Elemental composition and proximate analysis of five commonly used African medicinal plants

Abstract

The global acceptance of the therapeutic relevance of plants as cure for several diseases is due to the presence of myriad of bioactive phytoconstituents. The five selected plants used in this study include: Telfairia occidentalis, Ocimum gratissimum, Vernonia amygdalina, Hibiscus sabdariffa and Moringa oleifera traditionally serve as sources of food and nutraceuticals in Nigeria. Therefore, this study was designed to estimate proximate and elemental contents of selected parts of five commonly used African plants collected from African Centre for Herbal Research Institute (ACHRI) farm in University of Ilorin, Ilorin, Nigeria. This was carried out using standard procedures of analysis (proximate analysis) as well as Spectrophotometry and Atomic Absorption Spectrophotometry (elemental analysis). The proximate analysis of the plants revealed that leaves of Ocimum gratissimum had the highest (12.65%) moisture content while Calyces of Hibiscus sabdariffa had the lowest (9.57%) moisture. The fat content for seeds of Moringa oleifera was highest (21.00%) with leaves of Vernonia amygdalina having the lowest fat (13.4%). Also, leaves of Ocimum gratissimum had the highest contents of Ash and Crude Protein (28.00% and 0.23% respectively), while the lowest concentrations for Ash and Crude Protein were recorded for leaves of Telfairia occidentalis(14.00% and 0.11% respectively). Meanwhile, leaves of Telfairia occidentalis had the highest crude fibre composition (64.33 %) and the lowest crude fibre was found in seeds of Moringa oleifera (17.18 %). All the plants showed various concentrations (in mg/g) for Na, K, Ca, Cu, Fe, Zn, Cr and Ni. Although Pb was absent in three of the five plants, Cd and Cr were present in trace amount. The presence of appreciable quantities of important nutrients in the plants, beneficial in healthcare,supports their popular medicinal use in the management of diseases. Therefore, the plants can be potential sources of nutrientswith potential application in foods and nutraceuticals.