Endod: A Case Study of the Use of African
Indigenous Knowledge to Address Global Health
and Environmental Problems and Environmental Problems
Date: March 30, 1993
What Benefit for Ethiopia? New and Controversial Developments in
ENDOD: A CASE STUDY
This issue of RAFI Communique takes a look at the transfer of a Third World
technology to address a First World problem: the potential use of a traditional
African plant, Endod, to control the infestation of zebra mussels in North American
waters. The story of Endod offers a fascinating case study in the application (and
obstacles) to the use of a Third World technology to address global health and
The U.S.-based University of Toledo has applied for a patent on the use of Endod
to control zebra mussels, but royalties will not go to the plant's original
proprietors"--the Ethiopian people who have selected and cultivated Endod for
centuries. Nonetheless, if demand is created for Endod in the industrialized
world, will Ethiopian people benefit from their botanical treasure?
Endod (Phytolacca dodecandra), commonly known as the African soapberry plant,
is a perennial that has been selected and cultivated for centuries in many parts
of Africa, where its berries are used as a laundry soap and shampoo. Endod is
synonymous with "soap" in many African countries. People of the Ethiopian
highlands, for instance, use Endod berries to launder their traditional shamas,
the glistening white shawls characteristic of the region. The fish-killing property of
Endod is also well known and, traditionally, people in rural communities use
Endod as an intoxicant to collect edible fish.
ENDOD TO CONTROL SCHISTOSOMIASIS
In 1964, while conducting field work in his native Ethiopia, biologist Aklilu Lemma
observed that downstream from where people were washing clothes with the
soapberry plant, dead snails were found floating in the water. After several years
of intense research, Dr. Lemma discovered that the sun-dried and crushed Endod
berries were lethal to all major species of snails--but not harmful to animals or
humans, and completely biodegradable.
For Africa, where one of the most serious tropical diseases, schistosomiasis, is
transmitted by freshwater snails, the discovery of a low-cost and biodegradable
snail-killing agent (molluscicide) represents a major breakthrough. According to
the World Health Organization (WHO), schistosomiasis, a debilitating and
eventually fatal disease, is endemic in 76 countries in tropical Africa, Asia and
Latin America. Only malaria causes more sickness and debility in the developing
world. Over 600 million people are at risk of infection and another 200 million
infected. Some 200,000 deaths per year are due to schistosomiasis.
Although chemical molluscicides are available to eliminate the parasite-carrying
snails that transmit schistosomiasis, the cost is prohibitive. A chemical
molluscicide called Bayluscide, manufactured by the Bayer Co. of Germany, sells
for US $25,000-30,000 per ton. Despite the fact that this expensive chemical
compound is out-of-reach for many developing nations, it is the only molluscicide
currently recommended by the World Health Organization for global use.
Over the past 29 years Dr. Lemma's goal has been to develop Endod as a safe,
low-cost alternative to expensive chemical molluscicides. Early field trials in one
Ethiopian village showed remarkable success. Using locally-collected Endod to kill
target snails, transmission of schistosomiasis was reduced from 63% to 33% in
the overall population. Among children, the infection rate fell from 50% to 7%. In
addition to effectively controlling disease-carrying snails, Dr. Lemma views Endod
as a traditional African plant that can be developed as a capacity-building
technology by and for African communities. In the words of Dr. Lemma:
"Through the development and use of simple, appropriate agronomic techniques
and extraction and application procedures, people could easily grow, process
locally and use Endod products to control schistosomiasis on a community
With suppport from international donors, Endod has been the subject of
agrobotanical and extraction studies in Ethiopia, Zambia, Swaziland and
Zimbabwe. These countries have undertaken research on large-scale cultivation
of Endod, processing and distribution of the plant extract for the dual purposes of
producing a locally-available molluscicide, and as a detergent for village-level use.
