Issues Magazine

Research into Traditional Medicinal Plant Research

By Subramanyam Vemulpad and Joanne Jamie

A Macquarie University research group has been building partnerships with indigenous Australians to preserve their unique medicinal plant knowledge and to identify natural medicinal agents.

New Medicines from Nature

Infection and disease have been an integral part of human development. It is only logical that humans have turned to nature in their fight against them. All forms of life (microbes, plants and animals) are known to produce a variety of metabolic products (natural products) on which we base the majority of our current medicines.

Despite the importance of natural products as medicines, during the 1980s and 1890s major pharmaceutical companies either terminated or scaled down their natural product isolation operations. Instead, many focused on drug discovery using combinatorial chemistry, a synthetic technique developed in the 1980s for generating vast libraries of molecules that can be screened for biologically active substances. However, combinatorial chemistry failed to live up to expectations.

This decrease in newly synthesised medicines and the threat of emerging diseases and of potential global threats such as drug-resistant microbes, SARS and avian influenza, has led to a renewed interest in research into discovering new drugs derived from natural products. Compounds with intricate structures that are otherwise difficult to obtain by synthesis are also produced in nature. This includes taxol and artemisinin, which are among the most important current treatments for cancer and malaria, respectively.

The use of plants as medicine can be traced to the beginning of human civilisation. Natural products derived from plants are the origin of many of our current pharmaceuticals. Plants are also used as the primary medicine source for up to 80% of the world’s population, which has no access to modern primary health care. According to Ilya Raskin and colleagues in 2002 (Trends in Biotechnology), even the remaining 20% of the world’s population has extensively used herbal neutraceuticals, with global sales exceeding US$15 billion.

According to Robert Verpoorte (Journal of Pharmacy and Pharmacology), in 2000 only 6% of the 250,000 plant species worldwide had been investigated for biological activity. This is evidence that the world’s natural library of compounds is by no means exhausted.

Various approaches to accessing useful plant products for medicines have been enlisted. These include random screening, chemotaxonomic and ethnobotanical approaches .

Issues with an Ethnobotanical Approach

Indigenous medicinal plant knowledge is being lost all over the world, including in Australia, as a result of untimely deaths of the traditional custodians of that knowledge and acculturation of indigenous peoples due to their modernisation or “westernisation”. Given that the majority of plant-based medicines have arisen from indigenous knowledge systems, the disappearance of this information would be a significant loss to the wider scientific community. The World Health Organization (WHO) and governments, including the Australian government, acknowledge the value of traditional medicinal knowledge, and protection and preservation of these knowledge systems is an objective of many of them.

Governments, private industry and scientists have shown unprecedented interest in indigenous medicinal knowledge in the past decade, especially due to the search for new medicines. In some cases, the medicinal knowledge of the world’s indigenous people has been treated as a resource to be exploited. The Convention of Biological Diversity recognises the importance of indigenous rights, ensuring the results of research and development and benefits are shared in an equitable way.

Ethnobotanical research therefore requires the research community to engage with indigenous people in a spirit of cooperation, consultation and support. For this to occur, researchers must follow best practice by conforming to rigorous ethical principles and developing relationships of trust with individual indigenous communities.

To abide by these international guidelines, scientists need to have sufficient time and commitment for negotiations with indigenous people and the development of benefit-sharing schemes. Due to this major commitment needed and often limited funding for the relationship-building component of ethnopharmacological studies, pharmaceutical companies tend not to conduct such research and some scientists only investigate traditional medicines already reported in the public domain, avoiding the need to collaborate directly with indigenous communities.

Indigenous Bioresources Research Group Initiative

The Indigenous Bioresources Research Group (IBRG) at Macquarie University is a multidisciplinary team directed by a medical micro-biologist (Dr Subra­manyam Vemulpad), medicinal chemist (Assoc. Prof. Joanne Jamie), ethnobotanist (Assoc. Prof. Jim Kohen) and bioinformatician (Prof. Shoba Ranganathan). Its major objectives are to systematically document first-hand traditional medicinal plant knowledge of indigenous people using best ethical practices and to apply this knowledge to identify medicinally important compounds following targeted chemical and biological studies.

