Effect of Alkaloids Isolated fromPhyllodium pulchellumon Monoamine Levels and Monoamine Oxidase Activity in Rat Brain

Abstract

Phyllodium pulchellum(P. pulchellum) is a folk medicine with a significant number of bioactivities. The aim of this study was to investigate the effects displayed by alkaloids fractions, isolated from the roots ofP. pulchellum, on neurotransmitters monoamine levels and on monoamine oxidase (MAO) activity. Six alkaloids, which had indolealkylamine orβ-carboline skeleton, were obtained by chromatographic technologies and identified by spectroscopic methods such as NMR and MS. After treatment with alkaloids ofP. pulchellum, the reduction of DA levels (54.55%) and 5-HT levels (35.01%) in rat brain was observed by HPLC-FLD. The effect of alkaloids on the monoamines metabolism was mainly related to MAO inhibition, characterized by IC50values of37.35±6.41and126.53±5.39 μg/mL for MAO-A and MAO-B, respectively. The acute toxicity indicated thatP. pulchellumextract was nontoxic.