Controversy, Adulteration and Substitution: Burning Problems in Ayurveda Practices

Ayurveda is an Indian traditional system of medicine. In present era, world is looking towards herbal medicine because of acceptability and safety. Medicinal plants constitute an effective source of Ayurvedic and other traditional system of medicines as well as modern medicine. In India, about 80% of the rural population depends on herbal medicines in primary health care level. A large percentage of plants used in herbal industries are subject of controversy. Non-availability of plants, poor understanding and parallel evolved knowledge systems are some of the reasons attributed to it. The existing practices of polynomial nomenclature system of Sanskrit, different perceptions in various communities, vernacular equivalents, all are cumulative factors for controversy, adulteration and substitution. “ Sandigdha Dravaya “ is a term used for that type of medicinal plants which are mentioned in Ayurvedic classics but their exact botanical source is not known. Adulterants and substitutes are the common practices in herbal raw material trade. Adulteration is a debasement of an article. The motives for intentional adulteration are normally commercial that which involves deterioration, admixture, sophistication, inferiority, spoilage and other unknown reasons. Substitution is a replacement of equivalent drugs in place of original drugs. The principles to select substitute drugs are based on similar Rasa, Guna, Virya, Vipaka and mainly the Karma. At present the adulteration and Substitution of the herbal drugs is the burning problem in herbal industry and in Ayurvedic practices. So it is necessary to develop reli-able methodologies for correct identification, standardization and quality assurance of Ayurvedic drugs.


Introduction
Ayurveda is an Indian traditional system of medicine. It is a science of life and believed to be prevalent for last 5000 years in Indian Subcontinent. It is one of the most noted systems of medicine in the world [1]. In Ayurvedic system of medicine, treatment is based on Chikitsa Chatuspad (Tetra-pod of treatment) and for success of treatment, all these pods most contain special qualities [2]. Aushadh (Drugs) is one of the major pod, and for success of treatment potent drugs are the primary requirement. Medicinal plants are the major source of drugs in Ayurveda.
India is one of the world's top 12 mega diversity countries. It has more than one fourth (8000) of the world's known medicinal plant species (30,000), which provides an important source of medicinal raw materials for traditional medicine systems as well as for pharmaceutical industries [3]. Medicinal plants are globally valuable sources of new drugs. There are over 1300 medicinal plants used in Europe, of which 90% are harvested from wild resources; similar figure in India also. Furthermore, up to 80% of people in developing countries are totally dependent on herbal drugs for their primary healthcare, and over 25% of prescribed medicines in developed countries are derived from wild plant species [4]. Due to an increasing demand for medicinal plants and a loss and fragmentation of natural habitats, close to 300 species of Indian medicinal plants have been so far assessed as under threat in the wild. Around 1,000 species are estimated to be facing various degrees of threat across different biogeographic regions in the country [5]. Due to such a high demand and less availability of natural sources and unavailability of crude genuine drugs, practices of substitution and adulteration are increasing day by day. Similarly a large percentage of plants used in herbal industries are subject of controversy. Nonavailability of plants, poor understanding and parallel evolved knowledge systems i.e. knowledge of naming of plants by identifying species with partly similar or fully similar properties, inherent qualities of accent and dialects, nonmedical literature describing flora etc. are some of the reasons attributed to it [6].
At present the adulteration and Substitution of the herbal drugs is the burning problem in herbal industry and in Ayurvedic practices. Due to adulteration, faith in herbal drugs has declined and led to one of the greatest drawbacks in promotion of Ayurveda and Herbal products. Adulterants are also creating health hazards or adverse events. Similarly controversy is creating problem for uniformity in standardization and reliability of Ayurvedic products and due to use of substitutions, it is difficult to get the appropriate effects as the genuine drugs could give.

Controversy and controversial drugs
Controversial drugs or Sandigdha Dravyas are those plants which are mentioned in Ayurveda classics but their botanical identification is not clear. The Ayurvedic and Sanskrit literature has described a herb with many synonyms, which do not precisely indicate the botanical source but many a times attribute to therapeutic utility of the plant [7]. For a single herb various synonyms are mentioned in Ayurvedic lexicons on the basis of morphology, habitat, origin, therapeutic uses etc. by using different similes which are leading causes of controversy. Quantum of information gained from Ayurvedic and other Sanskrit literature revealed various incidences where on common vernacular name is used for two or more entirely different plant species in Ayurvedic and other traditional system of medicines [7] e.g. Amrita is used both for Tinospora cordifolia, and Terminalia chebula which are totally different drugs. Synonyms of herbs are also given according to the local languages. India is a country having a variety of languages and population dependent on different tribal and folklore medicine. Sometimes this is also responsible for confusion in the nomenclature of different plants having similar name.

