Civilization diseases associated with memory disorders are important health problems occurring due to a prolonged life span. The manuscript shows the results of an in vivo study targeting the emergence of two drug candidates with anti-amnestic properties. The preceding quantitative structure-activity relationship (QSAR) studies provided information on the ability of berberine and magnoflorine to cross the blood-brain barrier (BBB). In the light of these findings, both compounds were purified from crude plant extracts of barberries: berberine-from Berberis siberica using a method published earlier, and magnoflorine-from Berberis cretica by centrifugal partition chromatography (solvent system: ethyl acetate:butanol:water-0.6:1.5:3 v/v/v). Both the compounds were evaluated for their memory enhancing and scopolamine inhibitory properties in an in vivo passive avoidance (PA) test on mice towards short-term and long-term memory. Cognition enhancing properties were observed at the following doses: 5 mg/kg (i.p.) for berberine and 20 mg/kg (i.p.) for magnoflorine. In addition, both the tested isoquinolines with the co-administered scopolamine were found to block long-term but not short-term memory impairment. No influence on the locomotor activity was observed for the tested doses. The results confirmed a marked central activity of magnoflorine and showed the necessity to lower the dosage of berberine. Optimized purification conditions have been elaborated for magnoflorine.
Keywords: Berberis; alkaloids; counter-current chromatography; memory and learning; mice; passive avoidance test.