Analysis of Essential Trace Elements in Selected Medicinal Plants Used In Kenya

Abstract

Kenya is endowed with nature where hundreds of medicinal plants are available. During photosynthesis and respiration process in plants, animals and other organisms, ions of metal elements play a major role with a few of the elements being essential to the body as nutrients. Trace elements Zn, Cr, V and Se with known immunological response and healing properties were analysed from selected medicinal plants available in Kenya. These plants were; Prunus africana, Urtica massaica, Maytenus obscura, Maytenus putterlickiodes, Azadiracta indica (Neem), Mondia whytei, Zanthoxylum usambarense, Maerua edulis, Trigonella foenum-graecum (fenugreek) and Glycyrrhiza glabra. The concentrations of elements were determined using Energy Dispersive X-ray Fluorescence Spectrometer (EDXRF). The levels of zinc varied from 25.94±1.89 to 70.58±4.70 mg/kg (mean 45.94± 12.42 mg/kg). Vanadium from 1.69±0.18 to 9.99±0.86 mg/kg with an average level of 5.89± 2.09 mg/kg. Chromium from 1.44±0.30 to 6.94±0.59 mg/kg with a mean of 3.49±1.32 mg/kg. For selenium the levels varied from 53.21±5.45 to 124.01±4.41 μg/kg with a mean of 90 ±19.17 μg/kg. The levels of the trace elements were compared with recommended dietary intake (RDI) and were found to provide these essential elements as part of therapeutic utility. The levels in different plant parts were found not to be statistically significantly different (P>0.05) except for vanadium levels in urtica massaica (P=0.05). The results of this study will be used to sensitize the public on the presence of essential trace elements in the studied medicinal plants and to contribute to the advancement of knowledge.