ABSTRACT
This study examined the minerals, heavy metals, phytochemicals and antioxidant properties of the leaves and stem of OSU (Hunteria umbellate) plant which were obtained from Ogida quarters in Egor local government area in Benin City, Edo State. The samples were washed, sundried, ground to fine particles and analysed for minerals and heavy metal content such as calcium, magnesium, zinc, copper, nickel, iron, lead and cadmium. Some selected (primary and secondary metabolite) phytochemical such as tannin, saponin, phenolic compound, alkaloids, flavonoids, and vitamin c and the antioxidant properties of both. The mineral and heavy metal compositions in the samples were determined by Atomic Absorption Spectrophotometer after digestion. The studies revealed that the leaves sample was high in elements such as magnesium, zinc, copper and lead, with concentrations of 145 mg/kg, 50mg/kg, 1mg/kg and 3mg/kg respectively, whereas the stem sample contained more of calcium, nickel and iron, with concentrations of 2810mg/kg, 12mg/kg and 1380mg/kg respectively. In both samples cadmium content was below the detection limit. The phytochemical qualification analysis revealed that both extracts were rich in phytochemicals as all the phytochemicals tested were positive. The results also showed that the stem samples contained more of phenolic compounds whereas the leaves sample contained more of protein. The quantification analysis of the phytochemicals revealed that the stem sample was high in saponin, phenolic compound, alkaloid and vitamin c content whereas the leaves sample was high in tannin and flavonoid. The antioxidant analysis reveals that the stem has a higher antioxidant activity compared to the leaves. This may be due to its Half-maximal inhibitory concentration IC50 value. The IC50 value of the stem was 219.34µg/ml whereas that of the leaves was 255.64 µg/ml. This study revealed that OSU (Hunteria umbellata) plant will have great health benefits such as antiinflammatory, anti-aging, anti-cancer agent and so on.
