Analysis of heavy metals in herbal extracts of high altitute growing plants Hippophae rhamnoides and Rhodiola imbricata

Seabuckthorn (Hippophae rhamnoides L., Elaeagnaceae), growing at high altitude of 2500-4000 m, is a dwarf to tall (2-5m) plant whereas Rhodiola (Rhodiola imbricata Edgew, Crassulaceae), known as golden root, is a perennial herb growing on rocky slopes in drier areas of Western Himalaya at an altitude of 4000-5000 m. Both the medicinal plants contain wide range of bioactive substances and used in traditional medicines. Heavy metal toxicity of herbal preparations is of major concern. The concentrations of heavy metals (As, Pb, Hg, Cd, Zn, Cu, Cr) were measured by atomic absorption spectrometry in the aqueous extracts of Seabuckthorn leaf and berries, and Rhodiola roots and compared with the maximum permissible values. The studied heavy metal concentrations in aqueous extracts of both the plant products, except chromium, were below the maximum permissible values. The chromium levels in vacuum dried aqueous extract of dried Rhodiola roots and lyophilized aqueous extract of dried Seabuckthorn leaves were 3.2 ppm and 3.0 ppm, respectively, slightly higher than the WHO proposed limit of 2.0 ppm. The results suggest that the Seabuckthorn and Rhodiola herbal products were safe in respect of heavy metals.