Medicinal plants for the treatment of “nervios”, anxiety, and depression in Mexican Traditional Medicine

The term “nervios” is referred as a folk illness recognized by Mexican Traditional Medicine, and also widely reported across many countries in Latin America. “Nervios” are characterized by a “state of bodily and mental unrest”, which decreases the ability to achieve daily goals. The causes are varied; in fact, any situation that alters the emotional state or mood is interpreted as a possible triggering agent. Depression and anxiety are psychiatric disorders, which share symptoms, or can be included in the same group of disorders with “nervios”. The therapies are designed to reassure health, i.e. “calm the nerves”. For this propose, the oral administration of plants infusions is common. In this review we compile information regarding the plants used for the treatment of “nervios” in México, along with those for which reports of anxiolytic or/and antidepressive activity exist. We found 92 plant species used in folk medicine for the treatment of “nervios”, among these, sixteen have been studied experimentally. The most studied plant is Galphimia glauca Cav., Malpighiaceae, which current clinical studies have validated its efficacy in patients, and their active components, the triterpenes galphimine A, B, and C, identified. Inter-estingly only nine plants were found to be reported in folk medicine for the treatment of sad- ness or/and depression, but their antidepressant activity has not been investigated. However, among the plants used in folk medicine for treatment of “nervios”, several, as Litsea glaucescens Kunth, Lauraceae, have been proven to show antidepressant activity in experimental models, and some of their active compounds have been determined. These species could be a potential source of compounds with activity in the central nervous system.