title: Alternative preparation of propolis extracts: comparison of their composition and biological activities.
abstract: BACKGROUND
  Propolis is the bee product noted for multiple biological effects, and therefore it is widely used for the prevention and treatment of a variety of diseases. The active substances of propolis are easily soluble in ethanol. However ethanolic extracts cannot be used in treatment of certain diseases encountered in ophthalmology, pediatrics, etc. Unfortunately, the main biologically active substances of propolis are scarcely soluble in water, oil and other solvents usually used in pharmaceutical industry. The aim of this study was to investigate chemical composition, radical scavenging and antimicrobial activity of propolis extracts differently made in nonethanolic solvents.
  
  
  METHODS
  Total content of phenolic compounds in extracts was determined using Folin-Ciocalteu method. Chemical composition and radical scavenging activity of extracts were determined using HPLC system with free radical reaction detector. Antimicrobial activity of examined preparations was evaluated using the agar-well diffusion assay.
  
  
  RESULTS
  Total amount of phenolic compounds in extracts made in polyethylene glycol 400 (PEG) and water mixture or in PEG, olive oil and water mixture at 70 °C was comparable to that of ethanolic extract. Predominantly identified compounds were phenolic acids, which contribute ca. 40 % of total radical scavenging activity. Investigated nonethanolic extracts inhibited the growth and reproduction of all tested microrganisms. Antimicrobial activity of some extracts was equal or exceeded the antimicrobial effect of ethanolic extract. Extracts made in pure water or oil only at room temperature, contained more than 5 - 10-fold lower amount of phenolic compounds, and demonstrated no antimicrobial activity.
  
  
  CONCLUSIONS
  Nonethanolic solvent complex and the effect of higher temperature allows more effective extraction of active compounds from propolis. Concentration of total phenolic compounds in these extracts does not differ significantly from the concentration found in ethanolic extract. Propolis nonethanolic extracts have radical scavenging and antimicrobial activity.
authors.affiliation: Department of Drug Technology and Social Pharmacy, Lithuanian University of Health Sciences, A.Mickeviciaus 9, LT-44307, Kaunas, Lithuania. redakcija@efarmacija.lt.
authors.forename: Loreta
authors.initials: L
authors.lastname: Kubiliene
authors.affiliation: Department of Biology, Vytautas Magnus University, Vileikos 8, LT-44404, Kaunas, Lithuania. virginija.gailiunaite@gmail.com.
authors.forename: Virginija
authors.initials: V
authors.lastname: Laugaliene
authors.affiliation: Department of Microbiology, Lithuanian University of Health Sciences, Eiveniu 4, LT-40009, Kaunas, Lithuania. alvydas.pavilonis@lsmuni.lt.
authors.forename: Alvydas
authors.initials: A
authors.lastname: Pavilonis
authors.affiliation: Department of Biology, Vytautas Magnus University, Vileikos 8, LT-44404, Kaunas, Lithuania. a.maruska@gmf.vdu.lt.
authors.forename: Audrius
authors.initials: A
authors.lastname: Maruska
authors.affiliation: Department of Drug Technology and Social Pharmacy, Lithuanian University of Health Sciences, A.Mickeviciaus 9, LT-44307, Kaunas, Lithuania. daiva.majiene@lsmuni.lt.
authors.forename: Daiva
authors.initials: D
authors.lastname: Majiene
authors.affiliation: Department of Biology, Vytautas Magnus University, Vileikos 8, LT-44404, Kaunas, Lithuania. Karolina.Barcauskaite@fc.vdu.lt.
authors.forename: Karolina
authors.initials: K
authors.lastname: Barcauskaite
authors.affiliation: Institute of Cardiology, Lithuanian University of Health Sciences, Sukileliu 17, LT-5016, Kaunas, Lithuania. raimondas.kubilius@lsmuni.lt.
authors.forename: Raimondas
authors.initials: R
authors.lastname: Kubilius
authors.affiliation: Department of Drug Technology and Social Pharmacy, Lithuanian University of Health Sciences, A.Mickeviciaus 9, LT-44307, Kaunas, Lithuania. giedre@kasparavicius.eu.
authors.forename: Giedre
authors.initials: G
authors.lastname: Kasparaviciene
authors.affiliation: Department of Drug Technology and Social Pharmacy, Lithuanian University of Health Sciences, A.Mickeviciaus 9, LT-44307, Kaunas, Lithuania. Arunas.Savickas@lsmuni.lt.
authors.forename: Arunas
authors.initials: A
authors.lastname: Savickas
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D001516:Bees; D002626:Chemistry, Pharmaceutical; D002851:Chromatography, High Pressure Liquid; D000431:Ethanol / Q000737:chemistry; D062385:Hydroxybenzoates; D000069463:Olive Oil; D010636:Phenols / Q000737:chemistry / Q000494:pharmacology; D010938:Plant Oils / Q000737:chemistry; D011429:Propolis / Q000737:chemistry / Q000494:pharmacology; D012995:Solubility; D012997:Solvents / Q000737:chemistry*; D013696:Temperature; D014867:Water / Q000737:chemistry
chemical_list: D000890:Anti-Infective Agents; D000975:Antioxidants; D062385:Hydroxybenzoates; D000069463:Olive Oil; D010636:Phenols; D010938:Plant Oils; D012997:Solvents; D014867:Water; D000431:Ethanol; D011429:Propolis; C017616:phenolic acid