Evaluation of the Phytochemical composition, Micronutrient status and Antioxidant Properties of Aloe vera, Piper nigrum, Telfairia occidentalis, and Vernonia amygdalina Found in South-Eastern Nigeria

Vegetables occupy prominent positions in the diets of several Nigerian ethnic groups. This study compared the phytochemical, antioxidants and micronutrients composition of four varieties of medicinal plants. The aqueous extracts of freshly plucked leaves were obtained using standard procedures. The phytochemical, antioxidant and micronutrient content of the vegetables were quantified using standard analytical methods. The result shows a significant variation (P<0.05) in the concentration of alkaloid in Aloe vera compared to Piper nigrum, Vernonia amygdalina and Telfairia occidentalis leaf with a concentration of 11.28 mg/100g. The flavonoids contents of Piper nigrum significantly varied (P<0.05) compared to other medicinal plants with a concentration of 9.30 mg/100g while T. occidentalis has the least flavonoid with a concentration of 2.7 mg/100g. A. vera has a significantly high levels of glycoside and tannin compared to other phytochemical with a concentration of 13.60 and 89.50 mg/100g respectively, while P. nigrum had a higher concentration of steroids compared to other medicinal plants, with a composition of 9.28 mg/100g. The result of vitamin analysis shows a higher concentration of vitamin A, E and and C in V. amygdalina compare to other medicinal plants. The result of ferric reducing and ferric chelating properties shows that V. amygdalina has the ability to degrade iron easily compared to other medicinal plants with a composition of 4.93 umol/l compared to T. occidentalis with a composition of 7.82 umol/l and was able to chelate iron compared to other medicinal plants. The scavenging effects of A. vera, P. nigrum, V. amygdalina, T. occidentalis extracts on DPPH radicals were excellent, especially in the case of V. amygdalina compare to vitamin C but T. occidentalis revealed a low value of antioxidant activity. In all, V. amygdalina leaf revealed the best antioxidant properties. From the results, the generated data could help to draw attention to the benefits accruable from consumption of these vegetables and hence recommend their sustained inclusion in human diet