Extraction, séparation et activité antibactérienne des tanins de marrube blanc (Marrubium vulgare L.)

Abstract

Marrubium vulgare L. or white horehound is a widespread species in the Mediterranean and is widely used for its therapeutic properties. The objective was to verify the specificity of this plant including the antiseptic and antibacterial activity of tannins. The extraction of tannins allowed us to obtain high yields equals to 11.44%. The isolated compounds were separated by thin layer chromatography (TLC) and their antibacterial activity towards the bacterial strains responsible for certain infectious diseases was determined in vitro on Mueller-Hinton and Sabouraud. Comparison tests (antibiotic: rifampin) were also included in the trials. The results showed firstly that the tannin extract is composed of four compounds with frontal reports more or less reconciled. From the antibacterial tests performed with isolated tannin, it is clear that the growth inhibition of strains varies depending on the nature of the bacterial species, the concentration of the extract and the culturemedium used. A significant antibacterial effect was observed towards the strains considered among the most resistant to antibiotics and that can cause infections, often serious, such as Pseudomonas aeruginosa 7244 and Staphylococcus aureus. The zones of inhibition far exceed those caused by the antibiotic rifampin.