The use of plants, animals, mineral substances and other natural materials in traditional medicine by indigenous peoples, throughout the world and across time, is a well documented practice. Although plants and plant-derived materials constitute the principal source of ingredients for traditional medicine, the identification of animal resources for medical cures is also important [1, 2].
Animal-based medicines can be prepared from the entire animal, from parts of the animal's body, from products of its metabolism (body secretions and excrement), or from other materials related to animals (nests and cocoons) . The practice that uses animal or animal-derived products in human healing is known as zootherapy , according to the zootherapeutic universality hypothesis , zootherapy is widespread across most human cultures [5–8]. Traditional medicines use animal or animal-derived products from all taxonomic groups like echinoderms, insects, arthropods, reptiles, birds and mammals [9, 8, 10, 11]. For example, in Sudanese traditional medicine fresh manure of a dromedary (Camelus dromedaries L. 1758) is used to alleviate arthritis ; in Nigeria, the hippo tusks (Hippopotamus amphibious L. 1758) are used as an aphrodisiac, the fat extracted from a manatee (Trichechus senegalensis Link 1795) is used to cure rheumatism, boils and backache ; in China, earthworm extract is prescribed to treat over 80 diseases like asthma, hypertension, ulcers, and epilepsy among other things .
The use of arthropods in traditional medicine is also widespread. In Chhattisgarh (India) over 500 insects, mites and spiders have been reported as useful to medicine to cure common and complicated ailments. For example, the red velvet mite (Trombidium grandissimum Koch 1867) is commonly used for paralysis, the bed bug (Cimex lectularius L. 1758) is used in the treatment of epilepsy, piles, alopecia and urinary disorders . In different ethnic communities of India, 22% of the animals reported in traditional medicine (of a total of 109) are invertebrates used for diseases like asthma, tuberculosis, coughs and colds . In northeast Brazil, the use of insects is common in medicine (14% of the listed medicinal animals in this region) principally for asthma, pneumonia, sinusitis, and coughs . In the region of Chiapas (Mexico), 12 insects (16% of the animals listed) are used in the traditional medicine of the Mayan communities to cure coughs, warts and stammering .
A common use of spiders by man, in addition to keeping tarantulas as pets, is their consumption as food. In Cambodia, it is traditional to eat fried tarantulas (Haplopelma albostriatum Simon 1886: Aranea, Theraphosidae), and the Piaroa Indians of Amazon eat the Goliath bird-eating tarantula (Theraphosa blondi Latreille 1804) to become better hunters. The use of spiders in traditional medicine is very little documented. It was cited in India by Oudhia  and reported by Lev  with the use of crab spiders for healing in medieval times. Unfortunately, no details of spider species or their uses in traditional medicine are provided. A few other works report the use of spiders in medicine; in Brazil, Costa-Neto  reported the use of the chelicerates from the Goliath bird-eating tarantula to treat 'erysipelas' (or 'Holy fire'), fortification of teeth and asthma, and Costa-Neto and Resende  reported, in the city of Feira de Santana (Bahia State), the use of toasted bird-spider (referred to as mygalomorphs spp.) for sufferers of asthma; in Chiapas, Enríquez Vázquez  mention that Tzotziles and Tzetzales ethnic groups use a 'big spider' in their medicine and, Hunn  describes the use of a tarantula also in Chiapas (Mexico) to treat tumors, the patient being bitten in the affected zone. In this case, we may suspect that the tarantula in question is the Mexican redrump tarantula (Brachypelma vagans Ausserer 1875), as it is the only one known to occur in this area .
The use of tarantulas throughout the world is often to treat asthma-like conditions as mentioned above. Various species of tarantulas were used to treat the diseases and many themselves provoke asthma following the inhalation of tarantula hairs [18, 19]. The most likely hypothesis to explain the role of tarantula setae in the asthma reaction is the action of the chitin particles [for more details of the mechanism of action see: 20,19].
Mexican redrump tarantula
The genus Brachypelma (Mygalomorphae: Theraphosidae) comprises 21 species, registered in the CITES data base; among them, 14 occur in Mexico. The limited geographic distribution of this genus, the destruction of its habitat by landscape fragmentation, the high mortality rates in juveniles, the late age of sexual maturity (7-8 years for males, 9-10 years for females), and their high value in the pet trade, make all species of Brachypelma endangered [21, 22] and therefore listed in appendix II of CITES since 1995.
Brachypelma vagans, commonly known as the Mexican redrump tarantula, has the widest distribution, being reported in the South of Mexico, Belize, El Salvador, Guatemala, Honduras and Costa Rica . However, it has also been recorded in the wild in Florida , as trade has promoted its dispersion out of its natural range. This species is big, conspicuous and very abundant in some parts of the study area . Recent ecological studies [24, 25] show the close relation between the presence of B. vagans tarantulas and the traditional Mayan villages in the peninsula of Yucatan (Mexico). This relation is also common in Chiapas (Mexico) under similar conditions (unpublished data). The tarantulas are present and numerous in the center of the villages, in an open place used as a football or volley ball field and particularly for school activities, and in the backyards of the surrounding houses with 0.02 to 0.1 individuals per square meter [24, 25]. A genetic study indicated that the Mexican redrump tarantulas occur in populations with a high number of related individuals. Each population is also genetically characteristic of each village where they are found . These results seem, to confirm the probable relationship between the human populations of this region and the presence of B. vagans.
The Choles are indigenous peoples living in southeastern Mexico, mainly in the highland of Chiapas (named 'Los Altos'). After their rebellion (18th century), with other Mayan ethnic groups (Tzoltziles and Tzeltales) in opposition to the Spanish colonial invasion, the Chol community settled mainly at the borders of the rainforest in Palenque, Tila, Tumbalá and Bachajón in Chiapas and Retalhuleu in Guatemala. Now, the two major communities of Chol are in Tila and Tumbalá.
The main economic activity is agriculture especially corn and beans ('frijol'), as well as sugar cane, rice, coffee, and various fruits. The Choles call themselves 'Winik', a Mayan word that means 'man or male'. They are the 'milperos' which refers to the people whose lives and existence have revolved around the cultivation of maize, their most sacred food. The Chol culture is very rich in traditional medicine. The medicine man, or 'hierbatero', plays a fundamental role in the community, not only as a doctor but also as a friend, psychologist, confessor, and re-establisher .
In the unusual 1921 Mexican census, residents of each state were asked to classify themselves in several categories, including pure indigenous, indigenous mixed with white and white. Chiapas State had a total of 98105 persons (five years of age and older) speaking at least twenty-five indigenous languages, representing 27.4% of the over 5 state population. The Chol language was spoken by 10.5% (10330 speakers) of those using indigenous languages in 1921. According to the 2000 census, the population of persons, five years old and more, who spoke indigenous languages amounted to 809592 individuals in Chiapas of which the Chol language represented 17.4% (104806 speakers) .