title: Combined antiparasitic and anti-inflammatory effects of the natural polyphenol curcumin on turbot scuticociliatosis.
abstract: The histiophagous scuticociliate Philasterides dicentrarchi is the aetiological agent of scuticociliatosis, a parasitic disease of farmed turbot. Curcumin, a polyphenol from Curcuma longa (turmeric), is known to have antioxidant and anti-inflammatory properties. We investigated the in vitro effects of curcumin on the growth of P. dicentrarchi and on the production of pro-inflammatory cytokines in turbot leucocytes activated by parasite cysteine proteases. At 100 μm, curcumin had a cytotoxic effect and completely inhibited the growth of the parasite. At 50 μm, curcumin inhibited the protease activity of the parasite and expression of genes encoding two virulence-associated proteases: leishmanolysin-like peptidase and cathepsin L-like. At concentrations between 25 and 50 μm, curcumin inhibited the expression of S-adenosyl-L-homocysteine hydrolase, an enzyme involved in the biosynthesis of the amino acids methionine and cysteine. At 100 μm, curcumin inhibited the expression of the cytokines tumour necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) produced in turbot leucocytes activated by parasite proteases. Results show that curcumin has a dual effect on scuticociliatosis: an antiparasitic effect on the catabolism and anabolism of ciliate proteins, and an anti-inflammatory effect that inhibits the production of proinflammatory cytokines in the host. The present findings suggest the potential usefulness of this polyphenol in treating scuticociliatosis.
authors.affiliation: Departamento de Microbiología y Parasitología, Instituto de Investigación y Análisis Alimentarios, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: N
authors.initials: N
authors.lastname: Mallo
authors.affiliation: Departamento de Microbiología y Parasitología, Instituto de Investigación y Análisis Alimentarios, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: A P
authors.initials: AP
authors.lastname: DeFelipe
authors.affiliation: Departamento de Microbiología y Parasitología, Instituto de Investigación y Análisis Alimentarios, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: I
authors.initials: I
authors.lastname: Folgueira
authors.affiliation: Departamento de Microbiología y Parasitología, Instituto de Investigación y Análisis Alimentarios, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.|Departamento de Biología Celular y Ecología, Facultad de Biología, Instituto de Acuicultura, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: R A
authors.initials: RA
authors.lastname: Sueiro
authors.affiliation: Departamento de Biología Celular y Ecología, Facultad de Biología, Instituto de Acuicultura, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Lamas
authors.affiliation: Departamento de Microbiología y Parasitología, Instituto de Investigación y Análisis Alimentarios, Universidad de Santiago de Compostela, Santiago de Compostela, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Leiro
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D000981:Antiprotozoal Agents / Q000494:pharmacology*; D016770:Ciliophora Infections / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D003474:Curcumin / Q000494:pharmacology*; D005393:Fish Diseases / Q000276:immunology* / Q000469:parasitology; D005412:Flatfishes; D007113:Immunity, Innate; D016802:Oligohymenophorea / Q000502:physiology*; D010447:Peptide Hydrolases / Q000378:metabolism; D015800:Protozoan Proteins / Q000378:metabolism
chemical_list: D000596:Amino Acids; D000981:Antiprotozoal Agents; D015800:Protozoan Proteins; D010447:Peptide Hydrolases; D003474:Curcumin
keywords: 
  Philasterides dicentrarchi
  ; S-adenosyl-L-homocysteine hydrolase; cathepsin L-like; curcumin; leishmanolysin; proteases