槐花對Ibotanic acid誘發大白鼠學習記憶障礙效用之研究

THE STUDY IN EFFECT OF FLOS SOPHORAE ON IBOTENIC ACID-INDUCED LEARNING-MEMORY DISTURBANCE RATS

一些研究發現槐花和銀杏相似，含有蘆丁（rutin ）和槲皮素（quercetin ），銀杏葉的萃取物被認為有抗氧化傷害和抗血小板凝集的作用，已被廣泛的用來治療痴呆症或腦血管意外（cerebrovascular accident ）。痴呆主要的臨床表現是認知功能的障礙，也就是學習記憶的減退，或喪失，因此本研究的目的在探討槐花對學習記憶障礙的效用。我們建立一個學習記憶障礙的動物模型，將ibotenic acid （IBO, 0.06 M, 0.5 μl ）於Sprague-Dawley （SD ）大白鼠兩側的基底前腦核（nucleus basalis magnocellularis, NBM ）注射，製造一個類似人類痴呆學習記憶障礙的動物模型，每日早晚分別餵食槐花（0.3 g/kg ），連續6 天或連續14 天，以被動迴避試驗的明室滯留時間（retention time ）為指標，來觀察槐花對學習記憶障礙大白鼠的效用。結果發現IBO 於SD 大白鼠的兩側NBM 注射後，它們的被動迴避試驗的明箱滯留時間比沒有注射IBO 之Sham 組為短，連續餵食槐花6 天或14 天，兩者都能延長IBO 所造成的明室滯留時間的縮短。結論是槐花能延長IBO 所造成的被動迴避試驗的明箱滯留時間的縮短，說明槐花有改善學習記憶障礙的作用，但它的作用機轉不明，至於槐花是否可用來治療人類的痴呆症，須做進一步的研究。Several studies found that Flos Sophorae (FS) has abundant rutin and quercetin similar to the extracts of Ginkgo biloba. The extract of Ginkgo biloba has anti-oxygen free radicals and is considered to have anti-platelet aggregation action, which widely used to treat cerebrovascular accident and dementia. The main clinical manifestation of dementia is cognition disturbance that is characterized by degeneration or loss of learning-memory ability. Therefore, the aim of the present study is to investigate the effect of FS. We established an animal model of human dementia by injecting ibotenic acid (IBO, 0.06 M 0.5 μl) into the nucleus basalis magnus (NBM) of Sprague- Dawley (SD) rats. Rats were fed with FS (0.3 g/kg) in the morning and in the evening respectively for six days and 14 days. The retention time in the light-room of passive avoidance test was used as an index to evaluate FS influence on rats with learning-memory disturbance. Results showed that retention time in the light room of passive avoidance test was shortened in the IBO-treated rats than that in sham group without IBO injection, but FS feeding for 6 days or 14 days lessen the disturbance induced by IBO. In conclusion, FS may prolong the retention time in the IBO-treated rats, suggesting that FS has decreasing effect to IBO-induced learning-memory disturbance. However, the actual pharmacological mechanism still remains unclear. As to applying FS on treating human dementia, more studies will need to be performed.