Ethnopharmacology: From Folk Use to Drug Discovery

What ethnopharmacology is

Ethnopharmacology is the study of traditionally used natural products and their biological activity. [1] Researchers read records of traditional use, test the plants in the laboratory, isolate active compounds, and then, if a compound looks promising, test it in animals and people. The step from folk use to a medicine is long and most leads do not make it. This page describes what has happened, with careful framing. The records come from ethnobotany; see how plant knowledge is recorded.

Traditional use as a starting point

A review of ethnopharmacology and drug discovery says that descriptions of the use of natural products in traditional medicine have served as starting points for new therapeutics. [2] The same authors say that details such as traditional harvest, preparation, storage and administration can give valuable information about the active compounds. [2]

Natural products more broadly matter to medicine. A long-running review of drugs approved from 1981 to 2019 found that the influence of natural product structures is quite marked, with the anti-infective area especially dependent on them. [3] That review counts natural products and their derivatives, not only those with a traditional use history.

Worked example: artemisinin

The Nobel Prize committee describes how Tu Youyou in China turned to traditional herbal medicine to tackle the challenge of developing novel malaria therapies. [4] An extract of Artemisia annua emerged as an interesting candidate. [4] Results were inconsistent, so she revisited the older literature, found clues that guided her, and went on to show that the purified component, artemisinin, was highly effective against the malaria parasite. [4]

The lesson is about method. The tradition suggested where to look. The proof came from isolating the compound and testing it. A tea made from the plant is not the same product as the purified drug. For more, see drugs with traditional origins.

Why most leads do not become treatments

Reviewers of ethnobotany-guided discovery note that there has been a sharp decline in the ability to translate laboratory research into successful clinical programs. [1] Evidence labels help here:

A headline saying a herb "kills cancer cells in a dish" is preclinical. It is not a treatment, and it is not advice to take the herb.

Example: from folk use to a product, with limits

Pelargonium sidoides is described as one of several tuberous Pelargonium species that are important traditional medicines with a rich ethnobotanical history, and the review credits convincing proof of concept among the elements of its success as a commercial phytomedicine. [6] A Cochrane review of the extract rated the evidence as low quality for main outcomes in acute bronchitis in children and adults and very low for acute sinusitis and the common cold, and found adverse events more common with the extract, none serious. [7] So a commercial success and a trial record are two separate things. Read more at Devil's claw and Pelargonium.

Bioprospecting, consent and sharing benefits

Bioprospecting, also called biodiversity prospecting, is the seeking and documenting of traditional medical knowledge or the biodiversity it is attached to, and its conversion into a commercial product. [8] Reviewers of large programs say agreements need to address genetic access, prior informed consent, intellectual property and the sharing of benefits. [8] Critics describe cases in which patenting by corporations disregarded the ownership of knowledge held by indigenous communities. [9] The same ethnopharmacology review warns that this resource is threatened by the loss of traditional medicine knowledge and extinction of organisms. [2] See traditional knowledge protection and biopiracy and cultural appropriation and traditional healing products, where the community side is covered.

The Nagoya Protocol, in force since 12 October 2014, concerns fair and equitable sharing of benefits from genetic resources. [10] Researchers working with communities are expected to obtain educated prior informed consent before research begins. [11]

What this means for you

A drug discovered from a plant is made, tested and dosed as a medicine. Using the raw plant is not the same, and a herb may differ in content, strength and interactions. Do not replace or stop prescribed medicine on the basis of a discovery story. Ask a clinician or pharmacist about any herbal product you use. [12] For research summaries, see the therapies research and evidence.