Multifunctional Monoamine Oxidases and Cholinesterases Inhibitory Effects, as well as UPLC-DAD-MS Chemical Profile of Alkaloid Fractions Obtained from Species of the Palicoureeae Tribe

Abstract

In the present study, the effects were evaluated of alkaloid fractions (AFs) from Psychotria species and correlated genera, Palicourea and Rudgea, on monoamine oxidases (MAOs) and cholinesterases (ChEs). By HPLC-DAD and UPLC-DAD-MS analyses, indole alkaloids (IA) were detected in all AFs. For the Psychotria and Palicourea species, these IA corresponded to tetrahydro-β-carboline alkaloids (THβCA). On the other hand, pyrrolidinoindoline core compounds were observed for Rudgea species. Regarding their pharmacological activities, none of the AFs was able to inhibit AChE. However, the BChE activity was impaired by the Psychotria and Palicourea AFs. In addition, MAO-A was inhibited by both AFs, but only Psychotria nemorosa AF was able to inhibit significantly MAO-B. Rudgea AFs demonstrated a poor inhibitory profile on MAO-A. Taken together, our results highlighted the Psychotria and Palicourea genera as important sources of scaffolds for the development of MAO-A and BChE inhibitors aiming at the treatment of neurodegenerative and neuropsychiatric diseases.

Bioactive Azepine-Indole Alkaloids from Psychotria nemorosa

“…acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase A (MAO-A), MAO-B, and catechol-O-methyltransferase (COMT) has been demonstrated. [4][5][6][7][8][9][10][11][12][13] In this sense, Psychotria is considered as an important source of active compounds…”

“…Recently, it was demonstrated that the alkaloid fraction obtained from the leaves of P. nemorosa significantly inhibited BChE and MAO-A activities. 11 Multivariate calibration techniques, such as Partial Least Squares (PLS) and Orthogonal Projections to Latent Structures (O-PLS), were used to indicate four active peaks, correlating chemical and pharmacological data. 10 However, at that time, it was not possible neither to isolate nor to determine their chemical structures.…”

“…Recently, this preparation has attracted the attention of researchers due to its pharmacological potential, mainly to treat depression. − Other species have been described to treat dementia, which is corroborated by pharmacological studies. Their capacity to modulate key enzymes related to neurodegeneration, e.g., acetylcholinesterase (AChE), butyrylcholinesterase (BChE), monoamine oxidase A (MAO-A), MAO-B, and catechol- O -methyltransferase (COMT), has been demonstrated. − In this sense, Psychotria is considered as an important source of active compounds toward CNS.…”