AIM: To study the relationship between the effects of suberogorgin (Su
b) and its derivates on memory and their anti-acetylcholinesterase (AC
hE) actions. METHODS: The step-down latency (SDL) and the escape laten
cy (EL) of mice were determined at the same time in a passive avoidanc
e task after Sub, N-suberogorgamide-N-M-dicyclohexyl urea (Sub-DU), or
N-cyclohexyl suberogorgamide (N-CS) was injected ip. The AChE activit
ies in brain hemogenates were determined with calorimetry. RESULTS: Su
b 1.9, Sub-DU 3.0, or physostigmine (Phys) 0.15 mg . kg(-1) obviously
lengthened the SDL by 195 %, 271 %, and 210 %, and shortened the EL by
56 %, 61 %, and 33 %, and the two formers inhibited the brain AChE ac
tivities by 17 % and 19 %, respectively in aging (3-4 months) mice. Th
ese actions were decreased in a dose-dependent manner when Sub or Sub-
DU was increased to 2.9-4.3 or 4.5-6.7 mg . kg(-1) respectively. Sub 1
.9, Sub-DU 2.0, and Phys 0.15 mg . kg(-1) also lengthened the SDL by 1
87 %, 209 %, and 152 %, and shortened the EL by 52 %, 62 %, and 57 %,
respectively in aged (12-14 months) mice. Sub 1.3-1.9, Sub-DU 0.9-2.0,
or Phys 0.15 mg . kg(-1) reversed the cycloheximide- or scopolamine-i
nduced disruptions of memory retention. Na obvious effect of N-CS on t
he acquisition of memory and the AChE activity in mice was observed. C
ONCLUSION: The improvements of Sub and Sub-DU on memory were chiefly r
elated to their anti-AChE actions.