药用植物中乙酰胆碱酯酶抑制活性和抗氧化活性的筛选

目的:对24种药用植物醇提物的乙酰胆碱酯酶抑制活性和抗氧化活性进行筛选研究。方法:70%乙醇回流提取植物粗提物;目标粗提物采用氯仿、乙酸乙酯、正丁醇依次萃取,得到氯仿、乙酸乙酯、正丁醇和水部位;乙酰胆碱酯酶抑制活性测定采用改良的Ellman法和薄层色谱(TLC)生物自显影法相结合的方法;抗氧化活性采用清除DPPH自由基能力进行评价。结果:结合改良Ellman法和TLC生物自显影法对24种植物的醇提物的抗乙酰胆碱酯酶抑制活性进行评价,结果表明红毛七、金不换、飞龙掌血、白花映山红和八角枫5种植物粗提物具有显著的抑制活性,在终浓度为1 g.L-1时,其抑制率分别为(88.72±1.47)%,(82.25±1.32)%,(77.71±1.61)%,(77.00±1.38)%,(75.22±1.28)%,其清除DPPH自由基IC50分别为153.75,74.95,50.00,10.87,24.40 mg.L-1。在这5种植物粗提物不同萃取部位中,红毛七和金不换氯仿部位对乙酰胆碱酯酶抑制活性最强,其IC50为33.97,38.79 mg.L-1,其清除DPPH自由基的IC50为302.95,79.45 mg.L-1。结论:金不换和红毛七粗提物氯仿部位具有较强的乙酰胆碱酯酶抑制活性和抗氧化活性,可进行进一步的追踪分离研究。

Screening of Some Medicinal Plants for Acetylcholinesterase Inhibition and Antioxidant Activity

Objective: The ethanol extracts of 24 medicinal plants were screened for their anti-acetylcholinesterase(AChE) activity and antioxidant activity. Method: The medicinal plants were extracted by ethanol(70%) under reflux. The objective extracts would be extracted by different solvents-dichloromethane, ethyl acetate, n-butanol, and water respectively, in order to obtain their dichloromethane, ethyl acetate, n-butanol, and aqueous-soluble fractions. The AChE inhibitory activity was tested by TLC bioautographic method combined with modified Ellman's colorimetric method; Antioxidant activity was evaluated by 2,2-diphenyl-2-picrylhydrazyl(DPPH) radical scavenging method. Result: On the basis of the evaluation of 24 medicinal plants tested by TLC bioautographic method and modified Ellman's colorimetric method, some medicinal plants had taken on significant anti-acetylcholinesterase activity and DPPH free radical-scavenging activity, such as Leonfice robustum (Maxim.) Diels, Stephania kwangsiensis H.S.Lo, Toddalia asiatica (L.) lam., Rhododendron mucronatum G.Don and Alangium chinense (Lour.) Harms. The inhibition rates of the above medicinal plants were (88.72±1.47)%, (82.25±1.32)%, (77.71±1.61)%, (77.00±1.38)% and (75.22±1.28)% at the concentration of 1g·L^-1, respectively; And IC₅₀ value of DPPH free radical-scavenging activity were 153.75, 74.95, 50.00, 10.87, 24.40 mg· L^-1, respectively. Compared with the the various extracts based on kinds of solvents, dichloromethane fractions of L. robustum and S. kwangsiensis had the higher anti-acetylcholinesterase activity, which IC₅₀ value were 33.97, 38.79 mg· L^-1, while IC₅₀ value of DPPH free radical-scavenging activity were 302.95,79.45 mg· L^-1. Conclusion: Dichloromethane fractions of L. robustum and S. kwangsiensis extracts have shown high AChE inhibitory capacity and antioxidant activity, so they will be further performed bio-guided isolation and purified to obtain active compounds.