title: Micropropagation and vasorelaxant activity of Laelia autumnalis (Orchidaceae).
abstract: A simple and efficient protocol has been developed in order to obtain healthy seedlings by asymbiotic germination of seeds from Laelia autumnalis. Seeds from mature capsules were germinated asymbiotically after being cultured on full- or half-strength Murashige and Skoog's (MS) medium, without plant growth regulators and with 3.0% or 1.5% of sucrose. The percentage of germinated seeds (% GS) was recorded during 6 weeks using three different conditions of incubation: light (80% GS, p < 0.05), darkness (30% GS) and white light photoperiod (100% GS, p < 0.05). The best seed germination percentages were found on the light and white light photoperiod conditions. Moreover, we also investigated the vasorelaxant action of the methanolic extracts from wild L. autumnalis (roots, pseudobulbs and leaves) and plantlets generated in vitro. Results showed that the methanolic extract of roots and pseudobulbs produced a significant vasodilator effect, in a concentration-dependent and endothelium-independent manner on norepinephrine (NE) and potassium chloride (KCl)-induced contractions in rat aortic thoracic rings. Nevertheless, the methanolic extract of leaves and plantlets showed no relevant vasorelaxant activity. Therefore, the results suggest that pseudobulbs and roots were the main tissues of the plant where vasorelaxant compounds are stored.
authors.affiliation: Facultad de Farmacia, Universidad Autónoma del Estado de Morelos, Cuernavaca, Morelos, México.
authors.forename: Jorge
authors.initials: J
authors.lastname: Vergara-Galicia
authors.forename: Francisco
authors.initials: F
authors.lastname: Aguirre-Crespo
authors.forename: Patricia
authors.initials: P
authors.lastname: Castillo-España
authors.forename: Aurora
authors.initials: A
authors.lastname: Arroyo-Mora
authors.forename: Ana Laura
authors.initials: AL
authors.lastname: López-Escamilla
authors.forename: Rafael
authors.initials: R
authors.lastname: Villalobos-Molina
authors.forename: Samuel
authors.initials: S
authors.lastname: Estrada-Soto
mesh_terms: D018525:Germination; D029595:Orchidaceae / Q000737:chemistry* / Q000196:embryology / Q000502:physiology; D010936:Plant Extracts / Q000494:pharmacology*; D012639:Seeds; D014665:Vasodilator Agents / Q000494:pharmacology*
chemical_list: D010936:Plant Extracts; D014665:Vasodilator Agents