Safety and toxicity issues associated with lead-based traditional herbo-metallic preparations

Abstract

Ethnopharmacological relevance: Herbal and herbo-mineral preparations are being traditionally used in Indian medicines. The herbo-mineral preparations have several benefits that have been instrumental in their widespread use in treatment of different disorders by traditional medicinal practitioners. These include better stability, lower dosage, ease of storability and sustained availability. Naga bhasma (lead sulphide ash), a traditional Indian herbo-mineral medication prepared using lead and several herbal ingredients, has been used as an oral medicine in India for many years for the treatment of diabetes, spleen enlargement, diarrhoea and various skin diseases. The elaborate preparation protocol involved in the traditional medicines is believed to modify the toxic nature of the precursor (metal) and adds therapeutic value. But modern scientists claim that these preparations are toxic to health as they contain large amount of metal. Many factors such as preparation based factors, chemical nature based factors, vehicle used, therapy associated factors, pharmacological factors, etc, determine whether the traditional medicines are toxic or not. This review focuses on the safety and critical issues associated with Naga bhasma-a lead based ayurvedic medicine.

Materials and methods: The detailed review of literature about Naga bhasma apart from other lead based formulations are carried out by utilizing the resources including, classical Indian text books, databases such as Pub med, Scopus, Science direct and few other web sources.

Results: Though metallic lead is known to be toxic to the biological system, no compelling evidence has been put forth to suggest any toxic manifestations of Naga bhasma. The elemental characterization of preparations containing Naga bhasma has shown extremely high levels of lead content and various parameters must be taken into consideration in deciding the safety and critical issues present in traditional medicines. As there are no molecular targets available for most of the traditional medicine, it is difficult to assure the safety in using this traditional preparation. Highly intensive research encompassing physico-chemical, engineering as well as biological aspects need to be carried out to understand the applicability of such preparations in a modern context.

Conclusion: As there are no molecular targets available for most of the traditional medicine, it is difficult to assure the safety in using this traditional preparation. Highly intensive research encompassing physico-chemical, engineering as well as biological aspects need to be carried out to understand the applicability of such preparations in a modern context.

Keywords: Ayurveda (knowledge of life); Heavy metals; Herbo-metallic preparation; Naga bhasma (lead sulphide ash); Toxicity.