water maze, morphologic abnormalities of neurons in hippocampus region and the reduced expression of BDNF and TrkB were observed. ICA (60mg/kg/d) given orally 1h after subcutaneous injection of d-gal daily for 4months markedly attenuated d-gal-induced rats behavioral dysfunction and neurodegeneration, as evidenced by shortened escape latency and searching distance and rescued morphologic abnormalities, and also elevated the mRNA levels and the protein expressions of BDNF and TrkB in hippocampus, as evidenced by quantitative real-time RT-PCR and Western blotting analysis. But ICA had no significant influence on normal rats which were not injected d-gal. These results clearly demonstrated that d-gal produced learning and memory deficits after chronic administration, and ICA can protect neuron from d-gal insults and improve the memory loss.
Li
Fei
F
Department of Pharmacology, Zunyi Medical College, Zunyi 563000, PR China.
Gong
Qi-Hai
QH
Wu
Qin
Q
Lu
Yuan-Fu
YF
Shi
Jing-Shan
JS
D000818:Animals; D015153:Blotting, Western; D001923:Brain Chemistry / Q000187:drug effects; D019208:Brain-Derived Neurotrophic Factor / Q000096:biosynthesis; D034181:Epimedium / Q000737:chemistry*; D005419:Flavonoids / Q000302:isolation & purification / Q000494:pharmacology*; D005690:Galactose / Q000037:antagonists & inhibitors* / Q000633:toxicity*; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D007859:Learning Disabilities / Q000139:chemically induced / Q000188:drug therapy* / Q000523:psychology; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D008569:Memory Disorders / Q000139:chemically induced / Q000188:drug therapy* / Q000523:psychology; D009419:Nerve Tissue Proteins / Q000378:metabolism; D018696:Neuroprotective Agents; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D020813:Receptor, trkB / Q000096:biosynthesis; D020133:Reverse Transcriptase Polymerase Chain Reaction
D019208:Brain-Derived Neurotrophic Factor; D005419:Flavonoids; D009419:Nerve Tissue Proteins; D018696:Neuroprotective Agents; D012333:RNA, Messenger; D020813:Receptor, trkB; C056599:icariin; D005690:Galactose