Isolation and characterization of water soluble fraction of propolis and its antibacterial potential on bacteria causing conjunctivitis

Abstract

Propolis is a bee product with a variety of biological activities. Although chemical composition of propolis differs by the location but all propolis types possesses antimicrobial activity. The usage of propolis for apitherapeutic purposes has increased recently. But its ethanol solubility limits its usage in certain areas like ophthalmology. Main objective of this study is to isolate water soluble components of propolis and determination of its antimicrobial activity against two bacteria causing conjunctivitis namely Neisseria gonorrhoeae and Haemophilus influenzae. Isolation of water soluble fraction of propolis was carried out in two steps by using pectin-propolis micro beads. Isolated water soluble fraction and crude extract was examined by thin layer chromatography and HPLC analyses. Three main spots were screened on TLC plate after isolation. These spots could be explained by the presence of different class of compounds in the isolate. HPLC analyses showed that water soluble fraction contained phenolic acids, their esters and flavonoids like p-OH benzoic acid, t-cinnamic acid, pinocembrin and caffeic acid phenethyl ester. Low antimicrobial activity was achieved against tested microorganisms for the fraction. It can be concluded that isolation of water soluble fraction of the propolis extract could be a solution for its usage in restricted areas.