ABSTRACT
Aristolochia elegans Mast. (Aristolochiaceae) has been used to treat scorpion envenoming in Mexican traditional medicine. In vitro studies of the pharmacological activity of raw extracts from A. elegans roots have shown activity against scorpion bite. The aim of the present study was to determine for the first time the antagonistic effect of hexane and methanol extracts of the aerial parts and roots from micropropagated A. elegans plants in a model of isolated guinea-pig ileum contracted by scorpion bite. Results showed that the methanol extracts of aerial organs (74%) and roots (65%) of micropropagated plants have a similar antitoxin activity against scorpion poisoning to hexane extracts of wild plants (65%). These results suggest that using methanol extracts from the micropropagated plant material instead of wild plant root extracts from A. elegans is an alternative for treatment against scorpion bite symptoms, and will contribute to the conservation of this medicinal species.
Subject(s)
Antivenins/pharmacology , Aristolochia , Plant Extracts/pharmacology , Scorpion Venoms/antagonists & inhibitors , Animals , Antivenins/isolation & purification , Guinea Pigs , Ileum/drug effects , Ileum/physiology , Male , Muscle Relaxation/drug effects , Muscle Relaxation/physiology , Plant Components, Aerial , Plant Extracts/isolation & purification , Plant Roots , Scorpion Venoms/pharmacology , ScorpionsABSTRACT
The aerial parts of Tilia americana var. mexicana (Schltdl) Hardin (Tiliaceae) have been widely used in Mexican traditional medicine to relieve sleeplessness, headache, and nervous excitement. The anxiolytic effect of four extracts and several flavonoid fractions from the bracts of Tilia americana subsp.mexicana, var. mexicana (Schltdl) Hardin or Tilia mexicana (Tiliaceae) was studied. Administration of 100mg/kg of n-hexane, ethyl acetate, and aqueous extracts to elevated plus-maze (EPM)-exposed mice displayed no anxiolytic effect; however, identical doses of methanol extract was able to increase the time percentage that mice spent in the EPM's open arms, as well as the percentage of crossings in the EPM's arms. The dose-response curve produced by methanol extract showed anxiolytic activity since 25mg/kg; animals showed no motor activity alteration in the open field test (OFT). Methanol extract was subjected to a bioassay-guided fractionation to obtain four ascendant polarity fractions (F1-F4) which were administrated at 100mg/kg. Data results indicate that F1 displayed the main anxiolytic effect. The purification of F1 produced a rich flavonoid anxiolytic mixture (F1C). This fraction was purified by RP-18 open chromatographic column to obtain four polar descent fractions: F1C(1), F1C(2), F1C(3), and F1C(4), respectively. Tiliroside was the major ingredient from the active fraction. High performance liquid chromatography analysis indicated that F1C was constituted principally of tiliroside, quercetin, quercitrin, kaempherol, and their glycosides. These results supported the use of Tilia americana in Mexican traditional medicine as well as the anxiolytic effect of a rich flavonoid fraction without affect motor activity.