Mistake done during copying of manuscripts
In past there was no printing machine, Acharyas had written the manuscriptmanually in Bhurja-Patra or Taalpatra or other substances. During copying of Poor understanding of Sanskrit word in different context-Ayurvedic classics are mainly written in Sanskrit language [8][9][10]. Same word in different contexts give different meaning, and due to poor understanding of this type of words by commentator further creates controversy, for example Pippala denotes Bodhivriksha when used in malegender and the same in female gender denotes long pepper.
Substitute leading controversy-Due to non-availability or high cost in the market, there are chances of substitution of drugs. If this practice continues for long time the original identity of a plant may become obscure and the substitute will be considered as the original, which ultimately creates controversy later on. For example-Pashanbheda is used as urolithiasis (Ashmaribhedana) as the name indicates, so drugs like Bryophyllum pinnata (Patharchuda), Aerva lanata Juss etc. are used by name of Pashanbheda. But originally Bergenia ligualata (Wall.) Engle is identified as the source of Pashanbheda [8][9][10]. Parallel evolving knowledge system-Identifying species and naming them with partly similar or fully similar properties, inherent qualities of accent and dialects may create controversy. For example Brahmi is mentioned in Ayurveda calssics as brain tonic. Mandukparni is another drug mentioned as Medhya Rasayan (braintonic) in Charaka Samhita. Bacopa monnieri [8][9][10].
(L.) Pennel. is source for Brahmi but in North India Centella asiatica (L) urban (Mandookparni) is called as Brahmi due to similarity in therapeutic effects.
Vernacular names-Somewhere same name is used in different languages but having different meaning and identity which is also a cause of controversy, e.g. Matala in Tamil refers to Punica granatum Linn. Where as in Kannada it pertains to Citrus medica [8][9][10].
Polynomial nomenclature-Multiple names for single plant are given in Ayurvedic lexicons. This type of trends aroused during Nighantu Period. Different Nighantu written by different authors gave multiple names for a single drug especially for better understanding about the drug but they created controversy later on [8][9][10] ( Table 1).

Adulteration
Adulteration is a practice of substituting original crude drug partially or wholly with other similar looking substances but later is either free from or inferior in chemical and therapeutic properties. In simple word, it is debasement of an article [1]. On the basis of motive; adulteration is intentional or direct and accidental or indirect adulteration. Direct or intentional adulteration is mainly done for commercial benefits [11]. Deterioration, Admixture, Sophistication, Substitution, Inferiority and Spoilage are methods of adulteration. Intentional impairment in the quality of drug is Deterioration. Addition or mixing one substance to another accidentally or carelessly or due to ignorance is Admixture. It is a type of unintentional adulteration. Sophistication is the intentional or deliberate type of adulteration in which some totally different substance is added in place of genuine drug while Inferiority refers to adding of any substandard drug, and Spoilage is due to the attack of microorganisms or parasitic infestation [1].
Deterioration, Admixture, Sophistication, Substitution, Inferiority and Spoilage are methods of adulteration. Intentional impairment in the quality of drug is Deterioration. Addition or mixing one substance to another accidentally or carelessly or due to ignorance is admixture.
It is a type of unintentional adulteration. Sophistication is the intentional or deliberate type of adulteration in which some totally different substance is added in place of genuine drug while Inferiority refers to adding of any substandard drug, and Spoilage is due to the attack of microorganisms or parasitic infestation [1].

