Phenolic profile and effects of acetone fractions obtained from the inflorescences of Calluna vulgaris (L.) Hull on vaginal pathogenic and non-pathogenic bacteria

Abstract

The phenolic profile and the antibacterial activity against pathogenic commensal vaginal bacteria exhibited by different fractions of the acetone extract of heather were assessed. The acetone extract of Calluna vulgaris (L.) Hull was fractionated by silica gel column chromatography through an eluent system of increasing polarity, and 10 different fractions (Fr 1 to Fr 10) were obtained. The phenolic profile was analyzed by HPLC-DAD-ESI/MS. Type B (epi)catechin dimers, (−)-epicatechin and (+)-catechin, were the main phenolic compounds present in the fractions. The antibacterial activity was also analyzed against pathogenic bacteria and the effect on the beneficial microflora was also assessed. Some of the obtained fractions revealed the capacity to inhibit pathogenic microorganisms without affecting the beneficial microflora, especially Fr 7 and Fr 8. For instance, Neisseria gonorrhoeae was inhibited by both of the fractions, while Fr 7 was more active against Klebsiella pneumoniae and Morganella morganii, and Fr 8 was active against methicillin resistant Staphylococcus aureus (MRSA) and methicillin susceptible Staphylococcus aureus (MSSA), without affecting the Lactobacillus strains. This study corroborates the therapeutic use of this matrix in traditional medicine.