Effects of a memory enhancing peptide on cognitive abilities of brain-lesioned mice: Additivity with huperzine A and relative potency to tacrine

Zhiwen Xu, Hui Zheng, Sek Lun Law, Donna Dong So, Yifan Han, Hong Xue

Research output: Journal article publicationJournal articleAcademic researchpeer-review

8 Citations (Scopus)


Alzheimer's disease (AD) and related dementing disorders having cognitive manifestations represent an increasing threat to public health. In the present study, the effects of a memory enhancing NLPR tetra-peptide (MEP), huperzine A (Hup A), or a combination of the two on the cognitive abilities of brain-lesioned mice were evaluated and compared with tacrine in the passive avoidance and Y-water maze tests for the acquisition and retention aspects of cognitive functions. MEP at μg kg-1doses, and Hup A or tacrine at mg kg-1doses significantly reversed the cognition deficits induced by scopolamine. For acquisition ability, it was observed that mice administered with MEP (4.0 μg kg-1) spent less time escaping onto the platform in the water maze than those treated with tacrine (1.5 mg kg-1); whereas for memory retention, tacrine-administration resulted in a higher step-through latency in mice at the tested dose regime. In addition, co-administration of MEP (2.0 μg kg-1) and Hup, A [0.1 mg kg-1) exhibited an additive effect resulting in considerable improvements in both acquisition and retention abilities of brain-lesioned mice. The results demonstrated that MEP was highly efficient in the rescue of cognitive abilities of brain-lesioned mice and in particular, the effective doses of MEP were about two orders of magnitude lower than that of tacrine, a therapeutic currently used in the treatment of AD. Moreover, MEP and Hup A were effective at reduced doses when the two were co-administered, providing a rationale for their combined usage in the treatment of cognitive deficits.
Original languageEnglish
Pages (from-to)72-78
Number of pages7
JournalJournal of Peptide Science
Issue number1
Publication statusPublished - 1 Jan 2006
Externally publishedYes


  • Brain-lesioned mice
  • Huperzine A
  • Memory enhancing peptide
  • Passive avoidance response
  • Scopolamine
  • Tacrine
  • Y-water maze

ASJC Scopus subject areas

  • Structural Biology
  • Biochemistry
  • Molecular Medicine
  • Molecular Biology
  • Pharmacology
  • Drug Discovery
  • Organic Chemistry

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