Evaluación del método y solvente de extracción más eficientes para la obtención de metabolitos secundarios responsables de una actividad antioxidante y antibacteriana de 9 plantas medicinales en la ciudad de Cuenca-Ecuador

Abstract

The use of medicinal plants in the treatment or prevention of diseases has arisen since ancient times, it is considered as an alternative of pharmaceutical medicine, it can be used in combination with the previous one, benefiting the people who use it. The most efficient extraction method and solvent in obtaining secondary metabolites that have antioxidant and antibacterial activities was determined. Nine medicinal plants were selected by literature review and availability in the local environment. The extractive methods that were used and analyzed were: percolation, maceration, homogenization, sonication and infusion, the solvents evaluated: 100% methanol and a hydroalcoholic mixture: methanol: 80:20 water. The antioxidant activity was evaluated by the techniques of Ferric Reducing Antioxidant Power (FRAP) and 2,2-Diphenyl-1picrylhydrazyl (DPPH) and the antibacterial activity by the microdilution plate method. The results obtained by the DPPH and FRAP techniques revealed that the best extractive method was homogenization and the best solvent was 100% methanol, it was determined that the extracts of Borago officinalis were those that presented a greater antioxidant capacity compared to the other plants under study . In the antibacterial activity it was determined that the methanolic extracts of Otholobium mexicanum obtained by the methods of homogenization, sonication and percolation presented a limited activity against S. aureus, in the case of maceration the extracts were inactive, as well as the rest of the Extracts from the remaining 8 plants regardless of the extractive method.