Antimicrobial Activities and Chemical Characterization of Propolis Collected from Three Different National Areas of Ethiopia

Abstract

Background: Propolis has revealed versatile and valuable biological and pharmacological activities such as antibacterial, antimitotic and antiviral. It has other less obvious effects such as cytotoxic, antioxidant, anti-inflammatory and immunomodulation. The variation in the chemistry of propolis from different locations and plant sources has made it a source of new biologically active molecules, mainly antioxidative and antibacterial agents. Aim of the study: The purpose of the present study was primarily to establish and assess the variation (if any) in the antimicrobial activities of propolis samples from three different local areas of Ethiopia. The study also incorporates identification and characterization of the major antimicrobial component(s) of propolis that are responsible for the antimicrobial activity. Materials and methods: Pure cultures of two gram positive (S.aureus and methicillin resistant S.aureus (MRSA)), three gram negative (E. coli, P. aeruginosa, S. typhi) bacterial species and one fungal species (C. albicans) were obtained from the department of Microbiology and Bacteriology Laboratory center, Addis Ababa University. Three propolis samples were collected from South Wollo, Tembain and Holeta regions of Ethiopia during the summer season. 70% ethanolic extract preparation for each propolis sample was made by using maceration procedure. Agar plate disk diffusion using paper disks and Agar well diffusion methods were employed to study antimicrobial activity of ethanolic extract of propolis from Tembain (EEPT) and ethanolic extract of propolis from Holeta. Thin layer chromatography (TLC) phytochemical screening method using different TLC spray reagents (vanillin, aluminum chloride, diazotized sulfanilic acid and -anisaldehyde), TLC agar overlay bioautography method and column chromatography were employed to partially identify and characterize the antimicrobial active components of propolis from Holeta and Tembain regions. Conclusion: Ethanolic extract of propolis from Holeta and ethanolic extract of propolis from Tembain showed antibacterial activity against S. aureus and MRSA only without showing effect on other bacterial or the fungal strain. A variation in the chemical composition between EEPH and EEPT was noted. The antimicrobial activities of propolis could not be correlated with any single components of propolis therefore the bactericidal effects of propolis from this region may be as a result of the sum antimicrobial components.