Metal Toxicity in Terminelia avicennioides and Sida acuta Medicinal Plants from Gbongbofu and Swatamukun in Bida, Niger State.

Abstract

Traditional herbs are the oldest remedies of infirmities and man’s dependence on plants for health care is as old as civilization. The leaves, stems, barks and fruits of Terminalia avicennioides and the leaves and stems only of Sida acuta were randomly collected from Swatamukun and Gbongbofu based on the diverse cultural traditions associated with the use of these plants. The medicinal plant samples were digested using Method 975.03 of the AOAC and thereafter analyzed using AA500 Atomic Absorption Spectrophotometer for Cd, Fe, Pb, Mg, Mn and Zn contents. Also, proximate analyses of the samples were carried out using standard methods. Results showed that the metal contents varied in both plant parts from the two locations except Pb with a concentration of 13.15 μg/g in all the samples, which exceeded the 10.0 μg/g of WHO permissible limit. The range of concentrations in both Swatamukun and Gbongbofu for Fe, Mg, Mn and Zn were 0.00-77.00, 0.00-19.00, 0.00-47.10 and 4.00-35.60 μg/g respectively. Thus, Fe content was highest in most of the plant samples. The same concentration of Mn and Zn was obtained in the stems of Sida acuta from Gbongbofu (35.6 μg/g) while the fruit of Terminalia avicennioides had 31.5 μg/g of Zn, which are below the 100 μg/g of WHO permissible limit for Zn in medicinal plants. Cadmium was not detected in any of the plant samples. Terminelia avicennioides contained higher ash, crude fat, crude lipid and crude fiber contents as well as moisture content of 64.67, 76.00 and 78.00 % in the leaves, stems, and fruits than Sida acuta, which implies that it cannot be kept for long time. However, carbohydrate was higher in Sida acuta than Terminelia avicennioides.