Abstract
Phytochemicals in methanolic leaf extract of Hippocratea Africana using qualitative and Gas Chromatography-Mass Spectrum (GC-MS) analysis to determine the phytochemicals present and its effect on the histology of midgut of Sitophilus zeamais. Insects were administered with 10mg/kg of the plant extract using diffusion method where insects were put in a petri dish containing various concentrations and observed to see the stage they begin to die due to toxicity and observed for 5 minutes. They were collected into foil processing paper and fixed in Bouins fluid for 24 hours, repacked after 24 hours and folded in fresh foil immersed in buffered formalin for histopathological studies. Result revealed that a severe degeneration de-arrangement of the respiratory tract epithelial lining, secretory lining cells and gastrointestinal layers with the destruction of the muscular layer when compared with the control. The methanol leaf extracts of H. africana were preliminary screened for the phytochemicals. The extract shows the presence of cardiac glycosides, saponin, steroids/terpenes, flavonoids, alkaloids and phenols. GC-MS analysis of the extract showed the presence of showed eight major compounds as shown on Table 4. They were: 5-amino-1-tetrazolylacetic acid [RT- 83.55017, Peak Percentage- 1.173%], 2-amino-4-(2-methylpropenyl) -pyrimidin- carboxylic acid [RT- 83.978, Peak Percentage 1.713%], Cedrandiol [RT-87.201, Peak Percentage-2.445%], Malic acid [RT 88.740, Peak Percentage 1.431%], 1, 2 benzenedimethanethiol [RT-91.634, Peak Percentage – 2.045%], ethyl 5- (furan-2-yl)-1, 2-oxazole-3-carboxylate [RT-89.693, Peak Percentage-1.446%], Mephenesin [RT-92.587, Peak Percentage-1.911%]. The findings indicated that methanol extract of H. africana is rich in phyto-compounds having biological activities on the midguts’ histology of S. zeamais. Therefore, it is recommended as an alternative for the synthetic insecticide used by farmers for the preservation of stored grains.
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