Heavy Metal Accumulation in Some Herbal Drugs

Accumulation of heavy metals, namely Pb, Cd, Cu, and Zn, was estimated in some of the important herbal drugs of India, viz., Alpinia galanga, Artemisia parviflora, Butea monosperma, Coleus forskohlii, Curcuma amada, Euphorbia prostrata, Leucas aspera, Malaxis acuminata and Pueraria tuberosa. A total of 34 samples, genuine as well as market samples of aforesaid plant species, were procured for estimation of heavy metals. The concentration of Pb and Cd was found beyond the WHO permissible limits in most of the samples studied. It is also notable that difference in heavy metal concentration in a particular plant species collected from different regions is related to the site from where the samples were collected. For example, Junagadh sample of Artemisia parviflora leaves accumulated more Pb and Zn as compared to the Tarikhet sample. This may be due to higher industrial activity at Junagadh district of Gujrat State. Similarly, Lucknow samples of Alpinia galanga and Curcuma amada showed maximum concentrations of Pb, Cd, Cu and Zn, as compared to the other regional samples of the same species, and the air pollution due to automobiles is quite high in this city.