Phytoconstituent Screening of Roselle (<i>Hibiscus sabdariffa</i>), Moringa (<i>Moringa oleifera</i>), Ginger (<i>Zingiber officinale</i>) and Fluted pumpkin (<i>Telfairia occidentalis</i>) Leaves

Abstract

There is a growing concern associated with the safety of some medicinal plants as plant-based medicine stages a comeback in the last few decades. The phytoconstituent and acute toxicity of some selected food plants eaten as vegetables or spices in Nigeria and some other tropics of the world were evaluated in this study. The acute toxicity of the ethanolic extracts of roselle, moringa, ginger and fluted pumpkin was tested using albino rats (Rattus norvegicus). The extracts were then screened to identify the phytonutrients and phytochemicals in them, using standard protocols. The acute toxicity study shows the extracts were nontoxic to the rats, even at a high dose of 2000 mg/kg body weight. The phytonutrients in roselle extract are calcium, iron, zinc, magnesium, vitamin A and vitamin C, while ginger extract has zinc, magnesium, vitamin A and vitamin C. Moringa and fluted pumpkin have all the tested nutrients. The phytochemicals in roselle extract are alkaloids, tannins, glycosides, and reducing sugars, while moringa contains all the tested phytochemicals except flavonoids and phlobatanins. Ginger extract has glycosides, reducing sugars, saponins, and flavonoids, while fluted pumpkin extract has all the tested phytochemicals except reducing sugars and phlobatanins. The findings of the study show the food plants are rich in nutrients and antioxidants, but contain traces of potentially toxic chemicals whose long-term use safety levels need to be evaluated.

Keywords: Plant medicine, Phytoconstituent, Phytonutrients, Phytochemicals, Antioxidants