Effect of acute administration of Mitragyna speciosa Korth. standardized methanol extract in animal model of learning and memory

Abstract

Mitragyna speciosa Korth. or ketum is classified under medicinal plants, used by locals in Thailand and Malaysia to treat various types of diseases. Due to lack of information present on the effect of M. speciosa in learning and memory function, therefore this study is conducted to understand its effect on cognitive functions (learning and long-term memory). The aim of this study is to evaluate cognitive functions of rats after acute exposure of M. speciosa standardized methanol extract using avoidance tasks. Sprague-Dawley rats were treated with three different concentrations of M. speciosa standardized methanol extract (100, 500 and 1000 mg/kg). Morphine was given to positive control group and carboxyl-methyl-cellulose (CMC) and piracetam were given to negative control group. Learning and memory were evaluated using one-way passive avoidance test and two-way active avoidance test. This study showed significant improvement in learning acquisition in the M. speciosa standardized methanol extract treated group compared to controls, however no benefit was observed on memory consolidation, in both passive and active avoidance tests. In conclusion, acute administration of M. speciosa standardized methanol extract facilitated learning, but there was no benefit on long-term memory consolidation.