Biochemical characterization of leaves and seeds extracts of Ipomea pupurea (L.) Roth (Convolvulaceae) and evaluation of its effect on the monoamine oxidase

MARIA A. MONSALVO ; NATALIA COLETTIS; RENEE H. FORTUNATO; MARCELO L. WAGNER ; MARIEL MARDER ; RAFAEL A. RICCO

Ciudad Autónoma de Buenos Aires

Congreso; VIII Congreso Internacional de Fitocosmética y Fitoterapia IPPC Argentina; 2018

Ipomoea purpurea (L.) Roth (Convolvulaceae) traditionally used as a diuretic, to stop hemorrhage, as a purgative and to treat syphilis. Due to its content of ergot alkaloids, ancestral tribes used this species to achieve a mental state adaptable to divination during religious ceremonies and magical healing practices, being the hallucinogenic activity its transcendental characteristic and for which it is popularly known today. The aim of this work was to evaluate the activity of the extracts from this species on the central nervous system and assess its medicinal potential in neurodegenerative diseases. The quantitative composition of the flavonoids, hydroxycinnamic acid derivatives and total phenols of the aqueous and ethanolic extracts (70%) (10 g / 100 ml) of the leaves and seeds was determined by spectrophotometric methods. The monoamine oxidases (MAO) exist in two isoforms, MAO-A and MAO-B, both with substantial pharmacological interest. MAO-A metabolizes serotonin and norepinephrine in the central nervous system (CNS). Deficiency of these two neurotransmitters is associated with the development of depression. The oxidative deamination catalyzed by Mao-b is one of the main degradation pathways of dopamine in the human brain, so this isoform is a therapeutic target for the Parkinson's disease (PD). The ability of the extracts to inhibit the MAO-A and the recombinant MAO-B were evaluated by a fluorometric assay that measures the production of hydrogen peroxide (H2O2) from p-tyramine. H2O2 was detected using the reagent Amplex Red in the presence of horseradish peroxidase, where resorufin, a fluorescent product, is formed in stoichiometric amounts. All extracts (1 mg / ml) were able to inhibit both enzymes, with a higher effectiveness for MAO-B. The ethanol extracts were more active than the aqueous extracts, while extracts from seeds were more active than extracts from the leaves. The ethanolic extract of the seeds showed an inhibitory concentration value of 50% (IC50) for the MAO-B of: IC50 (95% confidence interval) = 0.46 (0.26-0.82) mg / ml. Therefore, extracts of I. purpurea present compounds capable of inhibiting MAOs and represent a promising contribution to the development of new natural drugs for the treatment of PD and concomitant depression.