Evidence for safety of Ayurvedic herbal, herbo-metallic and Bhasma preparations

Heavy metals in Ayurvedic formulations have been used for centuries with claimed efficacy and safety. However, concerns are often raised about the toxicity due to heavy metals used in Ayurvedic formulations. The aim of present study is to explore the effect of Calcury tablet, Energic-31 capsule and Basanta Kusumakara Rasa (BKR) on neurobehavioral activity and oxidative stress in rats. Male wistar rats weighing 200-250 g were used and divided into normal control, positive control (mercury chloride, lead acetate, cadmium chloride, sodium arsenite, each 10 mg/kg, p.o for 28 days) and treated group (Calcury tablets at doses of 130, 650, 1300 mg/kg, Energic-31 capsule at doses of 150, 750, 1500 mg/kg and BKR at doses of 26, 130, 260 mg/kg, p.o. for 28 days). After performing the behavioural parameters on the 29 ^th day, homogenate of rat's brain was used to determine malondialdehyde (MDA) and glutathione (GSH) levels and heavy metal level in brain. Results showed that there were no significant change in cognitive function, motor coordination, MDA and GSH levels as compared to normal control group at all doses of Calcury tablet, Energic-31 capsule and Basant Kusumkar Rasa. However, heavy metals level in rat's brain was higher as compared to normal control group at all doses of Calcury tablet, Energic-31 capsule and BKR. In conclusion, Calcury tablet, Energic-31 capsule and BKR in doses equivalent to the human dose does not have appreciable adverse effects on brain which demonstrates the non-toxic nature of metal based Ayurvedic formulations.

How are the heavy metals purified in Ayurveda?

 Heavy metals are integral to some formulations and are been used for centuries. ^[8] Ayurvedic formulations are produced after different processes like detoxification, trituration and heating etc., of raw material. Therefore, elements present in finished products do not produce toxicity. Ayurvedic textbooks takes note of the toxicity of heavy metals and recommend special pharmacological process to detoxify them. Those metals which are obtained from ores may contain several impurities. These impurities are removed by Shodhana process. The Shodhana process removes unwanted part from the raw material and separate out impurities. In context of Bhasma, Shodhana means purifying and making the product suitable for the next step i.e. Marana. Ayurveda classifies Shodhana into (a) general process and (b) specific process. In general process for Shodhana, the sheets of metals are heated till red hot and are successively dipped into liquids like oil, buttermilk, cow's urine etc., and the procedure is repeated 7 times. In specific process for Shodhana, for some metals a specific process is described for Shodhana e.g. for purification of Jasada, the molten mass is poured in cow's milk for 21 times. ^[9] 

 Heavy metals from outside are deliberately added and processed with herbal plants to form herbo-metallic drugs. ^[11] Each time before burning, the metallic powders are processed with fresh herb juices to neutralize their toxicity. Some of the metals are burnt up to 100 times to make sure the heaviness or toxic effect of the metal is nullified. Once the "Bhasma0" is ready it is tested for toxicity. One of the numerous tests the Bhasma has to pass through is called "Varitar" which means the Bhasma, once ready for internal use, floats on water indicating non-existence of heavy metal in it. The "Bhasma0" are then transformed to compound formulas by mixing herbal powders. Special herbal juices are used for processing the compound formula for no more toxic metals but for non-toxic herbo-metallic compounds. Therefore, it is claimed that heavy metals are detoxified with herbal extract and excreted out from the body without any harm to body. ^[12] Bhasmas are metal preparations which are subjected to physico-chemical processing called Samskaras to purify, detoxify and retain the therapeutic properties.