The Case of a Tropical Disease and Its Treatment by Santanello and Rehg

Part IV—Quest for a New Treatment*

The indigenous peoples of Costa Rica were no longer the only ones who were knowledgeable about the potentially useful properties of gavilana, or Neurolaena lobata, in treating Chagas disease. As it so happened, an ethnobotanical anthropologist who had been working with one group of Guaymi in Costa Rica for the last several years had collected detailed data on this group’s use of medicinal plants. Dr. Allison Woodrow’s data included interviews with Guaymi curanderos indicating that N. lobata and several other local plants were used to treat a variety of illnesses that induce fever. In particular, N. lobata was used to treat a condition that sounded similar to Chagas disease, including the symptom of eyelid inflammation.

A multinational pharmaceutical company based in the United States, Alpha Pharmaceuticals, continuously monitored ethnobotanical research. They were aware that approximately 25% of pharmaceuticals developed are based on natural products, primarily plants. A research and development employee discovered one of Dr. Woodrow’s publications listing medicinal uses of plants by the Guaymi. The company decided to pursue research on the pharmacological properties of this and other plants used by the Guaymi.

The pharmaceutical company had a standing agreement with the National Biodiversity Institute (INBio) in Costa Rica, such that INBio researchers and scientists could collect samples of natural materials (mainly from plants) in Costa Rica and provide these samples to Alpha Pharmaceuticals. Although INBio was a private organization, it could collect materials from public lands, incuding some forest reserves. Alpha Pharmaceuticals had arranged to pay INBio a set amount for thousands of plant samples, including specimens of N. lobata; however, any financial gains made from the development of useful products would belong only to Alpha Pharmaceuticals. The company planned to invest millions of dollars to test hundreds of plant species against many ailments, from influenza to cancer, to see if there were pharmacologically active properties in the plants that could be developed into marketable medications. If N. lobata could be developed into a treatment for Chagas disease, the company would market it throughout Central and South America at prices competitive with benznidazole and nifurtimox. With millions of infected individuals in this region, the company could make a good deal of money.

Background

Read Berger et al. (2001) regarding scientific studies of Neurolaena lobata (gavilana) and its effects on protozoan diseases like Chagas disease.

Questions

How does research on the potential effectiveness of N. lobata to treat Chagas disease follow the scientific method?
Based on this reading, compare what is known regarding the effectiveness of treatment of Chagas disease with N. lobata and what is known regarding the effectiveness of nifurtimox or benznidazole.
What additional research would be necessary to develop a marketable treatment for Chagas disease based on N. lobata? (See study by Cavin et al., 1987 for a possible model.)
If a drug based on N. lobata becomes popularly recognized as the drug of choice in the treatment of Chagas disease, what are some of the potential consequences to the status of this plant in natural environments?
Specifically, who will be harvesting the plant?
What are the possible effects of intensive harvesting of the plant on the environments in which it exists?

References

Berger, I., A.C. Barrientos, A. Cáceres, M. Hernández, L. Rastrelli, C.M. Passreiter, W. Kubelka. 1998. Plants used in Guatemala for the treatment of protozoal infections, II. Activity of extracts and fractions of five Guatemalan plants against Trypanosoma cruzi. Journal of Ethnopharmacology 62:107–115.
Berger, I., C.M. Passreiter, A. Cáceres, and W. Kubelka. 2001. Antiprotozoal activity of Neurolaena lobata. Phytotherapy Research 15:327–330.
Biswal, M. and D. Biswal. 2003. Issues relating to traditional knowledge systems and intellectual property rights (IPRS). XII World Forestry Congress, Quebec City, Canada.: http://www.fao.org/DOCREP/ARTICLE/WFC/XII/0911-A3.HTM. Accessed on Oct. 17, 2006.
Cavin, J.C., S. M. Krassner, and E. Rodriguez. 1987. Plant-derived alkaloids active against Trypanosoma cruzi. Journal of Ethnopharmacology 19:89–94.
Grajal, A. 1999. Biodiversity and the nation-state: Regulating access to genetic resources limits biodiversity research in developing countries. Conservation Biology 13(1):6–10.
Kate, K.T. and S.A. Laird. 2000. Biodiversity and business: Coming to terms with the “grand bargain.” International Affairs 76(1):241–264.
Merson, J. 2000. Bio-prospecting or Bio-piracy: Intellectual property rights and biodiversity in a colonial and postcolonial context. Osiris 15:282–296.
Rodríguez, S., and M.A. Camancho. 2002. Bioprospecting in Costa Rica: Facing new dimensions of social and environmental responsibility. In: Petter Utting (ed.) The Greening of Business in Developing Countries: Rhetoric, Reality and Prospects. Zed books—UNRISD. London. Pps. 58–74.
Roopnaraine, T. 1998. Indigenous knowledge, biodiversity and rights. Anthropology Today 14(3):16.

*Note: This part of the case asks students to explore the ramifications of a fictional agreement between INBio and the fictional company Alpha Pharmaceuticals using the actual Merck-INBio agreement as a model. Also, although the Guaymi and Bribri are indigenous peoples of Costa Rica and there has been ethnographic research on the Guaymi and Bribri and their use of plants, the specific information and use of plants attributed to these indigenous peoples described herein is completely fictitious.

Originally published at http://www.sciencecases.org/chagas/chagas4.asp