Effects of Erythrinian Alkaloids Isolated from Erythrina mulungu (Papilionaceae) in Mice Submitted to Animal Models of Anxiety

Abstract

The effects of acute oral administration of erythrinian alkaloids, i.e. (؉)-a a-hydroxy-erysotrine, erythravine and (؉)-11a a-hydroxy-erythravine isolated from the flowers of Erythrina mulungu were investigated in two animal models of anxiety in mice-the light-dark transition model (LDTM) and the elevated plus-maze (EPM). In the LDTM, erythravine (3, 10 mg/kg) and (؉)-11a a-hydroxy-erythravine (10 mg/kg) increased the time spent by the animals in the illuminated compartment and (؉)-11a a-hydroxy-erythravine (3 mg/kg) increased the number of transitions between compartments of the LDTM, suggesting an anxiolytic-like effect of these erythrinian alkaloids. Nevertheless, the third alkaloid studied, (؉)-a a-hydroxy-erysotrine, did not change any behavioral response with the range of doses used (3-10 mg/kg). Since the oral administration of the crude extract of E. mulungu (EM) (100-400 mg/kg) did not modify the conventional measures of anxiety in the EPM, this animal model was not chosen to evaluate the anxiolytic properties of the isolated alkaloids. These results suggest that the alkaloids erythravine and (؉)-11a a-hydroxy-erythravine are responsible for the anxiolytic effects of the crude extract of E. mulungu.

Tropical biodiversity: has it been a potential source of secondary metabolites useful for medicinal chemistry?

“…Commercial EM preparations are available in Brazil and in the USA as herbal medicine. 84,85 Several Erythrina species have been studied, and studies on E. mulungu conducted by our group have resulted in the isolation of three erythrinian alkaloids, (+)-11α-hydroxyerythravine (60), (+)-erythravine (61), and (+)-α-hydroxyerysotrine (62) ( Figure 15), as well as confirmation of the anxiolytic properties of these erythrinian alkaloids. The effects of these alkaloids associated with the low toxicity of one standard mixture are currently under study by a Brazilian Pharmaceutical Co. that aims to launch a herbal medicine whose effects could be similar to those produced by diazepam, a classic anxiolytic drug.…”

“…84,86 These results suggest that the erythrinian alkaloids isolated from E. mulungu play a major role in the anxiolytic effects of EM and support the popular use of the tincture as an anxiolytic medicine. 85 In Brazil, Senna species are known for several applications, including their ornamental use given their beautiful yellow blossoms. Our group has systematically studied Senna spectabilis, syn.…”

Ansiedade: aspectos gerais e tratamento com enfoque nas plantas com potencial ansiolítico

“…Alcalóides isolados das flores de E. mulungu apresentaram efeito ansiolítico no teste da caixa do claro/escuro (FLAUSINO et al 2007a, b). Além disso, tanto no tratamento agudo (ONUSIC et al, 2002), quanto no tratamento crônico (ONUSIC et al, 2003), o extrato hidroalcoólico da inflorescência de E. mulungu, mostrou efeito ansiolítico, relacionado com um comportamento defensivo, associado ao tratamento da ansiedade generalizada (SOUSA et al, 2008).…”

Seed Germination and Production of <i>Erythrina mulungu</i> and <i>Erythrina velutina</i> Plantlets

“…The sedative action of the Erythrina tea that is popularly consumed in Brazil has been reported in ethnobotanical studies [6] [7]. Moreover, numerous pharmacological studies carried out with animals validated the anxiolytic, anticonvulsant and antinociceptive effects of the hydroalcoholic extract of E. velutina and E. mulungu stem bark and flowers [8]- [17] However, even being a species relevant to the development of scientific researches, especially considering its diversity of use and validated therapeutic efficacy, only a few studies on Erythrina seed germination characteristics and production of seedlings have been carried out and those works are restricted to seed physical dormancy caused by its water-impermeable seed coat [18]- [21].…”