Abstract: Objective: To study the effects of n-butanol extracts from Portulaca oleracea on the learning and memory performances of senile mice induced by D-gal and its mechanisms. Method: The mice were randomly divided into 3 groups: control group, model group and the n-butanol extracts (0.5 g/(kg·d) and 0.25 g/(kg·d)) groups. The control group was given hypodermic injection of isotonic NaCl in the transverse part while the other groups successively administered with D-gal (1 g/(kg·d)). After injection of medicine in the afternoon of every day model animals were obtained after 42 d of treatment. Learning and memory performances were measured by step-through test and water maze test and the amount of MDA in mouse brain tissue and the activities of SOD and GSH-Px were determined. Results: Portulaca oleracea n-butanol extracts could improve the learning and memory performances of mice at both 0.5 g/(kg·d) and 0.25 g/(kg·d), and substantially reduce contents of MDA in brain tissues and improve activities of SOD and GSH-Px. Conclusion: Portulaca oleracea n-butanol extracts can markedly improve learning and memory performances of senile mice. The mechanisms of effects may be related to the improvement of SOD and GSH-Px activities and the decrease of MDA.

Key words: Portulaca oleracea, n-butanol, learning and memory, MDA, SOD, GSH-Px