Major intentional types of adulteration
• Substitution with substandard commercial varieties [1,12,13] • This is the most common type of adulteration in which low standard drugs are mixed which are morphologically, chemically and therapeutically resembles to the original crude drugs, for example Arabian senna is used instead of Indian senna.
• Using superficially similar inferior drugs -In this type of adulteration adulterants are superficially similar in appearance but may or may not having any chemical or therapeutic value as the original crude drugs. For example papaya seeds are adulterated with Piper nigrum, saffron is admixed with dried flowers of Carthamus tinctorious.
• Using artificially manufactured substance -In this type of adulteration artificially manufactured substances resemble to original crude drugs, are adulterated. This type of adulteration is done for costlier drugs. For example Calcium carbonate compounds are used by name of Vansha lochan.
• Using exhausted drug -This type of adulteration is usually done for those drugs which contain volatile oil, for examples fennel, clove, coriander, caraway etc. In this type same crude drug is adulterated but after extracting major chemical constituents, e.g. Volatile oil is extracted from bud of Lavanga (clove) and exhausted buds are adulterated. In this case sometimes extra additives are used to make the exhausted drugs attractive.
• Using synthetic chemicals to enhance natural character-Synthetic chemicals are used as adulterant which enhances the natural characteristics of original drug, for example, Citral is added in citrus oil like oil of lemon or orange oil.
• Presence of vegetative matter of same plant-Instead of proper used parts of crude drugs other parts of same species or miniature species grown around the large species are mixed with genuine crude drugs. For example instead of Moola (root) of • Bala (Sida cardifolia) stem or whole parts of plant is used. This type of adulteration occurs in both intentional and unintentional adulteration.
• Harmful adulterants -For increasing weight of crude drugs for commercial profit, some harmful substances are added with genuine crude drugs, for example stone pieces and sand particles mixed in Guggulu (gum of Commiphora mukul). •

Reason for adulteration
1. Intentional adulteration is done mainly due to commercial benefits, when there is high demand but less availability of drugs.
• Lack of knowledge about authentic source e.g. Calophyllum inophyllum is adultered with Mesua ferra.
• Similarity in color and morphology -For example Mucuna utilis and Mucuna deeringiana are used for Mucuna pruriens • Careless collection/improper collection -Definite part of herb should be collected in particular season, particular place and particular part of plant should be collected but ignorance of these things during collection and drugs collected carelessly may cause adulteration.
• Improper storage-Due to improper storage physical factors such as air (oxygen), humidity, light, and temperature can bring about deterioration directly or indirectly and use of such type of drug acts as adulterant.
• Imperfect preparation-Some of crude drugs should be processed before marketing, during such processing improper technique may destroy active constituents e.g. over drying of crude drugs, removal of cork from zinger etc. ( Table 2).

Substitution
Substitution is a replacement of equivalent drugs in place of original drugs on the basis of similar pharmacological actions and therapeutic uses. In Ayurveda, substitution is described by the name of Abhava Pratinidhi Dravya. During Samhita Period concept of adulteration and substitution was not existed but

Need for substitution
• Non-availability of the drug: Some drugs mentioned in Ayurvedic lexicon are not available nowadays, so those drugs are substituted by other drugs having similar therapeutic value [9,10,12,13,15]. For example most of drugs from Astavarga are not easily available so those drugs are substituted by other ones e.g. Meda and Mahameda are substituted by Shatavari.
○ Uncertain identity of the drug: The drugs which are mentioned in Ayurvedic classics but their botanical identity is not clear those are substituted by known one e.g. for the herb Lakshmana, different species such as Arlia quinquefolia, Ipomea sepiaria etc. are considered.
• Cost of the drug: Kumkuma (Crocus sativus) is more costly so it is substituted by less expensive Kusumbha (Carthamus tinctorius Linn.).
• Geographical distribution of the drug: Rasna (Pluchea lanceolata) is used in Northern India while in southern parts Alpinia galanga is used as Rasana and Vanda roxburghii is considered as source in Bengal.
• The adverse reaction of the drug: Vasa (Adhatoda vasica) is good Rakta-Pittahara (antihaemorrhagic) drug, but having abortificiant activity, so instead of this drug Laksha (Lacifer lacca), Ashoka (Saraca asoka) etc. are used in pregnant women for the same purpose.
• Seasonal availability of drug-Punarnawa (Boerhaavia diffusa) is commonly not found throughout the year so for that Trianthema portulacastrum (Varshabhu) can be used as substitute, which is found throughout the year [9, 10, 12, 13, 15].
• Substitution of species belonging in same family -Datura metal is substituted by Datura stamonium.
• Using different parts of same plant -Instead of root of Sida cordifolia whole plants of Sida cordifolia is used.