In Ethiopia, with support from the Netherlands government, over 500 varieties of
Ethiopian soapberry plants were collected under the direction of Dr. Legesse
Wolde-Yohannes of the Addis Ababa University. Sixty-five varieties of Endod were
cultivated, and 3 selected for their exceptionally high molluscicidal potency and
high berry yields. One variety, E-44, was identified as the most promising
candidate for molluscicidal properties, and has since been cultivated on an
experimental basis. With support from the International Development Research
Centre (IDRC) of Canada, extensive toxicity studies of Endod have also been
Unfortunately, Dr. Lemma's 29-year quest to see Endod widely used in Africa has
been repeatedly stalled by international regulatory obstacles. Despite rigorous
toxicological studies performed by Lemma over the course of two decades, the
World Health Organization disregarded Lemma's research (and the traditional
wisdom of people who have used Endod for centuries), insisting that the scientific
analysis conducted in Ethiopia be repeated under standardized "Good Laboratory
Practices" by internationally-recognized institutions. Reflecting on lessons learned
from his long struggle to overcome obstacles to widespread acceptance of
Endod, Dr Lemma observes:
"We have learned the hard way that the root problems of scientific research in
Africa are not only the lack of adequate facilities and funds, but also the biases
and reservations of some individuals and organizations in industrialized countries
who find it difficult to accept that any good science can come from our part of the
world... Also, except for occasional lip service, little credit is given to the wisdom
of traditional societies in their ability to select, over long periods of time, such
natural products as Endod for their continued and demonstrably safe use."
Much needed and well-deserved support came to Dr. Lemma in 1989 when he
and his colleague, Dr. Legesse Wolde-Yohannes, were recipients of the Right
Livelihood Award. The "alternative Nobel prize" was awarded them for
discovering a natural molluscicide and devising a community-based method of
employing it against the snails that carry the schistosomiasis parasite. At long
last, WHO plans large-scale field tests of Endod in Africa later in 1993. If
successful, Endod may someday become widely available for the dual purposes of
providing a molluscicide to control the spread of schistosomiasis, and as a
detergent for village-level use.
ENDOD TO CONTROL ZEBRA MUSSELS
A New Use for a Traditional African Plant
In addition to the use of Endod to control the spread of a tropical disease
afflicting millions of people in the Third World, the traditional African soapberry
plant promises to become one of the most effective means of preventing zebra
mussels from clogging water intake pipes in North American waters. In other
words, a Third World technology comes to the rescue of industrialized nations.
Ironically, the need to de-clog mussel-infested water pipes may seem petty in
comparison to the value of controlling schistosomiasis, but the economic
incentives for controlling zebra mussels are enormous.
The black and white striped zebra mussel (Dreissena polymorpha) is native to
western Russia near the Caspian Sea. Zebra mussels were accidentally
introduced into the Great Lakes in 1985, and have rapidly spread throughout the
region. The zebra mussels are disrupting municipal water facilities because they
restrict water flow by attaching themselves to pipes and other hard surfaces. In
addition, they are a serious threat to fisheries because the mussels cover rocks
in spawning areas, and remove algae (a source of nutrients) from the water.
Municipal water plants and ship owners already spend millions to rid their pipes
of zebra mussels. The U.S. Fish and Wildlife Service estimated in 1990 that the
zebra mussel would create a $2 billion loss to fisheries by the end of the decade.
Nobody knows for sure how much damage the zebra mussels will cause, but the
potential damage is far greater now that the mussels have spread into inland
The discovery that Endod is lethal to the zebra mussel came about when Dr.
Aklilu Lemma visited the United States in June, 1990 to receive an honorary
degree from the University of Toledo. Lemma and his U.S. colleague, biologist
Harold Lee, raised the question in casual conversation, and then tested it in the
laboratory. The result: Endod is lethal to adult zebra mussels after 4-8 hours of
exposure, and is biodegradable within 24 hours. Safety of Endod has been
evaluated by a consortium of laboratories in Canada, the Netherlands, Denmark,
Ethiopia and in the USA.
In October, 1990, just a few months after Lee and Lemma first exposed zebra
mussels to the Endod powder in the laboratory, the University of Toledo applied
for a U.S. patent on the use of Endod to control zebra mussels. If a commercial
product is developed in the future, the University of Toledo will share 50% of the
royalties with the "inventors", Drs. Harold Lee and Peter Fraleigh of the
University of Toledo, and Dr. Aklilu Lemma, who is presently working with the
United Nations Children's Fund (UNICEF) in Uganda. According to Dr. Lee, several
companies have expressed interest in developing a commercial Endod product to
control zebra mussels, but he would not reveal their identities because
negotiations are still in early stages.
