Protective effect of the ethanol extract of Magnolia officinalis and 4-O-methylhonokiol on scopolamine-induced memory impairment and the inhibition of acetylcholinesterase activity.

Abstract

Magnolol, honokiol, and obovatol are well-known bioactive constituents of the bark of Magnolia officinalis and have been used as traditional Chinese medicines for the treatment of neurosis, anxiety, and stroke. We recently isolated novel active compound (named 4-O-methylhonokiol) from the ethanol extract of Magnolia officinalis. The present study aimed to test two different doses of ethanol extracts of Magnolia officinalis (5 and 10 mg/kg/mouse, p.o., 1 week) and 4-O-methylhonokiol (0.75 and 1.5 mg/kg/mouse, p.o., 1 week) administered for 7 days on memory impairment induced by scopolamine (1 mg/kg body weight i.p.) in mice. Memory and learning were evaluated using the Morris water maze and the step-down avoidance test. Both the ethanol extract of Magnolia officinalis and 4-O-methylhonokiol prevented memory impairment induced by scopolamine in a dose-dependent manner. The ethanol extract of Magnolia officinalis and 4-O-methylhonokiol also dose-dependently attenuated the scopolamine-induced increase of acetylcholinesterase (AChE) activity in the cortex and hippocampus of mice, and inhibited AChE activity in vitro with IC(50) (12 nM). This study, therefore, suggests that the ethanol extract of Magnolia officinalis and its major ingredient, 4-O-methylhonokiol, may be useful for the prevention of the development or progression of AD.

• Authors: Yong Kyung Lee, Dong Yeon Yuk, Tae Il Kim, Young Heui Kim, Kyoung Tae Kim, Ki Ho Kim, Beom Jun Lee, Sang-Yoon Nam, Jin Tae Hong
• Journal: Journal of natural medicines (J Nat Med) Vol. 63 Issue 3 Pg. 274-82 (Jul 2009) ISSN: 1861-0293 [Electronic] Japan
• PMID: 19343477 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• 4-O-methylhonokiol
• Biphenyl Compounds
• Lignans
• Plant Extracts
• Ethanol
• Acetylcholinesterase

Topics

• Acetylcholinesterase (metabolism)
• Animals
• Biphenyl Compounds (pharmacology)
• Cerebral Cortex (drug effects, enzymology)
• Enzyme Activation (drug effects)
• Ethanol (chemistry)
• Hippocampus (drug effects, enzymology)
• Lignans (pharmacology)
• Magnolia (chemistry)
• Male
• Maze Learning (drug effects)
• Memory (drug effects)
• Mice
• Mice, Inbred ICR
• Molecular Structure
• Plant Extracts (chemistry, pharmacology)