Twenty years ago, in 2006, I was involved in the organisation of a regional meeting on traditional medicine in south Asia, which was held in Bangalore in India.
Recently, I have read some discussions about research on the safety and efficacy of traditional medicine. They reminded me of a speech given my friend Dr Bala on this theme in that meeting. Therefore, I have decided to share some extracts from his speech in this post.
Background to the Regional Meeting Held in Bangalore in 2006
I was asked to organise and coordinate a meeting on traditional medicine practices in South Asia by a group of international NGOs. Similar regional meetings were held in that period in other parts of the worlds. Final reports from those meetings were put together and provided to the department of Traditional Medicine in the World Health Organisation (WHO) in Geneva.
However, my participation in the whole process was limited to the meeting held in India, since I was busy in other research work in that period. My friends from People's Health Movement in India had played a fundamental role in organising that meeting.
Dr K. Balasubramaniam (1926-2011) from Health Action International Asia-Pacific (HAI-AP) had given the keynote address at that conference. Dr Bala, as everyone called him, had done pioneering work in access to essential medicines and was a key and respected figure in the international People's Health Movement (PHM) in those days. That meeting was also an opportunity to meet some of my old friends including Dr H. Sudershan from Vivekananda Girijana Kalyana Kendra, Dr Mira Shiva & Dr Ravi Narayan from PHM-India.
That conference was my first real encounter with traditional medicine. It was also the first time that I had visited an Ayurvedic medical college and understood the kind of training Ayurvedic doctors receive in India.
In this post, I would like to share some extracts of the keynote address of Dr Bala focusing on "Evaluation of Safety and Efficacy of Traditional Medicine". His keynote was much wider in scope. For example, he devoted a significant part of his speech to the subject of "Preserving and safeguarding biodiversity sustainability and traditional knowledges".
In the coming days, I want to share some more papers from that conference. If you wish to read more documents from that meeting, I invite you to check the final report of that conference, which can be freely downloaded.
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Evaluation of Safety and Efficacy of Traditional Medicine
Dr K Balasubramaniam, Sri Lanka
I believe that this conference will focus on herbal remedies which constitute the therapeutic armamentarium of traditional systems of medicine in the region.
The World Health Organization (WHO) has defined herbal medicines as "Finished labelled medicinal products that contain ingredients from aerial or underground parts of plants parts or other plant material or combination thereof, whether in the crude state or as plant preparations. The same WHO document adds "Medicines containing plant material combined with chemically defined active substances, including chemically defined substances and isolated constituents of plants are not considered to be herbal medicines".
It will therefore, follow that chemically defined isolated constituents of plants used in modern medicine are not herbal medicines, it has been estimated that these medicines derived from plants constitute about 25 percent in modern pharmacopoeia.
The World Health Organization posed a question 2002 whether a herbal medicine can be used clinically if no harm has been found after the use of that herbal medicine for generations and there is no documentation of such an effect. For an answer to the question, reference is made to an earlier WHO document published in 20003 which states "Absence of reported or documented side effect is not an absolute assurance of safety of herbal medicine. However, a full range of toxicology tests may not be necessary. Tests which examine effects that are difficult or even impossible to detect clinically should be encouraged. Suggested tests include immuno-toxicity, geno-toxicity, carcinogenicity and reproductive toxicity", It adds the following caveat, "only when there is no documentations of long historical use of a herbal medicine or when doubts exist about its safety; should additional tests be performed.
A rigid framework that has been prepared for modern synthetic drugs will never be possible for herbal medicines. There has to be some flexibility in toxicological requirements for herbal medicines.
Accordingly, a group of experts met in Chandigarh, India, to develop a suitable framework for carrying out toxicological studies on herbal medicines. The framework developed was broadly accepted by the Indian Council of Medical Research and the WHO. The actual tests to be carried out in the Chandigarh model are given in tables 1 & 2 (click on the tables for a bigger view).
The tests recommended by the WHO are given in Table 3 below (click on the tables for a bigger view).
WHO has called on clinical researchers to conduct clinical evaluation of traditional medicines within the specific framework of rigorous clinical pharmacological principles without ignoring or trampling on the concepts of the traditional systems of medicine.
I wish to take this opportunity to present an alternate view for evaluation of traditional medicine.
Traditional systems of medicine are a summation of several thousands of years of human experience in the selection of plants for preventive and curative healthcare. Practitioners of traditional systems of medicine argue that the efficacy of herbal remedies is due to the synergistic activity among the several ingredients of herbal mixtures. Complex mixtures of plants or herbs form the basis of traditional medicines. The mixtures are usually subject to crushing, heating, boiling, etc. It is possible that this process may change the chemical structure of the active ingredients in the plants.
