Traditional medicine (TM) is making dramatic comeback. Majority of people affected rely on TM mainly because it is relatively affordable and available to the populations who cannot afford orthodox medicine. TM is widely practiced in several parts of the world and notable systems include traditional Chinese medicine (TCM), ayurveda or traditional Indian medicine (TIM) and traditional African medicine (TAM). With drug resistance posing challenge to the scientific community, TM is right option for exploring novel chemical entities (NCE). Although there have been calls for TM to be incorporated into the healthcare system, less emphasis has been placed on ethical and regulatory issues. With increasing demand for TM, statuary bodies have been established for governing quality control, assurance and sales of TM. Besides, new discipline of phytopharmacovigilance is emerging. When it comes to opportunities, TM in strict sense represents reverse pharmacology (RP). Research in TM on basis of RP has yielded several investigational drugs for degenerative and auto-immune diseases.
Traditional medicine best describes systems of medicine on cultural, beliefs and practices handed down from one generation to another generation. The concept includes mystical and magical rituals, herbal medicine and other treatments which may not be explained by modern medicine. TM in true sense does not fall within the preview of conventional medicine. TM is widely practised in several parts of the world, but TCM, TIM, TAM, traditional unani medicine (TUM), acupressure, homoeopathy and western medical herbalism represent well identified systems of TM. Recently, various systems of TM have been included under complementary and alternative medicine (CAM).
TM is an integral part of human healthcare in several developing countries and also in developed countries, increasing their commercial value. In Africa, up to 80 per cent of the population uses traditional medicine for primary healthcare. Although use of various systems of TM in therapy has been well known for centuries in all parts of the world, the demand for TM, particularly TCM and TIM, has grown dramatically in recent years.
The world market for TM has reached US $60 billion, with annual growth rate between 5 per cent and 15 per cent. Industry has also invested millions of US dollars looking for promising medicinal herbs and novel chemical compounds.
The legal status regarding TM varies from country to country. In countries like India and China, TM is well established, whereas in other countries they are regarded as food and hence no therapeutic claims are allowed. Developing countries, however, often have a great number of traditionally used drugs and its folk have knowledge about them, but hardly have any legislative criteria to establish these traditionally used systems of medicines as part of drug legislation. Where herbal medicines and related products are neither registered nor controlled by regulatory bodies, a special licensing system is needed, which would enable health authorities to screen the constituents, demand proof of quality before marketing, ensure correct and safe use, and oblige licence holders to report suspected adverse reactions within a post-marketing surveillance system.
The World Health Organisation (WHO) launched its first ever comprehensive traditional medicine strategy in 2002. The strategy is designed to assist countries to:
● Develop national policies on the evaluation and regulation of TM/CAM practices
● Create a stronger evidence base on the safety, efficacy and quality of the TAM/CAM products and practices
● Ensure availability and affordability of TM/CAM, including essential herbal medicines
● Promote therapeutically sound use of TM/CAM by providers and consumers
● Document traditional medicines and remedies
TM, including phytomedicine, has gained an enormous increase in popularity over the past years. Many are turning to phytomedicine to compliment or substitute mainstream medicine. Scientific evidence from randomised clinical trials is only strong for several uses of acupuncture, some herbal medicines and some of the manual therapies. Further research is needed to ascertain the efficacy and safety of several other practices and TM. Unregulated or inappropriate use of traditional medicines and practices can have negative or dangerous effects. For instance, the herb "Ma Huang" (Ephedra) is traditionally used in China to treat respiratory congestion. In US, the herb was marketed as a dietary aid, whose over dosage led to at least a dozen deaths, heart attacks and strokes.
TM is definitely making a dramatic comeback. Studies done across the world have demonstrated increasing awareness about herbal medicine among the general population. Several factors are responsible for the comeback of herbal medicine. Drug resistance seems to be the prime cause. Cost-effectiveness is another factor where herbal drugs score over synthetic drugs. The efficacy of some herbal products is beyond doubt, the most recent examples being artemisia annua (i.e., artemesinin: wormwood derivative used to target cancers), silybum marianum (i.e., silymarin: seeds of the milk thistle effective in treating diseases of the liver) and taxus brevifolia (i.e., taxols: pacific yew derivative that exhibits antimitotic activity and is used for treating refractory tumors).
