Impetus demand in developing a Rasa (taste) assessment tool for Ayurveda crude drugs

Abstract

The identification of Rasa (taste) of any Ayurveda crude drug acts as a predictor of its pharmaco-therapeutic effects thereby helping assume its applicability as food and medicine. Therefore Rasa identification may facilitate the selection of rasas-based substitutes. Ayurveda literature points towards the role of rasa assessment in drug development and standardization of Ayurveda raw drugs. The aim of this paper is to highlight the scope and present status of rasa evaluation tool in Ayurveda. A thorough search of Electronic databases including Google Scholar and PubMed using the keywords "Rasa," "taste assessment," “Rasa nirdharana” and "Ayurveda" was performed. Ayurveda classical texbooks were thoroughly scrutinized to gain leads for the development and validation of tools for Rasa nirdharana. Presently studies use single‐blind trials to assess the Rasa of crude drugs wherein healthy volunteers of either sex having knowledge of Rasa were participants. Rasa was identified by virtue of a tool notably a structured proforma as well as direct identification of the taste. The structured proforma commonly in use was developed by Dr. Nisteshwar, a specialist in Ayurveda and Materia medica. This proforma is based on “Rasalakshana” the traits of each Rasa (taste) described in classical Ayurveda literature. This popular tool has been in use for a decade and there is no denying that the idea as to how to develop a Rasa assessment tool begins from it. Development and validation of a tool for Rasa assessment is the need of the hour. There are a few lacunas in the performance used in the Rasa assessment today. A though exploratory study model needs to be taken up to develop a suitable tool that justifies the unique description of each Rasa in Ayurveda scriptures.