Abhava pratinidhi dravya: A comparative phytochemistry of Ativisha, Musta and related species.

Authentic Ativisha (Aconitum heterophyllum) is a rare, endangered Himalayan species. Ayurveda classical texts of c. 15(th)-16(th) century, introduced "abhava-pratinidhi dravya" concept, wherein Ativisha was categorized as an abhava dravya (unavailable drug) and Musta (Cyperus rotundus) was suggested as a pratinidhi dravya (substitute) for it. C. rotundus is a weed, abundantly available pan-India. Cryptocoryne spiralis (Naattu Athividayam) and Cyperus scariosus (Nagarmotha) are also traded as Ativisha and Musta, respectively. Yet, there are no scientific studies to validate the use of substitutes. A. heterophyllum bears no similarity in terms of botanical classification with the other candidates. This article reviews published literature with an emphasis to look for similar phytochemicals or groups of phytochemicals in the species that could contribute to similar pharmacological activities, thereby supporting the drug substitution from a bio-medical perspective. Alkaloids like atisine were found to be the main focus of studies on A. heterophyllum, whereas for the Cyperus spp., it was terpenoids like cyperene. Although alkaloids and terpenoids were reported from both species, alkaloids in C. rotundus and terpenoids in A. heterophyllum were minor constituents. Reports on phytochemicals on Cryptocoryne spiralis and C. scariosus were very limited. Despite no significant similarities in chemical profiles reported, the dravyaguna (Ayurvedic drug classification) of Ativisha and Musta was quite similar warranting further exploration into the bio-functional aspects of the drug materials.