Abstract:
Over the years, herbal products have been used in various parts of the world for the cure of
human disorders. Although herbal products are often demanded to be beneficial and free of side
effects there have been reports of acute and chronic toxicity resulting from their use. One of the
main causes of toxicity of herbal medicines is the existence of heavy metals. Therefore the main
objective of this study is to analyze Ayurvedic powdered drugs, Ashwagandha churna (AC) and
Thipala churna (TC) of three different brands available in Sri Lankan herbal market for the
quantitative analysis of essential trace and heavy metals. The samples were prepared by wet
digestion method using hydrogen peroxide and nitric acid treatment. The presences of metals
were analyzed by Flame Atomic Absorption Spectroscopy using a HITACHI ZA3000 Polarized
Zeeman Atomic Absorption Spectrometer. The results were compared with the extraneous
maximum residue limit recommended by the Food and Agriculture Organization (FAO) /World
Health Organization (WHO) for herbal medicines. Lead and cadmium in brand A of AC were
not detected in the samples. However cadmium concentrations in other samples were below the
extraneous maximum residue limit. The extraneous maximum residue limits of the FAO/WHO
have not been established yet for copper, nickel, chromium and zinc in herbal medicine. The
results reveal that among the trace elements zinc (33.25 mg/kg) found in highest amount, but this
was below the acceptable daily intake limit (60 mg/day). Chromium was not detected in brand C
of AC and TC samples. In conclusion, the quality of herbal churna products sold in Srilankan
market is safe. However there is need for continuous monitoring of branded herbal churna
products sold for human consumption.
