Choline esterase inhibitory properties of alkaloids from two Nigerian Crinum species

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• 作者：Houghton ; Peter J. ; Agbedahunsi ; Joseph M. ; Adegbulugbe ; Aderonke
• 关键词：Crinum glaucum ; Crinum jagus ; Amaryllidaceae ; Alkaloids ; Acetylcholinesterase inhibition ; Alzheimer脙脙脙脙脙脙s disease
• 刊名：Phytochemistry
• 出版年：2004
• 期刊代码：85_00319422
• 类别：ch
• 出版时间：November, 2004
• 卷：65
• 期：21
• 页码：2893-2896
• 文件大小：257 K

摘要

The bulbs of Crinum jagus and Crinum glaucum are used in traditional medicine in southern Nigeria for memory loss and other mental symptoms associated with ageing. Alkaloidal extracts of bulbs from each species showed inhibition of acetylcholinesterase, an activity exploited therapeutically to raise the depressed levels of acetylcholine in the brain associated with Alzheimer芒芒芒s disease. Using the in situ bioautographic test method for enzyme inhibition, a number of alkaloids were isolated and their activity quantified using the Ellman spectrophotometric test. The most active alkaloids isolated were hamayne (IC₅₀ 250 芒芒M) and lycorine (IC₅₀ 450 芒芒M) whilst other alkaloids were comparatively inactive with haemanthamane giving 3%inhibition and crinamine giving 4.4%inhibition at 50 mgml^芒芒芒1 (174 芒芒M). These contrast with the positive control physostigmine which gave IC₅₀ of 0.25 芒芒M. Cholinesterase activity appears to be associated with the presence of two free hydroxy groups in this structural type of Amaryllidaceae alkaloid.