New insights in the mode of action of (+)-erythravine and (+)-11α-hydroxy-erythravine alkaloids

Abstract

Erythrinian alkaloids ((+)-erythravine and (+)-11-α-hydroxy-erythravine) have been pointed as the main responsible agents for the anticonvulsant and anxiolytic properties of Erythrina mulungu Mart ex Benth. The present work provides a new set of information about the mode of action of these alkaloids by the use of a complementary approach of neurochemical and electrophysiological assays. We propose here that the antiepileptic and anxiolytic properties exhibited by both alkaloids appear not to be related to the inhibition of glutamate binding or GABA uptake, or even to the increase of glutamate uptake or GABA binding, as investiga ted here by the use of rat cortical synaptosomes. Similarly, and even in a high concentration, (+)erythravine and (+)-11-α-hydroxy-erythravine did not modulate the main sodium and potassium channel isoforms checked by the use of voltage-clamp studies on Xenopus laevis oocytes. However, unlike (+)-11-α-hydroxy-erythravine, which presented a little effect, it was possible to observe that the (+)-erythravine alkaloid produced a significant inhibitory modulation on α4β2, α4β4 and α7 isoforms of nicotinic acetylcholine receptors also checked by the use of voltage-clamp studies, which could explain at least partially its anxiolytic and anticonvuls a nt properties. Since (+)-11-α-hydroxy-erythravine and erythravine modulated nicotinic acetylcholine receptors to different extents, it is possible to reinforce that small differe nces between the chemical structure of these alkaloids can affect the selectivity and affinity of targetligand interactions, conferring distinct potency and/or pharmacological properties to them, as previously suggested by differential experimental comparison between different erythrinia n alkaloids.

Ethnobotanical and Phytochemical Profiling of Medicinal Plants from Burkina Faso Used to Increase Physical Performance

“…Phenolic and flavonoids were detected in all of the six species concerned by the phytochemical screening. Alkaloids, detected in some reported species such as Annona senegalensis, Cassia sieberiana, Ficus tonningii, and Bauhinia tonningii, were reported by [34] to be the main responsible agents of the anticonvulsant and anxiolytic properties. Terpenes detected in all of the six species related to the phytochemical analyses (Table 3) have been reported to have anticonvulsant and anxiolytic activities with pronounced hypnotic and muscle relaxant effects [30].…”