Determination of some heavy metals in popular medicinal plants of Tehran ’s market

Document Type: Original Article

Abstract

Traditional medicines by medicinal plants have always played a key role in world health including Iran but
their safety profile is a major concern in this regard. In fact some factors such as the method of extraction,
contamination with microorganisms, existence of heavy metals, and pesticides may reduce the safety of
herbal based pharmaceutical products. The objective of this research was to determine the level of Cd, Pb, Ni,
Cu, and Hg as the major abundant heavy metals in some commonly used herbal medicines and herbal plants
of Iran’s market. For this purpose, 10 samples from eight different commonly used medicinal plants were
collected from 10 different traditional stores in Tehran . Standardized international protocols were followed
for the preparation of material and analysis of heavy metals contents. An automated continuous flow hydride
vapor generation system was used for mercury determination . Atomic absorption spectroscopy (AAS) was
also used for the determination of the concentration of Pb, Cd, Ni and Cu. Results show that Cuminum had
the lowest Pb level and Syzigium cumin the highest. Cadmium concentration varied between 0.19- 9.26
ppm .Syzigium cumin, showed the highest Cd levels and Cuminum Cyminm showed the lowest levels. The
concentration of Cu varied from 8.15 to 73.28 ppm. Cordia myxa contained the highest levels of Cu and
Plantago psyllium contained the lowest levels. The highest level of Ni was detected in Myristica fragrams and
the lowest in Plantago psyllium. Although the Hg concentration was not detectable in Cuminum Cyminm and
Cordia myxa ,some samples showed 0.71 ppm. Out of all samples , Syzigium cumin showed the highest Hg
concentration. Environmental contamination with heavy metals is one of the major concerns in developing
countries therefore regular controls on these plants should be perfomed by the government .It seems that
using cultivated plants under controlled conditions can the level of contamination.

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