Cyperus rotundus, a substitute for Aconitum heterophyllum: Studies on the Ayurvedic concept of Abhava Pratinidhi Dravya (drug substitution)

In the absence of a desired first choice medicinal herb, classical Ayurveda recommends use of a functionally similar substitute. Post 16th century Ayurvedic texts and lexicons give specific examples of possible substitutes. Here we report a preliminary study of one such Ayurvedic substitution pair: Musta (Cyperus rotundus L., Cyperaceae), a common weed, for the rare Himalayan species, Ativisha (Aconitum heterophyllum Wall. ex Royle; Ranunculaceae). The study's strategy was to use modern phytochemical and pharmacological methods to test the two herbs for biochemical and metabolic similarities and differences, and literary studies to compare their Ayurvedic properties, a novel trans-disciplinary approach. No previous scientific paper has compared the two herbs' bioactivities or chemical profiles. Despite being taxonomically unrelated, the first choice, but relatively unavailable (Abhava) plant, A. heterophyllum, and its substitute (Pratinidhi) C. rotundus, are not only similar in Ayurvedic pharmacology (Dravyaguna) profile, but also in phytochemical and anti-diarrheal properties. These observations indicate that Ayurveda may attach more importance to pharmacological properties of raw drugs than to their botanical classification. Further research into the nature of raw drugs named could open up new areas of medicinal plant classification, linking chemistry and bioactivity. Understanding the logic behind the Ayurvedic concept of Abhava Pratinidhi Dravya (drug substitution) could lead to new methods of identifying legitimate drug alternatives, and help solve industry's problems of crude drug shortage.