Anti-amnesic effect of alkaloid fraction from Lycopodiella cernua (L.) Pic. Serm. on scopolamine-induced memory impairment in mice.

Lycopodiella cernua (L.) Pic. Serm. (Licopodiaceae) has been used in Vietnamese folk medicine for treating central nervous system conditions. In this study, the alkaloid fraction from the methanol extract of this plant (VLC) was evaluated for in vitro acetylcholinesterase (AChE) inhibitory activity in cognition-relevant brain areas of mice. In in vivo study, the cognitive-enhancing effect of VLC on amnesic mice induced by scopolamine was investigated by assessing a passive avoidance and a Morris water maze test. VLC inhibited AChE activity in mouse frontal cortex, hippocampus and striatum with IC50 values of 26.7, 32.2 and 25.7μg/mL, respectively. Administration of VLC (10, 20, 50 and 100mg/kg, p.o.) significantly reversed cognitive impairments in mice by passive avoidance test. Treating with VLC (50mg/kg) reduced escape latencies in training trials and prolonged swimming times in the target quadrant during the probe trial in the water maze task (P<0.05). These results indicated that L. cernua originated from Vietnam has anti-cholinesterase activity and might be useful for the treatment of cognitive impairment.