title: Purification of a protein from coelomic fluid of the earthworm Eisenia foetida and evaluation of its hemolytic, antibacterial, and antitumor activities.
abstract: BACKGROUND
  Earthworm Eisenia foetida (Lumbricus rubellus), a traditional Chinese medicine, is used for treating many diseases, and its coelomic fluid has extensive biological functions.
  
  
  OBJECTIVE
  The hemolytic, antibacterial and antitumor activities of an earthworm protein purified from coelomic fluid were investigated in vitro.
  
  
  METHODS
  We used ultrafiltration, gel chromatography, and ion exchange chromatography in sequence to isolate and purify an earthworm protein from coelomic fluid (ECFP), and ECFP was characterized by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Hemolytic assay and antibacterial tests were applied to determine the cytolytic activity of ECFP. The MTT method was carried out to evaluate the antitumor effect of ECFP on HeLa cells and LTEP-A2 cells.
  
  
  RESULTS
  ECFP, with molecular weight determined to be approximately 38.6 kilodaltons (KDa), was shown to possess significant hemolytic activity to chicken red blood cells (CRBC) (minimal hemolytic concentration 0.39 µg/mL). Antibacterial effect of ECFP obviously tested against Escherichia coli (minimal bactericidal concentration, MBC 180 µg/ mL) and Staphylococcus aureus (MBC 90 µg/mL) were observed. Moreover, ECFP notably inhibited the proliferation of HeLa cells (IC₅₀ 77 µg/mL) and LTEP-A2 cells (IC₅₀ 126 µg/mL) both in a time- and dose-dependent manner.
  
  
  CONCLUSIONS
  ECFP could serve as a component of the innate defense system of earthworms against foreign organisms, and thus it has potential pharmaceutical application in the future.
authors.affiliation: College of Biological Science and Technology, HeiLongJiang BaYi Agricultural University, DaQing, China. huazi8541@sina.com
authors.forename: Zhang
authors.initials: Z
authors.lastname: Hua
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Wang
authors.forename: Hong-Wei
authors.initials: HW
authors.lastname: Cao
authors.forename: Li-Jun
authors.initials: LJ
authors.lastname: Pu
authors.forename: Yu-Dong
authors.initials: YD
authors.lastname: Cui
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000302:isolation & purification* / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000302:isolation & purification* / Q000494:pharmacology; D001826:Body Fluids; D045744:Cell Line, Tumor; D004353:Drug Evaluation, Preclinical / Q000379:methods; D006367:HeLa Cells; D006461:Hemolysis / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D008516:Medicine, Chinese Traditional / Q000379:methods; D009835:Oligochaeta; D011506:Proteins
chemical_list: D000900:Anti-Bacterial Agents; D000970:Antineoplastic Agents; D011506:Proteins