Memory-enhancing potentials of hydroalcoholic extract of Eragrostis tremula Hochst. exSteud. (Poaceae) in mice

Abstract

<strong>Background & Aim:</strong>Cognitive impairment is one of the age-related mental problems and a typical indicator of neurodegeneration. <em>Eragrostis</em> <em>tremula</em> Hochst. ex Steud. is a commonly used medicinal plant in Nigeria for memory enhancement. This study, therefore, aimed at evaluating the memory-enhancing potential of aqueous ethanolic extract of <em>E. tremula</em> in mice.<br /> <strong>Experimental: </strong>Classes of phytochemicals present in the extract were determined using standard protocol while its oral median lethal dose (LD50) in mice was estimated. The effect of <em>E. tremula</em> extract (125, 250 and 500 mg/kg) on learning and memory was evaluated in mice using behavioural paradigms: elevated plus maze (EPM), novel object recognition and Barnes maze. Open field and hole-board tests were also carried out to evaluate locomotion.<br /> <strong>Results:</strong> The phytochemical constituents of <em>E. tremula</em> were alkaloids, cardiac glycosides, flavonoids, tannins, saponins, steroids and triterpenes. Oral LD50 was estimated to be >5000 mg/kg. <em>E. tremula</em> extract significantly (P<0.05) decreased the transfer latency of mice during the retention phase of EPM test. In the novel object recognition test, it significantly (P<0.05) increased the discrimination index. In Barnes maze test, the extract significantly (P<0.05) decreased the mean primary errors during the acquisition trials. It also significantly (P<0.05) decreased the primary latency, primary error and increased the time spent in the target quadrant during the probe trial. <em>E. tremula</em> extract significantly (P<0.05) decreased the immobility time of mice in an open field at 250 mg/kg, while in the hole-board test, it significantly (P<0.05) increased the mean head-dip of mice at 125 mg/kg when compared to the negative control.<br /> <strong>Recommended applications/industries:</strong> The ethanol extract of <em>E. tremula</em> possesses memory enhancing properties which can be utilized in the management of amnesia and cognitive deficit.