Researchers investigated the effects of alkaloids isolated from the roots of the medicinal plant Phyllodium pulchellum on neurotransmitter levels and monoamine oxidase (MAO) activity. Six alkaloids were identified, and after treatment with the alkaloids, a reduction in dopamine and serotonin levels in the rat brain was observed. The alkaloids inhibited MAO activity, suggesting potential therapeutic use as MAO inhibitors. Acute toxicity testing showed the plant extract was nontoxic. Further research may explore the potential of P. pulchellum alkaloids as treatment for conditions such as depression and Parkinson's disease.