IBRG began working with the Yaegl and Bundjalung elders of northern NSW 5 years ago following requests by elders from these communities for IBRG to assist in the documentation of their medicinal plant knowledge and assessment of the medicinal value of these plants. The elders have considerable knowledge of medicinal plants, having used them throughout most of their lives, following the transmission of this knowledge orally from their elders and generations before them. They have especially used plant preparations topically for treatment of conditions indicative of microbial infections.

To document the medicinal plant information, IBRG interviews elders with specific knowledge of medicinal plant use. The information collected includes the botanical and Aboriginal names of the plants; what stages of growth and what parts of the plants are used; the use and preparation in the literature (if any); and, most importantly, the way of preparation and application of the remedy by the communities.

Crude extracts of medicinal plants are then assayed by the IBRG team in a manner relevant to their medicinal use (as determined from the ethnobotanical data). For example, the preparation is tested for antibacterial activity if it is used to heal a bacterial infection. Subsequent bioassay-guided purification is then undertaken to isolate the biologically active extracts or compounds of the most active crude extracts.

By assessing the effectiveness of the traditional medicinal plant remedies in treating particular ailments, this project will allow health workers to provide informed advice about a traditional remedy, such as whether it will be sufficient to cure a particular condition or whether it should be used in conjunction with a western remedy. This is important because some indigenous community members, particularly the elderly, are reluctant to use health services and access to some western medicines is limited. Positive cultural outcomes can also occur when traditional plant knowledge is maintained and passed on and where health services respect indigenous modes of practice.

The information gathered by IBRG from the communities and augmented by literature searches and bioactivity assays is transferred back to the communities in the form of community-specific, easy-to-update databases. The databases also serve as a vital repository of cumulative knowledge and as an educational aid for Aboriginal school children and future generations. Because these databases reflect the customary knowledge of the communities, they are password-protected and access privileges are determined in consultation with the communities.

True Partnerships with Indigenous Communities

IBRG follows the principles of the Convention of Biological Diversity along with the stepwise Participatory Action Research Methodology of UNESCO and the ethical guidelines of the National Health and Medical Research Council for conduct of research with indigenous people. When an Aboriginal community or organisation expresses interest in working with IBRG, human ethics approval is obtained from Macquarie University to engage in further discussion aimed at establishing a cooperative relationship. A member of IBRG then visits the local community or Aboriginal organisation. Important issues, such as who is the appropriate authorising body and which elders should be consulted, are clarified.

All Aboriginal participants are invited to participate in all aspects of the project to play an integral role in its direction. A collaborative agreement, detailing the roles and responsibilities of all groups, is then signed by both Macquarie University and the authorising Aboriginal body. The agreement includes recognition of ownership of the customary knowledge by the communities and joint ownership of any subsequent intellectual property from the research, co-authorship of published materials and the necessity to provide benefits back to the communities.

Benefits and Outcomes

Tangible benefits to the communities have included employment and training opportunities for Aboriginal people (for example in documentation and field work), development of bush and food medicine gardens and, following specific requests of elders, the establishment of the Indigenous Science Education Program to increase the motivation of indigenous youth to complete their high school studies.

This research conserves Australian Aboriginal knowledge of historical, cultural and scientific significance and applies this knowledge to the discovery of new medicines, including those that may help address the growing need for new antimicrobial treatments. The Genetic Resources Management Section of the Australian Government has proposed to advocate this model for collaboration between Australian Aboriginal communities and research scientists.

IBRG has received support from Macquarie University to assist the development of the collaborative partnerships as well as the scientific endeavours, prior to obtaining external funding, initially from the Australian Institute of Aboriginal and Torres Strait Islander Studies and in 2008 from the National Health and Medical Research Council. IBRG is indebted to the communities of Yaegl and Bundjalung country for allowing us to work with them.