A case of substitution in Nepal
Rohitaka is mentioned in almost all classics of Ayurveda such as Brihattrayee (Charaka Samhita, Sushruta Samhita, and Ashtanga Hridya) and other lexicons such as Sharangdhara Samhita, Bhavaprakasha Nighantu, and Yoga Ratnakar. It is also mentioned in maximum numbers of Nighantu (Ayurvedic lexicons). It is mentioned as Yakritpleehagulmodar Roga-hara (useful in liver diseases, spleen disorders, and abdominal lumps). Tecomella undulata (Sm.) Seem. from Bignoniaceae family is a genuine source of Rohitaka. It is commonly known as "Rohida" or "Desert Teak" and an important deciduous, ornamental, and medicinal tree [19].
In crude drug market of Nepal Rhododendron arboreum Sm. is sold by the name of Rohitaka and considered as substitute of Tecomella undulata (Sm.) Seem. The Nepali name of Rohitaka is given as Guransa in Chandra Nighantu which is a hand written famous manuscript in Nepal and kept in Singha Darbar Vaidyakhana Vikas Samiti (SDVKVS) in Kathmandu. In this manuscript manually drawn picture of Rohitaka is given which is Guransa and is botanically identified as Rhododendron arboretum Sm. Traditional practitioners use this drug for liver disorders like Jaundice (Kamala), hepatitis, hepatomegaly etc. Leaves, flowers, bark are used for various purposes traditionally and in Ayurvedic practices [19].
The genuine source of Rohitaka is identified as T. undulata (Sm.) Seem. However, due to non-availability of the genuine source, various other drugs are used as substitute. Stem bark of R. arboreum Sm. is commonly found by the name of Rohitaka in herbal raw drugs trade in Nepal. The rationality behind selection of Pratinidhi Dravya (substitute drug) isbased on similarity in Rasa, Guna, Veerya, and Vipaka with that of original drug. On organoleptic evaluation, both drugs are bitter in taste substantiated the similarity in Rasa. The pharmacognostic and analytical studies have confirmed the genuinity and purity of both the drugs (R. arboreum Sm. and T. undulata [Sm.] Seem.). Both the drugs have few common phytochemicals such as carbohydrates, alkaloids, tannins, and phenols which are responsible for their pharmacological actions. Chromatographic study showed

Discussion
Controversy, Adulteration and Substitution are interrelated with each other. Substitution practices if exists for long time the original identity of a plant may become obscure and the substitute will be considered as the original, leading to create controversy. Nonavailability and high market price of crude drugs led to adulteration. Similarly controversy about authentic botanical source of medicinal plants dealt in classical Ayurveda texts led a cause of substitution because of lack of proper authentication, the drugs having similar morphology or similar therapeutic effects might be practiced. Controversy, adulteration and substitution create problems for standardization of Ayurvedic practices and herbal products. Substitution of genuine drug is need of time because of unavailability of genuine drugs due to deforestation, global warming, lack of adequate cultivation practices etc. Although substitution should be only done for endangered and red listed plants and the major constituent of a preparation should not be substituted. The rational substitution in Ayurveda is based on similarities in Guna of both the drugs and not on inferior qualities. It should be properly validated in contemporary context using both Ayurvedic principles and Modern Scientific tools. World Health Organization (WHO), in its publication on quality standards for medicinal plant materials, recommends rejecting any batch of raw material, which has more than 5% of any other plant part of the same plant (e.g. stem in leaf drugs), never the less if they are derived from the authentic plant. Based on these standards, adulteration whether, intentional or unintentional, should be rejected. Collectors, suppliers and traders should be educated for authentic sources of drugs. Intentional adulteration should be discouraged by strictly implementing the regulatory laws. Due to adulteration faith in Ayurvedic practices and drugs has declined and adulteration in market samples is the greatest drawback in promotion of herbal drugs. So for quality, safety and standardization purpose of Ayurvedic products and practices the problem related with controversy, substitution and adulteration of drugs should be resolved for its worldwide acceptance.
The prime factor for resolution of controversy is the proper authentication of botanical source of medicinal herbs mentioned in classics, for this, literature review, ethno-botanical survey, medicinal plants survey and drug evaluation (morphological, microscopic, chemical, physical and biological evaluation) should be done. Similarly for determination and detection of adulteration, various steps of drug evaluation should be applied. Substitution of drugs should only suggested when therapeutic efficacy of substituted drug is similar to original one.
The uniformity in selection of crude drugs for pharmaceutical preparations and practices should maintain the standardization of Ayurvedic products and for this Ayurvedic pharmacopeia of India (API) and Ayurvedic formulary of India (AFI) is playing a vital role, so maximum number of drugs mentioned in classics and practiced traditionally should be incorporated in API and AFI.

Conclusion
• Controversy about drugs is mainly due to polynomial system of nomenclature in classical texts.