ABSTRACT
Porophyllum ruderale (Jacq.) Cass. (Asteraceae) has antiprotozoal properties and contains extractable phenolic compounds by the maceration method (M). However, new extraction proposals such as ultrasound (U), microwaves (MW), and ultrasound/microwaves (U/MW) have emerged to optimise yields, but it is unknown if these methods modify effectiveness. Therefore, the study consisted of extracting the aerial part of P. ruderale with ethanol using the M, U, MW and U/MW methods to study its composition by RP-HPLC-ESI-MS, its total polyphenol content and its effect against Entamoeba histolytica. The study showed that U, MW and U/MW did not modify the extraction yield compared to M, but they did change the composition and the total polyphenol content. All extracts contain phloretin, caffeic acid 4-O-glucoside, todolactol A, quercetin 3-O-glucoside, quercetin 3-O-rhamnoside, luteolin and 3,7-dimethylquercetin, and affected the growth of E. histolytica. However, M and U extracts were the most effective at 5 mg/mL.
ABSTRACT
The present research focused on evaluating the antibacterial effect and the mechanism of action of partially purified fractions of an extract of Persea americana. Furthermore, both its antioxidant capacity and composition were evaluated. The extract was fractionated by vacuum liquid chromatography. The antimicrobial effect against Staphylococcus aureus (ATCC 6538), Escherichia coli (ATCC 11229), Pseudomonas aeruginosa (ATCC 15442), and Salmonella choleraesuis (ATCC 1070) was analyzed by microdilution and the mechanism of action by the Sytox green method. The antioxidant capacity was determined by DPPH, FRAP, and ABTS techniques and the composition by Rp-HPLC-MS. All fractions showed a concentration-dependent antibacterial effect. Fractions F3, F4, and F5 (1000 µg/mL) showed a better antibacterial effect than the extract against the bacteria mentioned. The F3 fraction showed inhibition of 95.43 ± 3.04% on S. aureus, F4 showed 93.30 ± 0.52% on E. coli, and F5 showed 88.63 ± 1.15% on S. choleraesuis and 86.46 ± 3.20% on P. aeruginosa. The most susceptible strain to the treatment with the extract was S. aureus. Therefore, in this strain, the bacterial membrane damage induced by the extract and fractions was evidenced by light fluorescence microscopy. Furthermore, the extract had better antioxidant action than each fraction. Finally, sinensitin was detected in F3 and cinnamoyl glucose, caffeoyl tartaric acid, and cyanidin 3-O-(6''-malonyl-3''-glucosyl-glucoside) were detected in F4; esculin and kaempferide, detected in F5, could be associated with the antibacterial and antioxidant effect.
ABSTRACT
Tagetes lucida Cav. (Asteraceae = Compositae) se usa para tratar infecciones estomacales. El estudio se centró en evaluar la composición y el efecto antimicrobiano de un extracto de T. lucida Cav. La planta se extrajo con etanol al 10% p/v, y la composición del extracto se analizó por Rp-HPLC-MS. El efecto antibacteriano se evaluó contra Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa y Salmonella choleraesuis utilizando métodos de difusión por disco, microdilución y bioautografía. Los ensayos de sytox y cometa fueron utilizados para evaluar el mecanismo de acción. De esta forma, se detectaron nueve compuestos fenólicos en el extracto de T. lucida. El extracto exhibió actividad solo en S. aureus (MIC de 4.000 mg/ml). La bioautografía reveló que los compuestos fenólicos podrían actuar sinérgicamente. Las pruebas de sytox y cometa mostraron una acción antibacteriana del extracto sobre la membrana bacteriana y el ADN de esta cepa bacteriana.
Tagetes lucida Cav. (Asteraceae=Compositae) is used for treating stomach infections. The study focused on evaluating the composition and antimicrobial effect of an extract of T. lucida Cav. The plant extracted with ethanol at 10% w/v, and the extract composition analyzed by Rp-HPLC-MS. The antibacterial effect was evaluated against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Salmonella choleraesuis using disk diffusion, microdilution and bioautography methods. The sytox and comet assays were used to evaluate the mechanism of action. In this way, nine phenolic compounds were detected in the extract of T. lucida. The extract exhibited activity only on S. aureus (MIC of 4.000 mg/ml). The bioautography revealed that the phenolic compounds could act synergistically. The sytox and comet tests showed an antibacterial action of the extract on the bacterial membrane and DNA of this bacterial strain.
