title: Relationship between total phenolic contents and biological properties of propolis from 20 different regions in South Korea.
abstract: BACKGROUND
  Propolis (or bee glue), collected from botanical sources by honey bee, has been used as a popular natural remedies in folk medicine throughout the world. This study was conducted to assess growth inhibitory effects of ethanol extracts of propolis (EEPs) from 20 different regions in South Korea on human intestinal bacteria as well as their human β-amyloid precursor cleavage enzyme (BACE-1), acetylcholinesterase (AChE) inhibitory, antioxidant, antiproliferative, and anti-human rhinovirus activities.
  
  
  METHODS
  The Bonferroni multiple-comparison method was used to test for significant differences in total polyphenol and flavonoid contents among EEP samples using SAS 9.13 program. Correlation coefficient (r) analysis of the biological activities of EEP samples was determined using their 50 % inhibition concentration or minimal inhibitory concentration values and their polyphenol or flavonoid contents in 20 native Korean EEP samples.
  
  
  RESULTS
  The amounts of total polyphenol and flavonoids in the Korean EEP samples ranged from 49 to 239 mg gallic acid equivalent (GAE)/g EEP (Brazilian, Chinese, and Australian samples, 127-142 mg GAE/g EEP) and from 21 to 50 mg quercetin equivalent (QE)/g EEP (Brazilian, Chinese, and Australian samples, 33-53 mg QE/g EEP), respectively. Correlation coefficient analysis showed that total polyphenol contents may be negatively correlated with 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (r = -0.872) and total flavonoid content has no correlation with the activity (r = 0.071). No direct correlation between BACE-1 inhibition, AChE inhibition, or antiproliferative activity and total polyphenol or total flavonoid content in Korean EEP samples was found. Gram-positive and Gram-negative bacteria were observed to have different degrees of antimicrobial susceptibility to the EEP samples examined, although ciprofloxacin susceptibility among the bacterial groups did not differ greatly.
  
  
  CONCLUSIONS
  Further studies will warrant possible applications of propolis as potential therapeutic BACE-1 blocker, antioxidant, antiproliferative agent, and antimicrobial agent.
authors.affiliation: Entomology Major, Department of Agriculture Biotechnology, Seoul National University, Seoul, 151-921, South Korea.
authors.forename: Xue
authors.initials: X
authors.lastname: Wang
authors.affiliation: Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, South Korea.
authors.forename: Karuppasamy
authors.initials: K
authors.lastname: Sankarapandian
authors.affiliation: WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, 151-921, South Korea.
authors.forename: Yizhe
authors.initials: Y
authors.lastname: Cheng
authors.affiliation: National Academy of Agricultural Science, Rural Development Administration, Jeonju, 560-500, South Korea.
authors.forename: Soon Ok
authors.initials: SO
authors.lastname: Woo
authors.affiliation: Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, South Korea.
authors.forename: Hyung Wook
authors.initials: HW
authors.lastname: Kwon
authors.affiliation: Research Institute of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, South Korea. harijai2004@gmail.com.
authors.forename: Haribalan
authors.initials: H
authors.lastname: Perumalsamy
authors.affiliation: WCU Biomodulation Major, Department of Agricultural Biotechnology, Seoul National University, Seoul, 151-921, South Korea. yjahn@snu.ac.kr.
authors.forename: Young-Joon
authors.initials: YJ
authors.lastname: Ahn
mesh_terms: D000110:Acetylcholinesterase / Q000378:metabolism; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001516:Bees; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002800:Cholinesterase Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000032:analysis; D016166:Free Radical Scavengers / Q000378:metabolism; D006801:Humans; D010636:Phenols / Q000032:analysis*; D011429:Propolis / Q000737:chemistry*; D056910:Republic of Korea
chemical_list: D000900:Anti-Bacterial Agents; D002800:Cholinesterase Inhibitors; D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D011429:Propolis; D000110:Acetylcholinesterase