ABSTRACT
ETHNOPHARMACOLOGICAL RELEVANCE: The Q'eqchi' Maya possess a large selection of plants to treat neurological disorders, including epilepsy and susto (fright), a culture-bound illness related to anxiety disorders. AIM OF THE STUDY: To investigate the activity of antiepileptic and anxiolytic plants in the GABAergic system, and determine if there is a pharmacological basis for plant selection. MATERIALS AND METHODS: Ethanol extracts of 34 plants were tested in vitro for their ability to inhibit GABA-transaminase (GABA-T) or bind to the GABA(A)-benzodiazepine (BZD) receptor, two principal drug targets in epilepsy and anxiety. Pharmacological activity was correlated with relative frequency of use, based on informant consensus. RESULTS: Ten plants showed greater than 50% GABA-T inhibition at 1mg/ml, while 23 showed greater than 50% binding to the GABA(A)-BZD receptor at 250 microg/ml. Piperaceae, Adiantaceae and Acanthaceae families were highly represented and active in both assays. There was a significant positive correlation between GABA-T inhibition and relative frequency of use for epilepsy, and an even stronger correlation between GABA(A) binding and relative frequency of use for susto (fright). CONCLUSIONS: Clearly, Q'eqchi' traditional knowledge of antiepileptic and anxiolytic plants is associated with the use of pharmacologically active plants. Based on the evidence, it is suggested that the mechanism of action for some traditionally used plants may be mediated through the GABAergic system.
Subject(s)
4-Aminobutyrate Transaminase/antagonists & inhibitors , Anti-Anxiety Agents/pharmacology , Anticonvulsants/pharmacology , Epilepsy/drug therapy , Magnoliopsida , Plant Extracts/pharmacology , Receptors, GABA-A/metabolism , Anti-Anxiety Agents/therapeutic use , Anticonvulsants/therapeutic use , Anxiety/drug therapy , Belize , Ethnopharmacology , Humans , Indians, Central American , Medicine, Traditional , Phytotherapy , Plant Extracts/chemistry , Plant Extracts/therapeutic use , Plants, Medicinal , Tannins/analysisABSTRACT
Selected plants used to treat susto, a folk illness recognized by various groups of Latin America, were screened for anxiolytic and/or fear suppression activity in behavioral assays. We found that the plant used by most of the healers interviewed (Adiantum tetraphyllum Humb. & Bonpl. ex Willd.; Adiantaceae) suppressed certain components of anxiety and fear. To our knowledge, this is the first report on the biological activity of Adiantum tetraphyllum. This finding supports the contention that susto may represent what in the Western culture is defined as fear or anxiety, and hence may share the same psychological, biological or neural underpinnings. In light of the available literature, this represents the first experimental investigation of the biological activity of plants specifically in the perspective of their use in treating a culture-bound syndrome.