Levels of Potentially Toxic Metals In Selected Herbal Medicines In Lagos, Nigeria

Abstract

The increasing popularity and widespread use of herbs as alternative medicine has sparked an interest in understanding their safety. Potential toxic metals (PTM) have been identified as a risk to human health through the usage of herbal medicines. This study aimed to assess the level and pH of PTM (Fe, Cu, Pb, Cd, Ni and Zn) in selected herbal medicines sold in Lagos, Nigeria. Eight commonly consumed herbal medicines: E-5000, MT-CAPS, B-CAPS, DD-TEA, YC-BITTER, JHD-POWD, KA-POWD, and H-CAPS were analysed for PTM using Atomic Absorption Spectrophotometer after wet digestion of the medicines. The highest concentration (mg/kg) of Fe (257±0.1), Pb (33.8±0.01) and Zn (38.9±0.01) were found in KA-POWD. The result also showed that JHD-POWD had the highest concentration amount of Ni (54.0±0.01 mg/kg), while B-CAPS had the highest concentration of Cu (4.14 ±0.02 mg/Kg).  All the herbal medicines analysed are high in Fe content with range between 6.2 to 257 mg/kg. The pH values ranged between slightly acidic of 5.6 - 5.7 to slightly alkaline of 8.0 -8.65.  Twenty five percent of herbal medicines analysed had concentrations of Pb above the the WHO limits of 10 mg/kg, while all the samples had Cd above the permissible limits of 0.3 mg/kg. KA-POWD had the highest concentrations of Pb, Zn, Fe, and Cd determined.  All other PTMs in the other samples analysed are below the recommended permissible limits.

Keyword: Capsules; Herbal medicine; Lagos; Potentially toxic metals content; Powdered.