Analysis of Essential Trace Elements by EDXRF in Selected Medicinal Plants Used in Kenya

Abstract

Kenya is endowed with nature where hundreds of medicinal plants are available. During photosynthesis in plants, and respiration in animals and other organisms, metal elements play a major role with a few of the elements being essential to the body as nutrients. Trace elements for example Zn, Cr, V and Se with known immunological response and healing properties were analysed in selected medicinal plants available in Kenya. These plants were; Prunus africana, Urtica massaica (stinging neetle), Maytenus obscura, Maytenus putterlickiodes, Azadiracta indica (Neem), Mondia whytei, Zanthoxylum usambarense, Maerua edulis, Trigonella foenum-graecum (fenugreek) and Glycyrrhiza glabra(licorice). 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. Selenium (53.21±5.45 to 124.01±4.41 µg/kg, 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 to vary significantly (P<0.05) in some plants and not significantly (P>0.05) in others for a given species. The plants can provide can provide the elements as per required daily intake(RDI).