INVESTIGATION OF SELECTED METALLIC IMPURITIES IN ANTIMALARIAL HERBAL DECOCTIONS ‘AGBO IBA’ COLLECTED FROM FOUR LOCATIONS IN LAGOS STATE, NIGERIA

Abstract

Herbs constitute a common medicinal alternative for disease treatment in many cultures around the world. In Nigeria, these medicinal herbs are widely used in the treatment and prevention of various ailments including malaria, a global disease endemic to the tropics. In spite of their cultural trust and claimed medicinal properties, lack of standardization and poor-quality presentation make medicinal scientists to be wary of herbal medicinal preparations. However, due to their increasing patronage, the safety and quality of these herbal medicines have become increasingly important for health authorities, scientific community and the public alike. Thus this study was aimed at determining the amount of selected heavy metals in a herbal antimalarial decoctionpopularly known as Agbo iba consumed in selected areas of Lagos.

 

The investigated heavy metals: Pb, Ni, Hg and Cd were detected using Atomic Absorption Spectroscopy (AAS) after sample pretreatment with wet digestion using HNO₃. Heavy metal concentrations in the decoctions were found to be in the range of 0.331 - 0.896 mg/L for Pb, 0.185 - 0.338 mg/L for Ni, 1.612 - 17.894 mg/L for Hg, while cadmium was not detected in the samples. These concentrations exceededthe World Health Organization (WHO) Permissible Limits (PL) and sources of contamination could be from sources of plants, harvest and transport conditions, method of preparations, to mention but a few. These products should be governed by standards of safety, quality, and efficacy that are equivalent to those required for other medicinal productsof international standard.