Ethnobotany in a Modern City: The Persistence in the Use of Medicinal Plants in Guadalajara, Mexico

The traditional use of medicinal plants around the world has a long history, predominantly in low- and middle-income countries. Previous ethnobotanical research pertaining to urban environments demonstrated that the legacy of the use of medicinal plant species persists worldwide; however, information about the main city in the occidental part of Mexico is scarce regarding this traditional knowledge and its variation during the last few decades. A database was created from interviews with local people who had inhabited the oldest neighborhoods of Guadalajara for at least 30 years and by using different electronic databases. In addition, the correct taxonomic identification of species was supported via corroboration through local and other digital herbariums. Furthermore, a Principal Coordinate Analysis (PCoA) was performed on the database information to search for relationships among the medicinal plant species used. An inventory of 137 medicinal plants was created, where the plant species most commonly used in the five old neighborhoods of Guadalajara City were muicle (<i>Justicia spicigera</i> Schltdl.), pirul (<i>Schinus molle</i> L.), manzanilla (<i>Matricaria chamomilla</i> L.), valeriana (<i>Valeriana</i> sp.), calabaza (<i>Cucurbita pepo</i> L.), cola de caballo (<i>Equisetum arvense</i> L.), tepezcohuite (<i>Mimosa tenuiflora</i> Poir.), salvia (<i>Salvia officinalis</i> L.), canela (<i>Cinnamomum verum</i> J. Presl.), tila estrella (<i>Tilia americana</i> var. <i>mexicana</i> (Schltdl.) Hardin), cedrón (<i>Aloysia citrodora</i> Paláu), uva (<i>Vitis vinifera</i> L.), jengibre (<i>Zingiber officinale</i> Roscoe) and gobernadora (<i>Larrea tridentata</i> (DC.) Coville). Illnesses of the cardiovascular, digestive, urinary, respiratory, nervous, muscular and reproductive systems, as well as culture-bound syndromes, were mostly treated with these plant species. Moreover, <i>J. spicigera</i>, <i>M. chamomilla</i> and <i>L. tridentata</i> were used for eight medical purposes, followed by <i>Z. officinale</i> with five medicinal practices. In contrast, only two medicinal uses were recorded for <i>C. pepo</i>, <i>M. tenuiflora</i> and <i>S. officinale</i>. The PCoA explained 65.88% of the variation accumulated at the first three ordination axes and formed four groups of species, which were related to their geographical origin. Eight of the fourteen species that are commonly used as medicinal plants are from America, and the rest come from Europe and Asia. This study confirms the persistence of traditional knowledge related to medicinal plants, and the diseases empirically addressed among the inhabitants of Guadalajara City are common in other parts of the world and in different regions of Mexico. These findings are supported by electronic databases that comprise multiple studies related to the phytochemical compounds and medical validation regarding their biological activity, supporting the empirical use and efficacy of these medicinal plants.