Determination of Nutrient, Antinutrient Compositions and Median Lethal Dose of Leaves of Microdesmis puberula Grown in Nigeria

Abstract

Aims: To evaluate the nutrient, antinutrient, mineral element and phytochemical compositions as well as acute toxicity profile of leaf extract of Microdesmis puberula. Study Design: Quantitative nutrient, antinutrient and mineral elements assessment assays, quantitative phytochemical assays as well as acute toxicity test of leaf extract of Microdesmis puberula. Place and Duration of Study: Department of Chemistry, Faculty of Science, Department of Pharmacognosy, Faculty of Pharmacy, University of Uyo, Nigeria, July 2016 - September 2017. Methodology: Standard methods were used to evaluate the concentration of ash, moisture, crude protein, crude fibre, crude lipids, carbohydrate, phytic acid and hydrocyanide in the leaf extract of Microdesmis puberula. Levels of calcium, magnesium, iron, potassium and zinc were also evaluated in addition to the quantitative determination of alkaloids, saponins, flavonoids and cardiac glycosides. Results: Qualitative phytochemical screening revealed the presence of alkaloids, saponins, flavonoids, cardiac glycosides and terpenes, while anthraquinones, phlobatannins and tannins were absent. Quantitative phytochemical determination (mg/100 g) gave the following: 12.80 ± 0.02, 5.85 ± 0.01, 2.48 ± 0.01 and 1.25 ± 0.01 for alkaloids, saponins, flavonoids and cardiac glycosides respectively. Proximate analysis indicated moisture content (48.17 ± 0.07 %) with crude protein, crude fibre and lipid were also present in appreciable quantities. Mineral elements determination (mg/100 g dry weight) showed calcium (163.50 ± 2.01), iron (188.70 ± 2.50), magnesium (168.40 ± 1.50), potassium (42.55 ± 0.55) and zinc (40.80 ± 1.01). Antinutrient analysis indicated low levels of phytic acid (18.220 ±0.030), hydrocyanide (0.002 ± 0.000) and oxalate (1.861 ± 0.002). The LD50 (i. p. mice) of M. puberula was 2872.28 mg/kg. Conclusion: The leaf extract of Microdesmis puberula is rich in nutrients and mineral elements which are required for human nutritional wellbeing and development. The presence of phytochemicals in the leaves of M. puberula which have much pharmacological importance lends credence to the many ethnomedicinal uses of this plant. The low levels of antinutrients which are far below the lethal doses as well as the acute toxicity test value of 2872.28 mg/kg indicate low toxicity and suggest that the consumption of the leaves of as food is not harmful.