Chemical and Biological Evaluation of the Aqueous Extract of Peumus boldus Molina (Monimiaceae) Leaves

Background: Traditional medicine has inspired the scientific community to discover natural compounds with the ability to inhibit the enzyme acetylcholinesterase (AChE) and with significant antioxidant capacity. These themes are associated with therapeutic processes to decrease the symptoms of Alzheimer’s disease (AD). Acetylcholine (Ach) is an important neurotransmitter in the central nervous system responsible for transmitting the nervous impulse and increasing intestinal motility and dilation of sphincters in the gastrointestinal tract. As the species Peumus boldus Molina is widely known and used in folk medicine to treat gastrointestinal discomfort, its constituents could have an affinity for AChE and could be used to treat AD. Materials and Methods: This study evaluated the chemical, inhibitory activity of AChE (using the Elmann method and in silico), antioxidant capacity (DPPH, ABTS, FRAP, and oxidation inhibition of the β-carotene/linoleic acid system), and quantification of total leaf phenols from a commercial sample of P. boldus. Results: The mass spectral analysis allowed identification of the alkaloids isoboldine, boldine, clocaurine, laurotetanine, N-methylurotetanine, reticuline, and N-methylcoclaurine. In the in silico prediction test, the alkaloid N-metillaurotetanine was the best acetylcholinesterase enzyme inhibitor, with energy of -10.1 kcal mol-1. Conclusion: These results are of scientific relevance for the discovery of new drugs to treat dementia associated with Alzheimer’s disease and stimulate the continuity of chemical and biological studies (anticholinesterase and antioxidant action) of prepurified fractions and substances isolated from P. boldus leaves.