Actividad antibacteriana del extracto etanólico del peciolo de Rheum rhabarbarum / Antibacterial activity of the ethanolic extract of the petiole from Rheum rhabarbarum

RESUMEN Los productos naturales poseen una amplia variedad de actividades biológicas que nos permiten encontrar nuevas alternativas terapéuticas. En este trabajo se evaluó la actividad antibacteriana in vitro del extracto etanólico del peciolo de Rheum rhabar barum frente a cepas ATCC de Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, Pseudomonas aeruginosa y Escherichia coli, y se determinó la concentración mínima inhibitoria (CMI) y la concentración mínima bactericida (CMB). Para solubilizar se empleó dimetilsulfóxido (DMSO) al 1%. Los resultados obtenidos demuestran que el extracto posee actividad antibacteriana, con valores de CMI ≥ 700 µg/mL para el extracto etanólico frente a Staphylococcus aureus, Staphylo coccus epidermidis, Klebsiella pneumoniae, Pseudomonas aeruginosa y Escherichia coli. Su efecto podría ser de tipo bacteriostático y no bactericida. Por tanto, se concluye que la especie vegetal Rheum rhabarbarum es considerada como promisoria para el control bacteriano.

Summary Natural products have a wide variety of biological activities that allow us to find new therapeutic alternatives. In this work, the in vitro antibacterial activity of the ethanol extract of the petiole of Rheum rhabarbarum against ATCC strains of Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli was evaluated, determining the minimum inhibitory concentra tion (MIC) and the minimum bactericidal concentration (CMB). To solubilize, 1% dimethylsulfoxide (DMSO) was used. The results show that the extract has antibac terial activity, with MIC values ≥ 700 µg/mL for the ethanolic extract against Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, Pseudomonas aeruginosa and Escherichia coli. Its effect could be bacteriostatic and not bactericidal. Therefore, it is concluded that the plant species Rheum rhabarbarum is considered promising for bacterial control.

Prevention of aortic lesions and hyperlipidaemia by alfalfa seed extract in cholesterol fed rabbit.

Extract of alfalfa seed (ethanolic 50 % v/v) prevents the development of plaque formation and hyperlipidaemia in cholesterol fed rabbits. It inhibits the elevation of serum total cholesterol, triglycerides, phospholipids, LDL-cholesterol and total cholesterol/phospholipid ratio, while HDL-cholesterol/total cholesterol ratio increases, which is associated with a reduced incidence of atherosclerosis. Further reduction in total cholesterol and phospholipid contents of liver and heart muscle are suggestive of a beneficial role of the seed extract. The possible mechanisms of action are discussed.