Variability of Heavy Metal Content of Phytomedicine from Foreign and Local Source Sold in Nigeria.

Abstract

The popularity of herbal products has been on increase throughout the world; but one major challenge facing it is lack of guaranteed safety with respect to heavy metals contamination. In this study, Chinese, Indian and Nigerian phytomedicine were evaluated for Copper (Cu), Cadmium (Cd), Lead (Pb) and Zinc (Zn) in order to ascertain and compare their safety or level of contamination. The samples were purchased, processed and analyzed using Flame Atomic Absorption Spectrometer (FAAS). The results obtained were presented as mean concentrations of Cu, Cd, Pb and Zn in the Nigerian, Chinese and Indian phytomedicine as 1.23±0.03μg/g, 5.46±0.04μg/g, 5.16±0.01μg/g (Cu), 2.07±0.04μg/g, 9±0.06μg/g, 6.28±0.03μg/g (Cd), 4.42±0.18μg/g, 7.74±0.07μg/g, 5.05±0.06μg/g (Pb) and 2.90±0.04μg/g, 6.40±0.04μg/g, 2.53±0.04μg/g (Zn) respectively. The results indicated all the Nigerian herbal remedies analyzed and 33.33% of the Chinese and Indian herbal remedies contained cadmium above WHO permissible limit (0.3 μg/g) for herbals. The analysis of variance (ANOVA) results obtained at p-value 95% (p ˂ 0.050) ranges from significant to non-significant difference of means among the three countries. The correlation coefficient (r) also ranges from negative to strong degree of association. The variability of the heavy metals content could be associated to geographical, environmental, anthropogenic factors and heavy metals absorption potentials of the medicinal plants used. Environmental monitoring of herbal materials is required in order to ensure their safety from chemical pollutants that could lead to bio-accumulation of heavy metals in herbal materials.