title: This plant treats that illness? The hot-cold system and therapeutic procedures mediate medicinal plant use in San Miguel Tulancingo, Oaxaca, Mexico.
abstract: BACKGROUND
  Understanding the reasoning behind the choice of medicinal plants is relevant for both pharmacological and ethnobotanical quantitative studies. In this study, we analyze how the traditional medical system influences the choice of medicinal plants in a Mexican indigenous population.
  
  
  METHODS
  The study area was San Miguel Tulancingo, Oaxaca, Mexico, and the studied people the Rru ngigua (or Chocholtecs), an Otomangue group with only a few hundred speakers remaining. Through in-depth and repeated interviews of four traditional healers and ethnobotanical collections, we identified, described and classified the medicinal plants, the nosological units, the therapeutic procedures and the reasoning behind medicinal plant and treatment choice.
  
  
  RESULTS
  The hot-cold system, which considers illness to be a result of humoral imbalance, strongly influences treatment choice. "Hot" plants are used mainly to treat "cold" diseases, and vice versa. With some variation, plants are selected mainly for this hot-or-cold property, and the specific plant species is often not very relevant. In addition, many plants are associated with specific healing procedures, such as sweat baths. The procedures, in turn, may be used to treat various diseases.
  
  
  CONCLUSIONS
  The study shows that the relationship between medicinal plants and treated diseases is complex and indirect in most cases. It is strongly influenced by the hot-cold concept and by therapeutic procedures.
authors.affiliation: Laboratorio de Etnobotánica, Postgrado en Botánica, Colegio de Postgraduados, 56230 Montecillo, Texcoco, Estado de México, Mexico. Electronic address: ky_gahe@hotmail.com.
authors.forename: Karina Yaredi
authors.initials: KY
authors.lastname: García-Hernández
authors.affiliation: Laboratorio de Etnobotánica, Postgrado en Botánica, Colegio de Postgraduados, 56230 Montecillo, Texcoco, Estado de México, Mexico. Electronic address: heike@colpos.mx.
authors.forename: Heike
authors.initials: H
authors.lastname: Vibrans
authors.affiliation: Centro de Investigación en Etnobiología y Biodiversidad, Universidad Autónoma Chapingo, 56230 Chapingo, Texcoco, Estado de México, Mexico. Electronic address: marydesierto@hotmail.com.
authors.forename: María
authors.initials: M
authors.lastname: Rivas-Guevara
authors.affiliation: Herbario del Instituto Mexicano del Seguro Social, 06725 Mexico D.F., Mexico. Electronic address: herbarioimss@yahoo.com.mx.
authors.forename: Abigail
authors.initials: A
authors.lastname: Aguilar-Contreras
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008519:Medicine, Traditional; D008800:Mexico; D008517:Phytotherapy; D010946:Plants, Medicinal; D013696:Temperature
keywords: Chocholtecs; Meso- and South America; Selection of medicinal plants; Theories of illness; Therapeutic procedures; Traditional medicine