Plants, as we all know, are immensely important and an essential part of our life. They are being used for their medicinal properties since time immemorial, not only in India but also in many other countries. Each and every plant has some or other medicinal property, although some might not have been well tapped yet. The ancient, traditional and alternative system of medicine practiced in the Indian subcontinent is known as Ayurveda. It uses plant based medicines as one of the therapies. The importance of Ayurveda is being recognized globally, these days. The recent pandemic is a very good example, when we all witnessed that plant based preventive and curative measures were being promoted and adopted globally.
The medicinal properties of the plants are due to their active principles which are in form of chemical compounds present in them e.g. azadirachtin (in neem), bacosides (in brahami), phyllanthin (in bhui-amla), atropin, hyocyamin (in datura), eugenol (in tulsi), gingerols, shogaols (in ginger), curcumin (in turmeric), morphine (in poppy) to name a few handful. Since the efficacy of herbal product is based on percentage of active principle, it becomes mandatory that claimed percentage of active principle should be present in the finished product1. The quantity and quality of active principles in any plant is also affected by its habitat, season, age, etc. e.g. Brahami (B. monnieri) is used as brain tonic in Ayurveda. The activity is due to the presence of Bacosides. Suitable harvest times for high yields of bacoside-A were June and September through November1. Another study in Andrographis paniculata (Kalmegh) showed that the best harvesting time was observed at 120 days after sowing to get higher biomass containing maximum andrographolide content2. Therefore, these aspects also need to be considered when collecting any plant for crude drug preparations.
However, it is not as simple as it sounds. Each plant may have several different species/varieties. For the beginners, the different species/varieties of a particular plant have their own characteristics viz; morphological, anatomical, biochemical etc. which distinguish one species/varieties from another and aid in their identification. This identification plays a very important role in plant based Ayurvedic formulations. Therefore, one has to be aware of the specific plant and the plant part that would go in the formulation. The experts in the area of species identification (and classification) are called taxonomists and one may have to either resort to them or to the taxonomic literature for correct identification of species. So, identification and usage of right species is one of the very important aspects of these Ayurvedic formulations.
So far so good, however, there is more to it. The good things are generally scarce or become scarce with continuous use or high demand. This happens with the plants too. There are certain species of particular plant which are medicinally more important either, due to the exclusive presence of active principle or due to presence of the active principle in high amounts. In either case, there will be high demand of that particular species in the market. Many a times such species are either naturally scarce in nature or become depleted with times due to their overuse. This leads to adulteration, i.e. use of similar (but not exact) species, termed as adulterants. Adulteration may be either deliberate or ignorant. Ignorant adulteration is mostly due to incorrect identifications or careless collection of the species. Incorrect identification may be due to lack of knowledge, close similarity, confusing vernacular names etc. e.g. Fumaria parviflora and Mollugo pentaphylla are supplied often supplied interchangeably due to their vernacular names ‘Parpatta’ and ‘Parpadagam’, respectively3. Incorrect identification can affect the efficacy of the medication for the intended purpose and may also cause adverse effects or interactions in the body4.
Earlier, the identification of the species was mainly done on the basis of gross external morphology or more so anatomy. Nowadays, there are several sophisticated and advanced techniques that can help in correct identification of species, in any physical form, and not only individually but in mixture too. Further, with advancement in techniques, the species adulteration can now be tested even in the formulated products5. It is an important area of research and a lot of work has been done and is being continuously updated each day. The property on the basis of which genuine material can be distinguished from adulterants, substitutes and spurious drugs are termed as markers. These markers can be morphological, anatomical, chemical and DNA markers6. DNA based markers are most reliable due to their specificity and reproducibility. Various DNA markers like RAPD, SCAR, HRM, Bar-HRM, ITS markers etc., are frequently used for authentication and identification of species5, 7. This area of research holds great significance in standardization and quality assurance of crude drug and ayurvedic formulations.
Author : Dr. Neeraj Jain