Edak A Uyoh
University of Calabar, Nigeria
Edak A Uyoh is Working inDepartment of Genetics and Biotechnology, University of Calabar, Nigeria.He is also honorary professor in eight universities.
Food and pharmaceutical industries rely heavily on plants that show promise of health promoting benefits. This reliance, in recent times has received a big boost due to the global shift to the use of natural products which are presumed to be safer compared to synthetic counterparts. Against this background, selected plants used locally in Southern Nigeria as spice and/ or herbal medicine (Monodora myristica, Parkia biglobosa, Tetrapleura tetraptera, Eremomastax polysperma, and Eremomastax speciosa) were evaluated for their proximate, vitamins, mineral and phytochemical composition as well as their antioxidant potential in order to assess their nutritional and therapeutic significance. Results obtained indicate that the spice plant, T. tetraptera had high fat (24.71%) and carbohydrate (66.29%) contents and fairly low amounts of calcium (183.70 mg/100 g), magnesium (96.32 mg/100 g) and iron (1.92 mg/100 g). The medicinal plants, E. polysperma and E. speciosa had high nutritional value -crude protein (16.85-20.57%), crude fibre (11.64-12.06%) and carbohydrate (33.19-37.81%) and appreciable concentrations of bioactive constituents-alkaloid (2.87-3.61%), flavonoid (2.67-3.60%) and tannins (1.64-2.00%). Mineral analysis indicates higher concentrations of calcium (279.79 mg/100 g) and magnesium (157.40 mg/100 g) in E. polysperma while E. speciosa had higher potassium (234.35 mg/100 g) and iron (3.68 mg/100 g) concentrations. Higher vitamins A, C and E concentrations (253.25 μg/g, 285.37 mg/100 g and 26.57 mg/100 g respectively) were obtained in E. speciosa. Ethanol extracts of E. polyspema and E. speciosa showed good potential of antioxidant activity in vitro and scavenged 50% of stable DPPH free radicals at concentrations of 40.76 μg/ml and 89.14 μg/ml respectively. Results of the reducing power assay and total antioxidant capacity indicated that the extracts were potent in electron donation, thus were capable of reducing Fe3+ and Mo (IV) ions to their lower oxidation states. The abundance of nutrients and a wide variety of potent bioactive compounds in these plants justify their use in traditional cuisines and healthcare but more importantly should stimulate interest in their research. This will make possible their further exploitation in the food and pharmaceutical industries for production of natural dietary supplements, antioxidant additives and other relevant medicines