Report: Anxiolytic, sedative and toxicological effect of hydromethanolic stem bark extract of Maerua angolensis DC. in Wister rats.

Maerua angolensis DC is traditionally used for the treatment of epilepsy and insomnia. The present study was designed to investigate the anxiolytic, sedative and toxicological effect of hydromethanolic stem bark extract of M. angolensis using animal model. Sub-chronic doses of the plant extract on liver and kidney function test were investigated. Elevated plus maze (EPM) and diazepam-induced sleeping time test was used in this investigation. The possible involvement of M. angolensis with GABAA receptor was also investigated using flumazenil. The results of acute toxicity studies showed LD50 to be greater than 5000mg/kg body weight. The test extract (40 and 80mg/kg) significantly (p<0.05) increased the number of open arm entries and time spent in the open arm entries. However, flumazenil with 80mg/kg plant extract showed no significant (p >0.01) difference in the number of entries into open arm when compared to control. The stem bark extract of M. angolensis significantly (p<0.01) increased the duration of sleep induced by diazepam in a dose-dependent manner. However, flumazenil with 80mg/kg extract showed no significant (p>0.01) sedative effect when compared to normal control. In conclusion, the result of our present findings revealed that M. angolensis may apparently be safe and non toxic at therapeutic dose. However, the plant may possess anxiolytic and sedative properties, which exert their effect on GABAA receptors.