Toxicity assessment of methanol extract of <i>Combretum micranthum</i> in <i>Drosophila melanogaster</i>

Abstract

Combretum micranthum leaves have been used traditionally in West Africa to manage pyrexia, cough, bronchitis, diabetes, malaria and other related ailments. It has also been demonstrated to alleviate high blood pressure and skin inflammation. Drosophila melanogaster has been gaining acceptability in biomedical research because of homologs of its genes present in humans and the relative cost of research using the flies. The purpose of the study is to investigate the acute and sub-acute toxicity of Combretum micranthum leaves in Drosophila melanogaster. The leaves were extracted using 90%v/v methanol. The extract was screened for presence of phytochemicals, acute and sub-acute toxicity using fruit flies. Doses between 5- and 100 mg/10 g diet for the acute toxicity study while 0 (Control), 1.5, 3 and 6 mg/10 g diet for the sub-acute toxicity study. The phytochemical analysis of the extract revealed the presence of alkaloids, glycosides, saponins, flavonoids and tannins. The acute toxicity study revealed an LD50 of 26.42 mg/10 g diet. The methanol extract of Combretum micranthum have no effect on the weight of fruit flies (p<0.05) among the different interventions. It also did not affect negative geotaxis ability of the fruit flies irrespective of the dose. At 6 mg/10 g diet, the extract raised triglyceride and trehalose levels when compared to the other doses (p<0.05). Glucose and glycogen levels were not different among groups. Overall, the results indicated that the methanol extract of Combretum micranthum at a dose of 6 mg/ 10 g diet is tolerable in Drosophila melanogaster.