The application for a U.S. patent on Endod raises many questions about the true
"ownership" of Endod and the "discovery" of this traditional African plant as a
control for zebra mussels. This legal claim ignores centuries of indigenous
knowledge of Ethiopian people who have cultivated and selected Endod for
centuries, using it not only as a detergent and shampoo, but as a fish intoxicant.
If an Endod-based molluscicide is commercialized, the University of Toledo and
three scientists stand to benefit from royalties, but there is no guarantee that
the plant's true proprietors, the Ethiopian people, will be justly rewarded.
WHAT BENEFIT FOR ETHIOPIA?
If Endod is commercially developed as a molluscicide to control zebra mussels,
there would be immediate demand for large quantities of Endod berries. For
example, scientists at the University of Toledo estimate that treating a 100
million-gallon water treatment system at 5 parts per million for 8 hours would
require about 170,000 gallons of crude Endod extract. Rather than using Endod
in open waters, specialized reactor systems containing the Endod extract would
be placed at the entrance to water intake pipes.
According to Dr. Harold Lee of the University of Toledo, it is possible, but not
economically feasible to produce small quantities of the mussel-killing Endod toxin
in the laboratory using a technique known as "biosynthesis." However,
laboratory biosynthesis of Endod is far too expensive, and tremendous quantities
of the product will be needed for commercial use. Lee says that researchers in
the U.S. have made an "informal agreement" to buy raw materials of Endod
directly from Ethiopian sources.
Ideally, a new and substantial export market could be created in Ethiopia for
Endod as a raw material or processed product. The most potent variety of Endod,
the Ethiopian variety E-44, has already been cultivated on a large-scale by
Ethiopian researchers, yielding approximately 1.5 metric tons per hectare of the
berries. Under optimum conditions there can be two harvests of berries annually.
The outcome remains to be seen. Hopefully, Endod will become a positive
example of a sustainable technology for both First World problems and Third
NEW AND CONTROVERSIAL DEVELOPMENTS IN INTELLECTUAL PROPERTY
Agracetus Inc. (Middleton, Wisconsin, USA), a subsidiary of W.R. Grace and Co.,
has received a broad-based patent covering all genetically-engineered cotton
products. The unusually broad scope of coverage is unprecedented in plant
biotechnology and "may be an indication of how major corporations can use
biotech patents to get proprietary control of huge segments of agriculture"
(AgBiotechnology News, December 1992). Because it was first to develop
transgenic cotton, Agracetus claims rights to any and all transgenic cotton,
regardless of which engineering technique is used. All transgenic cotton products
will have to be licensed through Agracetus before they can enter the
Another broad-based patent was recently granted to Plant Genetic Systems
(PGS) of Belgium. The U.S. Patent covers many plants and seeds genetically
engineered with Bacillus thuringiensis (Bt) genes. According to PGS, it was the
first to demonstrate that Bt genes could be engineered into plants and,
accordingly, any company that genetically engineers Bt into most plant crops will
need to negotiate a licensing agreement with PGS (AgBiotechnology News,
(1) Lee, Howard and A. Lemma, H. Bennett, 1993, "Towards Control of Zebra
Mussels: The Use of Endod, (Phytolacca Dodecandra)" in Zebra Mussel: Biology,
Impact and Control, eds. T.F. Nalepa and D.W. Schloesser.
(2) Lemma, A., "Overcoming Obstacles to Science from the Third World: The Story
of Endod", a paper presented at the Biology Department of the University of
Toledo, Toledo, Ohio, on 15 June 1990.
(3) "Common African Plant Could Control Zebra Mussels", Press Release from
Office of Public Information, University of Toledo, October 15, 1990.
(4) Ohio Sea Grant, 1990, "Zebra Mussel Update," in Twine Line, February, p.3.
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