Ameliorating effects of constituents from Cortex Acanthopanacis Radicis on memory impairment in mice induced by scopolamine

OBJECTIVE:To investigate the effects of active constituents extracted from Cortex Acanthopanacis Radicison improving the impaired memory in mice models.METHODS:The mice models of memory impairment were established using scopolamine.Ameliorating effects of the fractions and constituents on scopolamine-induced memory impairment in vivo were investigated using passive avoidance and Morris water-maze task tests,and their anti-acetylcholinesterase(AChE)and antioxidant activities in vitro examined.The isolation of constituents was performed by chromatographic methods and their structures were identified on the basis of instrumental analysis.RESULTS:Among the fractions tested,ethylacetate fraction exhibited the anti-AChE activity(25.83%±0.23%)properly and excellent 2,2-diphenyl-1-picrylhydrazyl(DPPH)radical and superoxide anion scavenging capacity(87.50%±0.83%and 60.22%±0.43%,respectively).However,the methylene chloride fraction was much more active than the ethylacetate fraction in the passive avoidance task test(167.5%increase of step-through latency time)and Morris water-maze task test(33.3%decrease of es-cape latency time).Four constituents,β-sitosterol,stigmasterol,sesamin,and hyperin were isolated from the methylene chloride fraction,among them,hyperin showed anti-acetylcholinesterase and anti-oxidant activities remarkably.Moreover,hyperin exerted a potent effect(146±38)s on memory improvement in terms of passive avoidance task test compared with the reference compound tacrine(162±43)s at a dose of 2.5 mg/kg.CONCLUSION:Hyperin,a flavonoid glucoside isolated from Cortex Acanthopanacis Radicis,inhibited AChE activity and potently ameliorated scopolamine-induced memory impairment,and its action may be partially mediated by the acetylcholine-enhancing cholinergic nervous system.

Ameliorating effect of Zhizi(Fructus Gardeniae) extract and its glycosides on scopolamine-induced memory impairment

OBJECTIVE： To study the chemical constituents of Zhizi （Fructus Gardeniae） and their antiamnesic ef- fect in a mouse model of Alzheimer＇s disease. METHODS： Ameliorating effects of the extracts, fractions and constituents on scopolamine-in- duced memory impairment in vivo using a passive avoidance task system and their inhibitory activi- ties on acetylcholinesterase （ACHE） in vitro were ex- amined. The isolation of components was per- formed by chromatographic techniques and their structures were identified on the basis of spectral analysis. RESULTS： Activity-guided fractionation of the total extracts resulted in the isolation of two glycosides, geniposide and cr0cin from the n-butanol fraction and genipin and crocetin from the ethylacetate fraction. Among the fractions tested, n-butanol fraction showed the strongest AChE inhibition （43.4% at a final dose of 0.03 mg/mL） and also ex- hibited outstanding efficacy （65.9% at a dose of2.50 mg/kg） in an experimental model of amnesia. Geniposide showed a 22.8% AChE inhibitory activi- ty and a potent ameliorating effect on scopol- amine-induced memory impairment in amnesic mice of 93.4% as compared to the control group. CONCLUSION： Geniposide, a main constituent of gardenia should be considered a candidate for fur- ther clinical study for the purpose of developing a cognition activator and its mechanism of action may be mediated, at least in part, by the acetylcho- line enhancing cholinergic nervous system.