Compostos fenólicos em folhas de Eugenia uniflora L.: atividade citotóxica em adenocarcinoma gástrico (células AGS) e atividade anti-Helicobacter pylori

• Autor(a) principal: Oliveira, Fernanda Mirella Garcia de
• Data de Publicação: 2023
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal do Espírito Santo (riUfes)
• Texto Completo: http://repositorio.ufes.br/handle/10/12439
• topic: Química; E. uniflora L.; Compostos fenólicos; Citotoxicidade; H. pylori; Espectrometria de massas; Quimiometria

The infusion of Eugenia uniflora L. leaves is popularly used to treat viral and gastric symptoms, and the effectiveness of these treatments can be associated with the presence of flavonoids and tannins in its leaves. Eugenia uniflora L. is one of the species included in the National List of Medicinal Plants of Interest to the Unified Health System (RENISUS) and listed in the DRC on March 10, 2010 due to its importance in popular medicine. Furthermore, its leaves are used to treat sore throats, diarrhea, infections and gastrointestinal disorders. Among the secondary metabolites present in its composition, and which already have biological activities reported in the literature, flavonoids and tannins can be mentioned. Myricitrin is one of the flavonoids found abundantly in the leaves of Eugenia uniflora L. and has been associated with antioxidant, anti-inflammatory, antidiabetic, antihypertensive and antiviral activity. Oenotein B and gemin D/hipommannin A also have several related activities, including antibacterial activity. Thus, the objective of this study was to verify the anti-Helicobacter pylori activity and cytotoxicity of the extract and fractions of Eugenia uniflora L. leaves on gastric adenocarcinoma cells (AGS). Furthermore, verify better leaf collection conditions considering different locations (between mangrove, beach and mountain regions) and times (8:00 am, 1:00 pm and 6:00 pm), in addition to proposing FTIRPCA as a low-cost screening method for obtaining bioactive samples. The extracts and fractions had their chemical profiles determined by ESI(-)FT-ICR MS, ESI(-)FT-ICR MS/MS, ESI(-)LTQ MS and MSn. The aqueous fraction, rich in tannins, was considered the most active sample for Helicobacter pylori (MBC of 1024 µg/mL and MIC of 256 µg/mL) and the most cytotoxic for AGS cells (IC50 of 178 µg/mL). The strain analyzed showed resistance to metronidazole (MBC >1024 µg/mL and MIC of 512 µg/mL). For the FTIR-PCA analysis of the collection location, the samples from the beach and mangrove region were located in the PC1 > 0 direction, but separated along PC2. Those from the mountainous region were located at PC1 < 0. Regarding the separation by collection time, the samples collected at 1:00 pm were grouped at PC1 > 0. Considering the TIC values of the mass spectra and FTIR-PCA, the sample with the highest abundance of flavonoids is the one collected in the beach region at 1:00 p.m. In conclusion, the greatest cytotoxicity on AGS cells and anti Helicobacter pylori activity was found for the aqueous fraction of Eugenia uniflora L. leaves, which may be directly related to the presence of the tannins oenotein B and gemin D/hippomannin A. Finally, The best collection location and time to obtain bioactive extracts is at 1:00 pm in the beach area due to the high incidence of UV rays.