|The Need for Animal Study in TCM Research
Overview of Traditional Chinese Medicine
Traditional Chinese Medicine (TCM) has a long and rich history. It is one of the oldest forms of medicine that is still used today. TCM practice has been shaped over time by many factors such as culture, philosophy, politics, religion and science. Traditionally, the success of TCM treatment is measured through observation and how the patient feels. Its original foundation was established two thousand years ago and was shaped by accumulative and consolidated knowledge gathered from accomplished medical practitioners of different medical approaches who had the foresight to document their findings in medical literature. Therefore, it has not always had a sequential build up of knowledge based on the previous scientific contributions as has Western medicine.
TCM practices include various theories, diagnostic techniques and therapies such as herbal medicine, acupuncture, massage and Qigong. TCM theory is based on a number of philosophical frameworks such as the theory of Yin-Yang, the Five Elements and others. Diagnosis and treatment are conducted based on these concepts. However, it does not operate within a western scientific paradigm.
About Western Medicine Development
In Western medicine development, a drug goes through a long and expensive journey before reaching the shelves of a pharmacy. It is a difficult and laborious process lasting over ten years. Scientists develop new medicines based on their research, understanding of the human body and the disease of interest. Once a potential drug compound is identified, it proceeds through a series of biological tests, known as pre-clinical research. It consists of in-vitro (test tube) and in-vivo (animal model) testing. It is essential to demonstrate that the experimental drug compound is reasonably safe before initiating any human testing (clinical). Pre-clinical pharmacological and toxicological profile of the experimental drug is generally a necessity prior to the clinical study.
From Traditional to Modern
Nowadays, TCM is being accepted by greater numbers of the general public as an additional treatment for a variety of diseases. There is also increasing concern about the safety of medicinal plants, their toxicity and the potential for adverse effects. However, the role of TCM and its safety and pharmacological profile is still uncertain, and often the existing evidence-based data does not meet stringent Western criteria. Over the past few years, more and more scientific research has been done on establishing a scientific framework for the study of TCM in order to incorporate TCM into the Western medical framework.
TCM research íVUse of Animal Models
Tremendous efforts have been made to search for the molecular, cellular and pharmacological bases of traditional medicines. Many TCM research activities aim to identify the active ingredients of herbal treatments and investigate the mechanism of action. The models used by conventional medicine seem directly relevant. In addition, drug safety and efficacy evaluation must begin in vitro and then in animal for ethical reasons. Therefore, cell line models and animal models that have been successful in Western medicine are readily available for TCM development. When the disease can be induced in an appropriate animal, the TCM can be tested for its therapeutic effect as well as its effective dose and toxicological profile.
Drawbacks in Pre-clinical research
In the Western medical framework, animal models should be used to screen experimental drugs before they enter human trials, because it can give scientists the first picture of how do the drugs work in the living system and evaluate the toxicity at varying doses.
Although there have been high-stakes debates over which diseased animal models should be used to screen new drugs before they enter the clinical trials, there are certain animal models in different therapeutics areas respectively, for example the subcutaneous xenografts in cancer drug screening, remain the gold standard for drug screening in the pharmaceutical industry.
1 Clearly, the animal models used in the pre-clinical test are better than nothing, but the drawbacks are well known, both theoretical and practical. Mainly because of physiological and genetic differences between human and animals, the diseased models are often different from their human equivalents.
Traditional Chinese Medicine has had a long and noble history, and in many part of the world it is actively practiced today. It is unquestionable that many components of TCM are successful in suppressing different types of diseases in humans. However, there does not appear to be any evidence, which meets stringent Western criteria, to support their use. It is necessary to use animals like mice, rats, rabbits, or monkeys to test their efficacies before using them in humans.
Nonetheless, TCM treatment is based on a long-term process to restore the body's equilibrium and it is not a comparable scientific base. TCM has already been used in humans for millennia, therefore it would be better to focus on clinical development, instead of going back to animal models to gain evidence for a precise pharmacological profile. It would be better to study their efficacy by starting with clinical trials, while studies on mechanisms and active ingredients should be undertaken after efficacy has been confirmed.
||Garber K. Realistic rodents? Debate grows over new mouse models of cancer. JNCI 2006. 98(17), 1176-1178.
Compiled and edited by:
Jennifer Eagleton, BA, MA (Asian Studies), Integrated Chinese Medicine Holdings Ltd.
Stan Man, Integrated Chinese Medicine Holdings Ltd.