Original Articles: 2011 Vol: 3 Issue: 2
Evaluation of pharmacognostical parameters and heavy metals in some locally manufactured herbal drugs
Abstract
Five heavy metals lead (Pb), cadmium (Cd), zinc (Zn), iron (Fe) and cobalt (Co) were determined in four
(4) branded Pax-herbal products - Paxherbal Health Tea®, Paxherbal Potensine®, Paxherbal Malatreat
tea® and Paxherbal Black powder® using atomic absorption spectrophotometry (AAS) after acid
digestion. The samples were purchased from manufacturer’s (Pax-herbal) retail out-let in Yenagoa. The
concentration of lead (Pb), Cd, Zn, Fe and Co in all the samples ranged from BDL to 102.200 ± 1.838
μg/g, 0.249 ± 0.010 μg/g to 2.839 ± 0.018 μg/g, BDL to 14.638 ± μg/g, ), 88.557 ± 1.135 μg/g to 269.074
± 3.433 μg/g and 0.604 ± 0.002 μg/g to 9.781± 0.032 μg/g respectively. Pb content was below detection
limits (BDL) in Paxherbal Health Tea® and Paxherbal Potensine®, while the amount in Paxherbal
Malatreat tea and Paxherbal Black powder was 102.200 ± 1.838 μg/g and 49.528 ± 0.583 μg/g
respectively. The corresponding daily intake of heavy metals in herbal drugs were below limits stipulated
by regulatory agencies such - FAO/WHO, Canadian and American National Sanitation Foundation
(NSF) International, except for Paxherbal Malatreat tea where the value of 418.611 μg/day (based on
recommended dosage by manufacturer) was significantly above the FAO/WHO permissible limit of
232.14 μg/day, assuming an average body weight of 65 kg for an adult human.