Heavy metals in Ayurvedic traditional formulations -1

In 2004 Saper et al published their report on the heavy metal content of ayurvedic medicines. This was followed by several reports of heavy metal contamination in ayurvedic medicines (van Schalkwyk et al, 2006; Saper et al, 2008; Raviraja et al, 2010; Gunturu et al, 2011; Hore et al, 2012) . Almost all these studies were based on information obtained from ayurvedic medicines prepared from calcined metals and inorganic substances. Not much information is available on the content of heavy metals in traditional ayurvedic medicines prepared exclusively from herbs. The present study was therefore, undertaken to fill that lacuna. An attempt was also made to analyze the heavy metal content of some common ayurvedic herbs.

Samples of traditional ayurvedic medicines were purchased from various parts of Kerala. 27 kvatha, 14 churna, 24 taila, 10 ghrita, 17 lehyam, 6 asava, 23 arishta , 3 dravakam and 2 lepa were studied. Samples of ayurvedic herbs were procured from suppliers in various parts of the country. Multi-elemental standards for ICP-MS were prepared from stock solutions of Pb, As, Cd and Hg at 100 ppm concentrations. 250-500 mg of a sample of ayurvedic medicine or powdered herb were subjected to microwave-accelerated reaction system for 1 hour. The digested sample was analyzed using an Agilent 7700X inductively-coupled mass spectrometer (ICP-MS, Agilent Technologies, U.S.A.). The detection limit of ICP-MS is 50 ppb.

The 126 ayurvedic formulations analyzed in the present study contained Lead (Pb), Arsenic (As), Cadmium (Cd) and Mercury (Hg) in quantities appreciably below the levels permitted by Government of India; lead, arsenic, cadmium and mercury in any Ayurveda, Siddha or Unani medicine should not exceed 10, 3, 0.3 and 1 ppm respectively (Protocol for Testing of Ayurvedic, Siddha & Unani Medicines, pp. 36). The 34 ayurvedic herbs analyzed also contained these heavy metals in quantities below the permitted levels. The plant samples analysed represent all the geographical zones of India. Several of the formulations and ayurvedic herbs tested had these elements below detection limit (50 ppb). These heavy metals could not be detected in many samples as well. The negligible content of heavy metals in the herbs studied suggests that most of the herbs traded at present in India are procured according to good collection practices.

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