TM has definite role to offer to modern science. Medicinal plants are significant source of drugs and new chemical entities (NCEs). Phytochemistry (chemical composition) and phyto-pharmacology are rapidly making progress as far as research and development is concerned. In our view, medicinal phytochemistry should be a distinct subject in syllabus of herbal medicine. Several phytochemicals have been isolated from medicinal plants and screened for applied research. Several companies maintain natural products libraries. Drugs derived from herbal source can play a significant role in future healthcare system, keeping in mind emergence of drug resistance.
Herbal drugs are cheaper, if readily available. Several drugs have been synthesised from intermediates obtained from plant source. Bromhexine was derived from alkaloid vasicine isolated from adathoda vasica nees. The drug is popular antitussive (cough-suppressant). Herbal remedies, if purified according to methods mentioned in pharmacopeias and prepared according to the drug formulary, are relatively non-toxic. It is generally understood that herbal remedies are benign and free from side effects. However, evidence suggests that herbal remedies may pose side effects, if consumed without professional advice. With onset of scientific research in herbal medicine, data for side effects of herbal is accumulating. Based on herbal clinical practice, it can be said that side effect profile of herbals is however less as compared to synthetic drugs.
At the same time, the old sayings like 'herbal drugs are safe and can be consumed over a period of time without side effects,' must be disputed. Herbal-synthetic drug interactions are major challenge for practitioners. Hepatotoxicity and nephrotoxicity associated with certain medicinal herbs pose major health problem. Post-operative bleeding associated with herbal remedies is another cause of concern. It can be said that there is rise as well as fall in popularity of herbal medicines in recent times. Extracts/drugs prepared from medicinal plants having definite mechanism of action are respected among allopathic physicians. Herbal drugs are of much value in chronic and degenerative ailments of the body. There are several reports that some patients, after utilising herbal formulations over a period of time feel that they are therapeutically useless. In our view, there is an obvious difference between rigorously researched product and cheaply/unethically promoted product.
Several authors have reported favourable results with herbal drugs (mostly in form of extracts) either in animal or in human studies. ginkgo biloba L., echinacea purpurea L., hypericum perforatum L. and cimcifuga racemosa (L.) nutt., were subjected to clinical trials. Some studies reported usefulness of these herbal drugs. On the other hand, some trials reported failure of the same drugs. Several studies reported lack of efficacy of echinacea in the treatment of common cold. This drug once upon a time was popular treatment for common cold but soon it vanished from the stores. Same was the fate of ginkgo biloba (used for tinnitus and amnesia) and cimicifuga racemosa (used for hot flashes).
Hypericum perforatum was, however, an exception. In 1787, clinical studies were done on this plant and the results showed that this plant was effective in the treatment of mild to moderate depression. In Germany alone, the sale of hypericum perforatum was 20 times more then fluoxetine, the standard antidepressant. Soon, other uses of the plant were discovered as a result of the antiviral activity of hypericin, a red dye found in petals. Synthetic hypericin was synthesised and subjected to clinical trials for treatment of AIDS. Further research highlighted hyperforin as antidepressant principle of the plant. Soon hypericum perforatum magic started fading as heavy drug interactions were reported.
It is difficult to understand why studies done prior to 2000 never reported serious drug interactions with hypericum perforatum. Following that year, there were endless reports of drug interactions between hypericum perforatum and synthetic drugs. These types of studies (either authentic or vague) only created confusion, if somebody is interested in herbal prescription.
Silybum marianum L., the reputed hepatoprotective, has remained a golden standard in the treatment of liver ailments. Several years have passed but status of this herbal drug remains unquestioned. In India, a study reported that picrorrhiza kurroa royle is more potent than silybum marianum as hepatoprotective agent (however, this study is not complete in all aspects). If the results of the study were true, then more clinical trials were warranted with picrorrhiza kurroa.
Commiphora mukul (gugul) has been widely used as anti-inflammatory and anti-arthritic agent in ayurveda. Several animal studies have reported anti-inflammatory activity of guguulsterones, the active constituents.
Keeping in mind the latest trends in TM, there is a need for making forums and discussion groups among researchers and physicians. Complete studies should be done on reputed herbal drugs and then they should enter the market. This will not eliminate the uncertainty among physicians who are at stake while prescribing herbal drugs. FDA and WHO should ensure that bogus agenda against herbal drugs is not addressed. A blueprint indicating clinically efficacious TM drugs should be prepared.
(The author is senior lecturer with Dept. of Ayurvedic Pharmaceutical Sciences, Lovely Professional University, Punjab)