The Laboratory has documented the processing and purification of toxic substances from medicinal plants before they can be used as medicines. Documentation was from Ayurveda (classical texts and from living practices in South India). This was sponsored by The National Geographic Society. The information would be computerized and selected recommendations would be tested in the lab. TQS pertaining to medicinal plants have been documented from 11 Ayurvedic texts. Detailed field documentation on the collection and processing methods was completed for 10 selected toxic plants used in Ayurveda from traditional health practitioners (9 in no.) based in the three South Indian states of Kerala, Karnataka and Tamil Nadu.
In Traditional Indian practice, the white seeds of Jequirity (Abrus precatorius) are used in preference to the red seeds for medicine preparation. They are also purified before usage. However, the reasons for this are not known. We have conducted chemical and biological studies to compare the profiles to understand the relevance of the traditional methods of choice of raw drug and methods of purification.
From the physicochemical, chemical and biological study it is observed that the Abrus red seeds contain more phytoconstituents than the white seeds and exhibit increased antimicrobial effect. However, there is no significant difference in their bioactivity as observed in Brine Shrimp Assay. Purification of the seeds does bring about the change in the chemical profile and the biological profile as the concentration of the constituents is reduced and there is a decrease in the bioactivity. Of the two purification methods, viz., Purification by steaming and purification by soaking, steam purification seems to be more effective. However, further chemical and biological studies have to be undertaken to establish the nature of the chemical constituents and the chemicals that contribute to the toxicity of the seeds.
Oil extracted from the seeds of small ‘variety’ of castor (Ricinis communis) is considered better for internal consumption while that from the big seeds is better for external application. Are there differences in their chemical profiles and biological activities? Is yes, this is an important folk observation. In the case of castor seeds, the small seeds were found to be less toxic than the big seeds again indicating a purpose in the traditional recommendation.
The bioactivity of big seeds was significantly higher than that of the small seeds, which is well correlated with the higher alcohol soluble extractive values. The Chromatographic profile also indicates that though qualitatively the chemical profiles of both the type of seeds are similar, the big seeds contain higher amounts of the chemical constituents. The small seeds are probably used as medicines in folk tradition due to their lesser toxicity. Detailed chemical and biological investigation are required to pinpoint the differences in the nature of the phytoconstituents
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