Estudo de espécies de Senna da Caatinga e do Cerrado: documentação química e farmacológica na busca de novos fármacos

Abstract

The search for natural compounds with pharmacological properties has been a challenge for science, mainly due to the complexity of plant matrices. Species of the Senna genus have in their composition a wide variety of compounds, including metabolites from the classes of alkaloids, flavonoids and anthraquinones, which stand out for their pharmacological, economic and biotechnological potential. This work aimed to carry out a chemical and pharmacological study of seven species of the genus Senna, native to Caatinga and Cerrado. In this sense, an analytical method was developed for the comparative, systematic and comprehensive analysis of the chemical profile of leaves, flowers and fruits of the selected species. The developed method was validated, and its scope was evaluated through the application of analytical techniques HPLC-DAD and UPLC-QTOF-MS, making it possible to identify 46 compounds from various classes of secondary metabolites, in free and glycosylated forms. The results obtained indicate that the developed method is also applicable to the study of other complex plant matrices. Alternatively, the technique of Online Extraction - OLE coupled to UPLC-MS was used to generate the chemical profile of Senna species in a fast, efficient and green way. It was observed that the chromatographic profile obtained by the OLE technique is very similar to that obtained through the conventional extraction and analysis technique, but with important gains in extraction efficiency, time and amount of samples and solvents involved. The OLE technique was efficient in obtaining the complete chemical profile of the Senna spp. The pharmacological documentation of the species was performed by evaluating the antioxidant, cytotoxic and anticholinesterase activities of extracts from flowers of Senna macranthera and Senna spectabilis var. excellent. In the evaluation of cytotoxic and anticholinesterase activity, the studied species showed significant potential. For the extract of the flowers of Senna trachypus, in addition to the antioxidant and cytotoxic activities, the toxicity and locomotor activity in adult zebrafish was also evaluated. The results showed that the extract has significant biological potential and is non-toxic, absence of toxicity points to a possible herbal use.