Clinical pharmacologists and other scientists working on medicinal plants, on the other hand, focus all their attention on isolating and identifying biologically active ingredients in medicinal plants and herbs. When a promising new biologically active chemical ingredient is isolated, it goes through all subsequent investigations identical to those for a new synthetic chemical ingredient.
Traditional healers do not accept that the efficacy is necessarily due to the active ingredients in the plant.
According to the active ingredient approach the modern clinical pharmacologists, take the knowledge from the plant but throws away the wisdom of centuries.
If there is acceptable historical evidence that traditional herbal remedies have been effective in the treatment of certain diseases, but neither their active ingredients nor the mechanisms are known, is it ethically or morally acceptable to not use that treatment? Examples of successful treatment by traditional medicines will be useful to answer these questions,
In the fate 1980s children attending the Dermatology Department, Hospital for Sick Children, Great Ormond Street, London showed marked improvements in their eczema symptoms. These improvements were due to oral treatment with aqueous decoctions of a mixture of 10 Chinese medicinal herbs. Clinical experimentation and pharmacological testing revealed that a mixture of the 10 herbs were necessary and that the efficacy could not be attributed to any single active ingredient from any one of the 10 Chinese herbs, A placebo controlled double-blind clinical trial using the 10 Chinese herbs was carried out on 47 selected children with non-exudative eczema. The conclusions of the trial were to validate the standard of current conventional clinical trials utilized in the UK that the traditional Chinese therapy was efficacious.
If these children had to wait till the clinical pharmacologists had screened the 10 Chinese plants for active ingredients and tested them for biological activity, they would never have been given the chance of getting effective treatment with a mixture of 10 Chinese herbs.
Potential cytotoxic drugs are tested for their activity against experimental or human cancer cells. Efficacy depends on the ability to kill specific cancer cell types without affecting normal body cells. Studies on the effects of certain Ayurvedic herbal preparations for possible cytotoxic activity revealed that these herbal preparations did not kill the cancer cells but transformed them into normal healthy cells. These drugs, therefore, have a different mechanism of action, Classical testing methods would have missed this important anti-cancer activity.
I wish to pose a philosophical question. Is medical science one universal and uniquely expressed (western) paradigm – a biomedical paradigm? If it is possible to conceive of alternative methodologies, theories and practices in other domains such as music, logic, linguistics, art and politics, is it not possible to consider possibilities of alternative methodologies in medical science, knowing that doctors practice medicine within a biopsychosocial paradigm?
The guiding principles by which knowledge is built up in the biomedical paradigm are those of the scientific method where hypotheses are clearly stated, then tested and accepted or rejected as truth "until further notice" or "within the stated confidence limits” using only experimental or quasi-experimental designs – a deductive approach to problem solving.
Is it possible for research scientists to examine other methodologies, for example, using experiential methods – an inductive approach, to evaluate traditional herbal remedies?
There is an enormous amount of research on medicinal plants in research institutes in developing countries and the transnational drug industry.
Based on the WHO definition of herbal remedies and the herbal remedies used by practitioners of the traditional system, I wish to pose the following questions:
The Indian Council of Medical Research has taken the plant Pterocarpus marsupium from its use in folklore and Ayurvedic medicine to Phase III clinical evaluation for the treatment of diabetes mellitus using well accepted pharmacological principles. It was handed over to the industry for pharmaceutical development and marketing. This product will be marketed to practitioners of modern medicine. Table 4 (click on the tables for a bigger view) lists examples of modern drugs derived from plants that have been used in the traditional systems of medicine by ancient people around the world.
The question I wish to pose is as follows: "Will this type of research and development to isolate therapeutically active chemical ingredients achieve the objectives of this conference which is to promote the continuous development of traditional medicinal in the region to maximize its contribution in preserving and improving public health."
Let me make it clear that R & D to isolate therapeutically active ingredients from medicinal plants is of critical importance. There is no doubt about it.
But what I wish for you'll to discuss is the need for research to evaluate the safety and efficacy of the herbal remedies used by practitioners of the traditional systems of medicine. For example table 5 gives a 5 list of Ayurvedic remedies for some common ailments (click on the tables for a bigger view).
Is there a need to develop appropriate methods for clinical evaluation of traditional herbal medicines: methods and criteria not to be limited to the methods and concepts of modern biomedical science.
Interestingly much of the scientific literature for traditional medicine uses methodologies comparable to those used to support many modern surgical procedures: individual case reports and patient series with no control or even comparison group.
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For a full version of the keynote address by Dr Bala at the South Asia Regional Conference on Traditional Medicine, held in Bangalore, India in 2006, including the list of references, I invite you to download and read the conference report, that I had prepared. Please write to me at sunil.deepak@gmail.com if you would like any of the presentations made at the meeting.
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